FUNDAMENTAL-STUDY OF RELATIVE DELIGNIFICATION EFFICIENCIES .2. COMBINATIONS OF PULPING ADDITIVES

Reactions of 1-(4-guaiacyl)-2-(O-guaiacyl)-1,5-pentanediol (1) provide information on the relative rates of pulping reactions that involve q uinone methides (QMs). Model 1 was reacted with sulfite/anthrahydroqui none (AHQ), sulfide (kraft)/AHQ, and sulfide/sulfite reagent combinati ons at pH similar to 13. Both sulfite/AHQ and sulfide/AHQ systems enha nced beta-aryl ether cleavage when compared to their individual compon ent systems; the greatest fragmentation was observed for the sulfide/A HQ system. Several hypotheses are proposed for the observed synergism. beta-Aryl ether scission was not affected when sulfite was added to t he sulfide (kraft) system. This paper is the second in a three-part st udy designed to examine beta-aryl ether cleavage in multi-reagent pulp ing systems (e.g., alkaline sulfite/AQ/methanol [ASAM]).