Research On Preparation And Properties Of Polyolefin Elastomer By Non-titanocene Catalyst

Polyolefin elastomer is a kind of high performance polymer material which is widely used in industries.There are many kinds of industrial products in foreign countries,however the catalyst technology and solution polymerization technology which have been mature are almost patented.At present,we don’t fully grasp the preparation technology.This work targeted on synthesis of ethylene/?-olefin copolymers,we designed and synthesized two kind of non-titanocene catalysts.All complexes were systematically studied for catalytic properties and we studied copolymerization of ethylene/?-olefin which are performed in high pressure olefin polymerization system.The influences of incorporation ratio and branch length on the structure,crystallization,and thermal behavior and mechanics performances were investigated by NMR,DSC,WAXD and so on.Conclusions were summarized as follows:We optimize the synthesis process of titanium complexes with good catalytic properties and studied catalytic activity,chain-transfer ways,and thermal stability etc.It was revealed that catalysts exhibited high catalytic activity(>10~6 g/mol·h),and the resultant poly(ethylene-co-?-olefin)possessed relatively high molecular weights with narrow molecular weight distribution.Under the condition of similar comonomer content and molecular weight,the copolymers with longer chain of comonomer have higher elongation ratio and lower tensile strength,elastic recovery performance increased slightly.Under the condition of same comonomer and familiar comonomer content,copolymers with higher comonomer content have higher breaking elongation ratio,tensile strength,and better elastic recovery performance.We obtained high molecular weight copolymer and high incorporation of comonomer by adjust polymerization condition with breaking elongation ratio being more than 1000%,and elastic recovery is 80%above.