老挝黄金赌场长春应化所孙昭艳团队报道了聚合物网络中局部链结构与应力分布之间的相互作用。相关研究成果发表在2024年3月7日出版的《中国高分子科学杂志》。

聚合物网络的力学行为与局部链拓扑结构和链连接性有着内在的联系。

该研究中，研究人员通过粗粒分子动力学（CG-MD）模拟的视角深入研究了这种关系。研究目的是阐明聚合物单体、交联剂和具有不同交联连接的各种组分内的局部拓扑结构和应力分布之间的复杂相互作用，从而阐明它们对聚合物网络力学性能的集体影响。研究人员主要关注特定的局部结构如何对网络的整体力学响应做出贡献。特别是，使用局部应力分析来揭示这些结构的力学性质。研究结果揭示了各个组成部分在拉伸时的不同反应，如连接、链、连接之间的交联点和悬挂链末端。

值得注意的是，研究人员观察到这些组件表现出不同程度的变形容限，这突出了它们在决定网络机械特性方面的重要作用。研究强调，连接是应力累积的主要因素，而具有较高局部应力的颗粒显示出应力和Voronoi体积之间更强的相关性。此外研究结果表明，随着链长度的减少，连接处之间的链和交联点都表现出更高的应力水平。

该项研究增强了人们对微观结构水平上，控制交联聚合物体系机械属性的多方面因素的理解。

附：英文原文

Title: Exploring the Interplay between Local Chain Structure and Stress Distribution in Polymer Networks

Author: Jin-Tong Xue, Yang Bai, Li Peng, Xian-Bo Huang, Zhao-Yan Sun

Issue&Volume: 2024-03-07

Abstract: The mechanical behavior of polymer networks is intrinsically correlated with the local chain topology and chain connectivity. In this study, we delve into this relationship through the lens of coarse-grained molecular dynamics (CG-MD) simulations. Our aim is to illuminate the intricate interplay between local topology and stress distribution within polymer monomers, cross-linkers, and various components with distinct cross-link connections, thereby elucidating their collective impact on the mechanical properties of polymer networks. We mainly focus on how specific local structures contribute to the overall mechanical response of the network. In particular, we employ local stress analysis to unravel the mechanics of these structures. Our findings reveal the diverse responses of individual components, such as junctions, strands, cross-linkers between junctions, and dangling chain ends, when subjected to stretching. Notably, we observe that these components exhibit varying degrees of deformation tolerance, underscoring the significance of their roles in determining the mechanical characteristics of the network. Our investigations highlight junctions as primary contributors to stress accumulation, and particles with higher local stress showing a stronger correlation between stress and Voronoi volume. Moreover, our results indicate that both strands and cross-linkers between junctions exhibit heightened stress levels as strand lengths decrease. This study enhances our understanding of the multifaceted factors governing the mechanical attributes of cross-linked polymer systems at the microstructural level.

DOI: 10.1007/s10118-024-3099-3

Source: https://www.cjps.org/en/article/doi/10.1007/s10118-024-3099-3/