Hydrogels Based on Hemicellulose and Lignin from Lignocellulose Biorefinery: A Mini-Review

From inedible lignocellulosic biomass, a biorefinery produces biofuels or fibers as well as by-products, lignin and/or hemicellulose. Conversion of these by-products to high-value co-products will offset the cost of biofuel, improve the economy of lignocellulose biorefinery, minimize the waste discharge, and reduce the dependence of petroleum-based products. Hydrophilic functional groups on the backbones of hemicellulose and lignin allow them good feedstocks for hydrogels, which are important materials widely used in agriculture, petroleum oil drilling, biomedical engineering, and daily life. Methods for preparing hydrogels from hemicellulose and lignin are critically reviewed. and characteristics of the hydrogels are discussed in this min-review.