COMPETING REACTIONS AFFECTING DELIGNIFICATION IN PULPING SYSTEMS

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 (QM). The lignin model was treated with 2,6-xylenol, 1 ,5-anhydrocellobiitol, amylose, and amines; the levels of fragmentatio n and cyclization were determined. The results indicate that condensat ion reactions between the QM derived from 1 and phenolates or carbohyd rates are much slower than fragmentation reactions of 1 with sulfide o r anthrahydroquinone. The addition of amines to soda cooks of 1 provid ed little additional model fragmentation; instead, a vinyl ether was o bserved in substantial amounts.