DSC study of oxidation induction periods

A theory of the evaluation of kinetic parameters of induction periods for n on-isothermal processes is outlined and a method to obtain the parameters f rom non-isothermal differential scanning calorimetry measurements, based on the dependence of onset temperature of oxidation peak on heating rate, is presented. The applicability of the method is demonstrated on the study of oxidation induction periods of edible oils and polyolefines. In all cases, the parameters of an Arrhenius-like equation describing the temperature dep endence of induction period have been obtained. It is shown that the method gives the parameters not affected by oxygen diffusion which are transferab le to be used in modelling the non-isothermal induction periods where the e ffects of diffusion, heat transfer and evolution of reaction heat are expli citly involved. A method of estimating the residual stability after a therm ooxidative stress of the material is suggested.