FIELD: chemistry.
SUBSTANCE: invention relates to a composition for the production of a foamed thermoplastic polymer and a process for the preparation of a composition and the production of a foamed thermoplastic polymer that can be used to produce electrically insulating and thermally insulating articles, for example, cable insulation, twisted products, pipes. Composition comprises a mixture of an oxalate compound and a thermoplastic polymer selected from polymers having a melt processing temperature of at least 250°C, that is, from fluoropolymers, polyamides, polyamidoimides, polyetherimides, polyketones, polyphenylene sulphides, polysulphone derivatives, polybenzimidazoles, polyimides, polyethylene terephthalate, polybutylene terephthalate, polycyclohexane dimethyl terephthalates, syndiotactic polystyrene, polycarbonate. Oxalate compound is a component containing a transition metal, for example manganese oxalate. Thermoplastic polymers are foamed using a solid composition by heating the composition to a temperature in excess of 300°C. In preparing the composition for use in the preparation of a foamed thermoplastic polymer, the oxalate compound is selected and the thermoplastic polymer is selected. Mixture is processed in a melt processing apparatus and temperature of the components is not raised above 330°C before granules are obtained.
EFFECT: invention provides for the production of foamed polymers that withstand very high temperatures, with improved electrical insulating and thermal insulation properties, reduced smoke formation, and improved flammability characteristics.
27 cl, 3 tbl, 9 ex
