Studies on VOCl3/MgCl2/NaY/Al2Et3Cl3 complex support catalysts for the copolymerization of ethylene and propylene

Using VO²⁺ as a spin probe, a new method to obtain microenvironmental information on supports was developed which can be used in the choice of supports for coordination catalysts. Utilizing the above method, NaY was chosen as second support component. A complex support catalyst VOCl₃/MgCl₂/NaY/Al₂Et₃Cl₃ was prepared and used in ethylene–propylene copolymerization. Higher polymerization activity was obtained with this catalytic system. Alternating the ratio of two kinds of supports, the composition and sequence structure of copolymers could be controlled, which showed that NaY participated in the active species, affected the insertion of monomer, and changed the composition and sequence structure of copolymers. © 1994 John Wiley & Sons, Inc.