Polymer chemistry (carraher)

It is eminently useful for teaching polymer science in departments of chemistry, chemical engineering, and material science, and also for teaching polymerscience and technology in polyme

Sepour/Carraher's Polymer

Chemistry

Sixth Edition Revised and Expanded

Charles E Carraher, Jr.

College of Science Florida Atlantic University Boca Raton, and Florida Center for Environmental Studies Palm Beach Gardens, Florida, U.S.A.

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1 Modern Inorganic Chemistry, J J Lagowski

2 Modern Chemical Analysis and Instrumentation, Harold F Walton and Jorge Reyes

3 Problems in Chemistry, Second Edition, Revised and Expanded, Henry O Daley,

Jr., and Robert F O'Malley

4 Principles of Colloid and Surface Chemistry, Paul C Hiemenz

5 Principles of Solution and Solubility, Kozo Shinoda, translated in collaboration with

Paul Becher

6 Physical Chemistry: A Step-by-Step Approach, M K Kemp

7 Numerical Methods in Chemistry, K Jeffrey Johnson

8 Polymer Chemistry An Introduction, Raymond B Seymour and Charles E.

Carraher, Jr

9 Principles of Colloid and Surface Chemistry, Second Edition, Revised and

Expanded, Paul C Hiemenz

10 Problems in Chemistry, Second Edition, Revised and Expanded, Henry O Daley,

Jr, and Robert F O'Malley

11 Polymer Chemistry: An Introduction, Second Edition, Raymond B Seymour and

Charles E Carraher, Jr

12 Polymer Chemistry An Introduction, Third Edition, Revised and Expanded,

Raymond B Seymour and Charles E Carraher, Jr.

13 Seymour/Carraher's Polymer Chemistry: An Introduction, Fourth Edition, Revised

and Expanded, Charles E Carraher, Jr.

14 Seymour/Carraher's Polymer Chemistry: Fifth Edition, Revised and Expanded,

Charles E Carraher, Jr.

15 Principles of Thermodynamics, Myron Kaufman

16 Seymour/Carraher's Polymer Chemistry: Sixth Edition, Revised and Expanded,

Charles E Carraher, Jr.

Additional Volumes in Preparation

Copyright © 2003 by Marcel Dekker, Inc All Rights Reserved

To Raymond Seymour—educator, scientist, pioneer, prophet, historian, family man, and friend—we miss you

Polymer science and technology has developed tremendously over the last few decades,and the production of polymers and plastics products has increased at a remarkable pace

By the end of 2000, nearly 200 million tons per year of plastic materials were produced

ever-growing needs of the plastic age; in the industrialized world plastic materials are

used at a rate of nearly 100 kg per person per year Plastic materials with over $250 billiondollars per year contribute about 4% to the gross domestic product in the United States.Plastics have no counterpart in other materials in terms of weight, ease of fabrication,efficient utilization, and economics

It is no wonder that the demand and the need for teaching in polymer science andtechnology have increased rapidly To teach polymer science, a readable and up-to-dateintroductory textbook is required that covers the entire field of polymer science, engineer-ing, technology, and the commercial aspect of the field This goal has been achieved inCarraher’s textbook It is eminently useful for teaching polymer science in departments

of chemistry, chemical engineering, and material science, and also for teaching polymerscience and technology in polymer science institutes, which concentrate entirely on thescience and technologies of polymers

This sixth edition addresses the important subject of polymer science and technology,with emphasis on making it understandable to students The book is ideally suited notonly for graduate courses but also for an undergraduate curriculum It has not becomemore voluminous simply by the addition of information—in each edition less importantsubjects have been removed and more important issues introduced

Polymer science and technology is not only a fundamental science but also importantfrom the industrial and commercial point of view The author has interwoven discussion

of these subjects with the basics in polymer science and technology Testimony to thehigh acceptance of this book is that early demand required reprinting and updating of each

of the previous editions We see the result in this new significantly changed and improvededition.

Otto Vogl Herman F Mark Professor Emeritus Department of Polymer Science and Engineering

University of Massachusetts Amherst, Massachusetts

An explosive scientific and technological revolution is underway and at its center arepolymers This revolution is the result of a number of factors that complement one another.These factors include a better understanding of the science of materials and availability

of new and refined materials, synthetic techniques, and analytical tools Much of thisrevolution is of a fundamental nature and it is explored in the latest edition of this text.These advances are often based on new and extended understanding and application ofbasic principles initially presented in the core chemistry courses (organic, physical, inor-ganic, analytical, and biological)

Polymer Chemistry complies with the advanced course definition given by the

Amer-ican Chemical Society Committee on Professional Training, building on the foundationslaid in general, organic, physical, analytical/instrumentation, and inorganic chemistry Italso includes all the major and optional topics recommended in the syllabus adopted bythe joint polymer education committee of the American Chemical Society (Appendix D:Syllabus) The text integrates and interweaves the important core topic areas The coretopics are interrelated with information that focuses on polymer topics This assists students

in integrating their chemical knowledge and illustrates the connection between theoreticaland applied chemical information Also, industrial practices and testing procedures andresults are integrated with the theoretical treatment of the various topics, allowing thereader to bridge the gap between industrial practice and the classroom It is written sothat chapters can be taken out of order and not all the chapters need to be covered to gain

an adequate appreciation of the science of polymers Many of the chapters begin withtheory, followed by application Some readers will elect to read the more descriptivechapters dealing with polymer types before looking at the analytical/analysis/propertieschapters

This book is user friendly—it is appropriate as an advanced undergraduate text or

an introductory-level graduate-level course text It can serve as the text for the initial

course in a series taken by a student, or it can be the lone polymer text read by a student

in the study of polymers Students of chemistry, materials, engineering, medicine, istry, physics, and geology will benefit from an understanding of the material found inthis text

biochem-The application and theory of polymers continues to expand This new edition flects this growth and the continually expanding role of polymers There is an increasedemphasis on pictorializing, reinforcing, integrating, and interweaving the basic concepts.The first chapter is shorter in order to allow time for student orientation However,the other chapters should not require more than a week’s time each Each chapter isessentially self-contained, but each relates to the other chapters Whenever possible, diffi-cult concepts are distributed and reinforced over several chapters A glossary, biography,suggested questions (and answers), and learning objectives/summary are included at theend of each chapter

re-Application and theory are integrated so that they reinforce one another This is truefor all the various important and critical types of polymers including synthetic, biological,organometallic, and inorganic polymers The principle that the basic concepts that apply

to one grouping of polymers apply to all the other types of polymers is emphasized.The updating of analytical, physical, and spectral characterization techniques contin-ues, including expanded coverage of the theory and results arising from atomic forcemicroscopy and scanning probe microscopy Special sections dealing with industriallyimportant polymers are included, and the section dealing with soluble stereoregulatingcatalysis has been expanded

