Effect of chemical treatments on the mechanical and physical properties of kenaf-carbon fiber hybrid epoxy composites

This study investigates how different chemical treatments affect the physical and mechanical characteristics of hybrid composites that have epoxy as a matrix and kenaf and carbon fibers as the reinforced phase. The research focuses on the effects of surface treatments, specifically lead oxide, sodium hydroxide, and sulfuric acid treatment, on the fiber-to-matrix bonding. This is crucial for increasing the overall strength of the composites. In order to evaluate how well they are doing, the composites go through tests like tensile strength, flexural strength, impact strength, and water absorption. The outcomes indicate that chemical treatments improve the strength of the composites compared to untreated samples. The Kenaf-Carbon-Kenaf hybrid composite with treatment in lead oxide improved in tensile strength by 116 % with a tensile strength of 92.08 MPa, as compared to the untreated composite with a tensile strength of 42.70 MPa. On the same note, the flexural strength of the treated composite was significantly increased by 291 % giving a value of 118.17 MPa versus 30.23 MPa of the untreated composite. The sodium hydroxide-treated composite demonstrated the highest impact energy of 92.31 KJ/m 2 . In contrast, the sulfuric acid-treated composite showed lower mechanical performance than both the untreated and other treated hybrid composites. SEM analysis revealed that sulfuric acid treatment resulted in poor fiber-matrix bonding, contributing to the lower mechanical strength. In terms of water absorption, untreated composites showed the highest absorption, with a value of 32.86 % after 7 days of immersion. Comparatively, the lead oxide-treated composite exhibited the lowest water absorption at 8.01 %, indicating better moisture resistance. These composites show promise for use in a variety of sectors where strength and moisture resistance are indispensable, including aerospace, automotive, and construction. • Impact of chemical treatments on Kenaf-carbon hybrid composites explored. • Lead oxide treatment enhanced tensile and flexural strength significantly. • NaOH treatment improved impact strength of hybrid epoxy composites. • H 2 SO 4 treatment reduced fiber-matrix bonding, lowering strength. • Water absorption reduced by Pb 3 O 4 treatment, enhancing moisture resistance.