Читать книгу Adhesives for Wood and Lignocellulosic Materials - R. N. Kumar - Страница 25

Lignin contains characteristic methoxyl groups, phenolic hydroxyl groups, and some terminal aldehyde groups in the side chains. Only relatively few of the phenolic hydroxyls are free; most of them are occupied by linkages to neighboring phenylpropane units. The syringyl units in hardwood lignin are extensively etherified. Alcoholic hydroxyl groups and carbonyl groups are introduced into the final lignin polymer during the dehydrogenative polymerization process.