Highly acetylated lignocellulose prepared by alkaline extrusion pretreatment assisted acetylation reaction

Green and renewable cellulosic materials are considered promising candidates for replacing conventional petroleum-based plastics. Herein, alkaline extrusion pretreatment (AEP) assisted with acetylation was applied to prepare a thermoplastic material with a high degree of acetylation (52.2%) and directly from lignocellulose biomass. AEP, utilized as an innovative and industrial process, can efficiently swell lignocellulose fibres, destroy their structure, and promote the accessibility of lignocellulose. To explore the mechanism of the AEP process on the transformation of lignocellulose polymorphism, the compositions and crystalline structure of all samples were characterized and analysed. The obtained acetylated lignocellulose possesses great thermal and thermoplastic properties (low glass transition temperature of 135 °C). In general, the proposed industrially-viable approach in this work is conducive to developing a highly acetylated lignocellulose material via high-value utilization of the whole lignocellulose composition. Graphical abstract