Developing and Investigating a Polyester Resin Polymer Matrix Composite, Reinforced with E-Glass, Aluminum Oxide (Al2O3), and Coffee Husk as Reinforcement

Abstract

Nowadays, increased demand has arisen for structural materials that are lightweight with superior strength. Additionally, to reduce costs, weight, and environmental pollution, several companies are looking for more durable, sustainable, and environmentally friendly materials. The inexpensive cost, plenty, renewable, and biodegradable nature of agro waste-based materials make them attractive for use agro waste based composite. This study's primary goal was to create and examine polyester resin reinforced with E-glass, aluminum oxide, and coffee husk to fabricate lightweight, high-strength, biodegradable, low-cost, and eco-friendly materials. This composite was created using the hand layup technique and evaluated through a series of mechanical tests, including tensile strength testing, flexural strength testing, impact strength testing, hardness, water absorption, density, porosity, and SEM analysis. The experimental design used Taguchi method with a focus on optimization of reinforcement ratios using gray relational analysis. The results confirmed that the optimal composition of 20 wt.% E-glass, 2.5 wt.% aluminum oxide, and 20 wt.% coffee husk achieved the highest tensile strength of 101.1 MPa, flexural strength of 480.27 MPa, impact strength of 33.9 kJ, and hardness of 144.5. At the optimal composition water absorption tests revealed the addition of aluminum oxide and coffee husk significantly improves polyester resin composite's mechanical qualities by lowering the matrix's moisture absorption. Density and porosity tests showed low porosity because of the optimal composition's excellent interfacial bonding between the reinforcement and matrix. SEM analysis revealed well-defined features with good orientation and dispersion of reinforcing materials in the matrix. The results of this investigation show that the inclusion of E-glass, aluminum oxide, and coffee husk successfully improves the mechanical behavior of polyester resin composites. The test formulations with higher E glass content exhibited improved tensile and flexural strength, while the incorporation of aluminum oxide assisted in improving hardness, impact strength, and physical properties.