The kinetics of oxidation of methyl cellulose polysaccharide as a natural polymer by alkaline potassium
ferricyanide at a constant ionic strength of 1.0 mol dm−3 have been studied, spectrophotometrically.
The experimental results showed complex kinetics where the pseudo first-order plots were found to be
straight lines up to 60% of reaction completion, and then deviated from linearity. A first-order dependence
in Fe(CN)6
3− and fractional first-order kinetics with respect to the methyl cellulose concentration was
observed. The oxidation reaction was found to be base catalyzed. Again, addition of Fe(CN)6
4− product
to the reaction mixture leads to a remarkable retardation of the oxidation rates. A kinetic evidence for
the formation of 1:1 intermediate complex was revealed. The activation parameters have been evaluated
and a tentative reaction mechanism in good consistency with the kinetic results is discussed.