Changes in the Crystalline and Amorphous Components of Moso Bamboo (Phyllostachys Pubescens) with Increasing Age as Determined by X-Ray Diffraction and Microscopic Fourier-Transform Infrared Spectroscopy

Tomoaki Kiryu, Tsunehisa Mi

Abstract

The crystalline and amorphous components qualities of moso bamboo (Phyllostachys pubescens) at various ages (43 days to 9 years) were measured by X-ray diffraction and Fourier-transform infrared spectroscopy. The crystal size, lattice spacing, microfibril angle and crystallinity remained almost constant during aging process. In addition, several infrared absorption peaks due to lignin became more distinct in the period that had been reported in previous study as the lignin content increased, and after the components ratio became constant, some peaks due to lignin became broader and shifted to lower wave number. In the previous study, using the samples taken from the same bamboo culms as the culms in this paper, the possibility was suggested that the degree of polymerization and/or the crosslinking density of lignin increased in the period after the components ratio had become constant. As a result of discussion in this research, it was suggested that the reduction of the distance between functional groups of lignin and some kinds of molecules around the lignin and/or the forming of new chemical bonds in lignin occurred in moso bamboo in the period after the components ratio had become constant. These results of discussion support the conclusion in our previous report