摘要
以H2 气作为相对分子质量调节剂 ,采用MgCl2 负载TiCl4催化体系催化异戊二烯溶液淤浆聚合及本体沉淀聚合 ,合成低相对分子质量反式 1 ,4 聚异戊二烯蜡。研究了聚合条件如H2 气分压、聚合温度、时间、催化剂用量等对相对分子质量、催化剂效率和聚合物结构的影响。结果表明 ,H2 气能明显调节聚合物的相对分子质量。当H2 气分压为 2 4MPa时 ,聚合物的特性粘数降至 0 2 3dL/g,相应粘均相对分子质量为 3 80 0 ,数均相对分子质量约为 1 0 0 0。结构分析表明 ,所得聚合物反式 1 ,4 结构摩尔分数为 92 %以上 ,结晶度 3 0 %左右。聚合物相对分子质量分布指数ID为 5 0～ 80。
The solution polymerization and bulk precipitation polymerization of isoprene with supported titanium catalyst TiCl 4 /MgCl 2 Al( i Bu) 3 using hydrogen as relative molecular mass modifier have been carried out in order to synthesis low relative molecular mass trans 1,4 polyisoprene wax(LMTPIW). The effects of hydrogen pressure, n (Al)/ n (Ti) , n (Ti)/ n (Ip), and polymerization time and temperature on the relative molecular mass, catalyst efficiency and structure of polymer were studied. Increasing the hydrogen pressure results in the decrease of intrinsic viscosity of the polymer \. The \, viscosity average relative molecular mass and number average relative molecular mass were found to be decreased to 0 23 dL/g, 3 800 and 1 000, respectively, when H 2 pressure was increased to 2 4 MPa. The x (trans 1,4 unit) in the polymer was over 92%. The crystallinity of the polymer was ca . 30% with T m being 50～ 55 ℃ . The relative molecular mass distribution index( I D ) was 50～80.
出处
《应用化学》
CAS
CSCD
北大核心
2003年第5期447-451,共5页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金资助项目 ( 2 0 2 740 2 1)
关键词
异戊二烯
负载钛催化剂
配位聚合
氢气
低聚物
isoprene,supported titanium catalyst,coordination polymerization,hydrogen,oligomer
