THERMAL OXIDATIVE-DEGRADATION OF ISOTACTIC POLYPROPYLENE CATALYZED BY COPPER AND COPPER-OXIDE INTERFACES

In the reported experiments, the oxidative degradation of isotactic polypropylene films coated on well-defined Cu(Cu//2O), CuO//0//. //6//7, and CuO films in a temperature range of 90-120 degree C in a quartz-spoon-gauge-reaction vessel was studied. This catalytic reaction has been compared with the oxidation of polypropylene without copper or oxide films. Characteristic autoxidation curves obtained in the absence of H//2O and CO//2 showed induction periods that were shorter for copper oxide-polymer interfaces than for glass-polymer interfaces (i. e. , for uncatalyzed oxidation). Abnormalities were observed for Cu (Cu//2O)-polymer interfaces because of further oxidation of Cu during the reaction. The rates of oxygen consumption were faster for CuO//0//. //6//7-polymer and CuO-polymer than for the uncatalyzed reaction; the catalytic action of CuO//0//. //6//7 was somewhat larger than that of CuO. Arrhenius equations of oxygen consumption are given for all cases; the energy of activation calculated for the initiation of the uncatalyzed oxidation agrees with its literature value. Teh energy of activation for the initiation of the catalyzed reaction was a few kilocalories lower than that for the uncatalyzed reaction.