Selective Adsorption: A New Approach to Cellulose Protection During Bleaching

摘要

The efficacy of 2,4,6-triamino-1,3,5-triazine (melamine) as a selectively adsorbed protectant for cellulose during bleaching of a number of chemical pulps with chlorine or hypochlorine is evaluated under a variety of conditions. About 0.25% of this polynitrogen heterocycle, based on pulp, is found to provide the same level of protection as that afforded by 0.5% of the well-recognized cellulose protectant, sulfamic acid. The use of melamine does not lead to any deceleration of delignification or problems in brightness development. Other oxidatively-stable, cellulose-substantive nitrogen heterocycles, such as caffeine and guanine, behave similarly.