EFFECT OF STEAMING ON THE SOLUBILITY AND STRUCTURAL-CHANGES OF WOOD LIGNIN-POLYSACCHARIDE COMPLEX

IR spectroscopy was applied for the structural studies of in situ lign in-polysaccharide complex of aspen-, beech- and sprucewood in various steaming processes. The absorbance changes of the absorption band at 1 760 cm(-1) were found to be connected with splitting of the lignin-xyl an complex, deacetylation oi the glucuronoxylan component and ionizati on of its carboxyl groups, and does not reflect the preferential remov al of acidic xylan. Tn comparison with native wood, all steamed wood s amples show increased crystallinity of the cellulose component determi ned on the base of the absorbance ratios of absorption bands: 1108 cm( -1)/1091 cm(-1) 1430 cm(-1)/1403 cm(-1) and 1459 cm(-1)/1403 cm(-1).