Surface Dynamics of Polymer Glasses with Varying Chain Lengths

IF 5.2 1区化学 Q1 POLYMER SCIENCE

Macromolecules Pub Date : 2025-09-04 DOI:10.1021/acs.macromol.5c01701

Haiyang Zhang, , , Sisi Ge, , , Weilong Gong, , , Jintian Luo*, , and , Biao Zuo*,

引用次数: 0

Abstract

The surface dynamics of polymer glasses are complex due to strong coupling between the long-chain molecular structure and the surface mobility gradient. Herein, we investigated the surface relaxation of polymer glasses with varying chain lengths using an interfacial wetting-induced rheological (WIR) method. We identified rapid, Rouse-like motion on a short time scale, with activation energies independent of chain length, and slow, chain-dependent dynamics on a long time scale, with activation energies that increased with increasing chain length before attaining an asymptotic value. We attribute the former to the relaxation of the top strands of surface chains embedded in the surface mobility gradient and the latter to the relaxation of entire chains, which do not occur until the deepest segments of the surface chains are released. The findings of the study provide new insights into the hierarchical relaxation of interfacial polymers.

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不同链长聚合物玻璃的表面动力学

由于长链分子结构和表面迁移率梯度之间的强耦合，聚合物玻璃的表面动力学是复杂的。本文采用界面润湿诱导流变学（WIR）方法研究了不同链长的聚合物玻璃的表面弛豫。我们发现了在短时间尺度上快速的、类似劳斯的运动，活化能与链长无关；在长时间尺度上缓慢的、依赖链的动力学，活化能随着链长增加而增加，直到达到渐近值。我们将前者归因于嵌入在表面迁移率梯度中的表面链的顶部链的松弛，后者归因于整个链的松弛，直到表面链的最深部分被释放才会发生松弛。该研究结果为界面聚合物的分层弛豫提供了新的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Macromolecules 工程技术-高分子科学

CiteScore

9.30

自引率

16.40%

发文量

942

审稿时长

2 months

期刊介绍： Macromolecules publishes original, fundamental, and impactful research on all aspects of polymer science. Topics of interest include synthesis (e.g., controlled polymerizations, polymerization catalysis, post polymerization modification, new monomer structures and polymer architectures, and polymerization mechanisms/kinetics analysis); phase behavior, thermodynamics, dynamic, and ordering/disordering phenomena (e.g., self-assembly, gelation, crystallization, solution/melt/solid-state characteristics); structure and properties (e.g., mechanical and rheological properties, surface/interfacial characteristics, electronic and transport properties); new state of the art characterization (e.g., spectroscopy, scattering, microscopy, rheology), simulation (e.g., Monte Carlo, molecular dynamics, multi-scale/coarse-grained modeling), and theoretical methods. Renewable/sustainable polymers, polymer networks, responsive polymers, electro-, magneto- and opto-active macromolecules, inorganic polymers, charge-transporting polymers (ion-containing, semiconducting, and conducting), nanostructured polymers, and polymer composites are also of interest. Typical papers published in Macromolecules showcase important and innovative concepts, experimental methods/observations, and theoretical/computational approaches that demonstrate a fundamental advance in the understanding of polymers.