Experimental evaluation of mechanical, tribological, and morphological characteristics of alkali-treated pineapple leaf fiber reinforced epoxy composites for structural and biomedical applications

This study presents an experimental analysis of the mechanical, tribological and morphological performance of alkali treated pineapple leaf fibre (PALF) reinforced epoxy composite made by the hand lay-up method. The PALF content was adjusted between 5 and 25 wt% to determine the best level of reinforcement. Alkali treatment (5% NaOH) was used to increase the fiber- matrix interfacial bonding. The obtained results show that mechanical properties enhanced considerably to 15 wt% PALF. The tensile strength was improved to 78 MPa with 45 MPa neat epoxy and flexural strength was 122 MPa at the optimum ratio. The tensile modulus went up to 3.5 GPa and the flexural modulus was 3.7 GPa. Strengths of impact also changed to 12.4 to 17.8 kJ/m2, and Shore D hardness was also increased to 72 to 76. Tribological analysis showed that there was an enhanced wear resistance with a reduction in the coefficient of friction and wear rate of 0.58 and 5.2 × 10− 6 mm3/Nm respectively to 0.51 and 3.7 × 10− 6 mm3/Nm with 15 wt% PALF respectively. SEM micrographs verified the homogeneous distribution of fibres, the high level of interfacial bondage, crack deflection, and optimal distribution of fibre pull-out during optimal loading. However, greater quantities of fiber concentration greater than 15 wt% caused agglomeration, resin-deficient areas and development of micro voids, causing lower performance. Overall, PALF 10–15 wt% reinforcement offers the right combination of strength, toughness, hardness, and wear resistance, thus showing its possibility to be used in lightweight structural and non-load-bearing biomedical applications.