Materials Handbook 2011 Part 14 docx

Phospho mannan, produced by the fermentation of starch, is such a material used in adhesives... Starch sponge is an edible starch in the form of a coarse-textured, porous, crispy, sponge

Green fruits, especially bananas, often contain much starch, but theripening process changes the starch to sugars.

In general, starch is a white, amorphous powder having a specificgravity from 0.499 to 0.513 It is insoluble in cold water but can be

converted to soluble starch by treating with a dilute acid When

cooked in water, starch produces an adhesive paste Starch is easilydistinguished from dextrins as it gives a blue color with iodine whiledextrins give violet and red The starch molecule is often described as a

chain of glucose units, with the adhesive waxy starches as those with

coiled chains But starch is a complex member of the great group ofnatural plant compounds consisting of starches, sugars, and cellulose,and originally named carbohydrates because the molecular formulacould be written as Cn(H2O)x; but not all now-known carbohydrates can

be classified in this form, and many now-known acids and aldehydescan be indicated by this formula

Starch can be fractionated into two polymers of high molecular

weight Amylose is a straight-chain fraction having high adhesive properties for coatings and sizings, and amylopectin is a

branched-chain fraction best known as a suspending agent for stuffs Amylose is chemically identical with cellulose, but the chainunits of the molecule have an alpha linkage and are coiled, while thecellulose molecule is rigid It has a molecular weight of 150,000, whileamylopectin has a molecular weight above 1 million The 1–4 alphalinkage of amylopectin with random branches at the 6-carbon positionmakes the material easily dispersible in cold water but resistant togelling Amylopectin is thus best suited for thickening, but because itcan be combined and cross-linked with synthetic resins and is highlyresistant to deterioration, it is used with resins for water-resistantcoatings for paper and textiles

food-Tapioca is the starch from the root of the large tuber Manihot utilissima, now grown in most tropical countries It is called cassava

in southern Asia, manioc in Brazil, mandioca in Paraguay, and

yuca in Cuba This perennial vegetatively propagated shrub was

cul-tivated as far back as 2,500 years ago, and there is some indirect dence that it has been grown for 4,000 years in the Americas Itsfresh roots contain 30 to 40% dry matter and have a starch content ofapproximately 85% of the dry matter It is used in enormous quanti-ties for food in some countries, and in some areas much is used for theproduction of alcohol In the United States it is valued for adhesivesand coatings, and only a small proportion in globules and flakes,

evi-known as pearl tapioca, is used in foodstuffs Gaplek, used for

cat-tle feed in Asia, is not the starch, but is dried and sliced cassava root

Tapioca starch may be sold under trade names Kreamgel, used as a

thickener for canned soups, sauces, and pastries, is refined tapiocathat gives clear solutions without imparting odor or flavor

Potato starch, produced from the common white potato,

Solanum tuberosum, has been the most important starch in Europe,

but in the United States it is usually more expensive than cornstarch

It forms heavier hot pastes than tapioca It is also free of flavor and is

used as a thickener in foods It does not crystallize easily Arogum, of

Morningstar-Paisley, Inc., is potato starch used to give tough, resilient

coatings on paper and textiles, and Arojel P is pregelatinized potato

starch used as a beater additive to improve the strength and scuff

resistance of kraft paper Sweet-potato starch is from the tuber

Opomoea batata An average of 10 lb (4.5 kg) of starch is produced per

bushel The root has poor shipping qualities, and the starch is sive, but it has excellent colloidal qualities and gelatinizes completely

expen-at 165°F (74°C) It is used in some foodstuffs It has a pleasant, ish flavor, and in Latin countries great quantities are marketed in the

sweet-form of a stiff gel as a dessert sweet known as dulce de batata.

Arrowroot starch is from the tubers of the Maranta arundinacea

of the West Indies It is easily digested and is used in cookies and

other food products, especially baby foods Florida arrowroot is

from Zamia floridana East Indian arrowroot is from the plant

Curcuma angustifolia, which belongs to the ginger family Arrowroot

from St Vincent, used in instant-pudding mixes and icings, is keted as a precooked powder of about 200 mesh It swells in coldwater and does not add flavor

mar-The starches do not crystallize as sugar does, and they may beadded to some confections to minimize crystallization They are alsoused as binders in candies and in tablet sugar, but any considerablequantity in such products is considered as an adulterant Metabolism

of starch in the human system requires conversion to sugars, and thetaking in of excessive quantities of uncooked starch is undesirable

Modified starches are starches with the molecule altered by

chemi-cal treatment to give characteristics suitable for particular industrialrequirements The modified starches and especially prepared starches

are usually sold under trade names Superlose is amylose from starch, and Auperlose is amylose from potato starch Ramalin is amylopectin Amylon, of National Starch & Chemicals Corp., is corn- starch containing 57% amylose, and Kosul is cornstarch high in amy- lopectin Textaid, of the same company, is a modified starch which

corn-reacts with water to form a grainy structure It is used in

commin-uted meat products to give a firm texture The ColFlo thickening

agents, stable and soluble in frozen foods, are modified, waxy

corn-starches, high in amylopectin Pregelatinized starches are

pre-heat-treated starches that require no cooking for use in dry food

mixes or adhesives Snow Flake starch is a cornstarch of this type.

Wheat starch is a fine, white starch made by separating out the

gluten of wheat flour by wash flotation It is used in prepared mixes

for foam-type cakes and pie crusts to improve texture, add volume,and reduce the amount of shortening needed It replaces up to 30% of

the wheat-flour content of the mix Starbake starch, of Hercules, is wheat starch Paygel, of General Mills, is also wheat starch, but

alant starch, or inulin, (C6H10O5)6 H2O, is not a starch in the nary sense, but is an insoluble sugar which occurs as the reservepolysaccharide in many plants It is obtained from the roots of the

ordi-artichoke, Helianthus tuberosis, native to America but now grown

widely in Europe Unlike starch, the molecule has fructose units held

in glucoside linkage, and hydrolysis converts it to fructose

Starch acetate, or acetylated starch, is used for textile sizing, in

adhesives, and for greaseproofing paper The insertion of acetate cals reduces the tendency of the molecular chains to cling together.The acetylated starches are gums which gelatinize at lower tempera-tures than starch, and produce stable, nonlumping pastes which give

radi-strong, flexible films Miralloid and Mira-Film, of A E Staley Mfg Co., are acetylated cornstarches Morgum is a hydroxyethyl ether-

ized starch which gives high film strength in coatings The Kofilms

of General Mills are acetylated cornstarches which give greaseproof,craze-resistant coatings on paper and textiles

Laundry starches are usually ordinary starches, but silicone resin

emulsions may be added to starches to permit higher ironing tures, improve slipperiness, and improve the hand of the starched fabric

tempera-The so-called permanent starches, for household use, that are not

removed by washing, are not starch, but are emulsions of polyvinyl

acetate Oxidized starch, a resistant starch for coatings, is made by the chloro-oxidation of a starch solution Sumstar 190 is a diallyl starch

made by acid oxidation of cornstarch Small amounts of the powder added

to kraft, tissue, or toweling pulp increase the wet and dry strengths and

the folding endurance of the papers An ammoniated starch called

Q-Tac starch is cornstarch reacted with quaternary ammonium groups A

less than 1% solution improves paper strength Sulfonated starches

are used as dirt-suspending agents with detergents for cleaning textiles

Nu-Film is a starch of this type Clear Flo starch is a modified starch

containing a carboxyl group and a sulfonic acid group in the molecule Ithas high hydrating capacity and gelatinizes sharply at low temperatures

It is used in adhesives and water paints Cato starch is a carboxymethyl starch used in paper sizing to add strength Dry Flo starch is modified

to contain a hydrophobic radical, such as CH2, which makes the rial insoluble in water but soluble in oils It is used in paints

mate-Many enzymes hydrolyze starch to maltose, but some enzymes

con-vert the starch to the hard, tough glucosides known as mannans, such as the mannose of the ivory nut Phospho mannan, produced

by the fermentation of starch, is such a material used in adhesives

Granular starch, used in enzyme conversion processing, is in dense,

granular particles produced by flash drying Easy-Enz starch is such a starch Cationic starch is a starch with the molecules of sta-

ble negative polarity to give higher adhesion on the cellulose fibers of

paper or textiles Molding starch, for adding to sugar candies to give

sharp molding characteristics, is starch containing an edible oil

The phosphate starch of American Maize Products Co is an

orthophosphate ester of cornstarch, marketed in sodium salt form as

a light-tan, dry powder It has high thickening power and makes aclearer paste than cornstarch It has superior water-binding proper-ties at low temperatures Frozen foods made with it do not curdle orseparate when thawed, and canned foods thickened with the starchcan be stored for long periods without clouding It is also used as abriquetting binder for charcoal

Starch sponge is an edible starch in the form of a coarse-textured,

porous, crispy, spongelike material, used for confections by ing with chocolate or sweets In crushed form it is added to candy orcookies It is produced by freezing, thawing, and pressing starch paste.The freezing insolubilizes the starch so that no soluble starch goes off

impregnat-when the water is pressed out Lycasin and Polysorb are

hydro-genated starch hydrolysates produced by Roquette Corp for food and

feed applications Nitrostarch, or starch nitrate, C12H12O10(NO2)3, is

a fine, white powder made by treating starch with mixed acid It ishighly explosive and is used for blasting, as a military explosive, and

in signal lights Grenite is nitrostarch mixed with an oil binder for use in grenades Trojan explosive is a mixture of 40% nitrostarch

with ammonium and sodium nitrates and some inert material to

reduce the sensitiveness Sepol starch coagulants, of Grace Dearborn,

are used to break emulsions in waste treatment of lubricating oils, uble oils, and synthetic coolants, including oils containing dissolvedsolids and water

sol-STATUARY BRONZE. Copper alloys used for casting statues, plaques,and ornamental objects that require fine detail and a smooth, red-dish surface Most of the famous large bronze statues of Europe con-tain from 87 to 90% copper, with varying amounts of tin, zinc, andlead Early Greek statues contained from 9 to 11% tin with as much

as 5% lead added apparently to give greater fluidity for crisp details

A general average bronze will contain 90% copper, 6 tin, 3 zinc, and 1lead Statuary bronze for cast plaques used in building constructioncontains 86% copper, 2 tin, 2 lead, 8 zinc, and 2 nickel The nickelimproves fluidity and hardens and strengthens the alloy, and thelead promotes an oxidized finish on exposure The statuary bronzeused for hardware has 83.5% copper, 4 lead, 2 tin, and 10 zinc.Ω

STEARIC ACID. A hard, white, waxlike solid of composition

CH3(CH2)16COOH, obtained from animal and vegetable fats and oils

by splitting and distilling The hard cattle fats are high in stearicacid, but other fats and oils contain varying amounts It is also called

octodecanoic acid, and it can be made by hydrogenation of oleic

acid Stearic acid has a specific gravity of 0.922 to 0.935 and a ing point of about 130°F (54°C), and it is soluble in alcohol but insolu-

melt-ble in water It is marketed in cakes, powder, and flakes Emory

3101-D is isostearic acid which has the solubility and physical

properties of oleic acid while retaining the heat and oxidation

stabil-ity of stearic acid Pearl stearic acid is the material in free-flowing

bead powder The acid is used for making soaps, candles, paint driers,lubricating greases, and buffing compositions, and for compounding

in rubbers, cosmetics, and coatings

Successive pressings remove liquid oils, thus raising the melting

point and giving a whiter, harder product of lower iodine value Oleo

oil is a yellow oil obtained by cold-pressing the first-run cattle tallow Tallow oil is the oil following the first two grades of oleo oil Industrene 4518 is the single-pressed grade, available as a molten

liquid or in flakes, from Humko Chemical Div of Witco Corp

Industrene 5016 is the double-pressed variety Oleostearin, used for

treating leather, is the stearin remaining after extraction of the oils

Stearin is the glyceride of stearic acid Acetostearins are the

monoglycerides acetylated with acetic anhydride They are closelyrelated to fats, but are nongreasy and are plastic even at low temper-atures The highly acetylated stearins melt below body temperatureand are edible Acetostearins are used as plasticizers for waxes and

synthetic resins to improve low-temperature characteristics Stearite

is a trade name for synthetic stearic acid made by the

hydrogena-tion of unsaturated animal and fish oils It is used in rubber

com-pounding, as it is more uniform than ordinary stearic acid Hystrene,

of Humko Chemical, is purified and hardened stearic acid in grades of

70, 80, and 97% stearic acid, with the remainder palmitic acid, used

for candles, cosmetics, and stearates However, Hystrene 5016 is a triple-pressed oil Intarvin is a synthetic edible fat made from stearic acid by converting it to margaric acid, or daturic acid,

