Influence of alkali treatment on the interfacial shear strength of Agave lechuguilla fiber and its significance as a reinforcing material in polymer composites for mechanical applications

Abstract The aim of the research work was to fabricate the short Agave lechuguilla (AL) fiber‐reinforced epoxy composite and to improve its mechanical strengths. In order to do that, a single fiber pullout test was conducted to evaluate the critical length of the AL fiber and its interfacial shear strength (IFSS) in epoxy resin. To improve the IFSS, AL fibers were treated with varying concentrations (5%, 10%, and 15%) of NaOH, and it was found that 5% NaOH treatment exhibits excellent tensile strength and IFSS. Fibers treated with 5% NaOH and untreated fibers were used separately as reinforcement materials varying between 10% and 40% with a 10 wt% step in composites fabrication. The tensile strength, flexural strength, and modulus of the composites were evaluated as per ASTM standards. The results reveal that the composites reinforced with 30 wt% of untreated AL fibers give maximum tensile and flexural strength. When 5% NaOH‐treated fibers were used as reinforcement instead of untreated fibers, their tensile and flexural strength improved by 8.14% and 7.88%, respectively. To investigate the fracture mechanism of the tested samples, the specimen's fractured surfaces were analyzed using scanning electron microscope and reported in this paper.