Green Conversion of Total Lignocellulosic Components of Sugarcane Bagasse to Thermoplastics Through Transesterification Using Ionic Liquid

Abstract

Considering the recent environmental problems, it is critical to minimize our dependence on fossil fuels and maximize the utilization of sustainable and abundant lignocellulosic biomass. Herein, we present a facile approach for the green conversion of sugarcane bagasse, a lignocellulose-rich agro waste, to valorized thermoplastics by utilizing its total lignocellulosic constituents. To impart adequate thermal moldability to the bagasse without sacrificing the key mechanical properties, all hydroxy (OH) groups were substituted with long- and short-chains acyl groups via one-pot and two-step reactions, allowing for a precise control of the acyl group molar ratio. The esterified bagasse with hexanoyl and acetyl groups (∼20:80, mol/mol) demonstrated an excellent melt-flowability at 180 °C, while maintaining good mechanical properties (tensile strength: 35 ± 4 MPa and Young’s modulus: 1.6 ± 0.1 GPa), which were attributed to the plasticizer effects of the introduced long-chain acyl group as well as the retained hemicellulose and lignin components. Additionally, the material properties of the esterified bagasse were desirably tunable and dependent on the type of acyl groups and lignocellulose. Thus, these findings demonstrate the potential for lignocelluloses to be used as a high value-added biomass plastic in various fields, paving the way for the use of lignocellulosic components as polymeric materials.