Towards High Molecular Weight Poly(bisphenol A carbonate) with Excellent Thermal Stability and Mechanical Properties by Solid-State Polymerization

Poly(bisphenol A carbonate)(BPA-PC) was post-polymerized by solid-state polymerization(SSP) after supercritical CO2-induced crystallization in low molecular weight particles prepolymerized via melt transesterification reaction.The effects of the crystallization conditions on melting behavior and SSP of BPA-PC were investigated with differential scanning calorimetry(DSC),Ubbelohde viscosity method and gel permeation chromatography(GPC).The reaction kinetics of the SSP of crystallized prepolymers was studied as a function of reaction temperatures for various reaction periods.As a result,the viscosity average molecular weight of BPA-PC particles(2 mm) increased from 1.9 × 104 g/mol to 2.8 × 104 g/mol after SSP.More importantly,the significantly enhanced thermal stability and mechanical properties of solid-state polymerized BPA-PC,compared with those of melt transesterification polymerized BPA-PC with the same molecular weight,can be ascribed to the substantial avoidance of undergoing high temperature during polymerization.Our work provides a useful method to obtain practical product of BPA-PC with high quality and high molecular weight.