Methanol lignin from Eucalyptus regnans F. Muell. and its purification by countercurrent distribution

Publisher Website
Google Scholar
Abstract
Crude methanol lignin from immature and mature E. regnans has been separated by countercurrent distribution into lignin and degraded lignin. Chromatographic analysis of the separated lignin indicates the presence of a number of substances of differing dissociation constants. This is in accord with Brauns''s conception of lignin as a group of amorphous substances. The lignin of immature E. regnans is shown to possess the empirical formula based on a C9 unit of C9H6.68O1.30(OH)1.05(OH)0.35(O.CH3)1.45, where the aliphatic hydroxyl-group content is represented by 1.05 and the phenolic hydroxyl-group content by 0.35. The lignin of mature E. regnans does not differ significantly from this. An approximately equal number of syringyl and guaiacyl units are present in the lignin of E. regnans. Potentiometric determination indicates that 1 in 3 of the C9 units is phenolic and ionized in dimethylformamide, whereas spectrophoto-metric determination shows 1 in 5 to be ionized in methanolic 0-1 [image] KOH. The spectrophotemetric data suggest that of the phenolic groups ionized in the 0-1 [image]-KOH 60% are syringyl groups.

This publication has 0 references indexed in Scilit: