Study on pyrolysis characteristics of typical thermal insulation materials under light aging

Abstract

Due to the shedding of building facades, thermal insulation materials (TIMs) are usually aged by sunlight, leading to changes in physical and chemical performance. However, there are few studies on the fire hazards of TIMs under light aging. Pyrolysis is the first process of fire occurrence, and the pyrolysis gas provides gaseous fuel for gas-phase combustion. Therefore, pyrolysis characteristics of TIMs under light aging were studied in this study. Extruded polystyrene (XPS) was aged up to 180 days by accelerated aging experiments, and its pyrolysis characteristics were studied using thermogravimetric analysis. The kinetic parameters were estimated by the Coats-Redfern method and optimized using multiple optimization algorithms. Subsequently, the Fourier transform infrared spectrometric technique was applied to analyze the pyrolysis products. The results showed that the chalking appeared and the structure of XPS was destroyed with light aging. Pyrolysis mechanisms changed and the kinetic parameters decreased. Pyrolysis was easier to occur and the reaction required less energy, indicating an increase in its fire hazards. New functional groups were generated, and the intensity of vibration bands was strengthened. This study contributes to understanding of fire risk of aging TIMs and taking appropriate measures to prevent material aging, thereby reducing fire accidents.