ENHANCING FIRE RETARDANCY IN POLYPROPYLENE COMPOSITES USING ALKALI-TREATED DATE SEED POWDER AND SbO₃: A STUDY OF THE EFFECTS OF PARTICLE SIZE

Abstract

This study investigates the fire-retardant (FR) properties of polypropylene (PP) composites reinforced with alkali-treated date seed powder (DSP) of variable particle sizes (63 µm and 750 µm). These properties are described under different concentrations of NaOH treatment (0% control, 1%, 5%, and 10%), alongside varying concentrations of FR (5% and 10%). This research evaluates the composite’s thermal stability and flame-retardant performance by examining critical key parameters, including the limiting oxygen Index (LOI), ignition time and extent of burning. Results indicate that smaller particle sizes (63 µm) treated with a high concentration of NaOH (10%) exhibited better fire retardancy compared to larger particle sizes (750 µm), which demonstrated greater stability across all treatments because of uniform dispersion and char layer formation. The composite receiving 10% NaOH treatment and 10% FR achieved the highest LOI values of 20.71 for 63 µm DSP and 20.41 for 750 µm DSP, indicating a moderate level of flame resistance while highlighting the need for further optimisation for elevated fire safety standards. This study has revealed that employing bio-based fillers to enhance the flame retardancy of polymer composites represents a promising pathway for future sustainable materials in industries such as automotive, construction, and consumer goods. Other chemical treatments or further FR agents should be considered in future studies for improved fire resistance.