Engineering Research In Prepolymerization Process Of Polycarbonate Synthesis Through Melt Transesterification

Polycarbonate (PC) is an excellent engineering plastic due to its outstandingperformance and it is widely used in the field of electronics and optical materials, etc,which is very promising in future market. There are mainly two methods in thesynthesis of PC: interfacial polymerization and melt transesterification. The method ofmelt transesterification has a simpler work process and is more environment-friendly,which is becoming the future trend. Although developed countries have realized theindustrialization of polycarbonate production, China is falling far behind and totallyrelying on importation. It is urgent for China to develop polycarbonate industry.Otherwise, polycarbonate industry will be entirely controlled by foreign enterprises.Therefore, the research on polycarbonate synthesis and production is of greatsignificance. It will completely change current situation and provide powerfultechnical support for the rapid development of information industry in China.The reaction kinetics and laws of mass transfer in the prepolymerization processare investigated in detail in this paper. The study on kinetic model shows that thereaction rate is second order in the concentrations of BPA and DPC and the reactionrate constants are determined. The concept of limit of reversible reaction isintroduceded and proved. The optimized reaction conditions including thetemperature, pressure and circulation flow capacity are also gained through pilotexperiments. The prepolymerization process is greatly influenced by the temperatureand pressure while the circulation flow capacity's impact is not so remarkable. Theprocess of mass transfer in prepolymerization process is studied and a simplemathematical model of mass transfer for the foam devolatilization is established.