Synthesize Of The Novel Pyridyl Ligands And Application In The Preparation Of Polyketone

Polyketone prepared by the copolymerization of carbon monoxide (CO) and styrene (ST) has good mechanical strength, high crystallinity and excellent performance in other areas. But its expensive price of catalyst constrained progress of the research. In order to effectively lower the cost of the experiment, in this paper we studied how to synthesize novel 2,2'-bipyridyl derivatives and choose the excellent pyridyl ligands application in the copolymerization of carbon monoxide and styrene.4,4'-Dimethyl-2,2'-bipyridine(4,4'-dmpy) was synthesized by 4-methylpyridine using Palladium carbon(Pd/C) catalyst. The catalyst can be reused. The effects of the amount of the catalyst, reaction temperature and reaction time on the yield were investigated. 4,4'-Dicarboxylic acid-2,2'-bipyridine(4,4'-dcpy) was synthesized by 4,4'-dimethyl-2,2'-bipyridine. 4,4'-dimethyl-2,2'-bipyridine and 4,4'-dicarboxylic acid- 2,2'- bipyridine were characterized by Melting Point, NMR, IR, GC-MS and Element Analysis. We studied the influence of 4,4 spaces'different groups on N,N spaces'electron cloud density by Molecular Modeling with Gaussian 98 and brought forward a possible mechanism of experiments from the stability of the complexes.The effects of molar ratios of 4,4'-dimethyl-2,2'-bipyridine or 4,4'-dicarboxylic acid-2,2'-bipyridine, benzoquinone, p-toluenesulfonic acid and palladium(Ⅱ) on the catalytic activity of the copolymerization of carbon monoxide (CO) and styrene (ST) were studied, and the influence of the amount of solvent, the press of CO, reaction temperature on this copolymerization were also investigated. The catalytic activity of three kinds of bident ligands (4,4'-dimethyl-2,2'-bipyridine, 2,2'-bipyridine, 4,4'-dicarboxylic acid-2,2'-bipyridine) was compared. In order to decrease the production cost of the copolymerization, rare earth was added into copolymerization system of CO and styrene. The influence of different rare earth on the catalytic activity was studied, the effect of Pd2+/Ho molar ratio on the catalytic activity was also investigated. The structure of copolymer was characterized by Element Analysis, IR, DSC, TG and GPC. Result showed that the product was the linear alternating copolymer of carbon monoxide and styrene. The highest catalytic activity was 1284 gSTCO/gPd·h when reaching optimum condition. The highest catalytic activity was 2030.1 gSTCO/gPd·h when Ho(P204)3 being added into the copolymerization.