DIELECTRIC STUDY OF BETA-RELAXATION IN SOME CELLULOSIC SUBSTANCES

6-(2-Cyanoethylamino)-6-deoxycellulose (Cell-CEA) as a novel cellulose derivative was prepared from 6-bromo-6-deoxycellulose. The influence of the reaction conditions on the degree of substitution was studied i n detail. The dielectric characteristics of a Cell-CEA sample having d egree of substitution of 0.86, together with those of microcrystalline and regenerated celluloses, have been investigated in the temperature range from -60 to 120 degrees C, and frequency range 30 Hz to 100 kHz . One relaxation process, designated as beta, was recognised, which wa s attributed to side-group motions, probably -CH(2)X (X = OH or NHCH2C H2CN). The higher activation energy of this process and the shift to h igher temperature in Cell-CEA, compared with microcrystalline and rege nerated celluloses, reflects the enhanced steric constraints involved in the motion of the bulkier, -CH2NHCH2CH2CN, side groups. The results obtained are discussed in terms of the dielectric parameters epsilon( max)'', <(beta)over bar> and Delta epsilon.