Synthesis And Application Of Triphenylmethane Type Diamine Monomer

Polyimide(PI) had a unique molecular structure, which shown the higher temperature resistance and good mechanical property, was one of most promising materials application in resin composites field. But polyimide was difficult to dissolve in common organic solvents, and indicated non-melting and non-softening property at room temperature. These properties greatly restricted the popularized applications of polyimide materials. The focus of this study was to synthesize bisphenol AP though the rigid benzene ring replaces side-chain methyl of isopropyl in the bisphenol A structure. And the diamine monomers for bisphenol AP type, triphenyl methane structure, were further synthesized by bisphenol AP. Last, the polymerization reaction was conducted with diamine monomer and DTDA, producing the required polyimide.First section, the catalytic effect and yield in the synthesized bisphenol AP reaction were investigated respectively via six different catalysts(the single sulfuric acid, the composite for sulfuric acid and thioglycolic acid, hydrogen chloride gas, the composite for hydrogen chloride and thioglycolic acid, [DMAC]Al2Cl4, [Et3HN][Al2Cl7]. The bad catalytic effect and the lower yield of sulfuric acid and ionic liquid method were got by a series of optimized experimental conditions. However, the target product can obtain by hydrochloric acid, and then its structure were characterized and analyzed by FT-IR, MS and NMR spectra. The catalyst was made up of the main catalyst(hydrogen chloride gas) and the promoted catalyst(thioglycolic acid), made the higher reaction selectivity and activity, the higher conversion rate of aldehyde ketone. The yield can reach 51.81%.Second section, the dinitro-compound for bisphenol AP type was synthesized with the self-prepared bisphenol AP and parachloronitrobenzene under the catalysis of anhydrous K2CO3 or Na2CO3. The catalytic effect and the reaction time for K2CO3 catalysis was better than Na2CO3 though the optimized catalytic effect and the reaction time. The best reaction time was 18 h and the yield was 91.1%. Diamino-compounds were synthesized with the dinitro-compound by hydrogenation reduction reaction and its yield reached 35.1%. Then its structure was characterized by FT-IR spectra and this step achieved the optimization of reaction conditions and purification process.Third section, the polymerization reaction with the self-prepared diamino monomer(BAPPE) and ODPA was carried out, getting polyamide acid firstly and generating polyimide polymer though the thermal cyclization.In summary, the synthesis conditions of bisphenol AP have been optimized by the relative experiments, and then the dinitro-compounds were prepared using parachloronitrobenzene and bisphenol AP, exploring the synthesis process and raising the yield. The diamino monomer for triphenyl methane structure was obtained by the reduction with dinitro-compounds; the synthesized diamino monomer and dianhydride were used to prepare the polyimide by polymerization, which had the structure of triphenyl methane. And the performance was further studied.