Graphene Oxide as an Auxiliary UV Photoprotector for Polypropylene

Abstract

This work presents the preparation and characterization of polypropylene (PP)/graphene oxide (GO) nanocomposites by adding photostabilizing additives to obtain materials with enhanced resistance to photodegradation. The synthesized GO (modified Hummers' method) was characterized using state-of-the-art techniques. The results indicated that a high oxidation index and a relatively low stacking of GO layers were achieved. The PP/GO nanocomposites and reference PP composition (without GO) with different additives (antioxidants, UV absorber, and hindered amine light stabilizer—HALS) were prepared by compression molding. The films were subjected to UV light in an artificial aging chamber for up to 4 weeks and were characterized through visual aspect analysis, FTIR, and Differential Scanning Calorimetry (DSC). The results showed that HALS provided the best protective effect against photodegradation among all analyzed compositions, while the addition of GO also retarded the photodegradation process of PP. Conversely, the UV absorber alone was ineffective in protecting against photodegradation. However, a synergistic effect among HALS, UV absorber, and GO was observed as the best alternative to hinder the PP photodegradation reactions.