Loss compliance illustrations

In order to go further in the analysis, it is worth considering the loss compliance, /", shown at 1 Hz in Fig. 139. Indeed, the loss compliance allows one to perform quantitative comparisons based on additive contributions of the various units, as already mentioned (Sects. 6.3.1 and 7.1.1). Such an approach is illustrated as a function of temperature in Fig. 140 for MGIM36. 

Tan 5, storage compliance, and loss compliance values for these experiments are plotted as a function of time in Figure 8. This transient temperature cycle data illustrates interactions between the dynamic mechanical plasticization and blocking behavior just discussed as well as the epoxy s equilibrium moisture uptake behavior (3), and the temperature behavior of dynamic mechanical properties observed for this epoxy in Figure 2a. Perhaps the easiest comparison to consider involves the relationship between transient temperature cycling data of Figure 8 and the thermal behavior observed for N-5208 epoxy tan 6 data of Figure 2a. 

Accordingly, the loss compliance function presents a maximum in the frequency domain at lower frequency than the loss relaxation modulus. This behavior is illustrated in Figure 8.18, where the complex relaxation modulus, the complex creep compliance function, and the loss tan 8 for a viscoelastic system with a single relaxation time are plotted. Similar arguments applied to a minimum in tan 8 lead to the inequalities... 

FIG. 3-8. Loss compliance for system of Fig. 3-7 (curve Vll of Fig. 2-7), reduced to 25 C and plotted linearly against log partial integration by equation 53 (with finite limits) to determine Jn 1.11 X lO" cm /dyne. 

The above examples have been polymers with relatively weak intermolecular forces and no heterogeneity in composition or structure along the chain. There are other cases in which the entanglement spacing appears to depend more strongly on dilution—e.g., solutions of poly(n-butyl methacrylate) and poly(methyl methacrylate). To illustrate this behavior, still another experimental source of information is cited—the maximum in the retardation spectrum, which, with the corresponding maximum in the loss compliance, is the most characteristic symptom of the entanglement network. In Fig. 17-17, the retardation spectra are plotted... 

Figure 6.7 Schematic diagrams illustrating the simplest form of time-temperature equivalence for (a) compliance, J(t) b) loss factor, tan(5...

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