Effect of nanofillers on mechanical and water absorption properties of alkaline treated flax/PLA fibre reinforced epoxy hybrid nanocomposites

Abstract

Natural fibre reinforced polymer nanocomposites are gaining recognition in various technical areas like aerospace, defence, construction, and automobiles due to their low cost and environmental friendliness. However, the incompatibility between natural fibre and polymer matrices and the higher water absorption percentage of natural fibre is restricting their utilization in structural and semi-structural applications. To overcome these limitations, surface treatment of natural fibre and nanofiller addition into the polymer matrices have become among the most valuable ways to improve natural fibre composite performance. This work examined the alkaline-treated and untreated flax/polylactic acid (PLA) fibre reinforced epoxy hybrid nanocomposites, in which alumina and magnesia were used as nanofillers. The effect of surface treatment and nanofillers was explored in terms of mechanical properties (compression and interlaminar shear), water absorption behaviour, and morphology of composites. Substantial enhancements in compressive and interlaminar shear strengths were reported, as well as a notable reduction in the amount of water absorbed. The optimal nanofiller concentration was 3% in alkaline-treated and untreated flax/PLA fibre reinforced epoxy hybrid nanocomposite. The results reveal that nanofillers combined with surface treatment can appreciably improve developed laminates’ mechanical and water absorption properties, making them feasible for furniture, packaging, automobiles, and structural applications.

Keywords:

• Flax/PLA
• alumina
• magnesia
• mechanical properties
• water absorption properties
• surface treatment
• SEM

Acknowledgements

The authors wish to thank the Pakistani Higher Education Commission (HEC) HRDI-UESTPs scholarship and the Ministry of Higher Education Malaysia for Fundamental Research Grant Scheme with Project Code: FRGS/1/2018/TK09/USM/02/4.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this paper.

Additional information

Funding

This work was supported by the FRGS Grant [1/2018/TK09/USM/02/4].