Thermal and morphological characterization of biowaste date palm fiber‐reinforced polybenzoxazine and epoxy composites

Abstract Waste date palm fiber (DPF) has recently emerged as a promising natural fiber due to its abundance, renewability, and low cost. The study discussed the use of DPF as reinforcement in composites, particularly in polybenzoxazine (PBz), epoxy resin (EP), and their copolymer (EP‐co‐PBz) composites. The waste DPF underwent an alkaline treatment process, resulting in a high‐performance material that exhibits exceptional interaction with the matrix. The composite samples were fabricated using 5–20 wt% of alkali treated DPFs with polybenzoxazines and epoxy resins. The study examined the thermal and morphological properties of the resulting composites and found that they exhibited remarkable enhancements in various properties. For instance, the PNaphz‐COOH reinforced 5 wt% DPFs composite showed a significant increase in T_d5% and T_d10%, while the EP‐co‐PBz reinforced DPFs composites exhibited a remarkable increase in char yield (Y_c). The SEM analysis of the composite surface further validated these findings, highlighting the remarkable interfacial bonding between the DPFs and the matrix. The remarkable enhancements in thermal properties demonstrated in this study open up new possibilities for utilizing waste DPF in various applications. Highlights Waste date palm fiber enhances thermosetting polymer reinforcement for high‐performance composites. Alkaline treatment improves interfacial bonding between waste DPF and matrix. Composites reinforced with waste DPF exhibit outstanding thermal and morphological properties.