Effect of volatilization of stabilizers and oxidation products on polypropylene lifetimes


  • Presented at the annual conference of the Plastics Institute of America, Hoboken, New Jersey, November 1965.


Three methods of measuring thermal oxidative stability of polypropylene have been compared. The oxygen absorption and the sealed tube tests give comparable results. The polymer lifetimes in circulating oven-aging tests differ significantly from those obtained by the first two methods. The oven-aging lifetime is aparently influenced to a large extent by the volatilization of the added stabilizer and of the oxidation products, the former decreases whereas the latter increases the polymer lifetime. The optimum composition of a synergistic stabilizer system was found to vary with the test method.