硫化体系对热塑性硫化胶性能的影响

采用动态硫化法制备了丁基橡胶(IIR)/聚丙烯热塑性硫化胶(TPV),研究了不同硫化体系对TPV的硫化特性、热性能、动态力学性能和微观相态结构的影响。结果表明,由酚醛树脂硫化体系(PRV)、硫黄硫化体系(SV)和硫载体硫化体系(SCV)制备而得的TPV(依次相应为PRV-TPV、SV-TPV和SCV-TPV)中,PRV-TPV的动态硫化时间最长,SCV-TPV的转矩最小,流变性能最好;PRV-TPV的交联密度最大,SCV-TPV的交联密度最小;PRV-TPV的储能模量最大,Payne效应最弱。TPV的拉伸强度由大到小依次是PRV-TPV、SV-TPV、SCV-TPV,老化后强度的变化规律与老化前相同;PRV-TPV的耐热性能最佳。SV-TPV和SCV-TPV有2个损耗因子(tanδ)峰,PRV-TPV有1个tanδ峰,且玻璃化转变温度较高;PRV-TPV和SV-TPV的熔融温度(Tm)相差不大,而SCV-TPV的Tm较高;SV-TPV和SCV-TPV的结晶温度(Tc)相差不大,PRV-TPV的Tc较高。PRV-TPV和SV-TPV的相态结构为明显的海岛相态结构,PRV-TPV中的IIR交联颗粒粒径较小;SCV-TPV呈不明显的海岛相态结构,且IIR交联颗粒以拉伸的长条状为主。

Effect of curing systems on properties of thermoplastic vulcanizates

Butyl rubber(IIR)/polypropylene thermoplastic vulcanizate(TPV)was prepared by dynamic curing method.The effects of different kinds of curing systems on curing characteristics,thermal properties,dynamic mechanical properties and microstructure of TPVs were studied.The results showed that in the TPV prepared by different curing systems,PRV,SV and SCV(PRV-TPV,SV-TPV and SCV-TPV),the dynamic curing time of PRV-TPV was the longest,and Tq of SCV-TPV was the smallest and the rheological property was the best.The crosslinking density of PRV-TPV was the largest,and that of SCV-TPV was the smallest;the storage modulus of PRV-TPV was the largest,and Payne effect of PRV-TPV was the weakest;tensile strength from large to small was followed by PRVTPV,SV-TPV and SCV-TPV,and three kinds of TPVs had the same strength change after aging as before aging;PRV-TPV had the best heat resistance.SV-TPV and SCV-TPV had two tanδ,but PRV-TPV just had a tanδ,and its glass transition temperature was higher;melting temperature(Tm)of PRV-TPV and SV-TPV were not much different,and the Tm of SCV-TPV was the highest;crystallization temperature(Tc)of SV-TPV and SCV-TPV were not much different,and Tc of PRV-TPV was the highest.The phase structures of PRV-TPV and SV-TPV were obvious island phase and the crosslinked IIR particles in PRV-TPV had smaller particle size;that of SCV-TPV was an inconspicuous island phase structure,and the crosslinked IIR particles were mainly in the shape of a stretched strip.