Dynamic Mechanical Analysis part 10 docx

... stress relaxation modulus, E¢ is the storage modulus from the dynamic experiment, w is the dynamic test frequency, and E≤ is the dynamic loss modulus. A similar equation exists for the compliance, ... ( )( ) ¢ ≤≤ww w w 04 04 0014 10 EtJt d t() ( )-= Ú tt 0 1 ©1999 CRC Press LLC a mixing rule. A mixing rule is a quantitative relationship that relates the observed mechanical propertie...

Ngày tải lên: 05/08/2014, 09:19

... only plot dynamic stress vs. dynamic strain, but also get E¢, E≤, E*, tan d, h*, and other dynamic properties for each cycle. This allows us to plot those properties as a function of dynamic stress ... as ©1999 CRC Press LLC FIGURE 4.15 Results from dynamic stress–strain curves showing (a) the relationship between dynamic stress and strain and (b) tan d vs. dynamic strain for tw...

Ngày tải lên: 05/08/2014, 09:19

... Rheology, MIT, Cambridge, 1990. R. De le Garza, Measurement of Viscoelastic Properties by Dynamic Mechanical Analysis, Masters thesis, Univer- sity of Texas at Austin, 1994. R. Hagan, Polymer Testing, ... weight (usually 1 ¥ 10 6 Pa. s), the item is removed from its mold or form and post-cured. Post-curing involves heating the free-standing piece in an oven until full mechan...

Ngày tải lên: 05/08/2014, 09:19

... While estimates of the relative sensitivity of DMA to DSC or DTA vary, it appears that DMA is 10 to 100 times more sensitive to the changes occurring at the T g . The T g in highly ... furnace control. I do this in one run by programming a cycle with 2-minute isothermal holds at 100 °C and 200°C and a 10 C per minute ramp between the holds. A sample of indium is loaded und...

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... region of increasing viscosity associated with curing, and both the time required to exceed 1 ¥ 10 6 Pa. s and to reach vitrification. These materials, sold for the same application, would require ... different thicknesses. As dif- ferent times are required to reach a viscosity equal to or exceeding 10 6 Pa. s, the materials will need to be held for different times before they are solid...

Ngày tải lên: 05/08/2014, 09:19

... frequency of the dynamic test, and d g / dt the shear rate of the constant shear test. This rule of thumb seems to hold for most materials to within about ± 10% . Another approach, which ... method and added to the data collected by frequency scans. However, as creep is not the same as dynamic tests, sometimes the data are not even similar GN¢== ÆÆ Æ () () ()wwggyg wg g 2...

Ngày tải lên: 05/08/2014, 09:19