<Original>Three Dimensional Analysis of Elastic Constants of the Wood Cell Wall

Abstract

The elastic constants of wood cell wall were theoretically analyzed using two cell wall unit models and three sets of elastic constants for lignin-hemicellulose matrix. The Young's modulus of the cell wall layers in the direction perpendicular to the microfibril orientation increased remarkably with increasing Young's modulus and shear modulus of the matrix, although that in the microfibril direction didn't change significantly. The Young's modulus and shear modulus of the cell wall layers differed between the models depending on the volume fraction of cellulose and the presence of non-crystalline cellulose. The decrease in the longitudinal Young's modulus of the cell wall with the S_2 microfibril angle became more gentle with increasing Young's modulus and shear modulus of the matrix. A comparison between calculated and experimental results indicated that the wood cell wall would contain a non-crystalline cellulose with lower elastic moduli than crystalline cellulose and the Young's modulus of the lignin-hemicellulose matrix is at least more than 2 GPa.