Effects of vitamin E combined with antioxidants on wood flour/polypropylene composites during accelerated weathering

Abstract

Abstract The aim of this research was to investigate the influence of different antioxidant systems containing vitamin E (VE) and antioxidant 168 (AO) on the photodegradation of wood flour/polypropylene (WF/PP) composites, as well as to provide insight into the processes taking place in these systems during weathering. Five groups of composites were treated in a QUV accelerated weathering tester for a total of 960 h. The surface color and the flexural properties of the weathered samples were tested. Additionally, the weathered surface was characterized by SEM, ATR-FTIR, and XPS. The results were: (1) composites with VE and AO showed less loss of flexural strength and modulus, as well as less color fading and fewer cracks on weathered surfaces than surfaces without antioxidants; (2) AO reacted with hydroperoxide and quinones and showed a synergistic effect with VE to further improve the anti-weathering ability of the composites; (3) 0.2% VE and 1.0% AO was the optimal formulation, yielding the best anti-weathering properties among all.