C16H33COOH, and then esterifying with glycerin It is used as a fatfor diabetics as it does not undergo the beta oxidation to lose two car-bon atoms at a time and produce acetoacetic acid in the system as dothe even-carbon food acids

Wilmar 272 is refined stearic acid in flake form for use in candles

and coatings Hydrofol is a double- and triple-pressed rubber grade

that is also used in coatings and candles It is produced by Sherex

Chemical Co Flexchem B is sodium stearate, NaC18H35O2, in the

form of a water-soluble, white powder which is insoluble in oils It is

used as a bodying agent in cosmetic creams Myvacet is an

ace-tostearin used as an edible plastic coating for poultry, cheese, andfrozen fish and meats to prevent loss of the natural color and flavor It

is a white, waxy solid with melting points from 99 to 109°F (37 to43°C), but it also comes as an oil with congealing point of 45°F (7°C) for

use as a release agent on bakery equipment Alfol is a high-purity,

syn-thetic, linear primary alcohol from Vista Chemical Co A similar stearyl

alcohol, Adol, is from Sherex Chemical and is used as a chemical mediate Cachalot is a food-grade product of M Michel and Co.

inter-Stearin pitch is a brown-to-black by-product residue obtained in

the splitting and distillation of fats and oils in the manufacture of

soaps, candles, and fatty acids While the word stearin implies that it

contains only stearic acid, it usually comes from a variety of oils and

has mixed acids, and it may take the name of the oil, such as linseed

pitch or palm pitch It is used in varnishes and cold-molding

compositions

STEEL. Iron alloyed with small amounts of carbon, 2.5% maximum,

but usually much less The two broad categories are carbon steels and alloy steels, but they are further classified in terms of composi-

tion, deoxidation method, mill-finishing practice, product form, and/orprincipal characteristics Carbon is the principal influencing element

in carbon steels, although manganese, phosphorus, and sulfur arealso present in small amounts, and these steels are further classified

as low-carbon steels (up to 0.30% carbon), medium-carbon steels (0.30 to 0.60), and high-carbon steels (more than 0.60) The greater

the amount of carbon, the greater the strength and hardness, and the

less the ductility Alloy steels are further classified as low-alloy

steels, alloy steels, and high-alloy steels, those having as much as

5% alloy content being the most widely used The most common nation systems for carbon and alloy steels are those of the AmericanIron and Steel Institute and the SAE, which follow a four- or five-digitnumbering system based on the key element or elements, with thelast two digits indicating carbon content in hundredths of a percent

Plain carbon steels (with 1% maximum manganese) are

desig-nated 10XX; resulfurized carbon steels, 11XX; resulfurized andrephosphorized carbon steels, 12XX; and plain carbon steels with 1 to1.65% manganese, 15XX Alloy steels include manganese steels(13XX), nickel steels (23XX and 25XX), nickel-chromium steels (31XX

to 34XX), molybdenum steels (40XX and 44XX), num steels (41XX), nickel-chromium-molybdenum steels (43XX,47XX, and 81XX to 98XX), nickel-molybdenum steels (46XX and48XX), chromium steels (50XX to 52XX), chromium-vanadium steels

(61XX), tungsten-chromium steels (72XX), and silicon-manganesesteels (92XX) The letter B following the first two digits designatesboron steels, and the letter L leaded steels The suffix H is used toindicate steels produced to specific hardenability requirements.

High-strength, low-alloy steels are commonly identified by a 9XX

designation of the SAE, where the last two digits indicate minimumtensile yield strength in 1,000 lb/in2(6.9 MPa)

In contrast to rimmed steels, which are not deoxidized, killed

steels are deoxidized by the addition of deoxidizing elements, such as

aluminum or silicon, in the ladle prior to ingot casting Thus we have

such terms as aluminum-killed steel Deoxidation markedly

improves the uniformity of the chemical composition and resulting

mechanical properties of mill products Semikilled steels are only

partially deoxidized, thus intermediate in uniformity to rimmed and

killed steels Capped steels have a low-carbon steel rim

characteris-tic of rimmed-steel ingot and central uniformity more characterischaracteris-tic ofkilled-steel ingot, and are well suited for cold-forming operations.Steels are also classified as air-melted, vacuum-melted, or vacuum-

degassed Air-melted steels are produced by conventional melting

methods, such as open hearth, basic oxygen, and electric furnace

Vacuum-melted steels are produced by induction vacuum melting

and consumable electrode vacuum melting Vacuum-degassed

steels are air-melted steels that are vacuum processed before

solidifi-cation Vacuum processing reduces gas content, nonmetallic sions, and center porosity and segregation Such steels are morecostly, but have better ductility and impact and fatigue strengths.Steel-mill products are reduced from ingot into such forms as blooms,billets, and slabs, which are then reduced to finished or semifinishedshape by hot-working operations If the final product is produced by hot

inclu-working, the steel is known as hot-rolled steel If the final product is shaped cold, the steel is known as cold-finished steel or, more specifi- cally, cold-rolled steel, or cold-drawn steel Hot-rolled mill products

are usually limited to low- and medium-nonheat-treated carbon steels.They are the most economical steels, have good formability and weld-ability, and are widely used Cold-finished steels, compared with hot-rolled products, have greater strength and hardness, better surfacefinish, and less ductility Wrought steels are also classified in terms of

mill-product form, such as bar steels, sheet steels, and plate steels Bar steel used to reinforce concrete is called rebar, a low-grade steel

made from melted steel scrap and often coated with epoxy for

corro-sion protection Fermar is a higher-quality more corrocorro-sion- and

fatigue-resistant steel developed at the University of California,Berkeley Containing less carbon, thus less carbides, it is less suscepti-ble to electrolytic corrosion on water contact

Cast steels refer to those used for castings, and PM (powder metal) steels refer to powder compositions used for PM parts Steels

are also known by their key characteristic from the standpoint of

application, such as electrical steels, corrosion-resistant

stain-less steels, low-temperature steels, high-temperature steels, boiler steels, pressure-vessel steels, etc.

STEEL POWDER. Powder used mainly for the production of steel PMparts made by consolidating the powder under pressure and then sin-tering, and, to a limited extent, for steel-mill products, principallytool-steel bar products For PM parts, the powder may be admixed forthe desired composition or prealloyed; that is, each powder particle is

of the desired composition For mill products, prealloyed powder isused primarily Steel powder is widely used to make small to moder-ate-size PM parts, having compositions closely matching those ofwrought steels Among the more common are carbon steels, coppersteels, nickel steels, nickel-molybdenum steels, and stainless steels

Ancorsteel 41 AB, of Hoeganaes Corp., is a premixed, highly

com-pressible, low-alloy steel powder containing 0.5% carbon, 0.9 ganese, 0.85 molybdenum, and 0.75 chromium Formed parts areintended for surface hardening by carburizing, nitriding, carbonitrid-

man-ing, or nitrocarburizing Stainless Steel Plus, of the Specialty Metals

Division of Ametek, are powders of 303L, 304L, or 316L stainlesssteels blended with 10% powder of 15 nickel, 8 tin and copper Theyare said to provide greater corrosion resistance than conventionalstainless steel powders Powders for injection-molding PM parts areoften of iron-nickel or stainless steel but of very fine particle size

STEEL WOOL. Long, fine fibers of steel used for abrading, chiefly forcleaning utensils and for polishing It is made from low-carbon wirethat has high tensile strength, usually having 0.10 to 0.20% carbonand 0.50 to 1 manganese The wire is drawn over a track and shaved

by a stationary knife bearing down on it, and it may be made in a tinuous piece as long as 100,000 ft (30,480 m) Steel wool usually hasthree edges but may have four or five, and strands of various types aremixed There are nine standard grades of steel wool, the finest ofwhich has no fibers greater than 0.005 in (0.0027 cm) thick, the mostcommonly used grade having fibers that vary between 0.002 and 0.004

con-in (0.006 and 0.010 cm) Steel wool comes con-in batts, or con-in flat ribbon

form on spools usually 4 in (10 cm) wide Stainless steel wool is also made, and copper wool is marketed for some cleaning operations.

STILLINGIA OIL. A drying oil obtained from the kernels of the seeds of

the tree Stillingia sebifera, cultivated in China and the southern

United States The seeds contain about 23% of a light-yellow oilresembling linseed oil but of somewhat inferior drying power The oilhas a specific gravity of 0.943 to 0.946 and iodine value of 160 It hasthe peculiar property of expanding with great force at the congealing

point Stillingia oil is edible, but deteriorates rapidly, becoming bitter

in taste and disagreeable in odor Stillingia tallow, also known as

Chinese vegetable tallow, is obtained by pressing from the coating,

or mesocarp, of the seeds, yielding about 25 to 35% fat Sometimesthe whole seed is crushed, producing a softer fat than the true tallow.The tallow contains palmitic and oleic acids and is used in soaps andfor mixing with other waxes Some stillingia trees are grown in Texas

STRIPPABLE COATINGS. Coatings that are applied for temporary tection and can be readily removed They are composed of such resins

pro-as cellulosics, vinyl, acrylic, and polyethylene; they can be water-bpro-ase,solvent-base, or hot-melt The choice of base depends on the surface to

be protected Water-base grades are neutral to plastic and paintedsurfaces, whereas solvent-base types affect those surfaces Clear vinyl

strippable coatings, perhaps the most widely used, are usually

applied by spraying in thicknesses of 0.03 to 0.04 in (0.08 to 0.10 cm)

Acrylic strippable coatings impart a clear, high-gloss,

high-strength, temporary film to metal parts Polyethylene

strip-pable coatings are relatively low-cost and can be used on almost all

surfaces except glass Cellulosic strippable coatings are designed

for hot-dip application Film thicknesses range widely and can go ashigh as 0.2 in (0.51 cm) The mineral oil often present in these coat-ings exudes and coats the metal surface to protect it from corrosionover long periods

STRONTIUM. A metallic element of the alkaline group It occurs in

the minerals strontianite, SrCO3, and celestite, SrSO4, and bles barium in its properties and combinations, but is slightly harderand less reactive and is not as white in color It has a specific gravity

resem-of 2.54 and a melting point resem-of about 1418°F (770°C), and it poses in water The metal is obtained by electrolysis of the fused chlo-ride, and small amounts are used for doping semiconductors Itscompounds have been used for deoxidizing nonferrous alloys, andwere used in Germany for desulfurizing steel But the chief uses havebeen in signal flares to give a red light, and in hard, heat-resistant

decom-greases Strontium 90, produced atomically, is used in ship-deck

signs as it emits no dangerous gamma rays It gives a bright sign, andthe color can be varied with the content of zinc, but it is short-lived.Strontium is very reactive and used only in compounds

Strontium nitrate is a yellowish-white, crystalline powder,

Sr(NO3)2, produced by roasting and leaching celestite and treatingwith nitric acid The specific gravity is 2.96, the melting point is1193°F (645°C), and it is soluble in water It gives a bright, crimsonflame and is used in railway signal lights and in military flares It is

also used as a source of oxygen The strontium sulfate used as a

brightening agent in paints is powdered celestite The ore of Nova

Scotia contains 75% strontium sulfate Strontium sulfide, SrS, used

in luminous paint, gives a blue-green glow, but it deteriorates rapidly

unless sealed in Strontium carbonate, SrCO3, is used in nics, ceramics, and ceramic permanent magnets for small motors

pyrotech-Strontium hydrate, Sr(OH)2 8H2O, loses its water of tion at 212°F (100°C) and melts at 707°F (375°C) It is used in mak-

crystalliza-ing lubricatcrystalliza-ing greases and as a stabilizer in plastics Strontium

fluoride is produced in single crystals for use as a laser material.

