Crystallinity indexes of cellulosic materials

Abstract

A simple X-ray diffraction method for the measurement of crystallinity of cellulose was investigated. Principle of the method lies on the analysis of X-ray diffractograms of crystalline cellulose I or II mixed with varying amount of stable amorphous cellulose prepared from anhydro sulfurous acid-diethy-lamaine -dimethylsulfoxide solution of cellulose. In contrast to the Segal's method, 110 diffraction intensity (I110) and amorphous diffraction intensity at the same angle (I110B) were used to calculate the Crystallinity Index (C. I.) with cellulose I and II. C. I. of cellulose I and II with various amounts of amorphous cellulose obtained with following equation were on a straight line through the origin. The equation holds for the both reflection and transmission method with powder sample of cellulose. As to fibrous samples, only transmission method gave the good results. Crystallinity measurement method that utilizes Cauchy function or Ruland method, also gave the straight line through the origin for the relationship between C. I. and the mixed amount of amorphous cellulose. However from the view point of simplicity. 110 intensity method seems to be useful. © 1990, The Society of Fiber Science and Technology, Japan. All rights reserved.