A full-chain constitutive model for bidisperse blends of linear polymers
A full-chain constitutive model for bidisperse blends of linear polymers
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DOI：
10.1122/1.4707948
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发表时间：
2012-05
影响因子：
3.3
通讯作者：
D. Read;K. Jagannathan;S. K. Sukumaran;D. Auhl
中科院分区：
文献类型：
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作者：
D. Read;K. Jagannathan;S. K. Sukumaran;D. Auhl
我们开发了一个基于全链管的本构模型[沿着Graham等人的路线，J. Rheol. 47，1171（2003）]用于长和短线性聚合物的双分散共混物的非线性流变学。对于混合物中的测试链，我们使用胖管的物理图片，代表与长链的长寿命纠缠，以及细管，代表与所有链的纠缠。该模型包括爬行、轮廓长度波动（CLF）、约束释放和拉伸松弛过程。在线性流变学制度，我们确定了一个新的松弛过程：CLF沿着的脂肪管轮廓，实现了通过一个组合的链运动沿着的细管，和局部约束释放的细管，因为它探索的脂肪管的宽度。这个过程足够快，足以在爬行之前放松长链的重要部分。它提供了一个解释的终端时间减少的长链稀释后，与短链的框架中，运动沿着薄T…
We develop a full-chain tube-based constitutive model [along the lines of Graham et al. J. Rheol. 47, 1171 (2003)] for the nonlinear rheology of bidisperse blends of long and short linear polymers. For a test chain in the blend, we use the physical picture of a fat tube, representing long-lived entanglements with long chains, and a thin tube, representing entanglements with all chains. The model includes the processes of reptation, contour length fluctuation (CLF), constraint release, and stretch relaxation. In the linear rheology regime, we identify a new relaxation process: CLF along the fat tube contour, achieved via a combination of chain motion along the thin tube, and local constraint release of the thin tube as it explores the width of the fat tube. This process is sufficiently fast to relax a significant portion of the long chains before reptation. It provides an explanation of the decrease in terminal time of long chains upon dilution with short chains in a framework where motion along the thin t...