Evaluation of Reptation Models for Predicting the Linear Viscoelastic Properties of Entangled Linear Polymers

摘要: The ability of reptation theories to quantitatively predict the linear viscoelastic response polymer melts is systematically tested for various combinations almost monodisperse, bidisperse, and polydisperse polystyrene (PS), high-density polyethylene (PE), polycarbonate (PC) samples. Broad industrial HDPE PC samples have been fractionated according molar weight by preparative methods. experimental master curves dynamic moduli G' G" are compared with predictions obtained from experimentally determined molecular distribution (MWD) (by size exclusion chromatography) help models proposed in literature. We focus on Doi Edwards relaxation function, without fluctuation effects, des Cloizeaux time-dependent diffusion function. These functions combined double reptation. conclude that associated model, gives best results well-entangled polymers, which quantitative agreement data. Indeed, it only model able correctly intermediate region between Rouse relaxation. study influence short chains (slightly longer than critical weight) blends long chains. predicts smaller 4M(e) relax too quickly comparison After a modification also obtained.