A photon correlation spectroscopy study of the dynamic behavior of poly(α-methylstyrene) in moderately concentrated solution

Abstract

The dynamic behavior of a series of moderately concentrated solutions of a high molecular weight poly(α-methylstyrene) PAMS in toluene was investigated using photon correlation spectroscopy. The dependence of the shape of the scattered light temporal autocorrelation function on polymer concentration and scattering wave vector was carefully determined and the results did not agree with those predicted by scaling theories. Instead, the best description of the PCS results is provided by a new theory due to Ronca, which correctly predicts the general features of the observed dependence of the correlation function shape upon scattering wave vector and polymer concentration. While in the Ronca theory, entanglement behavior and its effect on the correlation function are treated expressly, current scaling theories do not consider entanglements in treating the dynamic behavior of moderately concentrated solutions. Considering the representative character of the solutions studied here, it is concluded that a successful description of the dynamic behavior of such systems requires consideration of entanglement behavior. © 1983 American Institute of Physics.