STRUCTURAL AND BENDING PROPERTIES OF JUVENILE AND MATURE SOFTWOOD

摘要

Bending and structural properties of Todo fir (Abies sachalinensis) xylems were investigated to study the structural and mechanical properties of juvenile and mature wood. Samples obtained near the pith tended to have a small Young's modulus in the longitudinal direction. Investigation of the properties of samples revealed that juvenile wood near the pith tended to have larger microfibril angles, shorter fiber length, smaller alpha-cellulose content and a lower relative crystallinity index than mature wood. In addition, after chemical treatment to remove lignin and hemicelluloses, the samples of juvenile wood near the pith tended to have a slightly lower relative crystallinity index than those of mature wood. FTIR analysis of the samples after the treatment indicated that some hemicelluloses still remained within the samples, but it is also possible that the juvenile and mature wood under study contained cellulose I-beta.