The Hygroscopic Nature of Wood,
COLORADO STATE UNIV FORT COLLINS
Pagination or Media Count:
The cell walls of wood are organized as a structural system involving filamentous microfibrils, oriented essentially in the direction of the longitudinal axis embedded in an amorphous matrix of noncrystalline cellulose, hemicelluloses, and lignin. The molecules in the amorphous regions, primarily because of the prominence of -OH groups in their structure, are all capable of forming hydrogen bonds. They are accessible to water molecules through diffusion from the surrounding atmosphere. Water molecules are themselves highly susceptible to hydrogen bonding. The intermolecular hydrogen bond that develops between them when a water molecule approaches within 0.3 nm we used to say 3 A of the attractive site on the polymer is the basis for the hygroscopicity of wood. The adsorbed water is bound to molecular surfaces within the polymer matrix which expands in proportion to the quantity of water adsorbed. The microfibrillar network is distended, mostly laterally, and we observe that the wood swells.