When doped with samarium, it gives an output wavelength around25,600 nin (650 nm)

STYRAX. A grayish-brown, viscous, sticky, aromatic balsam obtained

from the small tree Liquidambar orientalis of Asia Minor It is also

called Levant styrax It is used in cough medicines and for skin

dis-eases, as a fixative for heavy perfumes, and for flavoring tobacco and

soaps American styrax is obtained by tapping the sweet gum, L.

styraciflua, of Alabama, a tree producing 8 oz (0.2 kg) of gum per year.

It is a brownish semisolid and has the same uses as Levant styrax It

is shipped from Central America under the name liquidambar, and

in the southern United States is called sweet gum and storax The

gum is not present in large amounts in the wood, but its formation is

induced by cuts Benzoin is another balsam obtained from several

species of Styrax trees It is a highly aromatic solid with an odor like

vanilla, and is used in medicine and in perfumes and incense

Sumatra benzoin is from the tree S benzoin and comes in

reddish-brown lumps or tears In medicine it was originally called

gum Benjamin Siam benzoin, from southern Asia, is from the

trees S tonkinense and S benzoides It is in yellowish or brownish

tears The Sumatra benzoin contains cinnamic acid, while the Asiatic

gum contains benzoic acid Benzoic acid, or phenylformic acid,

C6H5COOH, formerly produced from benzoin, is now made

syntheti-cally from benzol and called carboxybenzene It is a white,

crys-talline solid melting at 252°F (122°C), soluble in water and in alcohol

It is used as a food preservative, as an antiseptic, for flavoringtobacco, as a weak acid mordant in printing textiles, and in the man-ufacture of dyestuffs, pharmaceuticals, and cosmetics Because it ispoisonous, not more than 0.1% is used in food preserving in the form

of its salt, benzoate of soda, or sodium benzoate, C6H5COONa,which is a white, crystalline powder A potassium salt is also available

from Mallinckrodt, Inc Sorbic acid, CH3CH:(CH)2:CHCOOH, a solidmelting at 273°F (134°C), occurs in unripe apples, but is made syn-thetically As a preservative and antimold agent it is more effective

than benzoic acid, is nontoxic, and is readily absorbed in the human

system It is used in cheese and other foods Sorbistat is a food grade

with antimicrobial activity against yeast, mold, and bacteria fromAshland Chemical Co For food preservation it is used in the form of

the water-soluble salt potassium sorbate In a concentration of 0.2% it does not affect taste or aroma Preservastat, a sorbic acid

from Tri-K Industries, Inc., can be used at approximately 25% lowerlevels than potassium sorbate to achieve the same results It is avail-

able as a powder, as granules, or in crystal form Anisic acid,

CH3OC6H4COOH, used for pharmaceuticals, is the methyl ether ofhydroxybenzoic acid It is produced synthetically from carbon tetra-chloride and phenol, and is a solid melting at 363°F (184°C) It is also

called methoxybenzoic acid, umbellic acid, and dragonic acid.

SUEDE Also called napped leather A soft-finished, chrome-tanned

leather made from calf, kid, or cowhide splits, or from sheepskin It isworked on a staking machine until it is soft and supple, and thenbuffed or polished on an abrasive wheel It has a soft nap on the pol-ished side and may be dyed any color Suede is used for shoe uppers,coats, hats, and pocketbooks, but is now largely imitated with syn-

thetic fabrics Artificial suede, or Izarine, of Atlas Powder Co., has

a base of rubber fabric Fine cotton fibers dyed in colors are cemented

to one side, and the underside of the sheet is beaten to make thefibers stand out until the cement hardens The fabric looks and feelslike fine suede Some suede is also made by chemical treatment ofsheepskins without staking It has a delicate softness, but is not aswear-resistant as calfskin

SUGAR. A colorless to white or brownish, crystalline, sweet materialproduced by evaporating and crystallizing the extracted juice of thesugarcane or the sugar beet Refined sugar is practically pure

sucrose, C12H22O11, and in addition to being a sweetening agent formany foods it is a valuable carbohydrate food and a food preservative.When used with cooked fruits to make jams and jellies, it is both apreservative and an added food Lack of sugar in the diet developsketosis, the disease of diabetics, and results in the wasting away ofmuscles, using up of reserve fats, and the production of poisonousketones When the blood-sugar level is low, a feeling of hunger isinduced which may not be satisfied even by overeating A smallamount of sugar curbs the appetite and obviates surplus eating of

proteins and fats that create obesity Natural brown sugar contains

about 2% of the minerals found in the plant, calcium, iron, rus, magnesium, and potassium, and although these are valuable asfoods, they are lost in the refining process

Sugar is at present most valued as a food and for the production ofby-product alcohol from the residue molasses, but the sucrose mole-cule is a convenient starting point for the production of many chemi-cals However, the production and distribution of sugar have beenhemmed in by restrictive laws based on its use for food The sucrosemolecule has two complex rings, a glucosido and a fructose It can be

regarded as a type of fructosido-glucose, but the fructose in sucrose has a different structure, a furanose, or five-ring form, instead of the

pyranose, or six-ring structure, of ordinary fructose Hydrolysis of

sucrose with acid gives dextrorotatory glucose and fructose, and the

mixture is called invert sugar Numoline is a noncrystallizing

invert sugar made by hydrolyzing sucrose to split the molecule intolevulose and dextrose It is used in confectionery and bakery prod-

ucts Oxidation of sucrose produces oxalic acid and saccharic acid,

(HCOH)4(COOH)2, which can be reduced to adipic acid Glycerin can

be made from sugar by hydrogenation to sorbitol and then splitting.Thus, because of the great versatility of the sucrose molecule, and theease with which the sugar can be grown, sugar is one of the most

valuable chemical raw materials Sucrose benzoate is a benzoic

acid derivative of sucrose used as a plasticizer and modifier for thetic resins for lacquers and inks

syn-Sugarcane, Saccharum officinarum, is a tropical plant, originating

in Asia and first brought to the Canary Islands in 1503 and thence tothe West Indies The plant will not withstand frost, but can be grown

in a few favored regions outside of the tropics such as Louisiana It isnow grown on plantations in Cuba, Hawaii, Brazil, the Philippines,Indonesia, Puerto Rico, Peru, and many other countries The cane orstalks of the plant are crushed to extract the juice, which is then con-centrated by boiling, crystallized, and clarified with activated carbon

or other material The yield of sugar in Hawaii is about 14 tons(12,698 kg) of raw sugar per acre (4,047 m2) Analysis of sugarcanegives an average of 13.4% sucrose by weight of cane The average yield

by milling is 91% of the contained sucrose, but yields as high as 98.8%are obtained by diffusion extraction of the cut-cane chips

The sugar beet is a white-rooted variety of the common beet, Beta

vulgaris, and grows in temperate climates It is cut up and boiled to

extract the juice, and the production and refining of the sugar areessentially the same as for cane sugar There is no difference in the

final product, although raffinose, or melitriose, C18H32O16, a less trisaccharide, occurs in the sugar beet, and may not be com-pletely changed to sucrose by hydrolysis, so that a greater quantitymay sometimes be needed to obtain equal sweetening effect The pectins and starches of the sugar beet are not extracted by theuse of the slicing and diffusion method

Refined commercial sugar contains 99.98% sucrose and is graded

by screening to crystal size The best qualities are the larger crystalsfrom the first and second runs The soft sugars are from further crys-tallizing, until the noncrystallizing brown sugars are reached Rawsugar testing 96° by the polariscope is the grade used as a basis forraw-sugar quotations Commercial sugar may have starch added The

ultrafine 6X confectioner’s sugar usually contains 4% cornstarch

as a noncaking agent, and block sugars may contain starch as a ing agent, but starch reduces the sweetening powder

bind-Cane sugar is the high-grade syrup or liquid sugar, while molasses is the heavy residual syrup left after the crystallization Edible molasses is the yellow to brownish, light, purified residue

syrup Blackstrap molasses is the final, inedible, unpurified residue

heavy syrup, used for the production of ethyl alcohol It contains 50 to60% sugar by weight, mostly sucrose but some glucose A purifiedgrade which retains the minerals is marketed as an edible blackstrapmolasses

Molasses powder, used for bakery products, is made by spray

dry-ing It is a free-flowing, noncaking powder Liquid sugar, much used

in food manufacturing because it saves handling costs, comes in ous liquid densities and in various degrees of invert The liquid sug-

vari-ars are usually not pure sucrose, and are called multisugvari-ars For

food manufacturing the calcium and other minerals may be left in,and they then have a yellow color Multisugars with 90% sucrose and10% levulose and dextrose crystallize in hard, aggregate clusters,

desirable in some confections Flo-Sweet is liquid sugar Sucrodex

is liquid sugar containing one-third dextrose and two-thirds sucrose,with a solubility of 72% compared with only 45 for dextrose and 67 for

sucrose Inverdex, for canning and for fountain syrups, is about 85% invert sugar and 15 dextrose Amberdex, used for cakes and cookies,

is an amber-colored 50–50 mixture of sucrose and dextrose with the

edible materials left in Caramel, used for flavoring and coloring

foodstuffs and liquors, has a deep-brown color and a characteristictaste It is burnt sugar marketed as a liquid or powder

The papelon of South America is solidified edible molasses Gur is unrefined brown sugar of India, and the pilancillo of Mexico is unre- fined brown sugar Treacle is an English name for edible molasses The refuse from sugar cane, called bagasse, is used as fuel and for making paper and insulating board Beet pulp, after extraction of

the juice, is marketed as cattle feed Despite restrictive controls overthe world supply of sugar, much sucrose is being used in the produc-

tion of chemical products Nonionic detergents, which are odorless,

biodegradable powders with low toxicity, are made by reactingsucrose with fatty acid esters of volatile alcohols Allyl sucrose is used

as a shellac substitute Sucrose acetate isobutyrate is available in

three grades: semisolid, in ethyl alcohol, in toluene The pure cal is a clear, viscous liquid boiling at 550°F (288°C), used as a plasti-cizer in synthetic resins to improve extrusion and to give flexibilityand adhesiveness in coatings As much as 70% is used in nitrocellu-

chemi-lose to give tough, flexible melt coatings Nitto ester is sucrose

ester made with sugar and stearic acid It is used as a food additive.

