Enhanced Mechanical and Thermal Properties of Alkali-Treated Coir Fibres Incorporated with Murraya Koenigii: A Comparative Study of Mono-Layer and Tri-Layer Biocomposites

Abstract

This study examined the surface morphology and thermal behaviour of the coir fibres incorporated with murraya koenigii before and after alkaline treatment. The mechanical properties of biocomposites reinforced by the untreated fibres, treated fibres, mono-layer and tri-layer treated fibres incorporated with murraya koenigii were systematically investigated. The experimental results showed significant enhancements in tensile strength, flexural strength, hardness, and impact resistance of the biocomposites reinforced by treated fibres. Notably, the alkaline treatment has produced a rougher surface on coir fibres, promoting improved mechanical interlocking between the fibres and the polyethene matrix. These effects become more significant when murraya koenigii particles are incorporated into the fibres. It was found that the tri-layer treated fibres incorporated with murraya koenigii biocomposites showed higher tensile and flexural strength, superior hardness and impact strength when compared to the mono-layer reinforcement biocomposites. At higher temperatures, the treated fibres showed better thermal stability than the untreated fibres and polyethene. Incorporating murraya koenigii particles increased the thermal resistance of the treated fibres, revealing the potential of this green synthesis approach for the development of thermally stable natural fibre composites.