Effect of Loading Parameters on Mechanical Properties of PA-HIPS-Kenaf Composite via Full Factorial

Abstract

Natural fiber-reinforced polymer composites (NFRPCs) are emerging as a sustainable alternative to conventional synthetic composites, offering advantages in environmental sustainability and biocompatibility. This study investigates the mechanical properties of NFRPCs utilizing kenaf fibers within polyamide 6,6 (PA) and hybrid matrices of polyamide and high-impact polystyrene (HIPS). A full factorial experimental design was employed to analyze the impacts of fiber content, polymer matrix, and compatibilizer (MAPP) on the elastic modulus and elongation at break. Mechanical testing was conducted in accordance with ASTM D638 standards using a universal testing machine (UTM). The results reveal that the interaction between kenaf fiber content and MAPP loading, as well as the relationship between MAPP loading and the matrix type, significantly affects the elastic modulus of the composites. Specifically, a lower MAPP content in the PA matrix, when combined with reduced kenaf fiber loading, leads to enhanced stiffness and elevated elastic modulus values. Among the tested variables, kenaf fiber loading is the only factor that positively correlates with the elastic modulus, indicating that increased kenaf content directly enhances material stiffness. The optimal conditions for maximizing elongation at break were found at the lowest kenaf fiber loading with the PA matrix. This outcome is attributed to the inherent chemical compatibility between PA and kenaf fibers, which facilitates superior bonding and flexibility. It also found that all interaction factors contribute significantly to the enhancement of elongation at break, thus improving the ductility of the composites.