Study On The Synthesis Of BPA-Polycarbonate By Solid State Polymerization

BPA Polycarbonates(BAPC) is applied extensively as a kind of engineering plastics due to it’s excellent mechanical behavior and light transmittance. But the production capacity in domestic cannot satisfy the market’s demand and the production technology is mostly monopolized by foreign. Moreover, interface phosgene polymerization and non-phosgene melt polymerization that are widely used in industry both have some disadvantages. So it is necessary to develop new technologies with independent intellectual property rights. In this paper, the structure, performance, application, and market of BAPC are summarized and the synthesis process is introduced in detail. Then in order to resolve the problem of melt polycondensation such as high temperature, the mass transfer and high viscosity, the solid state polymerization is identified using bisphenol A and diphenyl carbonate as raw materials. Several aspects are discussed in this paper, such as the catalysts, the pretreatment and crystallization process of BAPC prepolymer, the programmed temperatureof SSP, the influence of discharge temperature and so on. The results are as follows:the prepolymer of BAPC is made by melt polycondensation with tetraethyl ammonium hydroxide as catalyst; the solvent/anti-solvent of prepolymer is methylene chloride/methanol, their volume ratio is1:1, the best vacuum drying time of is2h for prepolymer and the best discharge temperature is200℃; the crystallinity of prepolymer is improved after solvent liquid-induced but the quality of BAPC isfailed toimprove; Using programmed temperature and improving the late polycondensation temperature moderately are good for the quality of BAPC.