Preparation and evaluation of lignosulfonates as a dispersant for gypsum paste from acid hydrolysis lignin.
In order to effectively utilize a by-product of the acid saccharification process of woody materials, the chemical conversion of guaiacyl sulfuric acid lignin (SAL), one of the acid hydrolysis lignins, into water-soluble sulfonated products with high dispersibitity was investigated. At first, SAL was phenolated (P-SAL) to enhance the solubility and reactivity. Lignosulfonates were prepared from P-SAL by three methods of hydroxymethylation followed by neutral sulfonation (two-step method), sulfomethylation (one-step method) and arylsulfonation. Surprisingly, all prepared lignosulfonates possessed 30 to 70% higher dispersibility for gypsum paste than the commercial lignosulfonate. Evaluation of the preparations for gypsum paste suggested that the higher molecular weights and sulfur contents of the preparations increased their dispersibility.
Matsushita
Yasuyuki
Y
Division of Biological Material Sciences, Department of Biosphere Resources Science, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan. ysmatsu@agr.nagoya-u.ac.jp
Yasuda
Seiichi
S
D000383:Agriculture / Q000379:methods*; D002133:Calcium Sulfate / Q000737:chemistry*; D003247:Conservation of Natural Resources / Q000379:methods*; D007220:Industrial Waste / Q000517:prevention & control*; D008031:Lignin / Q000031:analogs & derivatives* / Q000737:chemistry*; D008970:Molecular Weight; D009824:Ointments / Q000737:chemistry; D013501:Surface-Active Agents / Q000737:chemistry*; D014783:Viscosity
D007220:Industrial Waste; D009824:Ointments; D013501:Surface-Active Agents; C001545:lignosulfuric acid; D008031:Lignin; D002133:Calcium Sulfate