THE BLEACHING AND PHOTOSTABILIZATION OF HIGH-YIELD PULP BY SULFUR-COMPOUNDS .1. REACTION OF THIOGLYCEROL WITH MODEL QUINONES

The reaction of thioglycerol with quinones selected to model the chrom ophores present in high-yield pulp has been investigated. The reaction is rapid and complex, involving initial Michael addition, aromatizati on of the adducts to hydroquinones, and reoxidation of those hydroquin ones to new chromophores. The Michael addition is responsible for the bleaching effect of thioglycerol upon pulp, and the reoxidation is res ponsible for the eventual development of more intense color by treated pulp. Semi-empirical and ab initio molecular orbital calculations hav e been used as an aid to rationalizing the experimental results.