Evaluating Bio‐Derived Polysaccharides as Natural Binders for Fire‐Fighting Propellants

Abstract

ABSTRACT Halon fire extinguishing agents have been phased out to protect the ozone layer. Fire extinguishing aerosol‐forming pyrotechnic formulations (PyFs) are increasingly recognized as effective alternatives. In PyFs, binders play a critical role by consolidating the ingredients, ensuring uniform solidification, and imparting superior mechanical strength. Beyond structural integrity, binders enhance storage stability and facilitate reliable ignition by improving the overall homogeneity of the formulation. In light of growing concerns regarding health and environmental safety, our research has shifted toward the development of natural binder systems derived from renewable resources. Therefore, in the present work, inulin, a naturally occurring polysaccharide which belongs to a class of carbohydrates known as fructans, was comparatively investigated against two different established binder systems, galactomannan and phenol–formaldehyde resin (PFR), for gallic acid–KNO 3 –KClO 3 tertiary PyF. Results indicate that inulin (3% wt.) is the preferred binder for the gallic acid–KNO 3 –KClO 3 mixture. Specifically, the inulin‐based formulation achieved a linear burn rate of 12.34 mm/s and successfully extinguished a 4.57 kW n ‐heptane pool fire within 5 s. The minimum extinguishing concentration (MEC) was found to be 5.32 g/m 3 , with a combustion flame temperature reduction of 66% compared to PFR‐based formulations. Furthermore, mechanical testing revealed a compressive modulus of 110 MPa, ensuring high structural integrity, while thermal analysis confirmed a stable ignition temperature of 232°C. These findings demonstrate that inulin offers a high‐performance, environmentally benign alternative to synthetic resins in fire‐fighting applications.