膦-磷酰胺型镍催化剂制备聚酮树脂

Diphosphazane monoxide nickel catalysts for preparation of polyketone resins

摘要:

聚酮是一种新型绿色聚合物材料,具有冲击强度高、耐化学性、耐高温、抗磨损以及气体阻隔能力等优异性能,故应用于产品包装、机械零件、电子器件等诸多领域。目前,用于商品化聚酮制备的催化剂为双膦配体螯合的阳离子钯配合物,价格昂贵且难以回收,因此廉价的替代金属镍催化剂开发一直是聚酮领域研究的前沿。基于配体的电子调控策略,本文设计合成了一系列膦-磷酰胺(PNPO)型镍配合物,将其应用于乙烯/CO共聚及其与丙烯的三元共聚反应中,探究此类催化剂结构对乙烯羰化聚合影响的规律。其中,胺端为N,N-二甲基对苯基、氧化膦端为二乙氨基、膦端为2,6-二甲氧基苯基以及抗衡阴离子为四[3,5-双(三氟甲基)苯基]硼酸根离子的镍配合物的活性最高,所得聚酮的转化数高达15982 g (g Ni)-1。此外,该类镍催化剂也可以高效实现乙烯、丙烯与CO的三元共聚,制备出低熔点、易加工的商用聚酮材料。

Abstract:

Polyketone is a type of green polymer material, which has excellent impact strength, chemical, heat and wear resistance, and gas barrier properties. Therefore, such materials have found widespread applications in packaging, mechanical and electronic devices. Currently, the cationic palladium coordinated bidentate diphosphine ligand is the industrial catalyst for the commercial polyketone production, which suffers from high cost and catalyst recovery issues. Therefore, nickel complexes are appearing as cheaper and more alternative candidates for palladium catalyst and it represents a research frontier in such field. In this study, a series of nickel coordinated diphosphazane monoxide (PNPO) complexes have been designed based on the electronic modulation, and such catalysts are used for copolymerization of ethylene with CO and terpolymerization with propylene, in order to explore the relationship between catalyst structure and catalytic performance. It is discovered that the installations of N,N-dimethyl on aryl, 2,6-dimethoxyl phenyl on phosphorus and N,N-diethyl on phosphine oxide moieties, and tetrakis (3,5-bis- (trifluoromethyl)phenyl)borate) as metal counterion generates a highly active nickel catalyst, yielding a productivity of 15982 g PK (g Ni)-1 for copolymerization. In particular, such nickel can catalyze the terpolymerization of ethylene, CO with propylene, affording commercial polyketone with low melting temperature and easy processibility.