There is still an emphasis on naturally occurring polymers, and discussions ofsupercoiling, replication, and compacting are included As before, the interplay betweennatural and synthetic polymers is emphasized

A number of miscellaneous topics have been drawn together in one chapter, whichincludes sections on conductive polymers, smart materials, protomics, human genome,optical fibers, material selection charts, carbon nanotubes, and liquid crystals

Emphasis on nanotechnology and nanomaterials remains with added or expandedsections dealing with zeolites, nanotubes, nanocomposites, molecular wires, dendrites, andself assembly The chapter on polymer technology and processing has been rewritten andexpanded The section listing Web sites has been updated

The nomenclature section has been enlarged, and a new appendix on the ometry of polymers has been added

stereoge-Additional aids and appendixes are included: how to study, nomenclature, over 1500

trade names, about 400 citations to appropriate Journal of Chemical Education and mer News articles, Web sites dealing with polymer topics, and over 100 structures of

Poly-common polymers

Charles E Carraher, Jr.

I gratefully acknowledge the contributions of Herman Mark of the Polytechnic Institute

of New York; Charles L McCormick, University of Southern Mississippi; William Feld,Wright State University; Eli Pearce, Polytechnic Institute of New York; Fredinard Rodri-guez, Cornell University; and Otto Vogl, University of Massachusetts, for their reviewing,advising, and counseling efforts; and Charles Carraher III and Shawn Carraher for theirhelp in proofing and indexing

I also thank the following for their special contributions to the book: Charles ein, Les Sperling, Anglo Volpe, Stam Israel, Carl Wooten, Rita Blumstein, Eckhard Hell-muth, Frank Millich, Norman Miller, Rudy Deanin, Guy Donaruma, Leo Mandelkem, R

Gebel-V Subramanian, Charles Pittman, Brian Currell, C Bamford, Roger Epton, Paul Flory,Charles Overberger, William Bailey, Jim O’Donnell, Rob Burford, Edgar Hardy, John H.Coates, Don Napper, Frank Harris, G Allan Stahl, John Westerman, William A Field,Nan-Loh Yang, Sheldon Clare, E N Ipiotis, D H Richards, G Kirshenbaum, A M.Sarquis, Lon Mathias, Sukumar Maiti, S Temin, Yoshinobu Naoshima, Eberhard Neuse,John Sheats, George Hess, David Emerson, Kenneth Bixgorin, Thomas Miranda, M B.Hocking, Marsha Colbert, Joseph Lagowski, Dorothy Sterling, Amanda Murphy, JohnKloss, Qingmao Zhang, Bhoomin Pandya, Ernest Randolph, Alberto Rivalta, and FengchenHe

This book could not have been written without the long-time efforts of ProfessorHerman Mark, who was one of the fathers of polymer science

For the fourth edition, a special thanks for the assistance of Colleen Carraher

I acknowledge the kind permission of Gerry Kirshenbaum and Polymer News for allowing us to use portions of articles that have appeared in Polymer News.

Finally, I thank Edward S Wilks for his help with the section on “Chemical stracts–Based Polymer Nomenclature.”

Ab-Polymer Nomenclature

As with most areas of science, names associated with reactions, particular chemical andphysical tests, etc., were historically derived with few overall guiding principles Further,the wide diversity of polymer science permitted a wide diversity in naming polymers.Even though the International Union of Pure and Applied Chemistry (IUPAC) has along-standing commission associated with the nomenclature of polymers [reports include

“Report on nomenclature in the field of macromolecules,” Journal of Polymer Science,

8, 257 (1952); “Report on nomenclature dealing with steric regularity in high polymers,” Pure and Applied Chemistry, 12, 645 (1966); “Basic definitions of terms relating to poly- mers,” IUPAC Information Bull App., 13, 1 (1971); and “Nomenclature of regular single- strand organic polymers,” Macromolecules, 6(2), 149 (1973)], most of these suggestions

for naming of simple polymers have not yet been accepted by many in the polymer sciencecommunity

Although there is wide diversity in the practice of naming polymers, we will trate on the most utilized systems

concen-COMMON NAMES

Little rhyme or reason is associated with the common names of polymers Some names

are derived from the place of origin of the material, such as Hevea brasiliensis—literally

“rubber from Brazil”—for natural rubber Other polymers are named after their discoverer,

as is Bakelite, the three-dimensional polymer produced by condensation of phenol andformaldehyde, which was commercialized by Leo Baekeland in 1905

Portions adapted from C Carraher, G Hess, and L Sperling, J Chem Ed., 64(1), 36 (1987) and L H Sperling

W V Metanomski, and C Carraher, Appl Polym Science (C Craver and C Carraher, eds.), Elsevier, New

York, 2000.

For some important groups of polymers, special names and systems of nomenclaturewere invented For example, the nylons were named according to the number of carbons

in the diamine and carboxylic acid reactants (monomers) used in their syntheses Thenylon produced by the condensation of 1,6-hexanediamine (6 carbons) and sebacic acid(10 carbons) is called nylon-6,10

Similarly, the polymer from 1,6-hexanediamine and adipic acid (each with 6 carbons)

is called nylon-6,6 or nylon-66, and the nylon from the single reactant caprolactam (6carbons) is called nylon-6

SOURCE-BASED NAMES

Most polymer names used by polymer scientists are source-based; i.e., they are based onthe common name of the reactant monomer, preceded by the prefix “poly.” For example,polystyrene is the most frequently used name for the polymer derived from the monomer1-phenylethene, which has the common name styrene

The vast majority of polymers based on the vinyl group (CH2BCHX) or the dene group (CH2BCX2) as the repeat unit are known by their source-based names Forexample, polyethylene is derived from the monomer ethylene, poly(vinyl chloride) fromthe monomer vinyl chloride, and poly(methyl methacrylate) from methyl methacrylate:

vinyli-Many condensation polymers are also named in this manner In the case of ylene terephthalate), the glycol portion of the name of the monomer, ethylene glycol, isused in constructing the polymer name, so that the name is actually a hybrid of a source-based and a structure-based name

poly(eth-This polymer is well known by trade names, such as Dacron, or its common grouping,polyester.

