New Catalysts for Bisphenol A Polycarbonate Melt Polymerisation, 1. Kinetics of Melt Transesterification of Diphenylcarbonate with Bisphenol A

The catalytic activity of various compounds in the first stage of the melt transesterification of diphenyl carbonate and Bisphenol A (at 165°C) has been evaluated in order to identify new catalysts which may be of interest for the melt-phase preparation of Bisphenol A polycarbonate. Alkaline-earth and alkaline metals proved to be the most active catalysts; lanthanides were found to be rather active, while the catalytic activity of the other metals tested was much lower (except that of copper and cadmium). Some organic heterocyclic compounds were tested as transesterification catalysts as well, but they all had a very low activity.