Bio‐modified pyrotechnic composite materials for firefighting application

摘要

Summary The traditional aerosol‐forming composites are a mixture of potassium nitrate/chlorate and synthetic resins like phenol‐formaldehyde, melamine‐formaldehyde, polyurethane, and epoxy resin. Though these synthetic organic resins have excellent adhesion and mechanical properties, their high flammability and associated life‐threatening occupational hazard have limited their application. Such compositions' combustion flame may reach up to 2100°C and cause secondary fire risk in an explosive atmosphere, especially ship engine rooms and oil‐producing platforms. This study aimed to investigate the ability of natural flame‐retardant tannic acid, which is a natural phenolic compound abundant in many plants, to reduce the exothermicity of potassium nitrate/chlorate‐based pyrotechnic composite. In the present work, we newly developed a pyrotechnic composition that employed tannic acid as a reducer instead of synthetic resin. Its combustion behaviour, thermal properties, and fire extinguishing performance were comparatively evaluated against phenolic resin‐based traditional pyrotechnic composition. Though both the new and traditional pyrotechnic composition has shown similar fire extinguishing efficacy, the newly developed composition showed 57 lower combustion flame temperature, faster burn rate, and lower calorific value than the traditional composition. The physical and chemical characteristics of the discharged aerosol were characterized by a series of techniques viz; high‐resolution X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X‐ray analysis to understand the fire extinguishing mechanism.