FIELD: chemistry.
SUBSTANCE: invention relates to compositions intended for use in the preparation of a foamed thermoplastic polymer (fluoropolymers, polyamides, polyamidoimides, polybenzimidazoles, polyimides, polybutylene terephthalates, etc.), to a process for preparing a composition and a method for producing a foamed thermoplastic polymer. Composition includes a thermoplastic polymer that has a melt processing temperature of at least 250°C, and an oxalate compound which is selected from zinc oxalate and zirconium oxalate. Said oxalate compound comprises 1% by weight or less of water. Composition is in the form of granules. Foamed thermoplastic polymer, for example a fluoropolymer, is prepared by heating a mixture comprising an oxalate compound and said polymer to a temperature in excess of 300°. Composition for producing a foamed polymer is prepared from a mixture of an oxalate compound and a thermoplastic polymer, which is processed in a melt processing apparatus.
EFFECT: invention provides the use of an environmentally friendly method for the production of expanded thermoplastic polymers with high performance characteristics and suitable for high temperature processing of polymers.
28 cl, 7 ex
