Matsko Mikhail, Zakharov Vladimir
Boreskov Institute of Catalysis, Pr. Lavrentieva 5, Novosibirsk 630090, Russia.
Polymers (Basel). 2023 Nov 3;15(21):4316. doi: 10.3390/polym15214316.
In this review, we summarize and discuss our experimental data published in a number of papers on the transfer reactions of polymer chains in the polymerization of ethylene, propylene, and hexene-1, and the copolymerization of ethylene with α-olefins over multisite supported titanium-magnesium catalysts (TMC). Three groups of transfer reactions are discussed in the review: (1) transfer reactions with AlEt cocatalyst, (2) transfer reactions with hydrogen, and (3) transfer reactions with participation of α-olefins in the case of ethylene copolymerization with α-olefins. We have found polymerization conditions where it is possible to observe heterogeneity of active sites of TMC for all three groups of the indicated reactions. It is shown that (1) the transfer reaction with AlEt proceeds with higher reactivity on the active sites that produce polymers with low molecular weight; (2) the transfer reaction with hydrogen, in the case of α-olefin polymerization and copolymerization of ethylene with α-olefins, proceeds with higher reactivity on the active sites which produce polymers with high molecular weight; (3) the transfer reaction with α-olefins proceed with higher reactivity on the active sites that produce high molecular weight polymers.
在本综述中，我们总结并讨论了我们发表在多篇论文中的实验数据，这些数据涉及乙烯、丙烯和1-己烯聚合过程中聚合物链的转移反应，以及乙烯与α-烯烃在多活性中心负载型钛镁催化剂（TMC）上的共聚反应。本综述讨论了三组转移反应：（1）与三乙基铝助催化剂的转移反应；（2）与氢气的转移反应；（3）在乙烯与α-烯烃共聚情况下，α-烯烃参与的转移反应。我们发现了一些聚合条件，在这些条件下，对于上述三组反应都有可能观察到TMC活性中心的不均一性。结果表明：（1）与三乙基铝的转移反应在生成低分子量聚合物的活性中心上具有更高的反应活性；（2）在α-烯烃聚合以及乙烯与α-烯烃共聚的情况下，与氢气的转移反应在生成高分子量聚合物的活性中心上具有更高的反应活性；（3）与α-烯烃的转移反应在生成高分子量聚合物的活性中心上具有更高的反应活性。
