Pt催化剂对动态硫化SR/TPU热塑性弹性体力学性能及相态结构的影响

Influence of Pt Catalyst on Mechanical Properties and Phase Structure of Dynamically Vulcanized SR/TPU Thermoplastic Elastomers

采用动态硫化法制备了加成型有机硅橡胶(SR)/聚氨酯(TPU)热塑性弹性体(TPV),系统研究了Pt催化剂含量对共混扭矩、SR相交联度、SR/TPU热塑性弹性体相形态以及力学性能的影响。结果表明:随着Pt催化剂含量的增加,橡胶相交联度以及试样力学性能逐渐提高;当Pt催化剂含量高于0.16 phr,交联度基本保持不变,TPV的力学性能稳定。相态结构研究表明:随着动态硫化的进行,体系发生由双连续相向"海-岛"结构的相反转,且随着Pt催化剂含量的提高和硫化时间的延长,橡胶相尺寸减小。此外,还研究了SR/TPU配比对其TPV力学性能的影响,发现当SR/TPU配比为60/40时,热塑性弹性体的综合力学性能最佳。

Additional silicone rubber(SR)/polyurethane(TPU) thermoplastic elastomer(TPV) was prepared by dynamic vulcanization.The effects of Pt catalyst content on blending torque,crosslinking degree of SR,phase morphology and mechanical properties of SR/TPU thermoplastic elastomer were systematically studied.The results showed that with the increase of Pt catalyst content,the crosslinking degree of rubber and the mechanical properties of the samples were improved;when the content of Pt catalyst was higher than 0.16 phr,the crosslinking degree remained basically unchanged,and the mechanical properties of TPV were stable.The phase structure study showed that with the development of dynamic vulcanization,the system changed from bi-continuous phase to 'island-sea' phase,and the size of rubber phase decreased with the increase of Pt catalyst content and the extension of vulcanization time.In addition,the effect of SR/TPU ratio on the mechanical properties of TPV was also studied.It was found that when SR/TPU ratio was 60/40,the comprehensive mechanical properties of thermoplastic elastomers were the best.