Mechanical durability and degradation characteristics of long kenaf-reinforced PLA composites fabricated using an eco-friendly method

Abstract

The research has focused on evaluating the mechanical strength of long unidirectional kenaf-PLA composite and the degradation effect after accelerated weathering exposure. The composite was fabricated using a green traditional method of hot-pressing method with different compositions of non-chemically treated kenaf fiber to PLA with the ratio of 30:70, 40:60, 50:50, and 60:40. The finding of this work demonstrated fiber weight-matrix ratio of 50:50 gain a remarkable optimum strength with 224 % and 239 % enhancement for tensile and flexural strength respectively. The applied enhanced Rule of Mixture (E-ROM) model used in this study was reliable in predicting the experimental results whereby the composites reached an optimum value. Despite the successful enhancement of fiber–matrix compatibility and composite strength, the presence of fiber misalignment, structural imperfections, and voids observed in scanning electron microscopy (SEM) images still has some detrimental effects on its degradability. Nevertheless, a noteworthy strength reduction of PLA (80 %) as compared to the PLA-kenaf composite demonstrated better resistivity of weathering for the composite after 508 h. Hence, this study suggests deeper insights into the viability of eco-friendly combed methods as fiber treatments for kenaf as PLA reinforcement. It is proven that even without any chemical treatment, the composite demonstrated a remarkable mechanical resilience suitable for indoor non-structural applications.

Keywords

• Unidirectional fiber
• Long kenaf fiber composite
• Polylactic acid
• Mechanical PROPERTIES
• Accelerated weathering degradation