A type of edible sugar syrup is also obtained from the juice of a

variety of sorghum grass, Sorghum vulgare, native to South Africa,

but now grown in the southern United States The juice or syrup,

called sorghum syrup, or sorgo syrup, is light in color, has a

char-acteristic delicate flavor, and contains gums and starch, which vent crystallization It also contains other sugars besides sucrose, andconsiderable mineral salts of value as foods The total sugar in thejuice is from 9 to 17%, varying with the age of the plant It is used insome sections to replace sugar and is employed in some confectionery

pre-to give a distinctive flavor

Apple syrup, or apple honey, used as a sweetening agent in the

food industry, for curing hams, and as a substitute moistening agentfor tobacco, is made from cull apples The reduced syrup is treated toremove the bitter calcium malate It contains 75% solids of which 65%

consists of the sugars levulose, dextrose, and sucrose Palm sugar, or

jaggary, is the evaporated sap of several varieties of palm, including

the coconut and the palms from which kittool, gomuti, and palmyrafibers are obtained The sap contains about 14% sugar It is much

used in India and the Pacific Islands The palm wine known as

arrack is made by fermenting the juice, called taewak, of the flower

stems of the aren palm of Java A liter (1.06 qt) of taewak yields about 0.2 lb (0.09 kg) of brown palm sugar Wood molasses is made

by concentrating and neutralizing the dilute sugar solution produced

by pressure hydrolysis of wood chips using dilute sulfuric acid at hightemperature The molasses has a slightly bitter taste, but is used for

stock feed and for industrial purposes Wood sugars contain xylose,

CHO(HCOH)3CH2OH, which belongs to the great group of pentosans

occurring in plant life They have the same general formula with ferent numbers of the HCOH group Oxidation converts them to the

dif-respective acid, as xylonic acid from xylose, or arabinic acid from

the arabinose of gum arabic They can also be converted to the tones, and are related to the furanes, so that the wood sugars have awide utility for the production of chemicals

lac-Other plants yield sweetening agents, but few are of commercial importance The leaves of the caá heé, a small plant of Paraguay, are

used locally for sweetening Paraguayan tea The name, pronounced

kah-áh aye-áye, means sweet herb, and it has a more intense sweetening

effect than sugar Miracle Fruit powder, of International Minerals and

Chemical Corp., is a complex protein-based chemical derived from the

fruit pulp of the Agbayun shrub, Synsepalum dulcificum, of west Africa.

It has a strong sweetening effect and a pleasant natural flavor Stevia, a

potent low-calorie sweetener from the leaf of the South American shrub

Stevi rebaudiana and also grown in China, is restricted to use as a

dietary supplement

The 6-carbon sugar derivative known as glucoronic lactone, used

as an antiarthritic drug, is derived from dextrose Amino sugar, or

glucosamine, has an NH2group in the molecule in place of the alphahydroxyl group of glucose This sugar occurs in marine animals

Synthetic sweetening agents of no food value are used in diabeticfoods and in dietetic foods for the treatment of obesity Many of thesesynthetic sweeteners are toxic in excess and are cumulative in the

human system Thus, dietary foods that depend on the substitution

of chemicals in place of sugar should be taken only with caution and

under medical direction Saccharin, produced from coal tar, is

ben-zoic sulfinide, C6H4SO2NHCO It is 450 times sweeter than sugarand has no food value, but it has a disagreeable aftertaste It is a

water-insoluble white powder, but its salts, sodium saccharin, and

calcium saccharin, are soluble in water and are 300 times sweeter

than sugar Saccharin is also used as a pH indicator, and as a ener in nickel-plating baths

bright-The cyclamates were widely used in beverages and diet foods, but are now recognized as toxic drugs and are restricted Sodium

cyclohexylsulfamate, or sodium cyclamate, Na(C6H12NO3S)22H2O, is used in dietetic foods and in some soft drinks as it has nofood value It is 30 times sweeter than sugar, but at the 25% sweet-ening level of sugar it has an undesirable aftertaste, and at thesugar-sweetness level the off-taste predominates For both

sugar-free and salt-free diets, the calcium salt calcium cyclamate

is used Sucaryl, of Abbott Laboratories, is sodium cyclamate, and

Cyclan, of Du Pont, is calcium cyclamate Hexamic acid, a white,

crystalline powder which is cycle hexylsulfamic acid, is used as asupplement sweetener and intensifier with the cyclamates and sac-

charin Aspartame, also known as Nutrasweet, is a low-calorie

sweetener used alone or in combination with sugar or saccharin insome breakfast cereals, diet soft drinks, and other ready-mixed bev-

erages Peryllartine is the sweetest known substance, being 2,000

times sweeter than sucrose It is a complex aldehyde derived from

terpenylic acid, which occurs in combined forms in turpentine and

many essential oils

A number of other artificial sweeteners are also being developed

Acesulfame-potassium, known as Sunette in the United States,

is available in a table-top formula, Sweet-One, and as an

ingredi-ent in chewing gum and dry beverage mixes Produced by Hoechst

Celanese Corp., it is 200 times sweeter than sugar and slightlymore so than aspartame But since acesulfame-potassium suffersfrom a slight aftertaste, it is usually mixed with other sweeteners;the combination works synergistically, with the mixture being

sweeter than either component Xylitol is a naturally derived

sugar alcohol made from birch bark It offers few benefits oversugar, since it is about as sweet and has the same number of calo-ries Produced in Finland, it is marketed in the United States byAmerican Xyrofin primarily for specialty diet foods, such as for dia-betics and infants, in oral hygiene, and pharmaceutical products

Alitame, formed from the amino acids L-aspartic acid and nine by Pfizer, Inc., is 2,000 times sweeter than sucrose, just as

D-ala-heat-stable, and has a shelf life up to 4 times that of aspartame

Sucralose, being developed by McNeil Specialty Products Co., is

600 times sweeter than sugar, from which it is derived Natural

thaumatin, a protein that is 5,000 times sweeter than sugar, is

used mainly as a flavor enhancer Isomalt, a modified sugar, is used

in chocolates and confectioneries in Europe and Asia, and is produced by West Germany’s Subungsmittel GmbH It is also used

as a bulking agent with the highly sweet products Lev-O-Cal is a

left-handed L-sugar that is less sweet and has fewer calories than

the right-handed, or normal, sugar Polydextrose is another

low-calorie bulking agent

SUGAR PINE. The common name of the wood of the Pinus

lamber-tiana, a coniferous tree growing in California and Oregon The tree

grows ordinarily to a height of 150 to 175 ft (46 to 53 m) with a eter of 4 to 5 ft (1.2 to 1.5 m) Occasional trees are more than 200 ft(61 m) in height and 12 ft (3.7 m) in diameter, and are often free oflimbs up to 75 ft (23 m) from the ground It is the largest of thepines Sugar pine is durable, has moderate strength and fairly evengrain, and is not subject to excessive shrinkage or warping Because

diam-of the latter quality it has come into use to replace the scarcer ern pines for patterns It does not darken on exposure as western

east-pine does It is widely employed for construction work and for

fac-tory lumber for doors, frames, boxes, and wooden articles Sugar

pine is classified into three standard classes of grades according tofreedom from knots and faults as select, commons, and factory, orshop The selects are designated as Nos 1 and 2 clear, C select, and

D select The commons are graded as Nos 1, 2, 3, and 4; the factory

as No 3 clear, No 1 shop, No 2 shop, and No 3 shop The shops arejudged with the idea that they will be cut up into small pieces, andare consequently classified by the area of clear cuttings that can beobtained

SULFAMIC ACID. A white, crystalline, odorless solid of compositionHSO3 NH2, very soluble in water, but only slightly soluble in alcohol.The melting point is 352°F (178°C) The acid is stronger than othersolid acids, approaching the strength of hydrochloric It is used in bat-ing and tanning leather, giving a silky, tight grain in the leather Animportant use is for cleaning boiler and heat-exchanger tubes It con-verts the calcium carbonate scale to the water-soluble calcium sulfa-mate, which can then be flushed off and combined with sodiumchloride; it also converts the rust to ferric chloride and then to thewater-soluble iron sulfamate Pettibone Chemicals offers high-puritygrades for bleaching paper pulp and textiles, organic synthesis, gas-liberating compositions, and as a catalyst for urea-formalde-

hyde resins Ammonium sulfamate is the ammonia salt of the acid,

used as a cleanser and anodizer of metals, as a weed killer, and for

flameproofing paper and textiles Lead ammonium sulfamate,

Pb(SO3NH2)2, used in lead plating, is very soluble in water and has high

throwing power Aminoethylsulfamic acid, NH2CH2CH2OSO3H, isused for treating paper and textile fibers to increase wet strength and

water repellency Tobias acid, used in making azo dyes, is

naphthy-lamine sulfonic acid, NH2C10H6SO3H, in white needles decomposing

at 446°F (230°C)

SULFONATED OIL. A fatty oil that has been treated with sulfuric acid,the excess acid being washed out and only the chemically combinedacid remaining The oil is then neutralized with an alkali Sulfonatedoils are water-soluble and are used in cutting oils and in fat liquors for

leather finishing Sulfonated castor oil is called Turkey red oil.

Leatherlubric is the trade name of E F Houghton & Co for

sul-fonated sperm oil used for leather Solcod is the sulsul-fonated cod oil of the same company Sulfonated stearin and sulfonated tallow are

also used in leather dressing They are cream-colored pastes readily

soluble in hot water Mahogany soap is a name for oil-soluble

petro-leum sulfonates used as dispersing and wetting agents, corrosioninhibitors, emulsifiers, and to increase the oil absorption of mineral

pigments in paints Petronate is a petroleum sulfonate containing 62% sulfonates, 35 mineral oil, and 3 water Phosphorated oils, or

their sulfonates, may be used instead of the sulfonates as emulsifyingagents or in treating textiles and leathers They are more stable to

alkalies Phosoils are phosphorated vegetable oils Aquasol, of

American Cyanamid Co., is a sulfonated castor oil used as an

emulsify-ing agent Cream softener is a name used in the textile industry for

sulfonated tallow

SULFUR. One of the most useful of the elements, symbol S Its rence in nature is little more than 1% that of aluminum, but it is easy

to extract and is relatively plentiful In economics, it belongs to thegroup of “S” materials—salt, sulfur, steel, sugars, starches—whoseconsumption is a measure of the industrialization and the rate ofindustrial growth of a nation Sulfur is obtained from volcanicdeposits in Sicily, Mexico, Chile, and Argentina, and along the GulfCoast in Louisiana, Texas, and Mexico it is obtained from greatunderground deposits in the cap rock above salt domes Offshoredeposits worked in the Gulf of Mexico are 2,000 ft (610 m) under thebottom Strict environmental laws are driving the production of sul-fur recovered as a by-product of various industrial operations It isalso obtained by the distillation of iron pyrites, as a by-product of cop-

per and other metal smelting, and from natural gas The sterri

exported from Sicily for making sulfuric acid is broken rock rich in

sulfur Brimstone is a very ancient name still in popular use for solid

sulfur, but the District Court of Texas has ruled that sulfur obtainedfrom gas is not subject to tax as brimstone

Sulfur forms a crystalline mass of a pale-yellow color, with a Mohshardness of 1.5 to 2.5, a specific gravity of 2.05 to 2.09, and meltingpoint of 232°F (111°C) It forms a ruby vapor at about 780°F (416°C)

