Abstract: A melt-fabricatable or melt-fabricated composition comprising (i) a crystalline thermoplastic aromatic polyetherketone containing the repeat unit ##STR1## alone or in conjunction with other repeat units said polymer having an inherent viscosity of at least 0.7 and (ii) a glass and/or carbon fibre reinforcing agent, which composition is melt-fabricatable into a composition exhibiting, or alternatively (if melt-fabricated) exhibits, an increase in heat deflection temperature (HDT) of at least 3.degree. C. per 1% by weight of reinforcing agent above the HDT of the unreinforced polyetherketone and an increase in flexural modulus of at least 0.2 GN.sub.m.sup.-2 per 1% by weight of reinforcing agent above the flexural modulus of the unreinforced polyetherketone.

Abstract: A thermoplastic polycarbonate molding composition containing a particulate filler coated with a silane.

Abstract: A thermoplastic polymeric material comprises a copolymer which is a poly(bisphenol A tere- and/or isophthalate) copolycarbonate having a molar ratio of phthalate to carbonate units in the inclusive range from 2 to 10, preferably 3 to 8. The material, which may be prepared by techniques which are known, may be used in applications for high temperature transparent thermoplastics, eg transparencies for the aerospace industry.

Abstract: The present invention relates to polycarbonate composition characterized in the absence therefrom of phosphites and boric acid esters which compositions are made stable and bright by the incorporation of organic silicon compounds in combination with oxetane, dioxane or tetrahydrofurane compounds.

Abstract: Thermally stable polycarbonate compositions are obtained by admixing with a high molecular weight aromatic polycarbonate resin a stabilizing amount of a dioxane phosphite.

Abstract: A crude organic solvent solution of a polycarbonate containing an impurity is washed with an aqueous washing liquid by forming a water in oil dispersed phase by mixing the crude solution of the polycarbonate with a small amount of aqueous washing liquid in order to form the water in oil dispersed phase and then causing a phase inversion from the water in oil dispersed phase into an oil in water dispersed phase, and then, separating the organic solvent solution of the polycarbonate from the aqueous washing liquid.

Abstract: Alkali metal salts or/and alkaline earth metal salts of cyclic phosphorus compounds expressed by the general formula ##STR1## (wherein X.sub.1 to X.sub.8 each represent hydrogen, halogen, cyano group, acyl group, alkyl group, halogen-substituted alkyl group, aryl group, halogen-substituted aryl group or aralkyl group) are provided. These metal salts impart a specific flame retardancy to organic high molecular weight compounds prepared from alkylidenebisphenols as a raw material, without lowering the characteristic properties of substrates.