A green and efficient method for preparing acetylated cassava stillage residue and the production of all-plant fibre composites

Abstract Cassava stillage residue (CSR), a kind of agro-industrial plant fibres, was directly acetylated and converted into thermoplastic material by mechanical activation-assisted solid phase reaction (MASPR) in a stirring ball mill without the use of organic solvent and additives. As combining mechanical activation and chemical modification in the same equipment, the destruction of hydrogen bonds and crystalline structure of CSR induced by intense milling improved the reactivity of CSR, leading to the effective acetylation of CSR. After acetylation by MASPR, the modified CSRs possessed thermoplasticity, ascribing to the introduction of acetyl groups and the destruction of high crystallinity structure of cellulose. The self-reinforced all-plant fibre composites (APFC) were successfully produced with the modified CSRs as both matrix and reinforcement by hot pressing technology. The direct acetylation of CSR and successful production of APFC suggested that MASPR was a simple, efficient and environmentally friendly method for chemical modification of agro-industrial lignocellulose biomass.