Effects of alkylaluminum as cocatalyst on the active center distribution of 1-hexene polymerization with MgCl2-supported Ziegler-Natta catalysts

Effect of AlEt3 on 1-hexene polymerization with MgCl2-supported Ziegler-Natta catalyst was studied. Complete activation of active centers (C*) producing medium to low molecular weight polymer requires relatively higher Al/Ti than C* producing high molecular weight polymer. Raising Al/Ti from 30 to 300 caused continuous shifting of the active center distribution from centers of smaller number, fast chain propagation and slow chain transfers to centers of larger number, slow chain propagation and fast chain transfers. Chain transfer with AlEt3 is more evident in C* producing lower molecular weight polymer. (C) 2015 Elsevier B.V. All rights reserved.