Structure and properties of ultra‐high molecular weight bisphenol a polycarbonate synthesized by solid‐state polymerization in amorphous microlayers

Abstract

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.

Mononuclear Zn(ii) compounds supported by iminophenolate proligands binding in the bidentate (N, O) and tridentate (N, O, S) coordination mode: synthesis, characterization and polymerization studies

“…S61, ESI†) of the copolymer showed that the onset of decomposition (220 °C) was at a lower temperature than the literature reported value. 97 There was almost 99% degradation of the polymer at 430 °C. The value shows a slight deviation from the literature reported value 98 due to negligible polyether linkages in the polymer chain.…”

Surface Reactions in Selective Modification: The Prerequisite for Plastic Flotation

“…In addition, oxidation might occur on another active site, namely, the methyl group on the branch of PC and isomerization, the addition of oxygen, and hydrogen abstraction occur under the same conditions (Scheme b). Additionally, prolonged weathering and high temperatures also lead to hydrolysis, transesterification, and ester decomposition of PC (Scheme c,d). , Through the chain scission, the weak carbonic ester can at last be converted to hydrophilic −COOH and −OH on PC surfaces. The sedimentation of PC is attributed to the introduction of hydrophilic groups and the mechanism can refer to the above four reactions which cover chain scission, addition, radical generation, and molecular rearrangement.…”