We are currently undergoing maintainence, please come back soon. Jump to navigation Jump to search This article is about the wood polymer.
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of vascular plants and some algae. Lignin was first mentioned in 1813 by the Swiss botanist A. Candolle, who described it as a fibrous, tasteless material, insoluble in water and alcohol but soluble in weak alkaline solutions, and which can be precipitated from solution using acid.
An example of a possible lignin structure. The composition of lignin varies from species to species. An example of composition from an aspen sample is 63. As a biopolymer, lignin is unusual because of its heterogeneity and lack of a defined primary structure. The lignols that crosslink are of three main types, all derived from phenylpropane: 4-hydroxy-3-methoxyphenylpropane, 3,5-dimethoxy-4-hydroxyphenylpropane, and 4-hydroxyphenylpropane.
The former tends to be more prevalent in conifers and the latter in hardwoods. Lignin is a cross-linked polymer with molecular masses in excess of 10,000 u.