Preparation and evaluation of a dispersant for gypsum paste from acid hydrolysis lignin

Authors

  • Yasuyuki Matsushita,

    Corresponding author
    1. Division of Biological Material Sciences, Department of Biosphere Resources Science, Graduate School of Bioagricultural Sciences, Nagoya University
    • Division of Biological Material Sciences, Department of Biosphere Resources Science, Graduate School of Bioagricultural Sciences, Nagoya University
    Search for more papers by this author
  • Masanori Imai,

    1. Division of Biological Material Sciences, Department of Biosphere Resources Science, Graduate School of Bioagricultural Sciences, Nagoya University
    Search for more papers by this author
  • Takashi Tamura,

    1. Division of Biological Material Sciences, Department of Biosphere Resources Science, Graduate School of Bioagricultural Sciences, Nagoya University
    Current affiliation:
    1. Tokai-Pulp & Paper Company, Limited, Mukaizima-cho 4379 Shimada, Shizuoka, 427-0045, Japan
    Search for more papers by this author
  • Kazuhiko Fukushima

    1. Division of Biological Material Sciences, Department of Biosphere Resources Science, Graduate School of Bioagricultural Sciences, Nagoya University
    Search for more papers by this author

Abstract

The preparation of dispersants with carboxyl groups from acid lignin (a byproduct in the saccharification process of woody materials that are renewable resources) was investigated, and their dispersion efficiency was evaluated. In this study, sulfuric acid lignin (SAL) was selected as a representative acid lignin. To convert SAL to water-soluble polymers, it was first subjected to phenolation with sulfuric acid to enhance its chemical reactivity. The introduction of a carboxy group was carried out with two methods. One was carboxymethylation with bromoacetic acid, and the other was the Mannich reaction with glycine, sarcosine, and iminodiacetic acid. The carboxymethylation product [carboxymethylated phenolized sulfuric acid lignin (CP-SAL)] with 1.4 carboxymethyl groups per phenolated phenylpropane lignin base unit was soluble in water. The Mannich reaction products were also soluble in water with a lower addition of carboxyl groups than that for CP-SAL. Surprisingly, all the prepared water-soluble polymers possessed a higher dispersibility for gypsum paste than commercial lignosulfate. This may be due to the higher molecular weights of acid lignin derivatives. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2508–2513, 2005

Ancillary