Lignin: Isolation and preparing the lignin based hydrogel

Efficient recovery of valuable materials from by-products of pulping has been a strong asset to the environmental concern. The objectives of this research were to recovery and utilization of lignin from kraft black liquor. Lignins of oil palm empty fruit bunch were isolated from kraft black liquor by acidic method. Results showed that the optimal condition of kraft lignin precipitation was at pH 3, which contributed the higher yield and purity of isolated lignin. The chemical and physical properties of isolated lignin was characterized as a mixture of lignin-agarose hydrogel by fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. Lignin and agarose hydrogel were synthesized by chemical crosslinking of epichlorohydrin (ECH). The lignin-agarose hydrogel obtained at 5%lignin, 5% agarose and ECH 10 mL provided the higher mechanical properties when compared to other conditions. Gel strength of lignin-agarose hydrogel has been comprehensively determined by texture personal analysis (TPA).