When melted and cast, it forms amorphous sulfur with a specific

gravity of 1.955 The tensile strength is 160 lb/in2 (1 MPa), and pressive strength is 3,300 lb/in2 (23 MPa) Since ancient times it hasbeen used as a lute for setting metals into stone Sulfur also con-

com-denses into light flakes known as flowers of sulfur, and the

hydro-gen sulfide gas, H2S, separated from sour natural gas, yields a

sulfur powder Flotation sulfur is a fine, free-flowing sulfur dust

with particle sizes less than 157
in (4
m), recovered in gas tion from coal Commercial crude Sicilian sulfur contains from 2 to11% of impurities and is sold in three grades Refined sulfur is mar-keted in crystals, roll, or various grades of powder, and the Siciliansuperior grade is 99.5% pure This is the grade used in rubber manu-

produc-facture Crystex is a sulfur, 85% insoluble in carbon bisulfide, used

in rubber compounding The sulfur powder of Electronic Space

Products, Inc., used for semiconductors, is 99.9999% pure

Sulfur has twice the atomic weight of oxygen but has many similarproperties and has great affinity for most metals It has six valence

electrons, but also has valences of 2 and 4 The crystalline sulfur is

orthorhombic, which converts to monoclinic crystals if cooled slowlyfrom 248°F (120°C) This form remains stable below 248°F Whenmolten sulfur is cooled suddenly, it forms the amorphous sulfur whichhas a ring molecular structure and is plastic, but converts gradually

to the rhombic form Sulfur has a wide variety of uses in all tries The biggest outlet is for sulfuric acid, mainly for producing

indus-phosphate fertilizers Agri Sul, from Eagle-Picher Industries, Inc., is

available in prilled form or as a water-degradable grade, as a source

of elemental sulfur for correcting sulfur deficiencies in crops and

grasses Newsulfur, from Tri-K Industries, Inc., is a nonirritating

variety that can be mixed by hand with any kind of ingredient It isused for making gunpowder and for vulcanizing rubber, but for mostuses it is employed in compounds, especially as sulfuric acid or sulfurdioxide A vast number of so-called thio compounds have been pro-

duced The thio alcohols, or mercaptans, have an SH group

instead of the OH of true alcohols, and they do not react as alcohols,

but the thio esters are made directly from the mercaptans Thionyl

chloride, SOCl2, a yellow liquid, is a typical compound used as asource of sulfur in synthesis Most of the thio compounds have an

offensive odor Vegetable sulfur does not contain sulfur, but is

lyco-podium, a fine, yellow powder from the spores of the club moss, a

fernlike plant, Lycopodium clavatum, which grows in North America

and Europe It belongs to the group of lipochromes, or coloring

mat-ter of plants related to lycopene and carotene

Sulfur dioxide, or sulfurous acid anhydride, is a colorless gas of

composition SO2, used as a refrigerant, as a preservative, in bleaching,and for making other chemicals It liquefies at about 14°F (10°C) As

a refrigerant it has a condensing pressure of 51.7 lb (23.5 kg) at 86°F(30°C) The gas is toxic and has a pungent, suffocating odor, so thatleaks are detected easily It is corrosive to organic materials but does

not attack copper or brass The gas is soluble in water, forming

sul-furous acid, H2SO3, a colorless liquid with suffocating fumes Theacid form is the usual method of use of the gas for bleaching

SULFURIC ACID. An oily, highly corrosive liquid of composition H2SO4,having a specific gravity of 1.841 and a boiling point of 626°F(330°C) It is miscible in water in all proportions, and the color is yel-lowish to brown according to the purity It may be made by burningsulfur to the dioxide, oxidizing to the trioxide, and reacting withsteam to form the acid It is a strong acid, oxidizing organic materi-als and most metals Sulfuric acid is used for pickling and cleaningmetals, in electric batteries and plating baths, for making explosivesand fertilizers, and for many other purposes In the metal industries

it is called dipping acid, and in the automotive trade it is called

battery acid Fuming sulfuric acid, or oleum, of 100% purity,

was called Nordhausen acid The grade of sulfuric acid known as

oil of vitriol, or vitriol, is 66°Bé, or 93.2% acid A 96% grade, called Particulo, is available from General Chemical Co Sulfur trioxide,

or sulfuric anhydride, SO3, is the acid minus water It is a colorlessliquid boiling at 115°F (46°C) and forms sulfuric acid when mixed

with water It is used for sulfonation Sulfan, of Allied-Signal Corp.,

is sulfuric anhydride Sulfodox is a liquid sulfur dioxide of high

purity from Specialty Products Corp It is used for acidifying and

bleaching Chlorosulfonic acid, HClSO3, has equal amounts of fur trioxide and hydrochloric acid, and is a vigorous dehydratingagent, used also in chlorosulfonating organic compounds It has a spe-cific gravity of 1.752 and boils at 311°F (155°C) Mixed with sulfur tri-

sul-oxide, it has been called FS smoke for military smoke screens.

Niter cake, which is sodium acid sulfate, NaHSO4, or sodium

bisulfate, contains 30 to 35% available sulfuric acid and is used in

hot solutions for pickling and cleaning metals It comes in colorlesscrystals or white lumps, with a specific gravity of 2.435 and melting

point 572°F (300°C) Sodium sulfate, or Glauber’s salt, is a white,

crystalline material of composition Na2SO4 10H2O, used in makingkraft paper, rayon, and glass It was first produced from Hungarianspring water by Johann Glauber, and when obtained from mineral

springs, it is called crazy water crystals The burkeite, sodium

sulfate–sodium bicarbonate double salt, which separates out ofSearles Lake brine, is used to produce sodium sulfate and other

chemicals as by-products Salt cake, Na2SO4, is impure sodium fate used in the cooking liquor in making paper pulp from wood It is

sul-also used in freezing mixtures Synthetic salt cake, used for making kraft pulp, is produced by sintering soda ash and sulfur Chrome

cake is a greenish by-product salt cake which contains some

chromium as an impurity It is used in papermaking Kaiseroda is a

German name for salt cake of high purity obtained as a by-productfrom the production of magnesium chloride from potash minerals

Sodium sulfite, Na2SO3 or Na2SO3 7H2O, is a white to tan,

crys-talline powder very soluble in water but nonhygroscopic Santosite,

of Monsanto, is a grade of sodium sulfite containing 93% sodium fite with the balance chiefly sodium sulfate

sul-Sodium sulfide, Na2S, is a pink, flaky solid, used in tanneries fordehairing and in the manufacture of dyes and pigments The commer-cial product contains 60 to 62% Na2S, 3.5 NaCl, and other salts, and

the balance water of crystallization Sodium sulfhydrate, NaSH, is

in lemon-yellow flakes It has much less alkalinity than sodium fide, and is used in tanneries in unhairing solutions and for makingthiourea and other chemicals It contains 62.6% by weight of sulfur

sul-and is an economical material for sulfonating Sodium dithionate,

Na2S2O6 2H2O, is used in leather tanning, as an assist in textile ing and printing, and for making other chemicals It comes in trans-

dye-parent, prismatic crystals of bitter taste Sodium thiosulfate,

Na2S2O3 5H2O, known as hypo, is a white, crystalline compound

having a specific gravity of 1.73 and a melting point of 113°F (45°C)

It is used in photography to fix films, plates, and papers White

vit-riol is zinc sulfate in colorless crystals soluble in water and melting

at 102°F (39°C) It is used for making zinc salts, as a mordant, forzinc plating, and as a preservative in adhesives.

SUMAC. The dried, ground leaves of the bush Rhus coriaria of Sicily,

or R typhina of the eastern United States, used for tanning leather.

The Sicilian leaves contain up to 30% tannin, and the U.S leaves up

to 38% It contains gallotannin and ellagitannin and gives a rapidtan Sumac provides a light, strong leather of fine, soft grain and has

a bleaching action which can produce a white leather It is used forbook and hatband leathers Sumac grows profusely in the easternstates, but the gathering of the leaves is not organized commercially

SUNFLOWER OIL. A pale-yellow drying oil with a pleasant odor andtaste obtained from the large seeds of the common sunflower plant,

Helianthus annuus, of which there are many varieties The plant is

native to Peru but is now grown in many parts of the world, larly in California, Canada, Argentina, Chile, Uruguay, and Russia Itrequires boron in the soil The specific gravity of the oil is 0.925.Sunflower oil is used in varnish and soap manufacture or as a food

particu-oil Refined and unrefined grades, with trade name Trisun, are

avail-able for these applications from SVO Enterprises The by-product

cake is used chiefly for cattle feed, but sunflower meal is also

blended with wheat flour or cornmeal in foods It is higher in vitamin

B than soybean flour Sunflower seeds are also used as poultry feed.

Madia-seed oil is quite similar to sunflower oil and has the same

uses It is obtained from the seeds of the plant Madia sativa, native to

California The seeds contain 35% oil, and the cold-pressed oil has a

pleasant taste Watermelon-seed oil, produced in Senegal as bereff

oil, is an edible oil similar to sunflower It contains about 43%

linoleic, 27 oleic, 19.5 stearic, and 5 palmitic acids

The leaves of selected varieties of some species of sunflower contain

from 1 to 6% sunflower rubber and up to 8 resin The H

occiden-talis, H giganteus, H maximiliani, and H strumosus are cultivated in

Russia both for the oil seed and for the rubber in the leaves Theseperennials yield leaves up to 10 years Another similar rubber-bearing

plant of southern Russia is Asclepias cornuti, known as vatochnik It

is a perennial, producing leaves for 10 to 15 years The leaves yield 1

to 6.5% rubber and large percentages of resin

SUN HEMP. The bast fiber of the plant Crotalaria juncea It is used

for cordage and rope in place of jute, but is lighter in color and ismore flexible, stronger, and more durable than jute It resembles true

hemp, but is not as strong It is more properly called sann hemp

from the Hindu word sann It is also known as sunn fiber, Indian

hemp, and Bombay hemp The plant, which is a shrub, is cultivated

extensively in India It grows to a height of about 8 ft (2.4 m), withslender branches yielding the fiber The method of extraction is thesame as for true hemp The best fibers are retained locally for makinginto cloth It is also used in the United States for making cigarette

paper and for oakum Madras hemp is from another species of the

same plant

SUPERALLOYS. Iron-based, nickel-based, or cobalt-based alloys notedprimarily for high strength and oxidation and corrosion resistance athigh temperatures Because of their excellent high-temperature per-

formance, they are also known as high-temperature, high-strength

alloys Their strength at high temperatures is usually measured in

terms of stress-rupture strength or creep resistance For high-stressapplications, the iron-base alloys are generally limited to a maximumservice temperature of about 1200°F (649°C), whereas the nickel-andcobalt-based alloys are used at temperatures to about 2000°F (1093°C)and higher In general, the nickel alloys are stronger than the cobaltalloys at temperatures below 2000°F, and the reverse is true at tem-peratures above 2000°F Superalloys are probably best known for air-craft turbine applications, although they are also used in steam andindustrial turbines, nuclear power systems, and chemical and petro-leum processing equipment A great variety of cast and wrought alloysare available, and in recent years, considerable attention has beenfocused on the use of powder-metallurgy techniques as a means ofattaining greater compositional uniformity and finer grain size

The iron-based superalloys include solid-solution alloys and

precipitation-hardening (PH), or precipitation-strengthened, alloys.Solid-solution types are alloyed primarily with nickel (20 to 36%) andchromium (16 to 21), although other elements are also present in lesser

amounts Superalloy 16-25-6, for example, the alloy designation

indi-cating its chromium, nickel, and molybdenum contents, respectively,also contains small amounts of manganese (1.35%), silicon (0.7), nitro-

gen (0.15), and carbon (0.06) Incoloy 800, 801, and 802, of Inco Alloys

International, Inc., contain slightly less nickel and slightly morechromium with small amounts of titanium, aluminum, and carbon

Incoloy 803, of Inco, was developed for pyrolysis tubing in severe

ethyl-ene furnaces and other petrochemical applications It comprises 32 to37% nickel, 25 to 29 chromium, 0.15 to 0.6 aluminum, 0.15 to 0.6 tita-nium, 0.06 to 0.1 carbon, with maximum amounts of 1.5 manganese, 1silicon, 0.75 copper, and 0.015 sulfur, balance iron The alloy has highresistance to oxidation and carburization Protective scales, developed

by high-temperature exposure, provide the self-healing quality Thealloy has an ultimate tensile strength of 88,000 lb/in2 (607 MPa) and50% elongation At 1800°F (980°C), the tensile strength is 15,000 lb/in2

(103 MPa) N-155, or Multimet, an early sheet alloy, contains about

equal amounts of chromium, nickel, and cobalt (20% each), plus 3molybdenum, 2.5 tungsten, 1 columbium, and small amounts of carbon,nitrogen, lanthanum, and zirconium At 1350°F (732°C), this alloy has

a 1,000-h stress-rupture strength of about 24,000 lb/in2(165 MPa)

PH iron-based superalloys provide greater strengthening by

pre-cipitation of a nickel-aluminum-titanium phase One such alloy,which may be the most well known of all iron-based superalloys, is

