Sustainability of surface treatment of natural fibre in composite formation: challenges of environment-friendly option

Surface treatment of natural fibre has been considered as a viable option to strengthen the compatibility of natural fibres with the matrix in order to evolve more sustainable composite materials. The advantages of natural fibres over synthetic fibres drove the attention to bio-based fibres with overall gain on environment and biodiversity. Part of the progress recorded in many published works includes, but not limited to, low density, biodegradable, enhanced surface treatment, increases mechanical and thermal properties. While one may not be able to dispute these successes, it is very important to appraise the performance of some of these treated natural fibres and come up with a clear-cut discussion on effect of some of these treatments. In this paper, the authors review progress made in the application of chemical and physical treatment on natural fibres with emphasis on compatibility of these chemicals on natural fibre on one the hand and matrix on the other hand. Part of the discussion in this work focuses on some reported works where chemically modified natural fibres show poor physical and thermal properties as against the untreated fibre. The implication of these variations were reported and further recommendations advanced. This article also x-trays a sustainable treatment approach with their evolving challenges. It is hoped that this paper will assist researchers in future works when considering all options in natural fibre treatments.