Antioxidant behaviour of a nanosilica-immobilized antioxidant in polypropylene

A nanosilica-immobilized antioxidant was prepared and incorporated into polypropylene (PP) by melt compounding. It has been found that the antioxidant efficiency of the nanosilica-immobilized antioxidant was superior to the corresponding low molecular counterpart (AO), based on the measurement of the oxidation induction time (OIT) of PP/nanosilica-immobilized antioxidant and PP/AO compounds containing an equivalent antioxidant component. By paying attention to the changes of carbonyl absorption and tensile strength of PP compounds with thermal oven aging time, it was observed that the thermal oxidative stability of PP/nanosilica-immobilized antioxidant was much higher than that of PP/AO compound during the long-term accelerated thermal aging.