黏土含量与结构对天然橡胶拉伸诱导结晶行为的影响

Influence of clay content and lamella structure on strain-induced crystallization of natural rubber

采用熔体法制备天然橡胶/有机黏土纳米复合材料(NRCNs),重点考察黏土片层结构及其含量对拉伸结晶型橡胶拉伸诱导结晶行为的影响。并通过XRD、TEM等测试表征NRCNs的微观相态结构。实验结果表明:随着拉伸形变的增加,NRCNs的定伸应力逐渐增加;当达到某一临界应变值ε_0时,NRCNs的定伸应力快速增加——拉伸诱导结晶行为产生;随着有机黏土含量的增加,NRCNs拉伸诱导结晶行为在较低的应变下产生,这主要是因为纳米分散的有机黏土具有较大的形状系数,对橡胶分子链具有较强的限制作用,刚性平行黏土片层结构有利于促进柔性橡胶分子链在拉伸形变过程中快速取向。

Organic clay（OC）/natural rubber（NR） nanocomposites（NRCNs） prepared by melt blending were studied for the effect of clay structure and content on strain-induced crystallization of stretch crystalline rubber. Microscopic phase structures of NRCNs were characterized by XRD and TEM. The results showed that the stress of NRCNs increased gradually with increasing strain at beginning and increased rapidly after strain reached to a critical strain point（ε0） which strain-induced crystallization was occurred in NR. As clay was loaded higher, the crystallization started at lower strain. Dispersed OC nanoparticles with high shape aspect ratio restricted movement of rubber molecules, and also rigid parallel clay lamella structure promoted orientation of flexible rubber molecules in stretching process.