A-286 It contains 26% nickel, 15 chromium, 2 titanium, 1.25

molyb-denum, 0.3 vanadium, 0.2 aluminum, 0.04 carbon, and 0.005 boron

At room temperature, it has a tensile yield strength of about 100,000lb/in2 (690 MPa) and a tensile modulus of 21.1  106 lb/in2 (145,000MPa) At 1200°F (649°C), tensile yield strength declines only slightly,

to 88,000 lb/in2 (607 MPa), and its modulus is about the same orslightly greater It has a 1,000-h stress-rupture strength of about21,000 lb/in2 (145 MPa) at 1350°F (732°C) Other PH iron-based

superalloys are Discoloy, Haynes 556 (whose chromium, nickel,

cobalt, molybdenum, and tungsten contents are similar to those of

N-155); Incoloy 903 and Pyromet CTX-1, which are virtually

chromium-free but high in nickel (37 to 38%) and cobalt (15 to 16);

and V-57 and W-545, which contain about 14 chromium, 26 to 27

nickel, about 3 titanium, 1 to 1.5 molybdenum, plus aluminum, bon, and boron V-57 has a 1,000-h stress-rupture strength of about25,000 lb/in2 (172 MPa) at 1350°F and greater tensile strength, butsimilar ductility, than A-286 at room and elevated temperatures

car-Nickel-based superalloys are solid-solution,

precipitation-hard-ened, or oxide-dispersion-strengthened All contain substantialamounts of chromium, 9 to 25%, which, combined with the nickel,accounts for their excellent high-temperature oxidation resistance.Other common alloying elements include molybdenum, tungsten,cobalt, iron, columbium, aluminum, and titanium Typical solid-solu-

tion alloys include Hastelloy X (22 to 23% chromium, 17 to 20 iron,

8 to 10 molybdenum, 0.5 to 2.5 cobalt, 2 aluminum, 0.2 to 1 tungsten,

and 0.15 carbon); Inconel 600 (15.5 chromium, 8 iron, 0.25 copper maximum, 0.08 carbon); and Inconel 601, 604, 617, and 615, of Inco

Alloys International, Inc., the latter containing 21.5 chromium,

9 molybdenum, 3.6 columbium, 2.5 iron, 0.2 titanium, 0.2 aluminum,and 0.05 carbon At 1350°F (732°C), wrought Hastelloy X (it is alsoavailable for castings) has a 1,000-h stress-rupture strength of about18,000 lb/in2(124 MPa) and has high oxidation resistance at tempera-

tures to 2200°F (1204°C) Inconel 625 has a low-cycle (105) fatiguestrength of 110,000 to 120,000 lb/in2 (760 to 830 MPa) Inconel 625

LCF has low carbon, silicon, and nitrogen contents to improve

resis-tance to low-cycle fatigue Inconel 725 is an age-hardenable version

of Inconel 625, providing comparable corrosion resistance but greater

strength Inconel 783 is an oxidation-resistant, low-expansion, nickel-cobalt-iron superalloy for aircraft turbine parts RA333, from

Rolled Alloys, contains 45 nickel; 25 chromium; 18 iron; 3 each ofcobalt, molybdenum, and tungsten; 1 silicon; and 0.05 carbon Thealloy features good resistance to oxidation and carburization to2200°F (1200°C), has a tensile yield strength of 39,000 lb/in2 (269MPa), 47% elongation, and a creep-rupture strength of 4,300 lb/in2(30 MPa) for 10,000 h at 1400°F (760°C)

The precipitation-strengthened alloys, which are the most ous, contain aluminum and titanium for the precipitation of a second

numer-strengthening phase, the intermetallic Ni 3 (Al,Ti) known as gamma prime ( ′) or the intermetallic Ni 3 Cb known as gamma double prime ( ″), during heat treatment One such alloy, Inconel X-750

(15.5% chromium, 7 iron, 2.5 titanium, 1 columbium, 0.7 aluminum,0.25 copper maximum, and 0.04 carbon), has more than twice the ten-sile yield strength of Inconel 600 at room temperature and nearly 3times as much at 1400°F (760°C) Its 1,000-h stress-rupture strength

at 1400°F is in the range of 20,000 to 30,000 lb/in2(138 to 207 MPa).Still great tensile yield strength at room and elevated temperaturesand a 25,000 lb/in2 (172 MPa) stress-rupture strength at 1400°F are

provided by Inconel 718 (19% chromium, 18.5 iron, 5.1 columbium, 3

molybdenum, 0.9 titanium, 0.5 aluminum, 0.15 copper maximum,0.08 carbon maximum), a wrought alloy originally that also has been

used for castings Inconel 718SPF is for superplastic forming, as the

designation implies A vacuum-induction-melted and remelted alloy, it is produced to a fine grain size (ASTM 12), andreduced carbon and columbium contents to minimize carbide precipi-tation during forming Gas pressure of only 300 lb/in2 (2 MPa) at1750°F (954°C) and low strain rates are sufficient to form complexshapes Because of the low strain rates, forming cycles are long: 1 to 3

electroslag-h witelectroslag-h mill-annealed selectroslag-heet, welectroslag-hicelectroslag-h electroslag-has an ultimate tensile strengtelectroslag-h of162,000 lb/in2 (1,117 MPa), a yield strength of 118,000 lb/in2 (814MPa), and 33% elongation Aging increases the yield strength to192,000 lb/in2 (1,324 MPa) At 1200°F (649°C), the yield strength is160,000 lb/in2 (1,103 MPa) Among the strongest alloys in terms of

stress-rupture strength is the wrought or cast IN-100 (10%

chromium, 15 cobalt, 5.5 aluminum, 4.7 titanium, 3 molybdenum,

1 vanadium, less than 0.6 iron, 0.15 carbon, 0.06 zirconium, 0.015

boron) Investment-cast, it provides a 1,000-h stress-rupture strength

of 75,000 lb/in2(517 MPa) at 1400°F (760°C), 37,000 lb/in2 (255 MPa)

at 1600°F (871°C), and 15,000 lb/in2 (103 MPa) at 1800°F (982°C)

Other precipitation-strengthened wrought alloys include Astroloy;

D-979; IN 102; Inconel 706 and 751; M252; Nimonic 80A, 90, 95,

100, 105, 115, and 263; René 41, 95, and 100; Udimet 500, 520, 630,

700, and 710; Unitemp AF2-1DA; and Waspaloy Other cast alloys,

mainly investment-cast, include B-1900; IN-738; IN-792; Inconel

713C; M252; MAR-M 200, 246, 247, and 421; NX-188; René 77, 80,

and 100; Udimet 500, 700, and 710; Waspaloy; and WAZ-20.

A few of the cast alloys, such as MAR-M 200, are used to produce

directionally solidified castings, that is, investment castings in

which the grain runs only unidirectionally, as along the length of bine blades Eliminating transverse grains improves stress-rupture

tur-properties and fatigue resistance Grain-free alloys, or single-crystal

alloys, also have been cast, further improving high-temperature

creep resistance Developed mainly for aircraft-engine turbine blades,the first such alloys were pioneered by Pratt & Whitney Aircraft with

PWA 1480 and also include AM1 and 3; CMSX-2, -3, and -6; Rene N4; RR2000; SRR 99; and SX 792 These alloys contain 8 to 12%

chromium, 5 to 15 cobalt, 0 to 12 tantalum, 0 to 10 tungsten, 3.4 to6.0 aluminum, 1 to 4.7 titanium, 0 to 3 molybdenum, and, in somecases, small amounts of columbium, hafnium, and/or vanadium Theyhave similar creep-rupture properties but differ in various other per-formance criteria and single-crystal castability These alloys were fol-lowed with 3 to 6% rhenium alloys having less chromium (2 to 7) and

other compositional changes They include CMSX-4 and -10, PWA

1484, SC 180, and Rene N5 and N6 Compared with rhenium-free

SRR 99, the 6 rhenium CMSX-10 (RR3000) increases 500-h creepstrength by 46% and 20,000-cycle fatigue strength by 59%

At 1400°F (760°C), Cannon Muskegon’s CMSX-4 has a tensile yieldstrength of 140,000 lb/in2(965 MPa), and it retains useful strength up

to 2125°F (1163°C) Regarding powder-metallurgy techniques,

empha-sis has been on the use of prealloyed powder made by rapid

solidifi-cation techniques (RST) and mechanical alloying (MA), a

high-energy milling process using attrition mills or special ball mills

Dispersion-strengthened nickel alloys are alloys strengthened by

a dispersed oxide phase, such as thoria, which markedly increasesstrength at very high temperatures but only moderately so at inter-mediate elevated temperatures, thus limiting applications

TD-nickel, or thoria-dispersed nickel, was the first of such

super-alloys, and it was subsequently modified with about 20% chromium,

TD-NiCr, for greater oxidation resistance MA 754, 758, and 6000E

alloys combine dispersion strengthening with yttria and prime strengthening Alloys 754 and 758 are the same composition-

gamma-ally except for 20 and 30 chromium, respectively MA 6000 contains

69% nickel, 15 chromium, 4.5 aluminum, 4 tungsten, 2.5 titanium, 2molybdenum, 2 tantalum, 1.1 yttria, 0.5 carbon, 0.15 zirconium, and0.01 boron It provides high creep strength up to 2100°F (1150°C) and,

in England, is used for solid blades of industrial gas turbines Threepercent rhenium dispersion-strengthened alloys are roughly similar

in composition to the 3% rhenium single-crystal alloys, although theycontain more hafnium (1.4 to 1.5) plus small amounts of grain-bound-ary-strengthening elements carbon, boron and zirconium These

alloys are PWA 1426, Rene 142, and CM 186 LC, and have similar

creep-rupture strength to the original “first generation” rhenium-freesingle-crystal alloys CM 186 LC, however, does not require solutionheat treatment, thus reducing cost and avoiding recrystallization orincipient melting problems In early production, casting yields haveapproached 90%

Cobalt-based superalloys are for the most part solid-solution

alloys, which, when aged, are strengthened by precipitation of carbide

or intermetallic phases Most contain 20 to 25% chromium, tial nickel and tungsten and/or molybdenum, and other elements,such as iron, columbium, aluminum, or titanium One of the most

substan-well known, L-605, or Haynes 25, is mainly a wrought alloy, though

also used for castings In wrought form, it contains 20% chromium, 15tungsten, 10 nickel, 3 iron, 1.5 manganese, and 0.1 carbon At roomtemperature, it has a tensile yield strength of about 67,000 lb/in2(462MPa), and at 1600°F (871°C) about 35,000 lb/in2(241 MPa) Its 1,000-

h stress-rupture strength at 1500°F (815°C) is 18,000 lb/in2 (124

MPa) The more recent Haynes 188 (22% chromium, 22 nickel, 14.5

tungsten, 3 iron, 1.5 manganese, 0.9 lanthanum, 0.35 silicon, and 0.1carbon), which was developed for aircraft-turbine sheet components,provides roughly similar strength and high oxidation resistance to

about 2000°F (1093°C) MP35N (35% nickel, 35 cobalt, 20 chromium,

10 molybdenum) is a work-hardening alloy used mainly for

high-temperature, corrosion-resistant fasteners MP159 (25% nickel,

19 chromium, 9 iron, 7 molybdenum, 3 titanium, 0.2 aluminum) is awork and precipitation-hardening alloy for such fasteners It has anultimate tensile strength of 260,000 lb/in2(1,793 MPa), 205,000 lb/in2

(1,413 MPa) at 1100°F (593°C) Another alloy, S-816, contains equal

amounts of chromium and nickel (20% each), equal amounts of denum, tungsten, columbium, and iron (4 each), and 0.38 carbon.Primarily a wrought alloy, though also used for castings, it has a1,000-h stress-rupture strength of 21,000 lb/in2 (145 MPa) at 1500°F

(815°C) Other casting alloys include AiResist 13, 213, and 215;

