桥联胺基芴基二甲基钛配合物制备乙烯/降冰片烯共聚物

Preparation of Copolymers of Norbornene with Ethylene by Fluorenylamidodimethyl Titanium Complex

使用[t-BuNSiMe_2(3,6-t-Bu_2Flu)]TiMe_2 (A),[(1-金刚烷胺基)NSiMe_2(3,6-t-Bu_2Flu)]TiMe_2 (B),[t-BuNSiMe_2(3,6-OMe_2Flu)]TiMe_2 (C),[(1-金刚烷胺基)NSiMe_2(3,6-OMe_2Flu)]TiMe_2 (D)4种限制几何构型催化剂,以改性甲基铝氧烷(MMAO)/2,6-二叔丁基-4-甲基苯酚(BHT)为助催化剂,研究了胺取代基和芴基取代基改变对降冰片烯与乙烯共聚反应的影响。结果表明,催化剂A,B,C,D能有效催化共聚反应得到环烯烃共聚物,A,B催化活性、产物分子量均高于催化剂C,D。降低助催化剂含量,B仍能具有较高的聚合活性。产物分子量分布为单峰,共聚反应为单活性中心体系。通过13C-NMR谱图表明催化剂B催化所得的聚合物具有较高的降冰片烯插入率,插入率可高达46.6%。

The substituent effects of the amido ligand and fluorenyl ligand were investigated by using [t-BuNSiMe2(3,6-t- Bu2Flu)]TiMe2 (A),[(1-Adamantyl)NSiMe2(3,6-t-Bu2Flu)]TiMe2 (B),[t-BuNSiMe2(3,6-OMe2Flu)]TiMe2 (C),[(1-Adamantyl) NSiMe2(3,6-OMe2Flu)]TiMe2(D) together with MMAO/BHT as cocatalyst in the copolymerization of norbornene with ethylene. The results suggest that the activity and the molecular weight of polymers produced by A,B are higher than catalyst C,D. The activity of B remain high despite the low amount of cocatalyst. The copolymers obtain with both catalysts system have narrow MWD with unimodal GPC curves,which suggests that all complexes have one active center. The 13C-NMR spectra produced by B-MMAO/ BHT system show that the polymer have a higher insertion rate of norbornene,and the insertion rate can be 46.6%.