ReviewOil palm fiber (OPF) and its composites: A review

Twenty first century has witnessed remarkable achievements in green technology in material science through the development of biocomposites. Oil palm fiber (OPF) extracted from the empty fruit bunches is proven as a good raw material for biocomposites. The cellulose content of OPF is in the range of 43%-65% and lignin content is in the range of 13%-25%. A compilation of the morphology, chemical constituents and properties of OPF as reported by various researchers are collected and presented in this paper. The suitability of OPF in various polymeric matrices such as natural rubber, polypropylene, polyvinyl chloride, phenol formaldehyde, polyurethane, epoxy, polyester, etc. to form biocomposites as reported by various researchers in the recent past is compiled. The properties of these composites viz., physical, mechanical, water sorption, thermal, degradation, electrical properties, etc. are summerised. Oil palm fiber loading in some polymeric matrices improved the strength of the resulting composites whereas less strength was observed in some cases. The composites became more hydrophilic upon addition of OPF. However treatments on fiber surface improved the composite properties. Alkali treatment on OPF is preferred for improving the fiber-matrix adhesion compared to other treatments. The effect of various treatments on the properties of OPF and that of resulting composites reported by various researchers is compiled in this paper. The thermal stability, dielectric constant, electrical conductivity, etc. of the composites improved upon incorporation of OPF. The strength properties reduced upon weathering/degradation. Sisal fiber was reported as a good combination with OPF in hybrid composites.

Research highlights▶ Oil palm fiber is hard and tough and its porous surface morphology is useful for better mechanical interlocking with matrix resin for composite fabrication. ▶ Alkali treatment is the most common treatment on oil palm fiber to improve fiber-matrix interfacial adhesion. ▶ Oil palm fiber loading improved the strength of most of the composites whereas the strength of composite was less in some cases. ▶ The thermal stability, dielectric constant, electrical conductivity, etc. of composites were improved upon incorporation of OPF. ▶ Sisal fiber is a good combination with OPF in hybrid composites.