The process of foamcoke formation have been modelled at subsequent transformation from a composition to the foamcoke formed, but when we solved a reverse problem using experimental data the processes from foamcoke to the original polymeric composition were taken into consideration as well. By X-ray photoelectron spectroscopy the increase of polyphosphorus acid and carbon compound derivatives on the inner surface of the formed gas bubble have been determined according to the binding energy CIS close to graphite-like substances. In the temperature range, corresponding to the chemical and structural transformation, sharp heat capacity increase has been found. Optimal size of the gas bubble and its wall thickness have been defined. While solving the reverse problem the nature and the content of components (coke and gas-forming substances catylist of carbonization and adhesives) have been determined. The apparent density of the foamcoke obtained was close to that of calculated - 600 kg/m3 • The coating with a thickness of 10-3m ·resist s heat flows of 32 kWt/m2 at the intumescence that occurs on a thermally non-conductive substrate.