RESEARCH OF THE FEATURES OF THERMAL-OXIDATIVE DESTRUCTION OF ELASTIC POLYURETHANE FOAM FOR SOLVING DIAGNOSTIC PROBLEMS OF FIRE-TECHNICAL EXPERTISE

The method of synchronous thermal analysis was used to study the fire hazardous properties of elastic polyurethane foam at heating rates of 5 °C/min, 10 °C/min and 20 °C/min. A two-stage mode of thermal-oxidative destruction in the temperature range of 25–700 °C was established, including the stage of smoldering and the stage of flaming combustion. The intensity of heat release during the process of flaming combustion of elastic polyurethane foam is 5–6 times higher than the intensity of heat release as a result of smoldering. The values of the ignition temperature for the smoldering combustion mode and the autoignition temperature were determined at different heating rates using analytical signals of three thermoanalytical curves of synchronous thermal analysis. The kinetics of thermal-oxidative destruction of elastic polyurethane foam was studied by the method of dynamic thermogravimetry. The kinetic parameters (reaction order, activation energy, pre-exponential factor) were calculated using the Broido method at a heating rate of 20 °C/min. The use of the obtained kinetic parameters of the process of thermal-oxidative destruction will allow us to assess the possibility of ignition of elastic polyurethane foam in fire conditions with the formation of secondary fire sources.