Molecular Weight of α-Cellulose from Jute and Allied Long Fibers

Abstract

Four methods commonly employed for the estimation of cellulose, with special reference to jute, have been critically studied by means of viscosity measurements (and hence molecular weight) of the α-cellulose obtained with each in cuprammonium hydroxide. The cellulose molecule is de graded to different extents by all the methods of delignification ; the Cross and Bevan method, how ever, appears to give the least degraded product. Pure cellulose is much more degraded than lignocelluloses. Generally, the use of caustic soda higher in concentration than 9.3% to extract α-cellulose or mechanical action of disintegration of the material brings about further degradation. The molecular weights of α-cellulose from different fibers have been determined. From the results thus obtained, a formula is suggested to calculate the intrinsic viscosity, and hence molecular weight, from the relative viscosity of a cellulose solution at a single concentration.