Abstract: A cellular, foamed-polymer product is disclosed, which is constituted by a mixture comprising: at least one isocyanate, at least one anhydride, at least one vinylidene compound, poly-(vinyl chloride), at least one foaming agent, a heat stabilizer, calcium stearate and zinc stearate.The product production scraps and processing wastes and residues are not riskful for health and environment, and can be disposed of as "waste similar to solid municipal waste".

Abstract: An expanded polymer product with high distortion temperature, high flame resistance and low smoke toxicity and opacity comprises, in combination:between 18% and 25% of a mixture of at least two isocyanates;between 8% and 11% of a styrene and maleic anhydride mixture;between 19% and 42% of a PVC resin in emulsion form;between 4% and 7% of at least one expanding agent;between 0.5% and 1% of at least one temperature stabilizer;between 16% and 40% of TiO.sub.2.Said product is used particularly in sea, ground and air transport, and in numerous constructional applications in which the materials must combine high technical characteristics with adequate lightness.