Branch-Point Motion in Architecturally Complex Polymers: Estimation of Hopping Parameters from Computer Simulations and Experiments

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• 作者：Petra Ba膷ov谩 ; Helen Lentzakis ; Daniel J. Read ; Angel J. Moreno ; Dimitris Vlassopoulos ; Chinmay Das
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：May 27, 2014
• 年：2014
• 卷：47
• 期：10
• 页码：3362-3377
• 全文大小：704K
• 年卷期：v.47,no.10(May 27, 2014)
• ISSN：1520-5835

文摘

Relaxation of branched polymers under tube-based models involves a parameter p² characterizing the hop size of relaxed side arms. Depending on assumptions made in rheological models (e.g., about the relevant tube diameter for branch-point hops), p² had been set to values varying from 1 to 1/60 in the literature. From large-scale molecular dynamics simulations of melts of entangled branched polymers of different architectures, and from experimental rheological data on a set of well-characterized comb polymers with many (30) side arms, we estimate the values of p² under different assumptions in the hierarchical relaxation scheme. Both the simulations and the experiments show that including the backbone friction and considering hopping in the dilated tube provides the most consistent set of hopping parameters in different architectures.