Proactive insights on thermal interactions between textiles and flammable liquids: A comprehensive analysis of thermal characteristics, pyrolysis kinetics and gas emission patterns, using polyamide and diesel as illustrative example

The present study aims to provide valuable suggestions for mitigating fire risks associated with the penetration of flammable liquids into textile materials. By focusing on the case of diesel infiltrating polyamide—a prevalent combination of flammable liquid and textile material—the research delves into the pyrolysis behavior and characteristic parameters, devolatilization index, kinetics, thermodynamics and volatile composition alterations. The results indicate that the pyrolysis of polyamide changes from a one-stage to a three-stage reaction after the addition of diesel. With the advancement of the reaction and the increase of the heating rate, both the reaction difficulty and the energy required to sustain the pyrolysis reaction increase. The first and third stages can be considered as single-step reactions, with the major reaction occurring in the third pyrolysis stage. As the diesel content increases, the reaction rate in the third pyrolysis stage decreases, accompanied by a pronounced temperature hysteresis phenomenon. Concurrently, both the thermal stability of the system and the concentration of volatile components decrease, making the reaction more intense. The values of the kinetic and thermodynamic triplets are determined. Furthermore, the predictions for the third pyrolysis stage of polyamide with diesel, based on the single-step reaction model and obtained kinetic parameters, show great agreement with experimental results. The main pyrolysis products include CH4, NH3, H2O, HCN, CO, C3H6, CO2, C3H8 and C2H5O.