Electrochemical conversion of lignocellulosic biomass to carboxymethyl cellulose: Potential and applications of induced electric field.

This study used wheat straw (WS) and sugarcane bagasse (SB) to prepare biomass-cellulose by electrochemical pretreatment, combined with bleaching process. Subsequently, carboxymethyl cellulose (CMC) was synthesized from the obtained biomass-cellulose under an optimized electrochemical process. The results showed that the isolated cellulose had typical structure of cellulose-I as well as low molecular weight and crystallinity. The crystallinity of WS-cellulose and SB-cellulose were 20.1 % and 31.0 %, respectively. The optimized electrochemical parameters for the synthesis of CMC were 84 % ethanol-water medium with electric field strength of 14 V/cm, and etherification time of 2 h. The prepared lignocellulose-derived CMC possessed similar degrees of substitution (0.64 and 0.62) to commercial CMC, but with relatively lower molecular weights, degrees of polymerization, viscosities, and crystallinity. It was mainly related to a lower molecular weight of isolated biomass-cellulose and the depolymerization of polymer chains in carboxymethyl reaction during electrochemical synthesis. In addition, lignocellulose-derived CMC composite films exhibited good UV-blocking, mechanical properties and surface hydrophobicity. In conclusion, this study successfully isolated cellulose from lignocellulose, which was converted into biodegradable polymers. It provides a useful strategy for value-added application of lignocellulose.