Although it is often suggested that parentheses be used in naming polymers of morethan one word [like poly(vinylidene chloride)] but not for single-word polymers (likepolyethylene), many authors omit entirely the use of parentheses for either case (likepolyvinylidene chloride) Thus there exists a variety of practices with respect to evensource-based names

Copolymers are composed of two or more monomer units Source-based names areconveniently used to describe copolymers by using an appropriate term between the names

of the monomers Any of a half dozen or so connecting terms may be used, depending

on what is known about the structure of the copolymer When no information is specified

about the sequence of monomer units in the copolymer, the connective term co is used

in the general format poly(A-co-B), where A and B are the names of the two monomers.

An unspecified copolymer of styrene and methyl methacrylate would be called

—AAAAABBBBBAAAAA—, where each A or B represents an individual monomer

unit The proper source-based name for Kraton is

polystyrene-block-polybutadiene-block-polystyrene, with the prefix “poly” being retained for each block

repeat unit are found elsewhere [Macromolecules, 6(2), 149 (1973); Pure and Applied Chemistry, 48, 373 (1976), 57, 149 (1985), and 57, 1427 (1985)] However, once the order

is selected, the naming is straightforward for simple linear molecules, as indicated in thefollowing examples:

A listing of source- and structure-based names for some common polymers is given

in Table 1

LINKAGE-BASED NAMES

Many polymer “families” are referred to by the name of the particular linkage that connectsthe polymers (Table 2) The family name is “poly” followed by the linkage name Thus,

Table 1 Source- and Structure-Based Names

Table 2 Linkage-Based Names

those polymers that contain the carbonate linkage are known as polycarbonates; thosecontaining the ether linkage are called polyethers, etc.

CHEMICAL ABSTRACTS – BASED POLYMER NOMENCLATURE

The most complete indexing of any scientific discipline is done in chemistry and is vided by Chemical Abstracts (CA) Almost all of the modern searching tools for chemicalsand chemical information depend on CA for at least some of their information base It iscritical for polymer chemists to have some grasp of how CA names chemical compounds.The full description of the guidelines governing the naming of chemical compounds and

pro-related properties is given in Appendix IV at the end of the CA Index Guide This

descrip-tion is about 200 pages While small changes are made with each new edidescrip-tion, the mainpart has remained largely unchanged since 1972

CA organizes the naming of materials into twelve major arrangements that tie gether about 200 subtopics These main topic headings are

The section dealing with polymers is subtopic 222: Polymers The subsection on

polymers builds on the foundations given before Some of the guidelines appear to beconfusing and counterproductive to the naming of polymers, but the rules were developedfor the naming of small molecules Following is a description of the guidelines that aremost important to polymer chemists Additional descriptions are found in the CA Appendix

IV itself and in articles listed in the readings Appendix IV concentrates on linear polymers

A discussion of other more complex polymeric materials is also found in articles cited inthe readings section

General Rules

In the chemical literature—in particular, systems based on Chemical Abstracts—searchesfor particular polymers can be conducted using the Chemical Abstracts Service number,

Chemistry (IUPAC) and CAS have agreed on a set of guidelines for the identification,orientation, and naming of polymers based on the structural repeat unit (SRU) IUPACrefers to polymers as “poly(constitutional repeat unit)” while CAS utilizes a “poly(struct-ural repeating unit).” These two approaches typically give similar results

Here we will practice using the sequence “identification, orientation, and naming,”first by giving some general principles and finally by using specific examples

In the identification step, the structure is drawn, usually employing at least two repeat units Next, in the orientation step, the guidelines are applied Here we concentrate

on basic guidelines Within these guidelines are subsets of guidelines that are beyond ourscope

Structures will generally be drawn in the order, from left to right, in which they are

Greatest number of multiple bonds⬎

Shortest path or route (or lowest locant) to these substituents

Chains containing only carbon atoms

This is illustrated below

⬎ MOMCH2M ⬎

This order is partially derived from guidelines found in other sections such as Section

133, Compound Radicals, where the ordering is given as

Greatest number of acyclic hetero atoms⬎

Greatest number of skeletal atoms⬎

Greatest number of most preferred acyclic hetero atoms⬎

Greatest number of multiple bonds⬎

Lowest locants or shortest distance to nonsaturated carbons

The lowest locant or shortest distance refers to the number of atoms from one seniorsubunit to the next most senior subunit when there is only one occurrence of the seniorsubunit

This order refers to the backbone and not substitutions Thus, polystyrene and vinyl chloride) are contained within the “chains containing only carbon atoms” grouping

Heterocyclic⬎

Carbocyclic

but within the rings there is also an ordering (Section 138) that is

Nitrogenous heterocyclic⬎

Cyclic system occurring earliest in the following list of systems

spiro, bridged fused,

bridges nonfused, fused⬎

Largest individual ring (applies to fused carbocyclic systems)⬎

Greatest number of ring atoms

containing these alternating units would not be poly(thiomethyleneoxymethylene) but

would be named poly(oxymethylenethiomethylene)

with all other items being equal Thus 1,4-phenylene is senior to diyl, which in turn is senior to 2-cyclohexene-1,4-diyl, which is senior to 1,4-cyclohexaned-

2,5-cyclohexadiene-1,4-iyl For linear chainsMCHBCHMCHBCHM is senior to MCHBCHMCH2MCH2M,which is in turn senior to the totally saturated chain segment.

Route

number of atoms) to another like or identical unit or to the next most preferred subunit.Thus for the homopolymer poly(oxymethylene) it is simply going from one oxygen to thenext oxygen and recognizing that this is the repeat unit For a more complex ether thismeans going until the chain begins to repeat itself going in the shortest direction from the

MOMCMC-MOMCMCMCM is named 1,2-ethanediyloxy-1,3-propanediyl” rather than 1,3-propanediyloxy-1,2-ethanediyl

that the heteroatom “N” is first named and then the more highly substituted (carbonyl)unit appears next Thus, nylon 3,3, with the structure

2,5-dichl-oro-p-phenylene which in turn is senior to 2-chl2,5-dichl-oro-p-phenylene,

2,5-dichloro-p-phe-nylene,

2-chloro-p-phenylene that is senior to 2-iodo-p-2-chloro-p-phenylene.

the lowest locants; in rings, double bonds are senior to single bonds; in acyclic carbonchains, double bonds are senior to triple bonds, which are in turn senior to single bonds.Thus, the polymer from 1,3-butanediene polymerized in the so-called “1,4M” mode is

M(MCBCMCMCM)M and named poly(1-butene-1,4-diyl) with the appropriate “cis-”

or “trans-” designation Polyisoprene, typically drawn as

is frequently named poly(2-methyl-1,3-butadiene) but it is named as though its structureis

