Enhancement of UV-C irradiation protection of polystyrene matrix by tannin (Acacia mearnsii De Wild) additivation: Accelerated aging test

摘要

With the growing search for sustainable and economically viable materials, polyphenol-based plant extractives called tannins have been gaining space in the packaging market. In this work, tannin from black wattle (Acacia mearnsii De Wild) was used as an antioxidant additive in a polystyrene (PS). PS films were prepared with 1, 3, and 5 by weight tannin. The films were exposed for 3 weeks to accelerated aging process. The Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-Vis) were used to monitor the photodegradation. The samples were also evaluated by contact angle, scanning electron microscopy (SEM), and mechanical thermodynamic analysis (DMA). It was possible to verify the progressive reduction of the photodegradation process of the samples when subjected to the increasing addition of tannin over the weeks of exposure to UV-C light. The results showed that the film with 5 tannin additive presented the highest antioxidant protection among all analyzed compositions.