Modulus vs. temperature

Fig. 20. Logarithmic decrement (related to tan 5 and loss modulus) vs temperature for a fluorocarbon dibenzoxazole (148). After drying up to 200°C, the...

Fig. 7-18 Modulus vs. temperature dependence going through different processing stages.

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FIGURE 28.16 Storage modulus vs temperature of organoclay-loaded rubber nanocomposite. (From Teh, P.L. et al., J. Appl. Polym. Sci., 100, 1083, 2006.)... 

Fig. 22 Storage modulus vs. temperature for statistically random ethylene-octene and propylene-ethylene copolymers compared to an ethylene-octene OBC...

Figure 3. Log modulus vs. temperature for two 50-50 blends PVN with PE0 of different molecular weights...

The expansion coefficient is also similar to that of polycarbonate, and the same is true for the torsional modulus vs. temperature as shown in Figure 2. Trogamid T has a good tensile strength (ca. 500 kg.) even at temperatures as high as 100 °C. 

Figure 7. Storage modulus vs. temperature curves for (A) linear amorphous polymer (B) crosslinked polymer (C) semicrystalline polymer (D) PTMA/MDI/BD-segmented copolymer (32% MDl by wt) (E) PTMA/MDI/BD-segmented copolymer...

TDI Polyurethanes. Two 2,4-T-lP samples with different hard-segment concentrations were studied and found to display a broad a-relaxation maximum, also characterized by a decline in storage modulus of about two and one half orders of magnitude, as shown in Figure 5, a plot of storage and loss modulus vs. temperature at 11 Hz. The position... 

The dynamic mechanical properties of four 2,6-T-2P samples containing from 19 to 43 wt% hard segments are summarized in Figure 10. A low temperature s relaxation is apparent at about — 70°C for all compositions examined. The transition temperatures of these loss maxima and the associated activation energies are given in Table III. A second process, the c relaxation, can be noted as a shoulder on the high temperature side of the 8-loss maximum. The conclusion of this relaxation is marked by a change in slope of the loss modulus vs. temperature plots... 

An additional relaxation can be detected in plots of the loss tangent as a function of temperature for 2,6-T-2P-43, not shown. The relaxation occurred at 60°C (11 Hz) in the first examination of this sample. A weak ah relaxation can be detected in the loss modulus vs. temperature plots in Figure 13, but the process is more readily apparent in the tan(8) data. Upon retesting of this sample, the h dispersion was shifted to 71 °C. The activation energy for the ah relaxation did not change significantly with thermal history and was extremely weak or undetectable in 2,6-T-2P samples which contained less than 43 wt% hard segments. 

The glass transition temperature, T, was also determined for some of the test materials. Values given in this paper are somewhat higher than reported literature values as they were obtained from the temperature location of the principal maximum in the loss modulus vs. temperature data from tests made at 3 Hz. 

Figure 1-2. Schematic of the modulus vs. temperature behavior for a rubber and a plastic over a broad temperature range.

Figure 4-2. Shear modulus vs. temperature behavior for two polycarbonate samples of different molecular weights, along with the response of a partially crystallized sample. (See Chapter 5 for additional discussion.) [Adapted from J. P. Mercier, J. J. Aklonis, M. Litt and A. V. Tobolsky, J. Appl. Polym. Sci. 9, 447-459 (1965). Copyright 1965 Wiley Periodicals, Inc.,...

Figure 4-3. Comparison of ten-second modulus vs. temperature curves for three common thermoplastics polyvinyl chloride (PVC), polystyrene (PS) and polyethylene (PE).

For a polymer where crystallinity dominates its relaxation behavior, the situation is quite different. Figure 4-3 shows the 10-second modulus vs. temperature curve for such a crystalline polymer, polyethylene (PE). Included also in this figure is the modulus-temperature curve for polyvinyl chloride... 

Figure 4-8. Simulations of master curves and modulus vs. temperature curves for a glassy polymer, (a) The master curves, shown at increments of 5 °C tend to be spaced more widely as the temperature is lowered because of the nature of the WLF relationship used for the temperature dependence [see Figure (4-6)]. (b) Demonstration of the influence of measurement time on the shape of the modulus-temperature curve. As the measurement time increases (by 1-decade increments), the apparent Tg decreases but the sharpness of the transition increases. (Simulation uses Smith empiricism8 for glass transition and the KWW function for the rubbery flow region.)...

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