膦氮配体半茂钛体系催化乙烯均聚合及乙烯与丙烯共聚合

摘要

Two novel half-titanocenes catalysts containing phosphine nitrogen ligands were synthesized. The impact of the complex concentration, feedstock composition, molar ratio of Al/Ti, reaction time and pressure were investigated on ethylene polymerization and ethylene-propylene(E/P)copolymerization catalyzed by half-titanocenes/methyl aluminoxane/[Ph3C][B(C6F5)4] catalytic system as well as on the composition, relative molecular mass and distribution of the polymers. The results show that the catalysts prepared exhibit high activity of 0.62×106 g/(mol·h)in ethylene polymerization, moreover, the activity of the catalysts is similar to metallocene catalyst in E/P polymerization. The E/P copolymer prepared by the catalyst system feature single cite catalyst of high molecular mass with narrow molecular mass distribution. The research on the sequence of the copolymer indicates that rE×rP is about 1, the copolymers prepared are random.%合成了两种配合物中含有膦、氮的半茂钛催化剂，研究了甲基铝氧烷、四（五氟苯基）硼酸盐为助催化剂，不同n（Al）∶n（Ti）对乙烯均聚合及聚合物相对分子质量及其分布的影响。研究了催化剂用量、原料配比、反应压力、反应时间对乙烯与丙烯共聚合及共聚物组成、相对分子质量及其分布的影响。结果表明：合成的膦氮配体半茂催化剂可有效催化乙烯均聚合，在常压下，聚合活性可达0.62×106g/（mol·h），也可以有效催化乙烯与丙烯共聚合，与高活性茂金属催化剂催化效率相近；用该催化剂制备的高相对分子质量乙丙共聚物的相对分子质量分布窄，符合单活性中心催化剂的特点；共聚物的序列结构研究表明，乙烯与丙烯竞聚率之积接近1，共聚物无规性好。