硅烷与聚乙烯接枝反应的研究

Study on Graft Reactions of Polyethylenes with Silanes

用FTIR、DSC方法研究了不同引发剂 (DCP、DMTBH)引发两种硅烷 (VTEOS、VTMOS)与HDPE、LLDPE的接枝反应 ,确定了不同组合反应体系的反应活化能 (Ea)。结果表明 ,引发剂的分解特性 (分解温度和速度 )、硅烷的反应活性、PE的熔化特性 (熔点 )和反应能力是决定接枝反应特性 (温度范围、反应速度、接枝程度等 )的支配因素 ;DCP引发VTEOS接枝HDPE、LLDPE反应的Ea 分别为 190、16 0kJ/mol,VTMOS接枝HDPE反应的Ea 为 175kJ/mol;不同组合体系接枝反应特性的差异可由组分分子结构和Ea 不同来解释。

The graft reactions of HDPE and LLDPE with vinyl triethoxysilane (VTEOS) or vinyl trimethoxysilane (VTMOS), initiated by dicumyl peroxide (DCP) or 2,5-dimethy-2,5-bis(tert-butyldioxy) -3-hexyne (DMTBH), were studied by means of FTIR and DSC. The activation energies ( E a) of different systems with varied combination of the reactants were determined. The results show that the decomposition behavior (decomposition temperature and speed) of the initiators, the reactive activity of the silanes, the melting behavior (melting point) and reactive ability of the PEs are dominant factors of deciding the graft reaction characteristics (temperature range, reaction speed, grafted extent etc.). The E a of graft reaction of HDPE or LLDPE with VTEOS, initiated by DCP, is 190, 160 ?kJ/mol respectively, and that of HDPE with VTMOS is 175 ?kJ/mol. The differences in graft reaction characteristics of varied combination systems can be explained by the differences in molecular structure of the reactants and in E a.