摘要
以过氧化二异丙苯(DCP)为引发剂、1,4-丁二醇二丙烯酸酯(BDDA)为接枝单体,通过反应挤出制备长支链聚丙烯(PP),研究了PP链长及主链中乙烯嵌段含量对PP长链支化程度的影响。随着PP树脂分子链长度降低以及乙烯嵌段含量增加,PP大分子自由基发生接枝和双基偶合扩链反应的几率增大,导致BDDA在PP主链上的接枝率提高,反应挤出产物的熔体弹性效应增强以及在Cole-Cole曲线出现上翘所对应的动态黏度降低。黏度降低表明分子链松弛时间增加,PP长链支化程度增大。。
Polypropylene （PP） with long-chain branching was prepared with dicumyl peroxide （DCP） as initiator and 1,4-butanediol diacrylate （BDDA） as graft monomer via reactive extrusion. The influences of the length of the PP chain and the content of ethylene units in the PP chains on the degree of long-chain branching of the PP were investigated. With the decrease in the PP chain length and/or the increase in the content of ethylene units in the PP chains, the probability of occurring of graft reaction of BDDA on the PP chains and chain extension by coupling reaction between PP macromolecular radicals increased, as a result, the grafting ratios of BDDA onto the PP chains rose and elastic effect of melt in the reactive extruded products strengthened. The dynamic viscosity corresponding to the upturning of the Cole-Cole plot reduced, indicating that the relaxation time of the segments in the reactive extruded products became longer and the degree of long-chain branching was raised.
出处
《合成树脂及塑料》
CAS
北大核心
2013年第2期62-66,共5页
China Synthetic Resin and Plastics
关键词
聚丙烯
反应挤出
长链支化程度
链结构
polypropylene
reactive extrusion
degree of long-chain branching
chain structure