M(C(CH3)BCHMCH2MCH2M)nM

with the name poly(1-methyl-1-butene-1,4-diyl)

Substituents are named as one of several classes The most important ones are dealt withhere For monoatomic radicals from borane, methane, silane (and other Group IVA ele-ments) they are named by replacing the “ane” ending with “yl,” “ylene,” and “ylidyne”

to denote the loss of one, two, or three hydrogen atoms, respectively

H2BM boryl H3CM methyl H2CB methylene HC⬅ methylidyne

Acyclic hydrocarbon radicals are named from the skeletons by replacing “ane,” “ene,”and “yne” suffixes by “yl,” “enyl,” and “ynyl,” respectively

CH3MCH2M ethyl CH3MCH2MCH2M propyl MCH2MCH2M 1,2-ethanediylMCHBCHM 1,2-ethenediyl H2CBCHMCHB2-propenylidene



MCH2MCMCH2M 1,3-propanediyl-2-ylidene

|MCH2MCHMCH2M 1,2,3-propanetriylTable 3 contains the names of selected bivalent radicals that may be of use to polymerchemists

Searching

Polymers from a single monomer are indexed at the monomer name with the term polymer” cited in the modification Thus, polymers of 1-pentene are listed under themonomer

“homo-1-Pentene

homopolymer

Polymers formed from two or more monomers such as condensation polymers and mers, and homopolymers are indexed at each inverted monomer name with the modifyingterm “polymer with” followed by the other monomer names in uninverted alphabeticalorder The preferential listing for identical heading parents is in the order: (a) maximumnumber of substituents, (b) lowest locants for substituents, (c) maximum number of occur-rences of index heading parent, and (d) earliest index position of the index heading.Examples are

dichlorodiethyl-polymer with dichlorodiphenylsilane

Although the percentage composition of copolymers (i.e., the ratio of comonomers)

is not given, copolymers with architecture other than random or statistical are identified

as “alternating, block, graft, etc.” Random or statistical copolymer are not so identified

in the CA index Oligomers with definite structure are noted as dimer, trimer, tetramer, Often, similar information is found at several sites For instance, for copolymers of1-butene and 1-hexene, information will be listed under both 1-butene and 1-hexene, butbecause the listings are not necessarily complementary both entries should be consultedfor completeness

CA’s policy for naming acetylenic, acrylic, methacrylic, ethylenic, and vinyl mers is to use the source-based method, and source-based representation is used to depictthe polymers graphically; thus, a synonym for polyethene is polyethylene and not poly(1,2-

poly-Table 3 Names of Selected Bivalent Radicals

“Common” or

In this text we typically employ the more “common” (semisystematic or trivial) names of polymers, but it is portant in searching the literature using any CA-driven search engine that you be familiar with CA naming for both monomers and polymers.

IminoIminobis(sulfonyl)MethyleneOxybis[(1-oxo-2,1-ethanediyl)imino)]

1,5-Pentanediyl1,4-Phenylene

1,4-Phenylenebis(methylene)

1,4-Phenylenebis(oxy)1,10-Dioxo-1,10-decanediyl

1-Phenyl-1,2-ethanediyl

Sulfonyl2,3-Dihydroxy-1,4-dioxo-1,4-butanediyl

1,4-PhenylenedicarbonylThio

SulfinylCarbonyldiimino1,2-Ethenediyl

MCOM(CH2)4MCOMM(CH2)4M

MCOM

MCH2MCH2MMNHMMSO2MNHMSO2MMCH2M

MSMMSOMMNHMCOMNHMMCHFCHM

ethanediyl); a synonym for poly-1-propylene is polypropylene, and poly(vinyl alcohol) isnamed ethenol, homopolymer although ethenol does not exist Thus, these polymers arenamed and represented structurally by the source-based method, not the structure-basedmethod.

Examples

Following are examples that illustrate CAS guidelines for naming

the Registry file by name, search for

“Ethane, homopolymer”)M(CH2MCH2M)nM Poly(ethylene) (to search for poly(ethylene)

search for “Ethane, homopolymer”)

Poly(thio-1,4-phenylene)

phenylenecarbonyl)

Poly(oxy1,2-ethanediyloxycarbonyl-1,4-1,4-phenylenecarbonyl)

Poly(imino-1,4-phenyleneiminocarbonyl-TRADE NAMES, BRAND NAMES, AND ABBREVIATIONS

Trade (and/or brand) names and abbreviations are often used to describe materials Theymay be used to identify the product of a manufacturer, processor or fabricator and may

be associated with a particular product or with a material or modified material Tradenames are used to describe specific groups of materials that are produced by a specificcompany or under licence of that company Bakelite is the trade name given for the phenol-formaldehyde condensation polymer developed by Baekeland A sweater whose contentsare described as containing Orlon contains polyacrylonitrile fibers that are “protected”under the Orlon trademark and produced or licenced to be produced by the holder of theOrlon trademark Also, Carina, Cobex, Dacovin, Darvic, Elvic, Geon, Koroseal, Marvinol,Mipolam, Opalon, Plioflex, Rucon, Solvic, Trulon, Velon, Vinoflex, Vygen, and Vyramare all trade names for poly(vinyl chlorides) manufactured by different companies Somepolymers are better known by their trade name than their generic name For instance,polytetrafluoroethylene is better known as Teflon, the trade name held by DuPont Anextensive listing of trade names is given in Appendix B of this text

Abbreviations, generally initials in capital letters, are also employed to describematerials Table 4 contains a listing of some of the more widely employed abbreviationsand the polymer associated with the abbreviation

COPOLYMERS

Generally, copolymers are defined as polymeric materials containing two or more kinds

of mers It is important to distinguish between two kinds of copolymers—those withstatistical distributions of mers or at most short sequences of mers (Table 5), and thosecontaining long sequences of mers connected in some fashion (Table 6)

ACKNOWLEDGMENTS

The author thanks William Work, Les Sperling, and W V (Val) Metanomski for theirassistance with polymer nomenclature The author also acknowledges the assistance ofEdward S Wilks for his help in preparing the section on ‘‘Chemical Abstracts BasedPolymer Nomenclature.’’

