A STUDY OF SPRUCE WOOD LIGNIN ALTERATIONS DURING TREATMENT IN DIOXANE-WATER-HCL SOLVENT

The objective of the present contribution was to study the alterations (namely, condensation and fragmentation) of spruce wood lignin in the process of delignification in dioxane-water-HCl agent, under various conditions. All lignin preparations were characterized by either yield or recovery, molecular weights, yield and composition of products of nitrobenzene oxidation and IR spectroscopy. To obtain more information about condensation and degradative reactions of lignin during its iso lation, simulation of this process was carried out, too, Dioxane ligni ns isolated after 90 min, of extraction (according to Papper's method) at 82.5 and 98 degrees were therefore recooked for 360 min, under the same conditions as applied in lignin isolations. Concentrations of li gnin solutions prior to recooking were 1 and 10% to imitate approximat ely the lignin concentration inside and outside the wood meal during t he isolation of lignin. The obtained analytical data hint at the cours e of degradative as well as condensation reactions of the examined lig nin samples under experimental conditions.