Solution properties of lignin. Thermodynamic properties and molecular weight determinations


  • W. Brown

    1. School of Forestry, North Carolina State University at Raleigh, Raleigh, North Carolina 27607
    Current affiliation:
    1. Research Laboratory, West Virginia Pulp and Paper Co., Charleston, South Carolina 29406
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Number-average molecular weights and the thermodynamic parameters Δ1, Δ1, and Δ1 have been obtained for lignin in the solvents dimethylsulfoxide, dimethyl-formamide, and dioxane. Widely different molecular weights were found in the different solvents and at the different temperatures as a consequences of molecular association. Analysis of the thermodynamic parameters revealed that these quantities are dominated by the change in solvent structure accompanying the solution process. A correlation between the “goodness” of a lignin solvent and the Hildebrand solubility parameter is consequently misleading in such systems.