The radiothermoluminescence study of the inhibited oxidation of polypropylene

Abstract

The dissolved oxygen concentration changes during the inhibited oxidation of PP under diffusion conditions have been studied in the 453–493°K range. The effective rate constants of the oxygen absorption have been determined for the first time; these were 5·4 × 10 −4, 8·6 × 10 −3 and 2·1 × 10 −2 sec −1 at 453, 473 and 493°K respectively. The oxygen solubility increases in the PP on raising the temperature from 453 to 493°K; it increases from 4·3 × 10 −8 to 8·7 × 10 −8 mole/kg · Pa. The dissolved oxygen distribution was measured in the PP samples at various stages of their oxidation at 453°K. It has been found to decrease by about one order at a 1 cm distance from the sample surface under stationary conditions.