Oxygen/alkali oxidation of cellulose and model alcohols and the inhibition by iodide

Certain aspects of cellulose depolymerization by oxygen in alkali were investigated with model compounds. Oxidation of hydroxyl groups was studied using low molecular weight glycols and alcohols. Hydrogen peroxide was identified as the peroxidic intermediate observed during oxygen oxidations of carbohydrates. Oxidation of glucitol by either alkaline hydrogen peroxide or oxygen is autocatalytic with a discrete induction period. When hydrogen peroxide is initially present in the oxygen oxidation, the induction period is considerably reduced. In the presence of potassium iodide, the induction period is lengthened. Potassium iodide inhibits the depolymerization of cellulose by oxygen and alkali and, in the presence of magnesium ions, provides more stabilization than either alone. A mechanism to explain these results is proposed.