Relaxation Spectra Reduced to Corresponding States

We may now examine some detailed shapes of viscoelastic functions. For this purpose, it is convenient to reduce different polymers to corresponding states in which those portions of their relaxation spectra conforming to the flexible chain theories coincide. 

In equation 40 of Chapter 10, the time scale is set by the product cf. also 

Relaxation spectra of Fig. 12-4 reduced to corresponding states in which the portions at the long-time end of the transition zone coincide in accordance with the Rouse theory. Dotted line is the prediction of the modified Rouse theory with cutoff at minimum relaxation time of Marvin model. Curve for 2-ethyl butyl polymer is indistinguishable from that for butyl to the right of maximum, and from that for octyl to the left. 

The relaxation spectra of the six methacrylate polymers of Fig. 12-4 are plotted in this manner in Fig. 12-10. Their shapes coincide rather closely throughout the transition zone, though the maxima for the ethyl (experimentally uncertain) 

Relaxation spectra of various polymers reduced to corresponding states. Panel I (1) composite methacrylate polymers (2) polyisobutylene (3) polyhexene-1 (4) polyurethane rubber. Panel II (1) poly(vinyl acetate) (2) poly(methyl acrylate). Panel III (1) Hevea rubber. 

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