Synthesis Of Polycarbonate By Triphosgene And Its Reaction Kinetics

An important flame-retardant polycarbonate was successfully synthesized by phase-transfer-catalyzed polycondensation of tetrabromobisphenol-A(TBBPA) with (BTC). This synthesis was carried out in liquid-liquid reaction system, which was formed by the bis(trichloromethyl)carbonate (BTC)in l,2-dichloroethane(DCE) and TBBPA in caustic solution. Copolymerization of bisphenol-A (BPA) and tetrabromobisphenol-A with BTC at various feed ratios was carried out at 35℃ for 3h. The optimum reaction conditions for interfacial polymerization of bisphenol-A and tetrabromobisphenol-A based copolymerization using phase-transfer-catalyzer have been developed. The affections of temperature, concentration, catalyst, and time were also made a systematic study.The products were characterized by FTIR and limiting oxygen index (LOI). The limiting oxygen index experiment of the flame-retardant polycarbonate showed that the LOI is 55, which was much higher than the common bisphenol A polycarbonate.The liquid-liquid reaction between bisphenol A and triphosgene was investigated by measuring concentration of bisphenol A (BPA) anion and concentration of chloride anion in the water phase. Lots of factors including temperature, concentration, interfacial area and the catalyst had a great influence on the results of the reaction. During the reaction, samples, prepared by diluting with water, were detected using UV and selected electrode. Many data about the reactions were got. By analysizing these data, the kinetic rate equations were also got. Then we can define the critical process parameters. The reaction order in static reaction is 1.2 order and the reaction order in dynamic reaction is the second order.