Antioxidant functionalized silica-coated TiO2 nanorods to enhance the thermal and photo stability of polypropylene

Rutile TiO₂ is commonly used as UV shielding agent because of the absorption of UV light. In this research, we integrated the function of rutile TiO₂ nanoparticles and antioxidants (AO), and prepared a kind of multifunctional TiO₂ nanoparticles with the capacity of both UV absorption and antioxidation. Firstly, rutile TiO₂ nanorods were prepared and encapsulated by SiO₂ to decrease its photocatalytic activity. Then, antioxidant functionalized silica-coated TiO₂ nanorods (AO-KH550-SiO₂-TiO₂) were successfully synthesized by using aminosilane coupling agent (KH550) as a bridge. By melt blending method, AO-KH550-SiO₂-TiO₂ were incorporated into PP matrix. The results indicated that AO-KH550-SiO₂-TiO₂ could improve both photo stability and thermal stability of PP. PP/AO-KH550-SiO₂-TiO₂ film broke after 220 h UV irradiation, and the broken time of PP/TiO₂ film was only 80 h. And the oxidation induction time of PP/AO-KH550-SiO₂-TiO₂ sample was 4.7 min, while PP/TiO₂ sample showed no antioxidation effect. In addition, AO-KH550-SiO₂-TiO₂ exhibited excellent anti-extraction property. This novel design of AO-KH550-SiO₂-TiO₂ may open up a new avenue for fabricating multifunctional nanoparticles and facilitating their practical application.