茂金属-Ziegler-Natta催化剂协同催化丙烯聚合  

Propylene Polymerization Catalyzed by Metallocene/Ziegler-Natta Tandem Catalysis

作　　者：牛慧[1,2] 许泽楠 董金勇[1] 

机构地区：[1]中国科学院化学研究所工程塑料重点实验室,北京100190 [2]大连理工大学化工学院高分子材料系精细化工国家重点实验室,辽宁大连116024 [3]中国科学院大学,北京100049

出　　处：《石油化工》2015年第6期674-682,共9页Petrochemical Technology

基　　金：国家自然科学基金项目(51003105)

摘　　要：基于茂金属催化剂rac-CH2(3-t Bu-1-Ind)2Zr Cl2和以双醚化合物为内给电子体的Mg Cl2/Ti Cl4型Ziegler-Natta催化剂,以甲基铝氧烷(MAO)和三异丁基铝分别作为Zr和Ti两种催化剂组分的助催化剂,研究了Zr-Ti协同催化下的丙烯聚合,考察了丙烯压力、溶剂种类、两种催化剂比例等对聚合的影响;用1H NMR,GPC,SEM等手段分析聚合物的结构和组成。实验结果表明,将具有产生端基含乙烯基双键的聚丙烯大分子单体功能的茂金属催化剂和具有催化丙烯共聚功能的Ziegler-Natta催化剂组合后,在较低的丙烯聚合压力(0.2 MPa)下只得到大分子单体和线型聚丙烯的混合物,而在较高压力(0.4 MPa)下可获得支化聚丙烯,进一步增加Zr-MAO浓度可大幅提高大分子单体的转化率,聚合物的Mark-Houwink曲线呈长链支化特征,所得聚丙烯粒子具有良好的球形颗粒形态。A new method for the synthesis of branched polypropylene was proposed using the tandem systems of metallocene（rac-CH2（3-t Bu-1-Ind）2Zr Cl2） and Ziegler-Natta（MgCl2/Ti Cl4/diether）,in which methylaluminoxane（MAO） and triisobutylaluminium were used as cocatalysts for the Zr and Ti species respectively. The infl uences of propylene pressure,solvent types and Zr/Ti ratio on the polymerization were investigated and the polymers were characterized by means of ^1H NMR,GPC and SEM. The results revealed that after the metallocene catalyst,which was capable of promoting the function of macromonomer containing vinyl end-groups,was combined with the Ziegler-Natta catalyst which could catalyze the copolymerization of propylene,branched polypropylene was prepared under relatively high pressure（0.4 MPa of propylene）,while a mixture of macromonomer and linear polypropylene were obtained under relatively low pressure（0.2 MPa of propylene）. By increasing the Zr-MAO concentration the conversion of the macromonomer was remarkably improved in the copolymerization and a long chain-branching character was observed in the Mark-Houwink curves of the polymers. Moreover,the prepared polymers had good spherical granular morphology.

关 键 词：茂金属催化剂 ZIEGLER-NATTA催化剂 协同催化 丙烯聚合 支化聚丙烯 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业]