STUDY ON HIGHLY ACTIVE ZIEGLERNATTA CATALYSTS FOR POLYMERIZATION OF OLEFINS

In this paper, highly active Ziegler-Natta catalysts of MgCl2 supported TiCl4 for synthesis ofpolyolefins, using di-n-butyl phthalate （DNBP） as internal donor and diphenyl dimethoxyl silane（DPDMS） as external donor, have been prepared. The conditions controlling the treatment ofsupport were studied. The interactions of various components present in the catalysts and theirinfluences on catalytic performance were investigated. It is found that by using DNBP and DPDMSas internal and external donors together the polymer products with higher isotactic index can beobtained. Plausible structure model and mechanism were proposed.