Study on pyrolysis behaviors and mechanism of N-(4-hydroxy-3-methoxybenzyl)nonanamide

N-(4‑hydroxy-3-methoxybenzyl)nonanamide (PAVA) exhibits a broad spectrum of applications as a capsaicinoid in fields such as medicine, marine engineering, and riot control. Investigating its thermal stability and thermal decomposition properties is crucial for assessing the service life of PAVA-containing products, optimizing their efficiency, and evaluating the toxicity of the decomposition products. In this study, thermogravimetry/differential scanning calorimetry-Fourier transform infrared spectroscopy (TGA/DSC-FTIR) and pyrolysis-gas chromatography/mass spectrometry (PY-GC/MS) techniques were employed to investigate the pyrolysis behaviors of PAVA. A melting endotherm was observed at approximately 335.15 K (62 °C) and the extrapolated onset decomposition temperature was determined to be 534.15 K (261 °C) related to the heating rate in thermal analysis experiments. The most probable mechanism function for the thermal decomposition of PAVA was identified as G(α)=[(1+α)^1/3–1]². Furthermore, thermal pyrolysis results indicated that only pyrolysis reactions were found below 923.15 K (650 °C) under an aerobic environment, initiating between 523.15 K (250 °C) and 623.15 K (350 °C).