Effect of Fibre Surface Treatment and Nanofiller Addition on the Mechanical Properties of Flax/PLA Fibre Reinforced Epoxy Hybrid Nanocomposite

Natural fibre-based materials are gaining popularity in the composites industry, particularly for automotive structural and semi-structural applications, considering the growing interest and awareness towards sustainable product design. Surface treatment and nanofiller addition have become one of the most important aspects of improving natural fibre reinforced polymer composite performance. The novelty of this work is to examine the combined effect of fibre surface treatment with Alumina (Al2O3) and Magnesia (MgO) nanofillers on the mechanical (tensile, flexural, and impact) behaviour of biotex flax/PLA fibre reinforced epoxy hybrid nanocomposites. Al2O3 and MgO with a particle size of 50 nm were added in various weight proportions to the epoxy and flax/PLA fibre, and the composite laminates were formed using the vacuum bagging technique. The surface treatment of one set of fibres with a 5% NaOH solution was investigated for its effect on mechanical performance. The results indicate that the surface-treated reinforcement showed superior tensile, flexural, and impact properties compared to the untreated reinforcement. The addition of 3 wt. % nanofiller resulted in the best mechanical properties. SEM morphological images demonstrate various defects, including interfacial behaviour, fibre breakage, fibre pullout, voids, cracks, and agglomeration.

Automated summary

Natural fibre reinforced polymer composites are increasingly popular in automotive applications, with the addition of Al2O3 and MgO nanofillers showing significant improvements in mechanical properties. Surface treatment of fibres and nanofiller addition play crucial roles in enhancing the overall performance of the composites, demonstrating superior tensile, flexural, and impact properties in the hybrid nanocomposites. The SEM images reveal various defects that impact the mechanical behavior of the composites, highlighting the importance of optimizing the composition for enhanced performance.