Effect of Crosslinking on the Secondary Relaxation in Polyvinylethylene*

ABSTRACT: The effect of network formation on the secondary (Johari–Goldstein) b-relaxation was investigated for polyvinyl-ethylene (PVE). Crosslinking affects the segmental (a-) process in the usual fashion, the networks exhibiting slower and more temperature-sensitive dynamics. However, the effect on the b-process is the opposite. The secondary relaxation becomes faster and the activation energy slightly decreases with cross-linking. The strength of the intermolecular cooperativity gov-erning the behavior of the a-process was assessed using the coupling model, with consistent results obtained from analysis of both the timescale separating the a- and b-relaxations and the activation energy for the latter. VC 2010 Wiley Periodicals