室温自交联低密度聚乙烯结晶动力学的研究

Study on the Crystallization Kinetics of Self-crosslinking Low-density Polyethylene at Room Temperature

采用硅烷接枝、交联两步法制备了室温自交联低密度聚乙烯（PELD），通过傅里叶变换红外光谱、差示扫描量热仪研究了硅烷接枝和室温自交联对PE-LD结晶性能的影响。结果表明，硅烷接枝和自交联反应对PDLD的结晶行为有明显的影响，接枝和交联后，PE-LD的Avrami指数在3．8～6．0之间，高于纯PELD；Avrami指数随引发剂含量的增加先增加后降低，随催化剂含量的增加而降低；硅烷接枝PE-LD的结晶动力学速率常数高于纯PE—LD，而交联PE-LD的结晶动力学速率常数低干纯PE-LD。

Crosslinked PE-LD was prepared through a two-step method： silane grafting and room temperature self-crosslinking. Both grafted and crosslinked PE-LD were studied using FTIR and differential scanning calorimeter. It was found that the crystallization behavior of PE-LD was greatly affected by the silane grafted reaction and self-crosslinking, the values of Avrami index of PE-LD was 2.52, while it increased to 3.8- 6.0 when PE-LD was grafted or cross-linked. The values of Avrami index increased to the maximum and then decreased with increasing loading of initiator, while decreased with increasing loading of catalyst. Compared with neat PE-LD, the velocity constant of the crystallization of silane grafted PE-LD became higher,.while that of crosslinked PE-LD became smaller.