Relationship between the molecular structure and bending properties of chemically and thermally degraded maple wood. II. comparison of bending properties decrease with structural characteristics of polysaccharides

摘要

Hemicellulose fractions isolated at 160 and 190 deg from holocellulose prepartins of thermally and chemo-thermally treated maple wood and also the corresponding cellulose preparations were analysed with respect to their depolymerization and decomposition. The reciprocal dependence between chemical and macromolecular alterations of the polysaccharidic portion of tested maple wood specimens and their bending properties (MOR, MOE and IBS)~1 was examined. The obtained analytical data point out the role of alterations of maple wood hemicelluloses in decreasing of MOR and IBS values, which was proportional to the severity of the experimental conditions (temperature; concentration of sulphuric acid). However, cleavage effect of chemical linkages among the basic wood components on the bending properties of wood cannot be also excluded. Decrease of MOE values was connected mainly with the decomposition and depolymerization of cellulose.