Abstract
Oxidation of poly(vinyl alcohol) (PVA) by permanganate has been studied spectrophotometrically at 525 and 420nm. Under pseudo-first order conditions ([PVA] >> [MnO4]), the reaction rate increases with [PVA] and the kinetics reveals complex order dependence on [PVA]. The second-order kinetics with respect to [H2SO4] at low concentration shifts to first-order at higher concentration. Water soluble colloidal MnO2 has been identified as an intermediate in the reduction of MnO4- PVA. The hydrogen ions decrease the stability of colloidal MnO2. Poly(vinyl ketone) is found to be the final oxidation product of PVA. Inorganic electrolytes like NaF, Na4P2O7 and MnCl2, (a product of the reaction), have inhibitory and Composite effects (inhibition and catalysis) oil the reaction rate. Arrhenius and Eyring equations have been used to evaluate the activation parameters. The observed results are discussed ill terms Michaelis-Menten kinetic model. A mechanism has been proposed oil the basis of experimental findings.