Due to their key benefits, which include having a moderate strength and stiffness, being inexpensive, and being a material that is good for the environment, degradable, and renewable, natural fibers are seen as having potential application as reinforcing agents in polymer composite materials. Because of their natural hydrophilicity, they are prone to absorbing moisture, which can weaken or plasticize the adhesion of the fibers to the surrounding matrix and affect how well composite materials operate in ambient humidity, especially at high temperatures. The aim of this study was to examine the effects of treatments on the mechanical (tensile), morphological, and structural characteristics of pineapple leaf fibers using sodium hydroxide (alkali), 3-aminopropyltriethoxysilane (3-APS, silane), and combinations of the two. The effectiveness of the alkali and saline treatments in eliminating impurities from the fiber surfaces was demonstrated by scanning electron microscopy (SEM) examination. According to the morphological study of treated PALF by SEM, silane-treated fibers have less impurities, lignin, and hemicelluloses eliminated than those by other chemical treatments. The tensile strength of silane-treated PALF is greater than that of untreated, alkaline, and NaOH-silane-treated PALF. A single-fiber fragmentation test and data reduction technique were utilized to assess the interface quality of untreated, NaOH, silane, and NaOH-silane treated PALFs-epoxy composites, as well as the apparent interfacial shear strength (IFSS). It was found that treated samples greatly increase IFSS, indicating an increased level of adhesion. The silane-treated fibers exhibited the highest interfacial stress strength, whereas the PALF treated with alkali and silane had better interfacial stress strength, according to the droplet test. It is envisaged that fiber treatments will aid in the creation of high performance PALF reinforced polymer composites for industrial applications.
