The effect of glow discharge air plasma surface treatment on mechanical properties of natural fiber reinforced-epoxy sustainable biocomposites

Natural fiber composites are widely explored sustainable alternative to conventional composites in many applications. However, since they are weak compared to conventional composites, various surface treatments are adopted to improve their overall mechanical properties. The effect of glow discharge air plasma treatment of banana and pineapple leaf (PALF) natural fibers is investigated and presented in this study. Fibres were treated for different time periods, their surface were analysed, and composite laminates with standalone and hybrid were fabricated. Tensile, flexural and impact tests in different combinations of reinforcements were carried out. Spectroscopic, thermal and microscopic characterisations like Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), Thermogravimetric analysis (TGA), Field Emission Scanning Electron Microscopy (FESEM) were used to study the fibre surface, 3D digital microscope was used to study the fractography and a water absorption test was carried out to study the hydrophilicity were carried out to characterise the fibre surface and the laminates. Significant variations in thermal stability and improvements in tensile strength (even up to 275%) and flexural properties were observed. This investigation revealed the cause of the same was due to the enhancement in crystallinity, mechanical interlocking and improved fibre-matrix adhesion, which was evident from characterizations.