双链转移试剂协同促进钛催化乙烯配位链转移聚合反应

  配位链转移聚合可以实现对烯烃配位聚合物分子量、分子量分布、链末端基团等的调控，被用于制备单末端或双末端官能化的聚烯烃以及嵌段共聚物等材料。在工业生产中，这一聚合方法成功的应用于合成结构新颖、性能优异的乙烯/1-辛烯嵌段共聚物。在锆、铪催化剂催化高性能聚烯烃的大规模生产工艺中，二乙基锌通常作为链转移试剂被广泛应用。在聚烯烃生产过程中，钛金属催化剂常常会被烷基金属试剂所毒化，从而导致聚合活性降低。到目前为止，鲜有钛催化烯烃配位链转移聚合体系被应用于工业生产的报道。

  针对上述问题，我们创新性的开发了一类钛催化剂催化的双链转移试剂聚合体系。在胺基二酚钛配合物催化乙烯聚合体系中，加入等比例的三乙基铝（TEA）与二乙基锌（DEZ）组合作为链转移试剂，可以显著提高钛催化剂聚合活性、生成聚合物链数以及链转移效率。同时将双链转移试剂引入到多种非茂钛催化剂催化烯烃聚合反应中，对双链转移试剂组合的普适性进行了系统的研究。值得一提的是，该双链转移试剂体系链转移效率最高可达97.0%。并且通过核磁实验进行了初步的机理研究，初步研究表明三乙基铝抑制了二乙基锌对催化剂的毒化作用。

  本文利用双链转移试剂组合活化策略发展了一系列基于钛催化剂的高效配位链转移聚合体系，拓展了钛催化剂催化体系及配位链转移聚合的应用范围，具有一定的应用潜力。

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