Polycarbonates from 1,1‐dichloro‐2,2‐bis(4‐hydroxyphenyl)ethylene and bisphenol A: A highly flame‐resistant family of engineering thermoplastics

Abstract

Abstract Although the preparation of polycarbonates based on bisphenol A and 2,2‐bis(4‐hydroxyphenyl)‐1,1‐dichloroethylene was disclosed in 1964 by Porejko et al., little has been reported on their physical and flammability properties. To define the properties of this system these materials were prepared and evaluated. The results indicate that the copolymers and blends of the homopolycarbonates of the two different bisphenols result in transparent thermoplastics that have almost the same attractive physical properties as the homopolycarbonate from bisphenol A. In addition, many of these formulations possess flame‐resistant properties that exceed those of other transparent thermoplastics; for example, highest OI and lowest smoke and lowest ratings in the ASTM E84 tunnel and E162 radiant panel tests. Preliminary bioassay results with rats of the products from 500°C air pyrolysis gave an ALC 50 value greater than that of other common thermoplastics.