Threading–Unthreading Transition of Linear-Ring Polymer Blends in Extensional Flow,ACS Macro Letters

当前位置： X-MOL 学术 › ACS Macro Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Threading–Unthreading Transition of Linear-Ring Polymer Blends in Extensional Flow
ACS Macro Letters ( IF 5.1 ) Pub Date : 2020-10-02 , DOI: 10.1021/acsmacrolett.0c00607
Anine Borger ₁ , Wendi Wang ₂ , Thomas C. O’Connor ₃ , Ting Ge ₄ , Gary S. Grest ₃ , Grethe V. Jensen _{5,

6} , Junyoung Ahn ₇ , Taihyun Chang ₇ , Ole Hassager ₂ , Kell Mortensen ₁ , Dimitris Vlassopoulos _{8,

9} , Qian Huang ₂

Affiliation

Adding small amounts of ring polymers to a matrix of their linear counterparts is known to increase the zero-shear-rate viscosity because of linear-ring threading. Uniaxial extensional rheology measurements show that, unlike its pure linear and ring constituents, the blend exhibits an overshoot in the stress growth coefficient. By combining these measurements with ex-situ small-angle neutron scattering and nonequilibrium molecular dynamics simulations, this overshoot is shown to be driven by a transient threading–unthreading transition of rings embedded within the linear entanglement network. Prior to unthreading, embedded rings deform affinely with the linear entanglement network and produce a measurably stronger elongation of the linear chains in the blend compared to the pure linear melt. Thus, rings uniquely alter the mechanisms of transient elongation in linear polymers.

中文翻译：

延伸流中线性环聚合物共混物的穿线-脱线过渡

已知由于线性环穿线，向其线性对应物的基质中添加少量的环状聚合物会增加零剪切速率粘度。单轴拉伸流变学测量表明，与纯线性和环状成分不同，共混物在应力增长系数上表现出过冲。通过将这些测量结果与异位小角中子散射和非平衡分子动力学模拟相结合，表明这种过冲是由嵌入线性缠结网络中的环的瞬态穿线-脱线过渡驱动的。与纯线性熔体相比，在松开螺纹之前，嵌入的环会与线性缠结网络发生仿射变形，并在混合物中产生线性链的可测量的更强的伸长率。从而，

更新日期：2020-10-21

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11