Table 4 Abbreviations for Selected Polymeric Materials

Table 5 Short Sequence Copolymer Nomenclature

Table 6 Long Sequence Copolymer Nomenclature

While there are several important approaches to the naming of polymers, in this book weutilize common and source-based names because these are the names that are most com-monly utilized by polymer chemists and the general public and these names, in particularthe source-based names, allow a better understanding of the basics of polymers as afunction of polymer—structure relationships based on starting materials Even so, thosewishing to do further work in polymers must become proficient in the use of the guidelinesused by Chemical Abstracts and IUPAC

SELECTED READINGS

Compendium of Macromolecular Nomenclature, CRC Press, Boca Raton, Florida, 1991.

Polymer nomenclature, Polymer Preprints, 33(1), 6–11 (1992).

Basic classification and definitions of polymerization reactions, Pure Appl Chem., 66:2483–2486

A D Jenkins and K L Loening, Nomenclature, in Comprehensive Polymer Science (G Allen, J.

Bevington, C Booth, and C Price, eds.), Vol 1, Pergamon Press, Oxford, 1989, pp 13–54

N M Bikales, Nomenclature, in Encyclopedia of Polymer Science and Engineering, 2nd ed (H.

F Mark, N M Bikales, C G Overberger, and G Menges, eds.), Vol 10, Wiley, New York,

1987, pp 191–204

Definitions of terms relating to crystalline polymers, Pure Appl Chem., 61:769–785 (1989).

A classification of linear single-strand polymers, Pure Appl Chem., 61:243–254 (1989).

Definitions of terms relating to individual macromolecules, their assemblies, and dilute polymer

solutions, Pure Appl Chem., 61:211–241 (1989).

Use of abbreviations for names of polymeric substances, Pure Appl Chem., 59:691–693 (1987) Source-based nomenclature for copolymers, Pure Appl Chem., 57:1427–1440 (1985).

Nomenclature for regular single-strand and quasi single-strand inorganic and coordination polymers,

Pure Appl Chem., 57:149–168 (1985).

Notes on terminology for molar masses in polymer science: makromol chem., 185, Appendix to

No 1 (1984) J Polym Sci., Polym Lett Ed., 22, 57 (1984) J Macromol Sci Chem., A21,

903 (1984) J Colloid Interface Science, 101, 227 (1984) Br Polym J., 17, 92 (1985) Stereochemical definitions and notations relating to polymers, Pure Appl Chem., 53:733–752

(1981)

Nomenclature of regular single-strand organic polymers, Pure Appl Chem., 48:373–385 (1976) Basic definitions of terms relating to polymers, Pure Appl Chem., 40:479–491 (1974).

ADDITIONAL READING

Carraher, C.(2001) J Polym Materials, 17(4):9–14.

Carraher, C., Hess, G., Sperling, L (1987) J Chem Ed., 64:36–38.

Chemical Abstract Service, Appendix IV; Chemical Abstracts Service, 2540 Olentangy River Rd.,

PO Box 3012, Columbus, OH 43210

IUPAC (1952) Report on Nomenclature in the Field of Macromolecules, J Poly Sci., 8:257–277.

IUPAC (1966) Report on Nomenclature Dealing with Steric Regularity in High Polymers, Pure

Appl Chem, 12:645–656; previously published as M L Huggins, G Natta, V Desreus, and

H Mark (1962) J Poly Sci., 56:153–161.

IUPAC (1969) Recommendations for Abbreviations of Terms Relating to Plastics and Elastomers

Pure Appl Chem., 18:583–589.

IUPAC (1991) Compendium of Macromolecular Nomenclature, Blackwell Scientific Pubs., Oxford,

UK, 171 pp (Collection of summaries)

IUPAC (1976) Nomenclature of Regular Single-Strand Organic Polymers Pure Appl Chem., 48:

IUPAC (1989) A Classification of Linear Single-Strand Polymers Pure Appl Chem., 61:243–254.

IUPAC (1989) Definitions of Terms Relating to Individual Macromolecules, Their Assemblies, and

Dilute Polymer Solutions (1989) Pure Applied Chemistry 61:211–241.

IUPAC (1989) Definition of Terms Relating to Crystalline Polymers Pure Appl Chem., 61:769–785.

IUPAC (1993) Nomenclature of Regular Double-Strand (Ladder or Spiro) Organic Polymers Pure

IUPAC (1985) Nomenclature for Regular Single-Strand and Quasi-Single Strand Inorganic and

Coordination Polymers Pure Appl Chem., 57:149–168.

Polymer Preprints 32(1) (1991) 655; 33(2) (1992) 6; 34(1) (1993) 6; 34(2) (1993) 6; 35(1) (194) 6; 36(1) (1995) 6; 36(2) (1995) 6; 37(1) (1996) 6; 39(1) (1998)9; 39(2) (1998) 6; 40(1) (1999) 6; 41(1) (2000) 6a.

Polymeric Materials: Science and Engineering, 68 (1993) 341; 69 (1993) 575; 72 (1995) 612; 74 (1996) 445; 78 (1998), Back Page; 79 (1998) Back Page; 80 (1999), Back Page; 81 (1999)

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Studying Polymer Chemistry

2.4 Amorphous Bulk State

2.5 Polymer Structure–Property Relationships

2.6 Crystalline and Amorphous Combinations

3.2 Solubility

3.3 Average Molecular Weight Values

3.4 Fractionation of Polydisperse Systems

6.9 Polybenzimidazoles and Related Polymers

6.10 Polyurethanes and Polyureas

6.11 Polysulfides

6.12 Polyethers

6.13 Polysulfones

6.14 Poly(ether ether ketone) and Polyketones

6.15 Phenolic and Amino Plastics

POLYMERIZATION (ADDITION POLYMERIZATION)7.1 Cationic Polymerization

7.2 Anionic Polymerization

7.3 Stereoregularity

7.4 Polymerization with Complex Coordination Catalysts

7.5 Soluble Stereoregulating Catalysis

8.1 Initiators for Free Radical Chain Polymerization

8.2 Mechanism for Free Radical Chain Polymerization

8.3 Chain Transfer

8.4 Polymerization Techniques

8.5 Fluorine-Containing Polymers

11.2 Inorganic Reaction Mechanisms

11.3 Condensation Organometallic Polymers

12.5 Silicon Dioxide (Amorphous)

12.6 Silicon Dioxide (Crystalline Forms)—Quartz Forms

12.7 Silicon Dioxide in Electronic Chips

13.1 Theory of the Effect of Fillers

14.8 Curing Agents

14.9 Antistatic Agents (Antistats)

15.3 Reactions of Aliphatic Pendant Groups

15.4 Reactions of Aromatic Pendant Groups

16.1 Monomer Synthesis from Basic Feedstocks

16.2 Reactants for Step-Reaction Polymerization

16.3 Synthesis of Vinyl Monomers

16.4 Synthesis of Free Radical Initiators

18.9 Synthetic Biomedical Polymers

Appendix B: Trade Names

Appendix C: Sources of Laboratory Exercises

Appendix D: Syllabus

Appendix E: Polymer Core Course Committees

Appendix F: Polymer Models

Appendix G: Structures of Common Polymers

Appendix H: Mathematical Values and Units

Appendix I: Comments on Health

Appendix J: Comments on ISO 9000 and 14000

Appendix K: Electronic Education—Web Sites

Appendix L: Introduction to the Stereogeometry of Polymers

Appendix M: Variability of Measurements

Studying Polymer Chemistry

Studying polymer chemistry is similar to studying any chemistry Following are someideas that may assist you as you study polymer chemistry

