The structure and properties of ultrahigh molecular weight polycarbonate synthesized by solid-state polymerization in micro-layers (SSP m ) are reported. A low molecular weight prepolymer derived from the melt transesterification of bisphenol A and diphenyl carbonate as a starting material was polymerized to highly amorphous and transparent polycarbonate of molecular weight larger than 300,000 g mol 21 in the micro-layers of thickness from 50 nm to 20 mm. It was observed that when the polymerization time in micro-layers was extended beyond conventional reaction time, insoluble polymer fraction increased up to 95%. Through the analysis of both soluble and insoluble polymer fractions of the high molecular weight polycarbonate by 1 H NMR spectroscopy and pyrolysis-gas chromatography mass spectrometry (Py-GC/MS), branches and partially crosslinked structures have been identified. The thermal, mechanical and rheological properties of the ultra-high molecular weight nonlinear polycarbonates synthesized in this study have been measured by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and rheometry. The nonlinear chain structures of the polymer have been found to affect the polymer's thermal stability, mechanical strength, shear thinning effect, and elastic properties.

A detailed mathematical model is presented to describe the steady state behavior of a continuous multizone tubular reactor for the synthesis of aromatic polycarbonate by interfacial polycondensation mechanism. In this process, bisphenol‐A dissolved in a dispersed aqueous phase reacts with phosgene dissolved in a continuous organic phase and hence, the reaction initiates at the interface of the two phases. A liquid‐liquid mass transfer process is incorporated into a reaction kinetic model to calculate the reaction rates and polymer molecular weight distribution. The kinetic model has also been used in developing a steady state multizone tubular reactor model for continuous production of polycarbonate. The model simulations are compared with proprietary plant data and excellent agreement has been obtained. POLYM. ENG. SCI., 58:438–446, 2018. © 2017 Society of Plastics Engineers