Deep eutectic solvent extracted lignin from waste biomass: Effects as a plasticizer in cement paste

Sourced from biomass as a byproduct from cellulose separation, lignin has the potential to be valorized as a bioproduct. A low-pressure process that uses ecofriendly chemicals to separate out lignin from waste biomass has been investigated. Deep eutectic solvents are biodegradable, low volatility solvents that are capable of biomass deconstruction, even of recalcitrant secondary agricultural residues from food processing. In this study, lignin has been extracted from sugarcane bagasse and coffee chaff using deep eutectic solvents. In addition, lignin from sugarcane bagasse has been carboxymethylated. These lignins were added to cement to explore their effect on workability of the mix, and subsequent compressive strength and porosity. Pretreatment with deep eutectic solvent was found to successfully extract lignin-rich material from sugarcane bagasse and coffee chaff. These lignins extracted from waste biomass were found to be feasible plasticizer candidates, since when used as plasticizers at 0.3 wt% they increased the workability of cement paste.