Phenomenological Aspects of Viscoelastic Behavior

The viscoelastic behavior of polymer fibers is complex. Experimentally, it is important to perform simple laboratory tests from which information relevant to actual in-use conditions can be obtained. The viscoelastic characterization of polymer fibers often consists of condncting mechanical tests that are similar to those discussed in Chapter 15, but are modified so as to enable the observation of the time dependency of fibers response. Three most important viscoelastic tests are creep, stress relaxation, and dynamic mechanical testing. 

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Having examined some of the basic manifestations of the phenomenological aspects of viscoelasticity in Chapter 2, along with the efforts to model this behavior in Chapter 3, we now shift our emphasis to the results of experiments on polymers, and the interpretation of these results in terms of the accepted molecular mechanisms. We then explore the important idea of time-temperature correspondence and demonstrate the close relationship between these two variables in determining the viscoelastic responses of polymers. 

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