反应型增塑剂液体异戊二烯分子量对合成异戊橡胶的结构与性能影响

Effect of reactive plasticizer liquid isoprene molecular weight on structure and properties of synthetic isoprene rubber

考察了3种微观结构相近、不同相对分子质量的液体聚异戊二烯(LIR)及其用量对合成异戊橡胶(IR)硫化特性、加工特性、物理机械性能和动态力学性能的影响,表征了IR硫化胶的微观形貌。结果表明,随着LIR用量的增多,IR/LIR混炼胶的硫化时间略有延长,加工特性获得改善;3种LIR均可以参与硫化反应,成为橡胶交联网络的一部分;随着LIR分子量的增加,IR/LIR硫化胶的拉伸强度,扯断伸长率和300%定伸应力略有增加,邵A硬度、压缩生热和交联密度基本不变,IR硫化胶的耐磨性能降低;LIR可以改善炭黑粒子在IR硫化胶中的分散,降低高应变时的损耗因子。综合考虑,LIR分子量5万左右为宜,其增塑的IR混炼胶加工性能、综合力学性能较好和填料分散较优。

This paper examines three kinds of LIR with similar microscopic structure and different molecular weight,and studies the impact of the LIR amount on curing properties,processing characteristics,mechanical properties and dynamic mechanical properties of IR,characterizes the morphology of IR vulcanizates. The results show that,with the increase of the amount of LIR,the curing time of IR / LIR compound is slightly extended,and the processing characteristics is improved; all 3 LIRs can participate in the curing reaction,as part of a rubber crosslinking network; with increasing molecular weight of LIR,the tensile strength,elongation at break and 300% modulus of IR / LIR vulcanized rubber are increased slightly,Shore A hardness,compression heat and crosslink density are substantially unchanged,the wear resistance of IR vulcanized rubber is reduced; LIR can improve the dispersion of carbon black particles in the IR vulcanizates,and reduce loss factor of high strain. Considering,the molecular weight of LIR is more appropriate when it is about 50,000. In this case,the processing properties and mechanical properties of plasticized IR vulcanizates are better,and the filler dispersion is better too.