Classification of lignins with different genetic and industrial origins

Abstract

A total of 56 lignin preparations were classified according to their chemical structures following a recently developed analysis regime. The analysis involved a structural characterization in terms of the elemental and functional group composition of average phenylpropane units, in terms of the principal interunit linkages, and in terms of molecular masses and mass distributions. The application of an oxidative degradation technique based on potassium permanganate produced primary experimental results which made it possible to quantitatively classify lignins from different sources according to their poly(alkyl-aryl) ether nature and their carbon-to-carbon linking. Hydrolysis and condensation factors were defined by which lignins were numerically compared. This classification of lignins is expected to aid in quantitative structure - property relationship studies. 45 references, 12 figures, 4 tables.