The relaxation times of unentangled polymer melts with different molecular architectures

Abstract

Monte Carlo algorithm is adopted to simulate linear, ring, H-shaped and three-arm star polymer melts, and the dependence of relaxation times defined by different methods on polymer size is investigated. Statistical and dynamic properties of several unentangled polymer melts are also revealed for comparison. It is obviously that the numerical difference is small when relaxation times defined by the ratio of maximum mean-square end-to-end distance of several polymers as a function of corresponding mean-square radius of gyration, and data for different architectures collapse onto a universal curve in unentangled regime. The relaxation times for several polymer exhibits weak dependence on architecture. However, the special relationship cannot be found through the relaxation times defined by the position of the intersection of g2 and g3, end-to-end correlation function and mean-square radius of gyration, with stronger architecture dependence. The correctness of the relationship is also reflected by mean-square monomer displacement. The result provides a new understanding of the correlation between relaxation time and polymer size.