Tensile Properties Characterisation of Hybrid Luffa/GCW Fiber Reinforced Polymer Composite

Abstract

Extensive research has been conducted on fiber reinforced polymer (FRP) composites, which have demonstrated superior mechanical properties compared to their individual components. In order to add on to current research trends, the use of ground coffee waste (GCW) and Luffa fibers reinforced polyethylene (PE) composites were fabricated to produce a hybrid natural FRP composite. Tensile testing of the composite indicates that the optimum fiber volume to be between 15% and 35%, as the tensile strength exhibited 9.32 MPa and 8.75 MPa, respectively. Similarly, the tensile modulus of the fabricated composite peaked at 25% with 238 MPa, then declined to 173 MPa at 35%. This indicates that the fibers effectively reinforce the polymer matrix, but once the composite reaches its optimal fiber volume, a decrease in both tensile strength and tensile modulus is observed. The reduction in tensile properties can be attributed to an uneven distribution of load-bearing capacity throughout the composite, as the fibers are no longer able to fully support the matrix once the optimal fiber volume is reached. The specific tensile strength and specific tensile modulus also shows that with the inclusion of Luffa fiber and GCW microfiber contributed to a lighter weight composite. In a nutshell, the hybrid composite fabricated using 25% fiber volume exhibited a tensile strength almost similar to its neat matrix counterpart, though has a noteworthy value in terms of its tensile modulus. The hybrid composite can be as strong in terms of tensile strength, but far more significant in its rigidity, in comparison to the neat polyethylene laminate. Therefore, it showed that the hybrid natural Luffa/GCW FRP has the potential in the engineering industry, such as lightweight furniture, household appliances, automotive parts, and other composite engineering applications.