DIFFRACTOMETRIC METHOD FOR DETERMINING THE CRYSTALLINITY DEGREE OF CELLULOSE

ABSTRACT

Cellulose is one of the most important biopolymers and belongs to crystalline polymers. At the same time, it can exist in several crystalline modifications, giving a completely different diffraction pattern, or in an amorphous state. The crystallinity degree of cellulose significantly varies with different chemical and enzymatic treatments. A new method for crystallinity degree determining from X-ray diffraction data has been applied to cellulose samples. A calculation is based on estimating the rate of change in function I = f(2θ) in the whole range of scattering angles. For cellulose samples a linear relationship between the specified ratio of crystalline and amorphous parts and the calculated crystallinity index is obtained. The crystallinity index for any cellulose crystal modifications can be determined by this method. The crystallinity degree of cellulose samples from different origin was calculated with respect to cotton cellulose and gold.

Keywords: Crystallinity degree, X-ray diffractometry, polymers, bacterial cellulose