Application of selected chemical modification agents on banana fibre for enhanced composite production

Abstract

Banana fibre is an agricultural waste that is obtained after harvesting the fruit at no additional cost. Banana fibre has major drawbacks in composite production, such as low interfacial bond strength between fibre and matrix when compared with synthetic fibre. This research aims to investigate the effect of selected chemical treatment on Banana fibre. The effects on morphological, mechanical and chemical properties were investigated using the Scanning electron microscope, computerized Tensile machine and FTIR Instrument. The chemicals applied in fibre treatment were Alkali (NaOH), Permanganate (KmnO4), and Acetylation. The results obtained showed that the surface roughness of the fibres was increased, and the hydrophilic nature of the fibres was reduced. There was a void introduction on the fibre’s surface, thereby providing better mechanical locking properties and reduction of water absorption tendency. The FT-IR spectroscopy results showed gradual changes consistent with the removal of pectin, lignin, hemicelluloses, oil, and waxes as chemical treatment progressed. Alkali chemical surface modification treatment of fibres enhanced the properties of the fibres by disrupting hydrogen bonding in their network structure. Permanganate chemical handling accounted for the formation of cellulose radicals with MnO-3 ion formation and fibre surface modification treatment using acetic acid enhanced the reduction of the hygroscopic nature of the banana fibres leading to increased dimensional stability. Mostly, the α cellulose contents of the fibre were increased from 63.40% to 82.23% at Silane chemical handling, while the other major components were reduced comparatively. Mechanical properties of the fibres such as tensile strength, flexural modulus, and percentage elongation improved with chemical treatment. This work also investigated the potential of using chemically modified Banana fibres (BPF) as reinforcement for polyester composites manufacture. The composites were produced by varying the BPF from 5 to 20 wt%. The density, mechanical properties and microstructure of the composite were examined, and there were remarkable improvements in the engineering properties of the composites. A 181.5% improvement in tensile strength and 56.63% increase in flexural strength was obtained over that of the unreinforced polyester.