Effect of Rosemary Antioxidanton on the Stability of Polypropylene in Natural Weathering Tests

Abstract

Effects of Rosemary Antioxidanton (Rao), extracted from Rosmarinus officinalis, on the antioxidantive properties of polypropylene were evaluated by investigating the difference of mechanical properties and melt flowability between pre and post natural weathering tests. For comparison purposes, the effects of a synthetic phenolic commercial antioxidant (Irganox B215), were also analyzed. The results showed that the reduction of mechanical properties and the increment of melt flowability of polypropylene containing Rao were slower than that of the unstabilized reference during the aging process, which implies that Rao exhibits high efficiency as a thermal antioxidant for polypropylene. On the other hand, samples that contained Irganox B215 obtained further improved stability over the samples containing Rao during 105 days; however, the effectiveness of Rao lasted longer than that of Irganox B215. Rao has the characteristic of being harmless and having high activity, good stability and abundant resources to be a good natural antioxidant.