Reduced retardation spectrum, logarithm

FIGURE 5.14 The logarithm of the reduced retardation spectrum, Lp, shown as function of the logarithm of the reduced retardation time, A./uj , for the three urethane-end linked polybutadiene elastomers, (o) TB-1, ( ) TB-2, ( )TB-3. The response has been reduced to corresponding state temperatures of 74°C, 0°C, and 17°C, respectively, for the primary softening transition. 

Fig. 2.31. The logarithm of the retardation spectrum L of poly(methyl methacrylate) as a function of the logarithm of the reduced retardation time r/ar. The solid curve was calculated from the reduced Jr(t) curve obtained from creep data taken at lower temperatures (14.4-34.7 °C) and longer times (10° s < r < 10 s) and shifted to 13.1° C. The dashed line was calculated from the dynamic compliances obtained by Williams and Ferry at higher temperatures and frequencies To was chosen to be 10.8 °C. From [217] by permission.

FIG. 13-6. Logarithmic plot of retardation spectrum reduced to -30 C for poly(cis-isoprene) with molecular weight 1.75 X 10 (dotted curve) and 3.95 X 10 (solid curve). (Nemoto, Odani, and Ku-rata. ) Reproduced with permission from Macromolecules, 5,531 (1972). Copyright by The American Chemical Society. 

Figure 5.7 Storage and loss moduli versus reduced frequency for poly(vinyl acetate) with a very narrow MWD as calculated from creep data using the retardation spectrum as an intermediary (logarithmic scales). It was not possible to achieve superposition over the entire range of frequencies, and two shift factors were used to deal with data in high and low-frequency zones.The reference temperature is 60 °C. All the relaxation zones are clearly exhibited. From Plazek [31].

Figure 5.10 Retardation spectrum of the poly(vinyl acetate) of Figs. 5.7 and 5.8 versus reduced time (logarithmic scales). The slope is 1/3 in the glassy region reflecting Andrade creep.The plateau zone is between the two peaks, the second of which marks the start of the terminal zone. It was not possible to obtain superposition using a single reference temperature, and different values were used in short and long-time zones.This is reflected in the difference between the curves obtained with = 35 X (dashed line) and with 60 X (points). From Plazek [31].

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