The Reactions of Lignin with Alkaline Hydrogen Peroxide. Part II. Factors Influencing the Decomposition of Phenolic Structures.

Abstract

The reaction between .alpha.-methylsyringyl alc. (I) [33900-62-8] as model for lignin and aq. H2O2 in the pH range of 10.0-12.5 was studied using a kinetic method. The reaction rate exhibited a strong max. around pH 11.5 and at a const. pH value it was accelerated by the presence of CuSO4, FeSO4 and MnSO4 or Na2SO4; an increase in temp. also resulted in a strongly enhanced rate of reaction. In the presence of Na2SiO3 as stabilizer for H2O2 and under N, the I was stable against degrdn., indicating that the major reaction species are OH radicals, superoxide ions, and O formed in the decompn. of H2O2.