Enhancing Fire Resistance of Coconut Fiber-Reinforced Polymer Composites with Fire-Retardant Fillers

This study aims to enhance the fire resistance of fiber-reinforced polymer composites (FRPC) which are in high demand in modern industry, mainly due to their favourable weight-to-strength ratio. Despite their widespread use, FRPCs are generally highly flammable. To address this issue, this research focuses on improving the fire resistance of FRPC made from coconut fiber (coir) and low-density polyethylene (LDPE) by incorporating various fire-retardant fillers. A series of experiments were conducted following the UL-94 standard, using Aluminium trihydrate, Magnesium hydroxide, Boric acid, and Magnesium carbonate as fire retardants. The composites were subjected to the UL-94 horizontal burn (HB) test to evaluate their flammability. Results indicate that the burning rate of the composite increases with the increase in fiber content and decreases with an increasing percentage of fire retardant chemicals. Notably, the composite incorporated with 10% boric acid exhibited the lowest burning rate of 21.1 mm/min.  Findings demonstrate that the fire resistance of FRPCs improves with higher concentrations of fire retardants. Although the increase of additive filler percentage enhanced the fire resistance, it is still observed to be insufficient for the composite to get self-extinguished.