邻-酚羟基取代N-杂环卡宾[C，O]螯合烯丙基钯配合物／MAO催化降冰片烯的聚合

Polymerization of Norbornene via Allyl Palladium-Based Complexes Bearing o-Hydroxyarl N-Heterocyclic Carbenes [C,O] Ligands/MAO

研究了以3种N-杂环卡宾[C,O]螯合烯丙基钯配合物(NHC-Pd)1、2和3为催化剂,甲苯为溶剂,甲基铝氧烷(MAO)为助催化剂催化降冰片烯(NBE)的聚合。考察了催化剂2在不同反应温度、n(Al)/n(Pd)以及n(NBE)/n(Pd)等因素影响下的催化活性和聚合物性能。结果表明,该催化体系对降冰片烯系具有高催化活性,最高活性可达到3.2×107gPNBE/(mol Pd.h)。聚合物具有很好的耐热性能,其热分解温度高于400℃。通过对聚合产物FT-IR分析判断,降冰片烯聚合反应以烯烃加成聚合方式进行。

Three kinds of novel N-heterocyclic carbene allyl palladium complexes （Catalyst 1, 2 and 3） were synthesized. Norbornene polymerizations were carried out using three catalysts activated with methylaluminoxane （MAO） in toluene. The effects of reaction temperature, the molar ratio of aluminum to palladium and the molar ratio of norbornene to palladium on the catalytic activity and the property of polymer were investigated for catalyst 2. The results show that the catalytic systems display high catalytic efficiency. The highest catalytic efficiency is 3.2 × 10^7 g PNE/（mol Pd-h）. The resultant polymer is of excellent heat-resistant property. The decomposition is over 400 ℃. According to FT-IR spectra, the polymerization mechanism is vinyl-addition type polymerization.