Influence of thermal exposure on physical and chemical characteristics of thermoplastics

Abstract

This work examined the thermal degradation of several thermoplastic polymeric materials based on polyamide, polystyrene and acrylonitrile butadiene styrene to identify the temperature ranges of informativeness, within which the heating temperature following external thermal exposure can be determined from their physicochemical properties. In this study, simultaneous thermal analysis was used to determine the key thermoanalytical characteristics of the materials investigated, while infrared spectroscopy revealed characteristic absorption bands that indicate changes in molecular composition as a function of heating temperature. A correlation was drawn between the thermogravimetric indicators, thermal effects, and the chemical composition changes of the solid residue of the polymer material occurring during thermal degradation. It has been shown that for all the materials considered, the temperature range of information content extends from 300°C to 550°C. The results obtained can also be used for the diagnosis of unknown polymer materials, both initial and subjected to thermal destruction, and for assessing their fire hazard.