Interaction of lignin and polysaccharides in beech wood (Fagus sylvatica) during drying processes

C-13 CP MAS NMR spectroscopy was used to characterize the structural change s of cell wall polymers in beech wood Fagus sylvatica during drying process es. The analysis of five wood samples, namely, untreated, untreated dried, pre-treated by steam and/or NaOH subjected to drying showed partial depolym erization of lignin component as well as the change of the ratio of the cry stalline and of the amorphous parts of cellulose as the consequence of wood pre-treatment. In addition, T-1 rho(H-1) relaxation times were determined in beech wood sample pre-treated with steam at 135 degrees C and the lignin isolated from this sample. The magnitudes of the relaxation times were fou nd comparable in both samples as well as in the lignin-cellulose model comp ound. These unique T-1 rho (H-1) values indicate that spin diffusion is com plete and homogeneous due to spatial proximity of spins and confirmed the f ormation of lignin-cellulose complex during thermal treatment of wood.