MOLECULAR-WEIGHT DEPENDENCE OF RELAXATION-TIME SPECTRA FOR THE ENTANGLEMENT AND FLOW BEHAVIOR OF MONODISPERSE LINEAR FLEXIBLE POLYMERS

A simple model is proposed for the molecular weight dependence of the relaxation time spectrum of linear flexible polymers with molecules of nearly uniform length. A systematic approach for determining the para meters of the relaxation time spectrum from dynamic mechanical data, G '(omega) and G''(omega), shows the possibilities and the limits of thi s model. The necessary parameters are n(e), G(N)-degrees, and lambda(m ax) for the entanglement and flow behavior and lambda(c) and n(g) for the crossover to the high-frequency glass behavior. Generic values are proposed for polystyrene and polybutadiene of high molecular weight.