Acetylated plant-fiber-reinforced polyester composites: A study of mechanical, hygrothermal, and aging characteristics

The potential of acetylation of plant fibers to improve the properties of composites was studied. The chemical modification of oil palm empty fruit bunch (EFB), coconut fiber (Coir), oil palm frond (OPF), jute, and flax using noncatalyzed acetic anhydride were investigated. Proof of acetylation was indicated by the increase in weight percent gain (WPG). Acetylation at a reaction temperature of 120 degrees C had resulted in the reduction in the tensile properties (stress,modulus, and elongation at break) of EFB and Coir composites. However, at 100 degrees C, the acetylated samples exhibited improved properties. The mechanical properties of acetylated EFB- and Coir-fiber-reinforced polyester composites was evaluated at different fiber loadings. The tensile strength and modulus were improved, but elongation at break was slightly reduced upon acetylation, particularly at high fiber loading. Impact properties were moderately increased for those composites with fiber loadings up to 45%. Acetylation exhibited a low moisture absorption, comparable with glass-fiber composites. Acetylated EFB and Coir composites showed superior retention of tensile and impact properties after aging in water up to 12 months.