Hybrid Polyurethane–Inorganic Thermal Insulation: Fire Hazard and Thermo-Oxidative Decomposition

A comparative analysis of the properties of two samples of hybrid polyurethane–inorganic thermal insulation is presented. The indicators of their fire danger are determined by standard methods. Both samples are moderately combustible materials of group G2 according to GOST (State Standard) 30244–94 belong to the group of inflammable materials B3 according to GOST (State Standard) 30402–96 and exhibit moderate smoke generation ability in smoldering mode (group D2) according to GOST (State Standard) 12.1.044–89. It has been established that thermal-insulation samples retain their shape when heated under dynamic conditions in air up to 850°C. Shrinkage was up to 25–29% in different temperature ranges due to decomposition of the organic component. Thermal-oxidative decomposition of the investigated samples of hybrid thermal insulation is a multi-stage process. Based on the results of thermal analysis (TG, DTG, DSC) carried out in air at heating rates of 5, 10, 20, and 100°C/min, the mechanism and macrokinetic parameters of decomposition at each stage were determined. The obtained parameters are used to determine the regime that controls the process of gasification and shrinkage of samples of hybrid thermal insulation.