Isolation and preparation of lignin-based hydrogel derived from biomass waste.

The present research aims to prepare a lignin-based hydrogel in which the lignin was isolated from black liquor. Black liquor resulted as a by-product of oil palm empty fruit bunch (OPEFB) biomass waste pre-treatment. Lignin was isolated by treating with strong acid, hydrochloric acid, at various pH variations. The highest lignin isolation results were obtained at a variety of pH 2. This was indicated by the relatively higher lignin purity and yield, around 88-92% and 0.4-0.5%, respectively. The hydrogel was made by adding 1-5 ml of epichlorohydrin to a mixture of 1-5 %w/v lignin solution with agarose. There were five variations of the hydrogel produced in this study. The optimum result was obtained for hydrogel products A1 with the results of the morphology of homogenous distribution, compressive tests were around 0.09 MPa and the transition temperature was about 97.59°C. [ABSTRACT FROM AUTHOR]