Analysis of Mechanical Properties of Polymer Composite Materials with Coconut Filter Fibers

Abstract

The development of composites using natural fibers is currently developing rapidly. Natural fibers offer a variety of significant advantages over synthetic fibers, including being lightweight, recyclable, easily degradable by bacterial action, renewable, and relatively high in strength and rigidity. Natural fibers can be obtained from various plants; one is coconut fiber, which grows on new fronds and is easy to find throughout Indonesia. This study aims to analyze the tensile strength and impact strength of polymer-matrix coconut filter fiber composites. Testing was carried out on three comparative variations (volume fractions): 90% resin: 10% fiber, 85% resin: 15% fiber, and 80% resin: 20% fiber. The tensile test results showed that an 80% resin: 20% fiber ratio produced the highest tensile strength, i.e., an average tensile stress of 14.1 N/mm² (average strain 6.2%). Meanwhile, the 90:10 ratio has an average voltage of 10.8 N/mm², and the 85:15 ratio has 9.4 N/mm². For impact tests, results showed that increasing fiber content improved the composite's toughness. The highest average impact toughness of 766.09 J/mm² was obtained at a 80% resin:20 % fiber ratio. The 85:15 and 90:10 ratios yield 749.56 J/mm² and 722.42 J/mm², respectively. Overall, the study concluded that composites with a content of 20% coconut filter fibers showed an optimal combination of mechanical properties, namely tensile strength and impact toughness.