Performance evaluation of guar gum and conventional binders based fire-extinguishing aerosol-forming composites

Pyrotechnic-based firefighting systems have been found to be effective in a wide variety of firefighting applications. Binders in pyrotechnic mixtures play a significant role as they consolidate the ingredients, provide excellent mechanical strength and increase the storage life. The rise in health and environmental safety concerns in recent years has directed our research towards natural binder systems of biological origins. Therefore, in this work, galactomannan, also called guar gum, was comparatively investigated against four different types of conventional binders, phenol–formaldehyde resin, ethyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose sodium salt, which are being used in aerosol-forming pyrotechnic mixtures for firefighting application. It was found that the nature of the binder in an amount of 3% by weight significantly influences the combustion behaviour, fire suppression performance, mechanical and thermal characteristics of gallic acid–KNO₃–KClO₃ tertiary aerosol-forming pyrotechnic mixture for fire fighting application. The safety and performance characteristics of these formulations were evaluated by conducting analyses specific to pyrotechnic formulations, that is, burn rate measurement, heat of combustion, TGA/DSC thermal analysis, hygroscopic study, compression test and n-heptane pool fire suppression test. It can be inferred from the values obtained from these analyses that guar gum is a preferred binder to the other four-binder systems for the gallic acid–KNO₃–KClO₃ pyrotechnic mixture.