Much of chemistry is abstract While much of polymer chemistry is abstract, it iseasier to conceptualize—i.e., make mind pictures of what a polymer is and how it shouldbehave—than many other areas of chemistry For linear polymers, think of a string orrope Long ropes get entangled with themselves and other ropes In the same way, polymersentangle with themselves and with other polymer chains that are brought into contact with

them Thus, create mental pictures of the polymers as you study them.

Polymers are real and all around us We can look at polymers on a microscopic oratomic level or on a macroscopic level The PET bottles we have are composed of longchains of poly(ethylene terephthalate) chains The aramid tire cord is composed of aromaticpolyamide chains Our hair is made up of complex bundles of fibrous proteins, again

polyamides The chemistry you study is related to the real world in which we live We experience this “chemistry” at the macroscopic level every day of our lives and this macroscopic behavior is a direct consequence of the atomic level structure and behavior.

Make pictures in your mind that allow you to relate the atomic and macroscopic worlds

At the introductory level we often examine only the primary factors that may causeparticular polymer behavior Other factors may become important under particular condi-

tions The polymer chemistry you study at times examines only the primary factors that impact polymer behavior and structure Nevertheless, it does form the basis for both complex and simple structure–property behavior.

The structure–property relationships you will be studying are based on well-known

basic chemistry and physical relationships Because such relationships build on one other you need to study in an ongoing manner Understand as you go along Read the material BEFORE you go to class.

an-This course is an introductory-level course that builds on firm foundations in all ofthe core areas of chemistry Each chapter or topic emphasizes knowledge from one or

more of these areas Polymer chemistry also has its own language It is a language that requires you to memorize it Our memory can be short-term or long-term Short-term

memory may be considered as that used by an actor or actress for a TV drama It really

does not need to be totally understood or retained after the final “take.” Long-term memory

is required in studying polymer chemistry since it will be called on repeatedly and is used

to understand other concepts.

In memorizing, learn how you do this best—at what time of day, in what setting,

etc Use as many senses as necessary—be active—read your assignment, write out what

you need to learn, say it, listen to yourself say it Also, look for patterns, create mnemonicdevices, avoid cramming too much into too little time, practice associations in all direc-

tions, and test yourself Memorization is hard work.

While knowledge involves recalling memorized material, to really know something

involves more than simple recall It involves comprehension, application, evaluation, andintegration of the knowledge Comprehension is the interpretation of this knowledge, i.e.,making predictions, applying it to different situations Analysis involves evaluation of theinformation and comparison with other information Synthesis has to do with integration

of the information with other information

In studying polymer chemistry, consider doing the following:

Skim the text before the lecture.

Attend the lecture and take notes

Organize your notes and relate information

Read and study the assigned material

Study your notes and the assigned material

Review and self-test

Learning takes time and effort Study daily, skimming the text and other study material;think about it, visualize key points and concepts, write down important material, makeoutlines, take notes, study sample problems, etc All of this helps, but some approachesmay help you more than others, so focus on these modes of learning—but not to theexclusion of the other aspects

In preparing for an exam, consider doing the following:

Accomplish the above Do not wait until the day before the exam to begin studying.

Develop good study habits

Study wisely Study how you study best, i.e., time of day, surroundings, etc Take care of yourself Get plenty of sleep the night before the exam.

Attend to last-minute details Is your calculator working? Is it the right kind? Do

you have the needed pencils? Review the material once again

Know what kind of test it will be (if possible).

Get copies of old exams (if possible) Talk to others who have already taken the

course

During the test,

Stay cool; do not panic

Read the directions; try to understand what is being asked

In an essay or similar exam work for partial credit, plan your answers ahead of time

In a multiple-choice or true/false exam, eliminate obviously wrong choices.Look over the entire exam Work on questions that you are sure of, then go to lessobvious questions Check answers if time permits

Polymer chemistry comprises a variety of chemical content:

Facts The term polymer means “many” (poly) “units” (mers).

Concepts Linear polymers are long molecules like a string.

Rules Solutions containing polymer chains are more viscous, slower flowing, than

solutions that do not contain polymers; the relationship between the resistance toflow, viscosity, and molecular weight is given by the Mark-Houwink equation

M is molecular weight

Problems Given an LVN of 0.2 dL/g, a 0.55, and K  6  105dL/g, determinethe molecular weight of the sample

Although these categories are often integrated within any topic, in this introduction

to polymer chemistry the emphasis is often on concepts However, all aspects are important

The ancient Greeks classified all matter as animal, vegetable, and mineral Mineralswere emphasized by the alchemists, but medieval artisans emphasized animal and vegeta-ble matter All are largely polymers and are important to life as we know it.

The word polymer is derived from the Greek poly and meros, meaning many and parts, respectively Some scientists prefer to use the word macromolecule, or large mole- cule, instead of polymer Others maintain that naturally occurring polymers, or biopoly- mers, and synthetic polymers should be studied in different courses However, the same

principles apply to all polymers If one discounts the end uses, the differences betweenall polymers, including plastics, fibers, and elastomers or rubbers, are determined primarily

by the intermolecular and intramolecular forces between the molecules and within theindividual molecule, respectively, and by the functional groups present

In addition to being the basis of life itself, protein is used as a source of amino acidsand energy The ancients degraded or depolymerized the protein in tough meat by agingand cooking, and they denatured egg albumin by heating or adding vinegar to the eggs.Early humans learned how to process, dye, and weave the natural proteinaceousfibers of wool and silk and the carbohydrate fibers of flax and cotton Early South American

civilizations such as the Aztecs used natural rubber (Hevea brasiliensis) for making elastic

articles and for waterproofing fabrics

There has always been an abundance of natural fibers and elastomers but few plastics

Of course, early humans employed a crude plastic art in tanning the protein in animalskins to make leather and in heat-formed tortoise shells They also used naturally occurring

tars as caulking materials and extracted shellac from the excrement of small coccid insects

(Coccus lacca).

