双核水杨醛亚胺镍催化剂的制备及对降冰片烯聚合的催化性能

Synthesis of Bi-(Salicylaldininato) Nickel Complexes and Their Catalytic Behavior Towards Norbornene Polymerization

合成了3种5,5′-亚甲基-双-水杨醛亚胺配体,利用它们和trans-[NiCl(Ph)(PPh3)2]反应得到Cat1、Cat2和Cat3三种双核水杨醛亚胺镍催化剂,并通过红外(FT-IR)和元素分析进行了表征。研究了在甲苯为溶剂,MAO为助催化剂下,催化降冰片烯(NBE)单体聚合的催化性能,考察了聚合条件,如温度、Al/Ni物质的量比对降冰片烯的催化活性、单体转化率、聚合物分子量及分子量分布的影响。当在n(Al)/n(Ni)为1000,聚合温度为80℃的条件下,催化剂的催化活性达到最大值1.16×105g of PNB/(mol of Ni.h)。聚合产物的核磁共振(1H-NMR)和红外光谱分析结果表明,该聚合反应是以单体的乙烯基加成聚合机理进行的。

Three kinds of bridged ligand 5,5′-methylene-bis salicylaldehyde aniline were synthesized by the condensation reaction of 5,5′-methylene-bis salicylaldehyde and aniline or its derivatives,which easily coordinated with trans-[NiCl（Ph）（PPh3）2] to form the Cat 1,Cat 2 and Cat 3 complexes.The resulting nickel complexes were characterized by IR spectroscopy and elemental analysis.Norbornene polymerizations were carried out using three catalysts activated with methylaluminoxane（MAO） in toluene.The effects of reaction parameters,such as reaction temperature,time,the molar ratio of aluminum to nickel,on the catalytic activity were investigated for cat1.At the condition of n（Al）/n（Ni） 1000,the polymerization activity of Cat 1 reached 1.16×106 g of PNB（mol of Ni·h） at 80 ℃.According to Fourier transform infrared spectrum（FT-IR） and 1H nuclear magnetic resonance spectrum（1H-NMR） results,the polymerization is via vinyl-addition type polymerization mechanism.