Sustainable surface modification of sorghum residue-based fiber reinforced polymer composites: Properties and adhesion mechanism
Nametso Linda Moumakwa, Abubakar Sadiq Mohammed, Eyitayo Olatunde Olakanmi, Tobias Bader, Amare Gessesse
Abstract
• Hybrid treated fibers obtained from sorghum stalk dispersed well within the rLDPE matrix thereby producing a more homogenous composite material. • Thermo-alkali and thermo-laccase fibre modification treatments were employed to improve the properties of the composites. • The degradation temperature of the treated composites increased with treatment duration due to the improved removal of waxes and oils, and increased surface roughness leading to increased fiber/matrix adhesion. • Hybrid thermo-alkali treatment was better, in comparison to thermo-laccase treatment, at eliminating undesired contaminants in the fibers. • The thermo-alkali reinforced composite, which was treated for 10 days, be utilized for non-structural applications such as wall and floor paneling in buildings. Sorghum stalks and other agricultural residues in excess of farmers animal feed requirements are often burnt, contributing to environmental pollution. On the other hand, such residues could serve as useful sources of fibre with different applications. The aim of this study was to investigate agricultural residue-based fibres (ARFs), using sorghum stalks as a model, for use as reinforcements in recycled low-density polyethylene (rLDPE) for the manufacture of agricultural residue-based fibre reinforced polymer composites (ARFRPCs). Thermo-alkali and thermo-laccase fibre modification treatments were employed to improve the properties of the ARFRPCs. The thermal conductivity values of the ARFRPCs at 0.23 – 0.3 W/m‧k are higher than some commercially available insulators. Moreover, thermo-alkali reinforced ARFRPCs exhibited a tensile strength of 28.57 Mpa and improved microstructure/interfacial adhesion relative to intreated and thermo-laccase treated samples. The conclusion is that thermo-alkali reinforced ARFRPCs, which was treated for 10 days, be used for non-structural applications in buildings.