Differences in Morphological Characteristics of Bamboo Fibres and other Natural Cellulose Fibres: Studies on X-ray Diffraction, Solid State 13C-CP/MAS NMR, and Second Derivative FTIR Spectroscopy Data

Bamboo natural fibres were extracted and their crystalline structure was investigated by X-ray diffraction, FTIR spectra, and 13C NMR techniques and the results were compared with common fibres, e.g., ramie, flax, and cotton fibres. The allomorph content in bamboo fibres was calculated by 13C NMR and the result shows that bamboo fibres are Iβ-dominant type which has also been confirmed by FTIR analysis. The Iα phase in bamboo fibres is lower than that in ramie and flax fibres. A simple model was used to calculate crystallite size of bamboo fibres in NMR spectroscopy. The results indicate that bamboo fibres have the crystallite size similar to that of ramie, but larger than those of flax and cotton fibres. This finding is consistent with the result obtained by X-ray analysis. The crystallinity and crystallite orientation of bamboo fibres are similar to those of ramie fibres, but differ from those of flax and cotton fibres. Second derivative FTIR spectra indicate that more resolved networks of hydrogen bonds are responsible for predominant crystalline fibril in bamboo fibres. The difference of X-ray diffraction and NMR in characterization of natural cellulose is also discussed.