The Research Of Synthesis Of Bisphenol-A Polycarbonate Through Melt Transesterification Process

The synthesis of polycarbonate (PC) by melt transesterification from catalytic reactions of diphenol carbonate (DPC) with bisphenol A (BPA) using the orthogonal test design was experimentally studied,and the synthetic process condition of the ratio of raw material,discharging temperature,reaction time,the catalyst type and dosage on the influence of molecular weight and light transmittance were investigated. Differential scanning calorimetry (DSC),light transmittance,infrared spectroscopy (FT-IR) ,high performance liquid chromatography of product thermal properties, light transmittance and by-products were used during the study. And change operating conditions to make an on-the-spot investigation on the effects of the different temperature which the vacuum supply was started.Combining the analysis of the molecular weight of product with light transmittance,the result showed the molecular weight of polycarbonate precursors was best when the ratio of raw materials n (DPC) : n (BPA) was 1.04:1,discharge temperature of 270℃,the reaction time of 105min,acetic acid as catalyst. however,the less its dosage was,the better the light transmittance of polycarbonate was. It was better for the PC synthesis when the temperature was 160℃the vacuum supply was started with the influence of by-products through different temperature to start to supply vacuum and the molecular weight of the product and molecular weight distribution,light transmittance and product component indexes.