Haynes 21 and 31, the latter also known as X-40; Haynes 151; J-1650; MAR-M 302, 322, 509, and 918; V-36; and W1-52 Their

chromium content ranges from 19% (AiResist 215) to 27 (Haynes 21),and some are nickel-free or low in nickel Most contain substantialamounts of tungsten or tantalum, and various other alloying ele-ments Among the strongest in terms of 1,000-h stress-rupturestrength at 1500°F are Haynes 21 and 31: 42,000 lb/in2 (290 MPa)and 51,000 lb/in2(352 MPa), respectively

SUPERBRONZE. A name applied to brasses containing both minum and manganese They are ordinarily high brasses with 2 to3% manganese and 1 to 6 aluminum, with sometimes also some iron.They have greatly increased strength and hardness over the originalbrasses, but the ductility is reduced and they are difficult to work and

alu-machine The early superbronze was known as Heusler alloy Muntz

metal is also frequently modified with manganese, iron, and minum The alloys are used where high strength and corrosion resis-tance are required, and they are often marketed under trade names

alu-The name superbronze is a shop term rather than a technical

classifi-cation, and thus the name is often applied to any hard, high-strength,heat-treatable, copper-base alloy

SUPERCONDUCTORS. Materials having no electrical resistivity, thusmaximum electrical conductivity, at or below a specific temperature,typically well below zero degrees As long as the material remains at

or below its superconducting temperature, strong magnetic fields can

be generated for use in many applications, including levitating trains.Until recently, temperatures approaching absolute zero [459°F(272°C)] were required Some of the metals exhibiting superconduc-

tivity at such temperatures are columbium, lead, iridium,

mer-cury, tantalum, tin, and vanadium, as well as many alloys and

compounds Alloys considered among the best commercially available

include columbium-tin, columbium-tantalum,

columbium-tita-nium, and lead-molybdenum-sulfur Columbium-titacolumbium-tita-nium, in the

form of flexible wire, is probably the most widely used It has a conducting temperature of 441°F (263°C) and is generally limited

super-to magnetic fields below 80,000 G (8 T), particle accelerasuper-tors beingone application Magnets of greater strength—200,000 G (20 T)—have been made of columbium-tin Columbium alloyed with tin andtitanium is used for magnets in magnetic resonance imaging andmagnetic-energy storage devices Columbium-titanium wire coils,cooled by liquid helium to 452°F (269°C), have been proposed for

use in subway tunnels as a means of preventing voltage sags from

increasing numbers of accelerating trains Gallium-arsenide, grown

under certain conditions, is superconductive at 440°F (262°C) and,being compatible with semiconductor chips, could find electronic

applications Using laser-deposited films of the mercury

supercon-ductor HgBa2CaCu2O6 + gamma, IBM scientists have achieved acurrent density of about 6.45  105 A/in2 (105 A/cm2) at 279°F(173°C) in a magnetic field of 50 G (0.005 T) with the field at rightangle to the film plane, and about 108A/cm2 at 10 kG (1 T) with thefield oriented parallel to the film plane

In recent years various ceramic compounds have been found toexhibit superconductivity at higher temperatures These include

YBa 2 Cu 3 O 7x, also designated YBCO-123, with a superconductingtemperature of 294°F (181°C); Bi2 Sr 2 CaCu 2 O 10x, or BSCCO

2212, also 294°F; Bi2 Sr 2 Ca 2 Cu 3 O 12x, or BSCCO 2223, 262°F(163°C); Tl2 Ba 2 Ca 2 Cu 3 O 12x, or TBCCO 2223, 235°F (148°C);

and HgBa 2 Ca 2 Cu 3 O 10x, or HBCCO 1223, 221°F (140°C) Theprincipal advantage of such “high-temperature” superconductors isthat liquid nitrogen [321°F (196°C)] instead of liquid helium[452°F (269°C)] could be used as the cooling medium Potentialapplications include sonar transducers in submarines, high-powermotors for utilities and processing industries, power transmissioncables, magnetic bearings for energy-storage flywheels, electric cur-rent limiters, and electric current leads A 3.28-ft (1-m) long conduc-tor made by American Superconductor Corp of a BSCCO-typematerial can carry more than 2,300 A of direct current at 321°F, ormore than twice that typical of conventional underground copperconductors

At Los Alamos National Laboratory, a flexible thick film of YBCO onmalleable nickel tape, first treated with a layer of cubic zirconia to tex-ture the surface, has carried a current density of 6.45  106A/in2(106A/cm2) at liquid-nitrogen temperatures And the critical currentdegraded only by a factor of 3 or 4 in a magnetic field typical of mag-netic resonance imaging machines At Du Pont, a 2.6-ft (0.8-m) silver-encased BSCCO 2223 magnet surrounding a stainless-steel-wool-filledfilter can deliver 25,000 G (2.5 T) to remove magnetic contaminants inprocessing ores

Despite the great interest in such ceramic superconductors, metalones have the advantage of being more ductile and, thus, more read-ily fabricated into flexible forms, such as wire Here, too, recent devel-opments indicate increasing superconducting temperatures AtAT&T’s Bell Laboratories, a composition of nickel, boron, yttrium, andcarbon has demonstrated superconductivity at 418°F (214°C) Also,

the compound (NH 3 ) 4 Na 2 CsC 60 , a carbon fullerene modified with

alkali metals, has been found to change from insulator to ductor at 405°F (243°C)

supercon-SUPERCRITICAL FLUIDS. SCFs are fluids which, when compressedand heated above a critical pressure and temperature, have diffusionproperties similar to those of gases and densities similar to those ofliquids and, thus, are efficient solvents Critical parameters (pres-

sure, temperature, and density, respectively) for carbon dioxide are

1,072 lb/in2 (7.4 MPa), 88°F (31°C), and 0.017 lb/in3 (471 kg/m3); for

water, 3,209 lb/in2 (22 MPa), 706°F (374°C), and 0.012 lb/in3 (332kg/m3); for hydrogen, 188 lb/in2 (1.3 MPa), 400°F (240°C), and0.0012 lb/in3(33 kg/m3); for ammonia, 1,636 lb/in2(11.3 MPa), 270°F(132°C), and 0.0085 lb/in3 (235 kg/m3); and for methyl alcohol, or

methanol, 1,154 lb/in2 (8 MPa), 464°F (240°C), and 0.01 lb/in3 (277kg/m3)

Current and potential applications for SCFs, especially carbon ide and water, stem largely from regulatory pressures on ecology andsafety, and health trends They were first used in the 1970s for decaf-feinating coffee and tea, replacing trichloroethylene and methylenechloride, have replaced ethylene chloride in spice extraction, and havebeen recently introduced for metal cleaning, deasphalting, and spraypainting without volatile organic compounds Emerging or potentialuses for CO2 include ethanol purification; extraction of acetone fromantibiotics, fat and cholesterol from egg yolks, and vitamin E fromsoybean oil; and soil remediation CO2, being nonpolar, is effective inremoving nonpolar contaminants from virtually any matrix and mayprove economical for on-site removal of organic soil contaminants that

diox-do not easily volatize In pilot tests at the Westinghouse Hanfordnuclear site, CO2at 6,000 lb/in2(41 MPa) and 140°F (60°C) extractedmore than 95% of the diesel oil, polychlorinated biphenyls (PCBs),and bis (2-ethyl hexyl) phthalate

Union Carbide’s Unicarb process uses a compressed gas, usually

CO2, in the supercritical state to replace most of the solvent in ventional and high-solids topcoatings as well as in primers toreduce volatile organic compounds by as much as 80% and increasetransfer efficiency by reducing overspray Concern about the knownhuman carcinogen perchloroethylene in dry-cleaning processes maydrive some 10% of the 30,000 such establishments in NorthAmerica to supercritical CO2 systems by the year 2005 In Japan,this SCF has been found to be one-third as costly and more energyefficient than the conventional thermal process for pasteurizing liq-uid foodstuffs Also in Japan, this SCF with 1 to 3% tri-n-butyl

phosphate has recovered 99% of the uranium, including variouslanthanides and actinides, from spent nuclear-reactor rods dissolved

in nitric acid Moreover, the use of supercritical CO2may prove ical and/or energy efficient for the production of fluoropolymers,dimethyl carbonate, propylene carbonate, dimethyl terephthalate,and ethylene glycol At 212°F (100°C) and 4,000 lb/in2(27.6 MPa), ithas even achieved virtually 100% recovery of cedarwood oil fromjuniper-tree chips, about twice that of the usual steam distillationmethod Both supercritical CO2and nitrogen are used to make poly-ethylene and polypropylene foam products A supercritical nitrogen

econom-is the usual gas in Trexel Corp.’s process for making MuCell

microcellular foam.

Water at 3,400 lb/in2 (23 MPa) and 650 to 1100°F (343 to 593°C)has potential for treating various organic substances by supercriticaloxidation Organic liquids and gases mix with the water and aretransformed into CO2 and water while inorganics dissolve onlyslightly, allowing them to concentrate and be recovered Virtually all

of the organics are destroyed Potential abounds for waste treatment

at chemical, pulp and paper, and weapons plants At a U.S Navyfacility, a unit operating at 3,400 lb/in2(23 MPa) and 650°F (343°C) isintended to destroy mixtures containing paint, oil, chlorinated sol-vents, PCBs, and other hazardous compounds Supercritical wateroxidation is an economical alternative to incineration for destroyingessentially all pulp- and papermill-sludge organics, including PCBsand almost all dioxins and dibenzofurans In tests at 3600 lb/in2(24.8MPa) and 932°F (500°C) with oxygen as the oxidant, most of thematerial was converted to carbon dioxide and water, with inorganicash, acids, and salts Compared with incineration, the SCF treatmenteliminates the need for smokestacks, emits practically no nitrousoxides, and excess heat can be used as process heat or to cogenerateelectricity

Water is also in contention for soil remediation, having proved tive in removing virtually all of the polycyclic aromatic hydrocarbons insoil It is aimed at some 2,000 sites in the United States and Canadawhere town gas has been made from coal KerforschungszentrumKarlsruhe of Germany is combining supercritical CO2 extraction witheither supercritical water oxidation or indirect electro-oxidation tocleanse metal-laden sludge at a glass-grinding facility and for treat-ment of halogenated organic wastestreams

effec-The drug developer Aphios Corp has used supercritical carbondioxide, nitrogen, propane, and nonchlorinated freons in its processfor making protein nanoparticles for drug-delivery systems.Temperatures have ranged from 315 to 122°F (193°C to 50°C) and

pressures from 1000 to 6000 lb/in2 (6.9 to 41 MPa), but are usuallyambient temperature and 3000 lb/in2(20.7 MPa).

