This disclosure relates to olefin polymerization catalysts and compositions, their manufacture, and the production of polyolefins using specific catalyst compositions, including the use of chain-shuttling agents in the olefin polymerization process. Specifically, this disclosure provides for dual-headed and multi-headed chain shuttling agents (CSAs or MSAs) and for their use in preparing blocky copolymers. By controlling the ratio of dual-headed and multi-headed CSA sites to mono-headed CSA sites, a blocky copolymer can be provided having properties such as a narrow molecular weight distribution and/or improved melt properties.
本公开涉及烯烃聚合催化剂和组合物、其制造以及使用特定催化剂组合物生产聚烯烃,包括在烯烃聚合过程中使用链穿梭剂。具体而言,本公开提供了双头和多头链穿梭剂(CSA 或 M
SA)及其在制备块状共聚物中的用途。通过控制双头和多头 CSA 位点与单头 CSA 位点的比例,可提供具有窄分子量分布和/或改善熔融特性等特性的块状共聚物。