Why does the rouse model fairly describe the dynamic characteristics of polymer melts at molecular masses below critical mass

摘要: Generalization of the Rouse model without any use postulates concerning Gaussian distribution vector connecting ends segments is advanced. In initial (in general, nonlinear) Langevin equations, self-averaging over continuous fragments a macromolecule naturally defines linear term for tagged chain, and this differs from entropy classical only by numerical coefficient. According to inertia-free approximation, decay rates correlation functions normal modes are described independently character fluctuations Kuhn segment. This statement valid moment if equations treated in terms approximation dynamic self-consistency. Simulation Fraenkel chains method Brownian dynamics shows that autocorrelation shortwave fairly linearized given chain equation can be used long-wave modes. The results study make it possible explain marked difference between lengths estimated static experiments.