Synthesis Of Vanadium-Based Ziegler-Natta Catalyst And Their Catalytic Behavior For Ethylene/Propylene Copolymerization

The synthesis procedure of traditional vanadium based Ziegler-Natta catalysts is very sensitive to moisture and atmosphere, and causes environmental pollution, the postpocessing and recycling procedure is very complicated as well. In order to solve this problem, this paper using a new method to synthesize vanadium based Z-N catalysts, in order to make the processing method more environmental protection, at the same time guarantee the catalytic activity and reduce the cost of storage, recycling and transportation.The catalyst is synthesized in-situ by the reaction of sodium metavanadate, organic alcohol, and acid. Reseaches have been done on how the acidity of aquous phase is related to extraction efficiency, and it turns out that they have a positive proportional relation. FTIR results shows that after complex with vanadium, the characteristic peak of C-O group has blue shifted from 1041 cm-1 to 1014 cm-1 compare with pure organic alcohol.Researches have been done on the effect of different alcohol to vanadium molar ratio, different storage temperature, different storage time on the activity of catalysts. The monomer reacivity ratio of the reaction, the mircostructure, molecular weight, MWD, copolymer composition, gel content of obtained copolymer are characterized by 13C-NMR, FTIR, high-temp GPC, visicosity meter etc. respectively, and optimized polymerization conditions were summarized. Experiment results show that, rE=8.7, rP=0.15, rE×rP=1.33, when ROH/V molar ratio is 3 for ethylene/propylene copolymerization. rE=6.9, rP=0.15, rE×rP=1.05, when ROH/V molar ratio is 4 for ethylene/propylene copolymerization, which means that the random copolymers can be obtained.