Thermal hazard and decomposition mechanism of p-toluenesulfonyl hydrazide.

Foaming agents are widely used in the processing of polymer materials. The p-toluenesulfonyl hydrazide (TSH), as a foaming agent, generates foams that are fine and uniform. However, the extensive heat produced during the thermal decomposition of foaming agents greatly increases the risk throughout the process. Accidents involving TSH have caused severe economic losses of 300,000 RMB in China. In this study, a differential scanning calorimetry, adiabatic accelerating calorimeter, thermogravimetric-infrared spectrometer, and Gaussian molecular simulation software were adopted to explore the pyrolysis characteristics and decomposition mechanism of TSH and TSH containing impurities (water, urea). Experimental results indicated that the apparent activation energy of pure TSH was 173.39 kJ mol⁻¹. The potential for explosion is high when TSH decomposed, as it releases heat and gaseous products. The addition of water or urea reduces the hazard level of TSH, but urea promotes the decomposition of TSH. The time it takes for a reaction to reach its maximum rate under adiabatic conditions (TMR_ad) to reach 24 h (TD₂₄) and 8 h (TD₈) was 46.8 and 56 °C, respectively. Comparing the experimental results with molecular simulations, the products of thermal decomposition of TSH include nitrogen, water, aryl disulphides, and sulphide sulphonates. [ABSTRACT FROM AUTHOR]