The Processes Running during the Induction Period of Inhibiting Oxidation of Polyethylene

Abstract

Abstract Oxygen absorption in the induction period of polyethylene oxidation inhibited by a strong amine antioxidant N-phenyl-N-cyclohexyl-p-phenylenediamine (PCHA) in the temperature range of from 200°C to 230°C is investigated. It is found that the rate of O2 absorption during the induction period in the presence of antioxidant varies in the range of from 2 × 10−6 to 2 × 10−5 mol/kg (210°C). It is also stated that the main method of antioxidant consumption during the induction period consists of its direct oxidizing by molecular oxygen. The rapid oxidation of the polymer is shown to begin after the current antioxidant concentration reduction to the critical value. Kinetic parameters of the oxidation reaction in a wide range of initial antioxidant concentration are determined.