LACCASE-CATALYZED FUNCTIONALIZATION WITH PHENOLIC COMPOUNDS IMPROVES PAPER STRENGTH

摘要

The unbleached softwood kraft pulps were treated by laccase in presence of phenolic compounds aiming to improve the dry- and wet-strength of paper. The results showed that the phenolic compounds can graft on the fibers and functionalize the pulp. The laccase combined with phenolic acids treatment can improve the dry tensile strength of paper. The wet tensile strength of paper increased after laccase treatment in presence of methyl syringate with hydrophobic methyl group. The functionalized fibers had a higher total carboxyl group, opacity, kappa number and a reduced brightness after laccase treatment combined with most of phenolic compounds. The participation of phenolic compounds could enhance the reactivity of laccase to fibers. There was a close relationship between the compound structure and pulp properties.