| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 가을 (10/13 ~ 10/14, 제주 ICC) |
| 권호 | 30권 2호 |
| 발표분야 | 고분자 합성 |
| 제목 | Synthesis of Dinuclear CGC Catalysts and Their Performance in Copolymerization of Ethylene and Norbornene |
| 초록 | A series of polymethylene-bridged dinuclear constrained geometry catalysts (CGC) [Me2Si(Ind)(NtBu)TiCl2]2(CH2)n(1, n=6; 2, n=12) were synthesized and characterized by EA, 1H-NMR and 13C-NMR. Additionally, the corresponding two kinds of mononuclear CGC catalysts Me2Si(Cp’)(NtBu)TiCl2(3,Cp’=3-HexylInd;4,Cp’=Me4Cp) have been synthesized for comparison. To investigate the catalytic behaviors of these prepared catalysts, the copolymerization of ethylene and norbornene were carried out using MAO as cocatalyst. The microstructure of obtained polymers was characterized by GPC and 13C-NMR. It is found that the activity increases in the order of 1＜2＜3＜4, which indicates that the bridge in dinuclear CGC has a negative steric effect on activity as compared to mononuclear CGC, but the presence of the longer bridge between the two active sites contributes more effectively to facilitate polymerization activity of the dinuclear CGC. The molecular weight of resulted polymers decreases with the increase of [norborene]/[ethylene] feed ratio. As norbornene concentration is increased, norbornene incorporation also increases but is lower than 50% for all the copolymers. The 13C-NMR spectroscopy of copolymers shows that the microstructure of the resulting ethylene/norbornene copolymers is dependent on the geometry of catalyst. |
| 저자 | 하간간1, 주은방1, 노석균1, 이동호2, 류원석1 |
| 소속 | 1영남대, 2경북대 |
| 키워드 | metallocene; norbornene; dinuclear CGC; copolymerization |
