Influence of carbohydrate physical state on pulping and bleaching chemistry

The viscosities of pulp, cotton linters, crystalline cellulose, and amorpho us cellulose samples have been measured as a function of time during simula ted soda and soda/AQ pulping, oxygen delignification, and hydrogen peroxide bleaching. Typical drops in viscosities for amorphous cellulose samples we re 90%; while crystalline cellulose showed, under identical conditions, dro ps of 40% during simulated pulping and 0-10% during simulated oxygen delign ification and hydrogen peroxide bleaching. Anthraquinone did not cause sign ificant chain cleavage in amorphous cellulose. The addition of metals to ox ygen/alkali reactions of amorphous cellulose gave trends similar to that ob served in pulp reactions. The occurrence of very large molecular weight cha nges suggests that amorphous cellulose will be an ideal substrate for study ing carbohydrate chain cleavage reactions under a variety of simulated pulp ing and bleaching conditions.