Preparation of ethylene/α-olefins copolymers using (2-RInd)_2ZrCl)_2/MCM-41 (R:Ph,H) catalyst, microstructural study

摘要

(2-RInd)_2ZrCl_2 (R:Ph,H) catalyst was supported on MCM-41 and ethylene copolymerization behavior as well as microstructure of copolymers were studied. A steady rate-time profile behavior was observed for homo and copolymerization of ethylene using supported catalysts. It was noticed that increasing the comonomer content can result in lower physical properties. The obtained results indicated that (2-PhInd)_2ZrCl_2/MCM-41 had higher ability of comonomer incorporation than the non-substituted supported catalysts. The CCC, CCE, and ECC (C: comonomer, E: ethylene) triad sequence distribution in backbone of copolymers were negligible, that means no evidence could be detected for comonomer blocks. The polymer characterization revealed that utilizing 1-octene instead of 1-hexene as the comonomer leads to more heterogeneous distribution of chemical composition. The heterogeneity of the chemical composition distribution and the physical properties were influenced by the type of comonomer and catalyst. (2-PhInd)_2ZrCl_2/MCM- 41 produced copolymers containing narrower distribution of lamellae (0.3-1 nm) than the copolymer produce using Ind_2ZrCl_2/MCM-41 (0.3-1.6 nm).