The effect of containing Al2O3 microparticles in different matrix polymers on properties of pineapple fiber-reinforced composites

In this study, Al₂O₃ microparticle was used as a filler for pineapple fiber reinforced composites with different matrix polymers. The effect of Al₂O₃ microparticles in the epoxy and unsaturated polyester matrix on the mechanical, physical, and thermal properties of pineapple fiber reinforced composites was investigated. Pineapple fiber composite was manufactured by hand layup with various Al₂O₃ contents, 0, 5, 10, and 15 wt%, and a 30 wt% continuous pineapple fiber. The tensile, flexural strength, hardness, water absorption, and thermal stability were investigated according to ASTM. The results showed that flexural strength, hardness, density, and water resistance gradually increased, and the tensile strength rate gradually decreased with more the wt.% of Al₂O₃ microparticle. The TGA observation results indicated that the Al₂O₃ microparticles improved the composite's thermal stability. Composites with the epoxy matrix are superior in tensile strength and thermal stability compared to composites made of unsaturated polyester. In contrast, unsaturated polyester matrix composites had higher flexural strength, hardness, density, and water resistance than epoxy matrix composites. The effect of the content of 15 wt% Al₂O₃ microparticles in the composites resulted in the highest flexural strength, hardness, density, and water absorption resistance, while the tensile strength showed the lowest value.