Oxidation of nylon model systems

Abstract

The effect of light intensity, photosensitiser concentration, oxygen pressure, and temperature on the rate of the photochemical oxidation of a series of N-alkylamides R·CONR′R″ where R and R″ are alkyl groups and R′ is an alkyl group or hydrogen, has been studied. Sodium anthraquinone-2-sulphonate was a powerful photosensitiser. Rates of oxidation and apparent energies of activation are recorded for several amides. A stepwise variation in the rate of oxidation with N-alkyl substituent through the N-methyl, -ethyl, -propyl, and -butyl derivatives of acetamide and propionamide is found. A mechanism is advanced for the formation of hydrogen peroxide, acyl amides (R·CONH·COR), formylamides (R·CONH·CHO), and unsubstituted amide (R·CONH₂) among the oxidation products.