For copolymerization of ethylene and norbornene initiated by various metallocene catalysts such as rac-Et(Ind)2ZrCl2, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(Cp)2ZrCl2 and (n-BuCp)2ZrCl2 with modified methylaluminoxane(MMAO) cocatalyst, the alpha -olefins such as 1-hexene(H), 1-octene and 1-decene were added as a 3rd monomer. In this situation, the effects of the polymerization condition, the catalyst structure as well as the structure and the amount of added α-olefin on the catalyst activity as well as the properties and structure of polymer were examined. As results, it was found that the catalyst activity and thermal property of polymer depended on not only catalyst structure but also alpha -olefin structure. For rac-Et(Ind)2ZrCl2/MMAO catalyst system, it was possible to get high activity and controllable T(g) of polymer. Among alpha -olefins, H as a 3rd monomer exhibited the maximum enhancement in catalyst activity.

rac-Et(Ind)2ZrCl2, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(Cp)2ZrCl2, (n-BuCp)2ZrCl2 등의 메탈로센 촉매와 공촉매인 개질 메틸알루민옥산(MMAO)을 이용한 에틸렌과 노르보르넨의 공중합에서 1-헥센(H), 1-옥텐 및 1-데센 등과 같은 α-올레핀을 제3단량체로 첨가할 때, 중합조건, 촉매의 구조 및 α-올레핀의 종류와 첨가량이 촉매 활성, 생성 중합체의 열적 성질 및 조성 등에 미치는 영량을 조사하였다. α-올레핀의 첨가량에 따른 촉매 활성 및 중합체의 열적 성질의 변화는 촉매구조 뿐만 아니라 α-올레핀의 구조에도 의존하였다. rac-Et(Ind)2ZrCl2/MMAO계에서 촉매 활성이 높았고 중합체의 T(g)제어가 용이하였으며, 제3단량체로 H를 첨가한 경우에 가장 높은 촉매활성의 증가를 확인하였다.

Keywords: metallocene; ethylene; norbornene; cycloolefin copolymer; alpha-olefin