Preparation of ethylene/polyhedral oligomeric silsesquioxane(POSS) copolymers with rac-Et(Ind)₂ZrCl₂/MMAO catalyst system

To prepare the organic/inorganic hybrid copolymer, the norbornene derivatives of polyhedral oligomeric silsequioxane(POSS) such as norbornenylethyl-POSS (N-POSS) and dimethyl(norbornenylethyl)silyloxy-POSS(N-Si- POSS) had been copolymerized with ethylene by catalyst system of rac-Et(Ind)₂ZrCl₂/modified methylaluminoxane(MMAO). The catalytic activity decreased with the feed amount of POSS comonomer, and it was found that the reactivity of N-Si-POSS was larger than that of N-POSS. The unreacted POSS monomer was removed completely by washing the copolymerization product with n-hexane. The melting point of copolymer decreased with POSS content while the thermal stability, especially oxidation stability of copolymer was improved in a great extent relative to conventional polyethylene.