交联剂分子类型对橡胶力学性能影响的微观机制  

Crosslinking Agent Molecular Types Impact Analysis on Rubber Mechanical Properties Microscopic Mechanisms

作　　者：左俊杰 魏志刚[1] 张泽林 ZUO Junjie;WEI Zhigang;ZHANG Zelin(School of Mechanical Engineering,Anhui University of Technology,Ma'anshan,Anhui 243032,China)

机构地区：[1]安徽工业大学,机械工程学院,安徽马鞍山243032

出　　处：《塑料》2024年第6期161-167,共7页Plastics

基　　金：安徽省自然科学基金(2008085MA15);安徽省教育厅高等学校自然科学研究重点项目(023AH051122)。

摘　　要：基于分子动力学模拟(MD)方法,构建了交联聚异戊二烯橡胶(IR)模型,通过分析分子链平衡状态下的动力学特性参数和拉伸变形情况,研究了交联剂分子类型对材料动静态力学性能影响的微观机制。结果表明,在交联剂分子数目相同的情况下,与单硫和双硫剂相比,多硫交联剂构建的聚异戊二烯交联网络内的分子链运动能力受到了更大的限制,体系的玻璃化转变温度升高,均方位移及末端矢量自相关函数逐渐降低。除此以外,在拉伸过程中,多硫交联体系的拉伸强度提高,滞后损耗降低,当定伸长率为300%时,拉伸应力分别为双硫和单硫剂交联体系的1.6、3.7倍。通过增大交联剂分子长度能增强交联体系内分子链受到的约束效应,提高链段的抗变形能力,从而减小材料的黏性特征,揭示了该类材料变形机制,为改进材料力学性能和更好地应用提供参考。The model of crosslinked polyisoprene rubber(IR)was constructed using the molecular dynamics(MD)simulation method.The micro-mechanisms of the influence of crosslinking agent molecular types on the dynamic and static mechanical properties of the material were explored by analyzing the dynamic characteristic parameters and stretching deformation under the equilibrium state of molecular chains.The results indicated that under the same number of crosslinking agent molecules,the molecular chain movement ability within the polyisoprene crosslinked network constructed by polysulfide crosslinking agents was more limited compared to monosulfide and disulfide agents,specifically manifested by an increase in the glass transition temperature of the system,a gradual decrease in mean square displacement and end vector autocorrelation function.In addition,during the stretching process,the polysulfide crosslinked system could exhibit higher tensile strength and lower hysteresis loss.The tensile stress at a constant elongation of 300%was 1.6 and 3.7 times that of the double sulfur and single sulfur crosslinked systems,respectively.Analysis had found that increasing the molecular length of the crosslinking agent could increase the constraint effect on the molecular chains within the crosslinking system,improved the anti deformation ability of the chain segments,and thus reduced the viscosity characteristics of the material.The results provided a reference for revealing the deformation mechanism of this type of material,improving its mechanical properties,and better application.

关 键 词：橡胶 交联剂 分子动力学模拟 力学行为 微观机制 

分 类 号：TQ333.3[化学工程—橡胶工业]