Bagasse Fibers Surface Heat Treatment and Its Effect on Mechanical Properties of Starch/Poly (Vinyl Alcohol) Composites

Sugarcane bagasse (SCB) is a promising natural fiber for bio-based composites, but its high moisture absorption and poor interfacial adhesion with polymer matrices limit mechanical performance. While chemical treatments have been extensively explored, limited research has addressed how thermal treatment alone alters the surface properties and reinforcing behavior of SCB fibers. This study aims to fill that gap by investigating the effects of heat treatment on SCB fiber structure and its performance in starch/poly (vinyl alcohol) (PVA) composites. Characterization techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were employed to analyze changes in fiber morphology, surface chemistry, and crystallinity. Mechanical properties were assessed via tensile, flexural, and impact testing, and moisture absorption was also evaluated. Composites reinforced with SCB fibers treated at 200°C exhibited significantly superior mechanical properties compared to those prepared with untreated or differently treated fibers. The tensile, flexural, and impact performance of the composites were 15.13, 19.37 MPa, and 7.28 J/m, respectively. Composites treated at this temperature also retained better mechanical properties after exposure to humidity. These findings demonstrate that heat treatment is a simple and sustainable method to improve the durability and mechanical performance of nature fiber-reinforced composites, expanding their potential for environmentally friendly material applications.