Until Wo¨hler synthesized urea from inorganic compounds in 1828, there had beenlittle progress in organic chemistry since the alchemists emphasized the transmutation ofbase metals to gold and believed in a vital force theory Despite this essential breakthrough,little progress was made in understanding organic chemistry until the 1850s, when Kekule´developed the presently accepted technique for writing structural formulas However, poly-mer scientists displayed a talent for making empirical discoveries before the science wasdeveloped

Charles Goodyear grew up in poverty He was a Connecticut Yankee born in 1800

He began work in his father’s farm implement business Later he moved to Philadelphiawhere he opened a retail hardware store that soon went bankrupt He then turned to being

an inventor As a child he had noticed the magic material that formed a rubber bottle hehad found He visited the Roxbury India Rubber Company to try and interest them in hisefforts to improve the properties of rubber, but they assured him that there was no need

to do so

He started his experiments with a malodorous gum from South America in debtor’sprison In a small cottage on the grounds of the prison, he blended the gum, the raw rubbercalled hevea rubber, with anything he could find, e.g., ink, soup, caster oil While rubber-based products were available, they were either sticky or became sticky in the summerheat He found that treatment of the raw rubber with nitric acid allowed the material toresist heat and not to adhere to itself This success attracted backers who helped form arubber company After some effort he obtained a contract to supply the U.S Post Officewith 150 rubber mailbags He made the bags and stored them in a hot room while he andhis family went away When they returned they found the bags in a corner of the room,joined together as a mass The nitric acid treatment was sufficient to prevent surfacestickiness, but the internal rubber remained tacky and susceptible to heat

While doing experiments in 1839 at a Massachusetts rubber factory he accidentlydropped a lump of rubber mixed with sulfur on the hot stove The rubber did not meltbut rather charred He had discovered vulcanization, the secret that was to make rubber

a commercial success While he had discovered vulcanization, it would take several years

of ongoing experimentation before the process was really commercially useful Duringthis time he and his family were nearly penniless Although he patented the process, itwas too easily copied and pirated, so that he was not able to profit fully from his inventionand years of hard work Even so, he was able to develop a number of items

Charles Goodyear and his brother Nelson transformed natural rubber, hevea rubber,from a heat-“softenable” thermoplastic to a less heat-sensitive product through the creation

of crosslinks between the individual polyisoprene chain-like molecules using sulfur as the

crosslinking agent Thermoplastics are two-dimensional molecules that may be softened

by heating Thermosets are materials that are three-dimensional networks that cannot be

reshaped by heating Rather than melting, thermosets degrade As the amount of sulfurwas increased, the rubber became harder becoming a hard rubber-like (ebonite) material.The spring of 1851 found the construction of a remarkable building on the lawns

of London’s Hyde Park The building was designed by a maker of greenhouses so it wasnot unexpected that it had a greenhouse look This Crystal Palace was to house almost14,000 exhibitors from all over the world It was the chance for exhibitors to show theirwares Charles Goodyear, then 50 years old, used this opportunity to show off his overtwo decades worth of rubber-related products He decorated his Vulcanite Court with

rubber walls, roof, furniture, buttons, toys, carpet, combs, etc Above it hung a six-footrubber raft and assorted balloons The European public was introduced to the world ofnew man-made materials.

Within little more than a decade Charles Goodyear was dead Within a year of hisdeath, the American Civil War broke out The Union military used about $27 millionworth of rubber products by 1865 helping launch the U.S rubber industry

In 1862 Queen Victoria, while in mourning for her recently departed husband Albert,opened the World’s Fair in London One of the exhibitors was Alexander Parks He wasdispleased with the limited colors available for rubber products (generally dull and dark)

In his workshop in Birmingham, England he was working with nitrocellulose, a materialmade from the treatment of cotton and nitric and sulfuric acids Nitrocellulose solutionswere made from dissolving the nitrocellulose in organic liquids such as ethanol and ether.Thin films and coatings were made by simply pouring the nitrocellulose solutions ontothe desired item or surface and allowing the solvent to evaporate He wanted to makesolid objects from nitrocellulose After years of work he developed a material he calledParkensine from which he made buttons, combs, and many of the items that were made

of rubber, except that his materials could be brightly colored, clear, or made to shine likemother-of-pearl At the London World’s Fair he advertised “Patent Parkesine of variouscolours: hard elastic, transparent, opaque, and waterproof.” Even with his work he hadnot developed a material that could be “worked” or was stable, and even with his hypethe material never caught on except in exhibition halls

About this time, John Wesley Hyatt, a printer from Albany, New York who wasseeking a $10,000 prize for anyone who could come up with a material that was a substitutefor ivory billiard balls, developed a material that was stable and could be “worked” fromshellac and wood pulp He then turned to nitrocellulose discovering that shredded nitrocel-lulose could be mixed with camphor and heated under pressure to produce a tough whitemass that retained its shape This material, dubbed celluloid, could be made into the usualrubber-like products, but also solid pieces like boxes, wipe-clean linen, collars, cuffs, andping-pong balls Celluloid could also, like the shellac–wood pulp mixture, be cut, drilled,and sawed But celluloid was flammable and did not stand up well in hot water Thewearers of celluloid dentures truly could have their “teeth curled” when drinking a hotcup of coffee One of its best qualities was that it could be made to look like othermaterials—it could be dyed to look like marble, swirled to mimic tortoiseshell and mother-of-pearl, and even look and feel like ivory It did not make good billiard balls One accounthas billiard balls hitting and exploding like a shot that caused cowboys to draw their guns.Both cellulose and cellulose nitrate are linear, or two-dimensional, polymers, butthe former cannot be softened because of the presence of multitudinous hydrogen bondsbetween the chain-like molecules When used as an explosive the cellulose nitrate isessentially completely nitrated, but the material used by Parks and Hyatt was a dinitrate,still potentially explosive but less so Parks added caster oil and Hyatt added camphor toplasticize-reduce the effect of the hydrogen bonding—the cellulose nitrate

Worldwide, rubber gained in importance with the invention of the air-filled or matic tires by a Scotsman, John Dunlop in 1888 He had a successful veterinary practice

pneu-in Belfast In his off time he worked to improve the ride of his son’s tricycle His pneu-inventionhappened at the right time The automobile was emerging and air-filled tires offered amore gentle ride Thus was begun the tire industry

All of these inventions utilized natural materials as at least one ingredient After years

of work in his chemistry labs in Yonkers, New York, Leo Baekeland in 1907 announced in

an American Chemical Society meeting the synthesis of the first truly synthetic polymericmaterial, later dubbed Bakelite.

