Preparation and Characterization of Bisphenol A Polycarbonate Facilitated by Supercritical Impinging Stream

摘要

Based on the supercritical impinging stream technique, a novel synthetic process for preparing aromatic polycarbonate (PC) by transesterification between bisphenol-A (BPA) and diphenyl carbonate (DPC) was developed. Supercritical carbon dioxide (ScCO_2) is an excellent plasticizing agent and a good solvent for phenol, the by-product of the reaction. Impinging stream can markedly enhance heat and mass transfer, especially mass transfer between phases. In this process, phenol formed from the reaction was dissolved and diffused into ScCO_2 phase and the transfer process were accelerated through the impingement of two flows. The structure of the product was characterized by Fourier transform infrared spectrophotometry (FT-IR), ~1H-nuclear magnetic resonance (NMR) and C-NMR measurements. Thermal analysis was measured by a differential scanning calorimeter (DSC). The PC molecular weight (M_w) was determined by gel permeation chromatography (GPC) and can reach up to 4.28 × 10~4 g/mol.