Thermoplastic compositions having low smoke, methods of their manufacture, and uses thereof

Abstract

A low smoke density thermoplastic composition comprising, based on the total weight of the thermoplastic composition, 70 to 95 wt % of a polycarbonate copolymer comprising first repeating units and second repeating units, wherein the first repeating units are not the same as the second repeating units, and wherein the first repeating units are bisphenol carbonate units of the formula wherein Rand Rare each independently Calkyl, Calkenyl, Ccycloalkyl, or Calkoxy, p and q are each independently 0 to 4, and Xis a single bond, —O—, —S—, —S(O)—, —S(O)—, —C(O)—, a Calkylidene of formula —C(R)(R)— wherein Rand Rare each independently hydrogen or Calkyl, or a group of the formula —C(═R)— wherein Ris a divalent Chydrocarbon group; and the second repeating units comprise bisphenol carbonate units that are not the same as the first repeating bisphenol carbonate units, siloxane units, arylate ester units, or a combination of arylate ester units and siloxane units; and 5 to 30 wt % of a polyetherimide based on the weight of the composition, wherein an article molded from the composition has a smoke density (Ds-4) value of equal to or less than 300 as measured by ISO 5659-2 on a 3 mm thick plaque.