Baekeland was born in Belgium in 1863, the son of an illiterate shoe repairman and

a maid He was bright and received his doctorate with highest honors at the age of 20

He could have spent the remaining part of his life in academics in Europe, but heedingthe words of Benjamin Franklin, he sailed to America In the 1890s he developed the firstphotographic paper, called Velox, that could be developed in synthetic light rather thansunlight George Eastman saw the importance of this discovery and paid Bakeland

$750,000 for the rights to this invention

It was generally recognized by the leading organic chemists of the nineteenth centurythat phenol would condense with formaldehyde Since they did not recognize the concept

of functionality, Baeyer, Michael, and Kleeberg produced useless crosslinked goos, gunks,and messes and then returned to their research on reactions of monofunctional reactants.However, by the use of a large excess of phenol, Smith, Luft; and Blumer were able toobtain a hard yet meltable thermoplastic material

With his $750,000 Baekeland set up a lab next to his home He then sought to solvethe problem of making the hard material made from phenol and formaldehyde soluble.After many failures, he thought about circumventing the problem by placing the reactants

in a mold of the desired shape and allowing them to form the intractable solid material.After much effort he found the conditions under which a hard, clear solid could bemade—Bakelite was discovered Bakelite could be worked, was resistant to acids andorganic liquids, stood up well to heat and electrical charge, and could be dyed to givecolorful products It was used to make bowling balls, phonograph records, telephonehousings, gears, and cookware His materials also made excellent billiard balls

Bakelite also acted as a binder for sawdust, textiles, and paper, forming a wide range

of composites including Formica laminates, many of which are still used It was also used

as an adhesive giving us plywood

While there is no evidence that Baekeland recognized what polymers were, he peared to have a grasp on functionality and how to “use” functionality to produce thermo-plastic materials that could later be converted to thermosets Through control of the ratio

ap-of phenol to formaldehyde he was able to form a material that was a thermoplastic He

coined the term A-stage resole resin to describe this thermoplastic This A-stage resole resin was converted to a thermoset crosslink, C-stage Bakelite, by additional heating Baekeland also prepared thermoplastic resins called novolacs by the condensation of

phenol with a lesser amount of formaldehyde under acidic conditions The thermoplasticnovolacs were converted to thermosets by addition of more formaldehyde While otherpolymers had been synthesized in the laboratory, Bakelite was the first truly syntheticplastic The “recipes” used today differ little from the ones developed by Baekeland,showing his ingenuity and knowledge of the chemistry of the condensation of the trifunc-tional phenol and difunctional formaldehyde

While poly(vinyl chloride) was initially formed by Baumann in 1872, it awaitedinterest until 1926 when B F Goodrich discovered how to make sheets and adhesivesfrom poly(vinyl chloride)—and the “vinyl age” began While polystyrene was probablyfirst formed by Simon in 1839, it was almost 100 years latter, in 1930, that the giantGerman company I G Farben placed polystyrene on the market Polystyrene moldedparts have became common place Rohm and Haas bought out Plexiglas from a Britishfirm in 1935 and began the production of clear plastic parts and goods, including replace-ments for glass as camera lenses, aircraft windows, clock faces, and car tail lights

Polymer science was largely empirical, instinctive, and intuitive Prior to WorldWar I, celluloid, shellac, Galalith (casein), Bakelite, and cellulose acetate plastics; hevearubber, cotton, wool, silk rayon fibers; Glyptal polyester coatings; bitumen or asphalt; andcoumarone-indene and petroleum resins were all commercially available However, as

develop-ment in polymers prior to World War II because of a general lack of fundadevelop-mental edge of polymers But the theoretical basis was being built Only a few of the many giants

knowl-of the industry will be mentioned

Over a century ago, Graham coined the term colloid for aggregates with dimensions

this range, but it is important to remember that unlike colloids, whose connective forcesare ionic and/or secondary forces, polymers are individual molecules whose size cannot

be reduced without breaking the covalent bonds that hold the atoms together In 1860 anoligomer, a small polymer, was prepared from ethylene glycol and its structure correctlygiven as HM(MOCH2CH2M)nMOH But when poly(methacrylic acid) was made by Fittigand Engelhorn in 1880 it was incorrectly assigned a cyclic structure Polymers were thought

of as being colloids, or cyclic compounds like cyclohexane By use of the Raoult andvan’t Hoff concepts, several scientists obtained high molecular weight values for thesematerials and for a number of other polymeric materials But since the idea of largemolecules was not yet accepted they concluded that these techniques were not applicable

to these molecules rather than accepting the presence of giant molecules

Hermann Staudinger studied the polymerization of isoprene as early as 1910 trigued by the difference between this synthetic material and natural rubber, he began todevelop his studies toward such materials His turn to these questionable materials, ofinterest to industry but not academically important, was viewed unkindly by his fellowacademics He was told by one of his fellow scientists “Dear Colleague, Leave the concept

In-of large molecules well alone There can be no such thing as a macromolecule.” ButStaudinger systematically synthesized a variety of polymers In the 1920 paper “UberPolymerization” he summarized his findings and correctly proposed linear structures forsuch important polymers as polyoxymethylene and polystyrene X-ray studies of manynatural and synthetic materials were used as structural proof that polymers existed Fore-most in these efforts were Herman Mark and Linus Pauling Both of these giants contrib-uted to other important areas of science Pauling contributed to the fundamental understand-ing of bonding and the importance of vitamins Mark helped found the academic andcommunication (journals, short courses, workshops) basis that would allow polymer sci-ence to grow from its very diverse roots

Wallace Hume Carothers is the father of synthetic polymer science History is oftenmeasured by the change in the flow of grains of sand in the hour glass of existence.Carothers is a granite boulder in this hour glass Carothers was born, raised, and educated

in the U.S midwest In 1920 he left Tarkio College with his BS degree and entered theUniversity of Illinois where he received his MA in 1921 He then taught at the University

of South Dakota where he published his first paper He returned to receive his PhD underRoger Adams in 1924 In 1926 he became an instructor in organic chemistry at Harvard

In 1927 the DuPont Company decided to begin a program of fundamental research

“without any regard or reference to commercial objectives.” This was a radical departuresince the bottom line was previously products marketed and not papers published CharlesStine, director of DuPont’s chemical department, was interested in pursuing fundamentalresearch in the areas of colloid chemistry, catalysis, organic synthesis, and polymer forma-