Non-isothermal decomposition kinetics of flame-retardant ABS composites

In this study, the non-isothermal decomposition kinetics of acrylonitrile–butadiene–styrene (ABS) and flame-retardant-modified ABS composites were investigated. Neat ABS, red phosphorus (RP)-containing, and RP/zinc borate (ZnB)-containing composites were prepared by melt blending. Thermogravimetric analysis was performed at different heating rates under an inert atmosphere to evaluate the thermal degradation characteristics of the materials. The thermal decomposition kinetics were analyzed using the model-free Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) isoconversional methods. The results indicate that the incorporation of flame-retardant additives significantly alters the thermal decomposition behavior of ABS. While neat ABS exhibits a relatively simple degradation process, the presence of RP leads to a more complex decomposition mechanism, particularly at early stages, due to the formation of a protective char layer. The hybrid RP/ZnB system exhibits a moderate kinetic response, suggesting a synergistic effect that stabilizes the degradation process over a broader conversion range. Overall, the study demonstrates that non-isothermal kinetic analysis is a practical approach for evaluating the influence of flame-retardant additives on the thermal degradation behavior of ABS composites and provides valuable insights into the thermal degradation behavior of polymer systems containing RP and ZnB additives.