Fiber and future: Unleashing the power of industrial hemp waste through epoxy composites

Natural fiber composites offer a sustainable alternative to synthetic polymer composites, addressing the environmental concerns associated with traditional materials. This study aims to investigate the effect of flame-retardant additives (magnesium hydroxide Mg(OH)2 [A] and aluminum hydroxide Al(OH)3 [B]) on hemp fiber-based epoxy composites with a different fire retardant (FR) loading, that is, 0%, 8%, 12%, and 24%. An evaluation of flame-retardant effectiveness on composites was carried out using thermogravimetric analysis, limited oxygen index (LOI), UL-94 horizontal burning, morphological analysis scanning electron microscopy (SEM), and char residue analysis. The results show that introducing the flame retardants in the hemp-epoxy composites improved the thermal stability and flame retardancy of hemp-epoxy composites When composites were incorporated with flame retardants, the Horizontal burning rate was decreased, and LOI was increased. The lowest Horizontal burning rate of prepared composites was recorded as 11.6 mm/min, and the highest LOI was 25.3%. SEM shows uniform distribution of FR particles in the prepared composite. It is concluded that adding flame-retardant additives efficiently improves the flame retardancy properties of the prepared composites.