SELECTED PROPERTIES OF POLYPROPYLENE-TiO2 COMPOSITES AFTER EXPOSURE TO UV RAYS – PRELIMINARY STUDY

In this study the mechanical properties of polypropylene (PP) with a small amount of TiO₂,, after UV-C exposure were preliminarily analyzed. The effectiveness of titanium oxide was evaluated in two alternative applications: TiO₂ as the polymer filler and TiO₂ as a protective outer coating. The samples were exposed to UV-C rays for 1000 hours. It was found that an addition of 5 wt.% TiO₂ to PP matrix results in a 60% smaller decrease in R_g after 1000 h of exposure to UV-C than in the case of neat polypropylene. It was also found that the addition of TiO₂ to the polypropylene matrix is more effective than TiO₂ applied as a coating component. The R_g decrease after exposure is about 35% in this case. The research confirmed that TiO₂ submicrometric particles seem to be a very good component in reducing the sustainability of polypropylene to UV radiation.