Ultrasonic-Assisted alkali and polyvinyl alcohol treatment for enhancing the mechanical of sisal fiber and interfacial properties with starch

Sisal fibers treated with alkali and polyvinyl alcohol (PVA) through ultrasonic impregnation yield various modified fibers with enhanced properties. In this study, the influence of PVA adhesion on the tensile strength, water absorption and thermal stability of individual fiber and the change of interfacial shear strength with starch were investigated. The fiber was characterized by infrared spectroscopy and electron microscope. Results reveal that PVA not only coats the surface but also penetrates the fibers, significantly improving tensile strength. Weibull distribution analysis showed that the tensile strength of ASF increased by 42.99% and the interfacial shear strength increased by 140.5%. The tensile strength of the PSF-1.0, analyzed using Weibull distribution, increased by 50.1%, and the interfacial shear strength improved by 112.9%. The study confirms that alkali and PVA treatment is a cost-effective, biodegradable method to enhance the tensile and interfacial binding properties of natural fibers, making them suitable for reinforced starch-based composites.