SUPERPOLYMERS. Many plastics developed in recent years canmaintain their mechanical, electrical, and chemical resistance proper-ties at temperatures over 400°F (213°C) for extended periods Among

these materials are polyimide, polysulfone, polyphenylene

sul-fide, polyethersulfone, polyarylsulfone, novalac epoxy, matic polyester, and polyamide-imide In addition to

aro-high-temperature resistance, they have in common high strengthand modulus of elasticity, and excellent resistance to solvents, oils,and corrosive environments They are also high in cost Their majordisadvantage is their processing difficulty Molding temperaturesand pressures are extremely high compared to conventional plastics.Some of them, including polyimide and aromatic polyester, are notmolded conventionally Because they do not melt, the moldingprocess is more of a sintering operation Thus, parts are often

molded by resin producers, such as Du Pont for its line of Vespel polyimides, Furon Co for its Meldin 3000 polyimides, and Hoechst Celanese for its Celazole polybenzimidazole One indication of the

high-temperature resistance of the superpolymers is their glass tion temperature of well over 500°F (260°C), as compared to less than350°F (177°C) for most conventional plastics In the case of polyimides,the glass transition temperature is greater than 800°F (427°C), andthe material decomposes rather than softens when heated excessively

transi-Aromatic polyester, a homopolymer also known as polyoxybenzoate,

does not melt, but at 800°F (427°C) can be made to flow in a cous manner similar to metals Thus, filled and unfilled forms andparts can be made by hot sintering, high-velocity forging, and plasmaspraying Notable properties are high thermal stability, good strength

nonvis-at 600°F (316°C), high thermal conductivity, good wear resistance, andextra-high compressive strength Aromatic polyesters have also beendeveloped for injection and compression molding They have long-termthermal stability and a strength of 3,000 lb/in2 (21 MPa) at 550°F(288°C) At room temperature, polyimide is the stiffest of the groupwith a top modulus of elasticity of 7.5  106 lb/in2 (51,713 MPa), fol-lowed by polyphenylene sulfide with a modulus of 4.8  106 lb/in2(33,096 MPa) Polyarylsulfone has the best impact resistance of thesuperpolymers with a notched impact strength of 5 ft lb/in (267 J/m)

PMR-15 is an addition-type thermosetting polyimide having a glass

transition temperature of about 644°F (340°C) and a maximum usetemperature of about 600°F (316°C) However, it is rather brittle and

prone to microcracking and delamination in composites AFR700B,

a toughened chemical modification developed by Air Forceresearchers, increases use temperature to about 700°F (370°C).Interleaving PMR-15 with Ciba Geigy’s thermoplastic polyimide

Matramid 5218 in powder form reduces interply stress, thus

delami-nation tendency Aurum, a thermoplastic polyimide of Mitsui Toatsu

Chemicals of Japan, has a glass transition temperature of 482°F(250°C), a long-term continuous-use temperature of 350 to 446°F (177

to 230°C), and a low thermal coefficient for dimensional stability Ithas a tensile strength of 13,300 lb/in2 (92 MPa), a flexural strength of19,900 lb/in2 (137 MPa), a flexural modulus of 426,000 lb/in2 (2,937MPa), and a notched Izod impact strength of 1.6 ft lb/in (85 J/m).Adding 30% carbon fiber more than doubles strengths, boosts modulusmore than sixfold, and improves impact strength to 2 ft lb/in (107J/m) It also exhibits excellent performance as lubricated or nonlubri-cated bearings

Polyetherimide, such as General Electric Plastics’ Ultem, is an

amorphous thermoplastic that can be processed with conventionalthermoplastic processing equipment Its continuous-use temperature

is 340°F (171°C), and its deflection temperature is 400°F (204°C) at

264 lb/in2(1.8 MPa) The polymer also has inherent flame resistancewithout the use of additives This feature, along with its resistance tofood stains and cleaning agents, makes it suitable for aircraft panelsand seat component parts Tensile strength ranges from 15,000 to24,000 lb/in2 (103 to 165 MPa) Flexural modulus is 480,000 lb/in2(3,310 MPa)

Polyamide-imide has a glass transition temperature of 527°F(275°C), a tensile strength of 22,000 lb/in2 (152 MPa), a flexuralstrength of 34,900 lb/in2 (241 MPa), and heat-deflection temperature

of 532°F (278°C) at 264 lb/in2(1.8 MPa) Torlon is such a material of

BP Amoco Polymers Radel A, of this company, is polyethersulfone,

Radel R is polyphenylsulfone, Udel is polysulfone, and Mindel is a

modified polysulfone Polyethersulfone combines substantial strengthretention and excellent dimensional stability at temperatures to

390°F (200°C) and high creep resistance to 355°F (180°C) Ryton is a polyphenylene sulfide of Phillips Chemical Co., and Supec is one

made by General Electric Plastics

Polyimide foam is a spongy, lightweight, flame-resistant material

that resists ignition up to 800°F (427°C) and then only chars anddecomposes Some formulations result in harder materials that can

be used as lightweight wallboard or floor panels while retaining fire

resistance Kapton is Du Pont’s polyimide film.

Aromatic polyketones are high-performance thermoplastics They

include polyaryletheretherketone (PAEEK), which has a glass

transition temperature of 289°F (143°C) and a melting point of 649°F(343°C) Produced by Victrex USA, it is known by the brand namePEEK; has a continuous use temperature of 500°F (260°C); is highlyresistant to wear, water, steam, and many chemicals; and requires noflame-retardant additives for a V-0 flammability rating at 0.057-in

(1.45-mm) thickness XC-2, of ICI Fiberite, is PAEEK prepreg tape for

filament winding applications It has a maximum service ture of 600°F (316°C) and can be made in sheet form for compressionmolding Carbon-fiber-reinforced XC-2, developed by EGC Corp., has

tempera-a tensile strength of 300,000 lb/in2 (2,069 MPa) Uses include trifugal-pump rings and bushings in oil- and chemical-processing

cen-plants Other aromatic polyketones include polyaryletherketone

(PAEK), with a glass transition temperature of 310°F (154°C), and

polyaryletherketoneketone (PAEKK), with the same glass

transi-tion temperature and a melting point of 635°F (335°C) There are alsovarious ketone-based copolymers

SYCAMORE. The wood of the tree Acer pseudo-platanus, which is

also classified as a kind of maple, especially in England The species

cut as sycamore in the United States is largely Platanus occidentalis.

The wood has a close, firm, tough texture and is yellowish, with a reddish-brown heartwood The light-colored sapwood is up to 3 in (8cm) thick in commercial trees When quartered, the wood resemblesquartered oak The density is about 38 lb/ft3(609 kg/m3) The surface

is lustrous and takes a fine polish It is used for veneers, flooring, niture, cooperage, and handles and rollers Two other species grown

fur-in the southwest are California sycamore, P racemosa, and

Arizona sycamore, P wrightii.

TALC. A soft, friable mineral of fine colloidal particles with a soapy

feel It is a hydrated magnesium silicate, 4SiO2 3MgO  H2O,with a specific gravity of 2.8 and a Mohs hardness of 1 It is whitewhen pure, but may be colored gray, green, brown, or red with impu-rities The pure white talc of Italy has been valued since ancienttimes for cosmetics Talc is now used for cosmetics, for paper coatings,

as a filler for paints and plastics, and for molding into electrical lators, heater parts, and chemicalware The massive block material,

insu-called steatite talc, is cut into electrical insulators It is also insu-called

lava talc Talc dust is a superfine, 400-mesh powder from the

milling of steatite talc It has an oily feel and is used in cosmetics.The more impure block talcs are used for firebox linings and with-stand temperatures to 1700°F (927°C) Gritty varieties contain car-bonate minerals and are in the class of soapstones Varietiescontaining lime are used for making porcelain

Talc of specified purity and particle size is marketed under trade

names Asbestine is a talc powder of 325 mesh for use as a filler.

Ceramitalc is a talc powder used as a source of magnesia and to

prevent crazing in ceramics Sierra Fibrene is a California talc

milled to 400 mesh It is white and has a platy structure, and as anextender in paints, it wets easily and promotes pigment dispersion

French chalk is a high-grade talc in massive block form used for

marking The mineral occurs in the United States in the

Appalachian region from Vermont to Georgia Georgia talc for making crayons is mined in blocks Attasorb and Permagel are finely powdered, cream-colored, hydrated magnesium-aluminum

silicate from the mineral attapulgite, used for emulsifying and as

a flatting agent and extender in paints The material is also used in

starch adhesives to improve shear strength Attacote is the

mater-ial in superfine particle size for use as an anticaking agent for

hygroscopic chemicals Veegum F, of R T Vanderbilt Co., is a fine,

white, colloidal magnesium-aluminum silicate used as a suspendingagent for oils and waxes

Cordierite is a talclike mineral with a high percentage of

magne-sia used for refractory electronic parts It is found sparsely in Norway,Finland, and Connecticut, usually in granite and gneiss, or in vitri-fied sandstones When heated to 2624°F (1440°C), it is converted tosillimanite and glass Synthetic cordierite is made by Muscle ShoalsElectrochemical Corp by mixing pure silica, magnesia, and alumina

in various proportions and stabilizing with calcia It is marketed as apowder for producing refractory insulating parts Extruded cordieriteserves as a substrate for the active catalyst metals in auto catalyticconverters

Agalite is a mineral having the same composition as talc but with

a less soapy feel It is used as a filler in writing papers, but is morewearing on the paper rolls than talc The talc of northern New York,

known as rensselaerite, does not have the usual talc slip, and has a fibrous nature The hydrous aluminum silicate pyrophyllite, found

in California, is similar to talc but with the magnesium replaced byaluminum In mixtures with talc for wall tile it eliminates crazing It

is also substituted for talc as a filler for paints and paper Thix, used

as a thickening agent in emulsion paints, in cosmetics, and in textilefinishes, is a refined, hydrous magnesium silicate marketed as a 200-mesh powder It contains 56% silica, 26 magnesia, 2.8 calcia, 2.5

Na2O, and 1.1 lithia

Magnesium silicate, used as a filler in rubber and plastics, and

also as an alkaline bleaching agent for oils, waxes, and solvents, is awhite, water-insoluble powder of composition MgSiO4, having a pH of

7.5 to 8.5 In the cosmetic trade it is known as talcum powder.

Magnesol, of Westvaco Chemical Co., is finely ground magnesium

silicate Brite-Sorb 30 is a synthetic magnesium silicate with high adsorption and filtering power The magnesium trisilicate used in

pharmaceuticals as an antacid is of extreme fineness, the ing grade having 65% of the particles less than 197
in (5
m) in size

superbulk-The material known as killas from the tin mines of Cornwall is a

slaty schist It is finely ground and used as talc

TALL OIL. An oily, resinous liquid obtained as a by-product of the fite paper-pulp mills The alkali saponifies the acids, and the result-ing soap is skimmed off and treated with sulfuric acid to produce tall

sul-oil The name comes from the Swedish talloel, meaning pine sul-oil The

crude oil is brown, but the refined oil is reddish yellow and nearlyodorless It has a specific gravity of 0.98, flash point of 360°F (182°C),and acid number about 165 The oil from Florida paper mills contains

41 to 45% rosin, 10 to 15 pitch, and the balance chiefly fatty acids.The fatty acids can be obtained separately by fractionating the crude

whole oil The oil also contains up to 10% of the phytosterol

sitos-terol, used in making the drug cortisone.

Tall oil is used in scouring soaps, asphalt emulsions, cutting oils,insecticides, animal dips, in making factice, and in plastics and paint

oils It is marketed in processed and concentrated form Seecotol is crude tall oil from Georgia-Pacific Xtol, from the same firm, is a dis-

tilled grade for use in surfactants, soaps, asphalt, alkyds, and as a

chemical intermediate Acintol, from Arizona Chemical Co., contains

60 to 68% fatty acids, 30 to 38 rosin acids, and has an acid value of

185 Flextal is processed tall oil containing 60% rosin acids

Deter-gents are made by reacting tall oil with ethylene oxide Saturatedalcohols are produced by high-pressure hydrogenation of tall oil Thehigh linoleic acid content makes tall oil suitable for making drying

oils Lumitol is a German vinyl plastic produced by reacting tall oil with acetylene It is used for coatings Smithco RT, of Archer-

Daniels-Midland Co., used for varnishes and paints, is refined tall oil

esterified with glycerin Smithco PE is tall oil esterified with taerythritol Ardex PE, of the same company, is a varnish oil that

dries quickly to a hard film, made by esterifying tall oil with

pen-taerythritol Sulfonated tall oil is used to replace sulfonated castor oil in coating mixes for paper to increase folding strength Opoil is a crude tall oil, and Facoil is the refined oil with 60% fatty acid content and low rosin acid content Acolin, Acosix, and Aconon are grades

of refined tall oil Pamac, of Hercules Inc., consists of tall oil sic fatty acids, used in resin coatings Lytor 100 is a tall-oil rosin for

monoba-paper sizing, and for use as an adhesive and ink resin It is produced

by Georgia-Pacific