Effect of Glucuronoxylan on the Hornification of Eucalyptus globulus Bleached Pulps

The effect of 4-O-methylglucuronoxylan (GX) on the hornification of bleached kraft and acid sulphite Eucalyptus globulus chemical pulps has been investigated. Almost straight-line dependence of kraft pulp hornification from GX content was explained through the diminishing of fibrils aggregation and better accessibility of amorphous cellulose regions to water in GX enriched pulps. The higher hornification of sulphite than kraft pulp was assigned to lower GX content in the former and to unfavourable rearrangement of cellulose molecules in crystalline and amorphous regions during acid sulphite pulping.