PEP Review 91-3-1
Polycarbonates From Bisphenol Compounds Via Cyclic Oligomers By GE Plastics Technlogy
Published: November 1992
In the mid 1980s, GE Plastics developed a new technology to prepare polycarbonate with a very high molecular weight from bisphenol A (BPA) via cyclic carbonate oligomers. The technology was reviewed and a cyclic oligomer process was evaluated in PEP Report 50C, which was issued in January 1989. In this technology, BPA is phosgenated to form bischloroformate, which is then cyclized in the presence of a tertiary amine to form cyclic carbonate oligomers. The resulting cyclic oligomers are subject to ring*opening and condensation reactions to produce polycarbonate.
This study reviews developments in the technology since 1987. Also presented are updated economics for the cyclic oligomer process and the conventional interfacial process. SRI concludes that commercialization of the specialty products will depend on their competitiveness against thermosets and thermoplastics that are already in those markets.