Study On Additive And Synthesis Process Of Polycarbonate By Non-phosgene Melt Transesterification

The development, application, market and synthesis process of polycarbonate are introduced in the dissertation in brief. Based on the industrial application and environmental demand, it is focused on the study of polycarbonate (PC) synthesis via the melt transesterification from diphenyl carbonate (DPC, obtained through non-phosgene process) and bisphenol A (BPA). The viscosity-average molecular weight and color of PC prepared are much better than the domestic industry requirement. The polymerization process is discussed from several aspects, such as the purification of DPC, temperature of polymerization, discharging temperature, the selection of the nano catalysts, the reactor improvement, the selection of the blocking-agents and the adding ways of blocking agents. The results are as follows:crystallization with ethanol is an effective purification method-of DPC, with the purity of DPC increasing from 93.01% to 99.60%. Intrinsic viscosity of the product PC is 42.82mL/g and the solution color is 1.55. The optimal temperature for polymerization and discharging are 260℃and 305℃separately. Nanometer calcium carbonate is a better catalyst for the reaction than TEAH. Intrinsic viscosity is 61.29mL/g and the solution color is 1.05. The reactor designed by myself can help to enhance the mass transfer and heat transfer, removing small molecule by-products effectively. Adding blocking agents can improve the quality of PC and increase its thermal stability. Thermal degradation temperature increased 24℃. Intrinsic viscosity is 66.26mL/g and the solution color is 2.01.