Table 9.

Chemical treatments of natural fibres and their effects.

Chemical Treatment	Effects	References
Alkaline	It enhances the bonding of the rough surface of the fibre and improves the mechanical properties	[241,242]
Silane	It increases the physiochemical property between fibre and matrix	[243]
Acetylation	It enhances the dimensional stability and reduces the hydrophilic nature of the fibre	[244]
Bleaching	It enhances the mechanical properties and thermal stability of the fibre	[245,246]
Benzoylation	It enhances mechanical strength and thermal stability and improves the hydrophobicity	[247,248]
Acrylation and acrylonitrile grafting	It improves the stress transferability and enhances the adhesion between fibre and matrix	[49,249]
Maleated coupling agents	It improves the fibre wettability by providing efficient fibre–matrix interaction	[250,251]
Permanganate	It improves the interfacial bonding between fibre and the matrix	[252]
Peroxide	It enhances the mechanical strength of the composites and improves the interfacial bonding between fibre and matrix	[253]
Graft copolymerisation	It increases the thermal properties and mechanical strength	[248]
Polymer coating	It increases the bonding between the fibre and the matrix	[254]