Allomorphs of native crystalline cellulose I evaluated by two equatorial d-spacings

• Published in: Journal of wood science Vol. 47; no. 2
• Main Authors: Wada, M. (Tokyo Univ. (Japan)), Okano, T, Sugiyama, J
• Format: Journal Article
• Language: English
• Published: 01.01.2001
• Subjects: BACTERIA; CELLULOSE; PHYSICS; RAMIE; X RAY SPECTROSCOPY
• ISSN: 1435-0211; 1611-4663
• DOI: 10.1007/BF00780560

The aim of this study was to develop a facile method for categorizing native celluloses as the algalbacterial type or the cotton-ramie type and for estimating the I sub(alpha) / I sub(beta) (triclinic / monoclinic) ratio of the cellulose samples. We investigated various native celluloses by X-ray diffractometry; and discriminant analysis was carried out using two equatorial d-spacings: 0.59 - 0.62nm (d1) and 0.52 - 0.55nm (d2). All of the samples were classified into the two groups without error. The function used to discriminate between the two groups is represented as: Z = 1693d1 - 902d2 - 549, where Z > 0 indicates the algal-bacterial (I sub(alpha) rich) type and Z < 0 indicates the cotton-ramie (I sub(beta) ominant) type. Another X-ray diffraction study of hydrothermally treated Cladophora cellulose revealed the relation between the d-spacings (d1, d2) and the I sub(alpha) / I sub (beta) ratio. A calibrating equation by which the I sub(alpha) / I sub(beta) ratio was estimated from the two parameters, d1 and d2, was then prepared. In the case of relatively highly crystalline native celluloses, it was found that the I sub(alpha) / I sub(beta) ratio is easily determined by applying the two parameters in the equation.