Development and Characterization of Coconut Coir Fiber Reinforced Plastic Composite with Bio-Epoxy Resin

Abstract

The coconut coir fiber is a green and sustainable material from the coconut processing process. The composite fabrication using renewable material can reduce the use of polymers and other materials, thereby contributing to environmental protection. The study investigated the morphological and mechanical properties of a composite comprising coconut fiber and plastic, namely Low-Density Polyethylene (LDPE) and Polypropylene (PP). A bio-epoxy resin was employed to enhance the compatibility and adhesion between the plastic and fiber. Composite production involved varying coconut fiber percentages—30%, 50%, and 70%. The plastic, coconut fiber, and bio-epoxy were combined and poured into molds, then subjected to hot pressing to form the composite. The resulting samples were cut into square shapes for microstructure observation and rectangular shapes for flexural and tensile testing according to the ASTM standards. Tensile and flexural tests were conducted on the coconut plastic composite, alongside morphological property assessments. Notably, the composite consisting of 50% coconut fiber, 42% LDPE, and 8% epoxy exhibited the most favorable mechanical characteristics, with a recorded tensile strength of 6.64 MPa and flexural strength of 28.89 MPa. Similarly, the highest-performing PP-based composite contained 50% coconut fiber, 42% PP, and 8% epoxy, with recorded tensile and flexural strengths of 9.85 MPa and 32.58 MPa, respectively. The study suggests that combining coconut fiber and PP at a weight percentage of 50% yields the optimal mechanical properties for coconut fiber reinforcement. Microstructure observation revealed the presence of holes and voids in the composites, attributed to uneven distribution of plastic and fiber during the hot-pressing process. Composite materials exhibiting superior mechanical properties hold the potential to compete with existing goods and potentially surpass them in quality.