Zur Kenntnis des Lignins. IV. Mitteilung. Über lösliches Fichtenholzlignin verschiedener Darstellungsart.

Abstract

For the preparation of lignin soluble in organic solvents, wood powder was extracted with alcohol and 3-5% conc. HCl. The lignin precipitated by water showed a methoxyl content significantly higher than lignins prepared with highly concentrated HC1 and soluble only in lye. The higher methoxyl content indicates that alkyl groups are re-moved from the alcohol. This leads to the view that lignin is bound (but not by a chemical union) to cellu-lose as an ester or acetal, and that this bond is broken in the preparation by alcohol. Soluble lignins are also obtained by treating wood with glacial acetic acid or acetone in the presence of dilute HC1. In all cases, the method determines the properties of the resulting lignin, but glacial acetic acid gives the highest yield. Hence the term lignin refers to a mixture of similar compounds containing the methoxyl group.