Polyhedral oligomeric silsesquioxane trisilanols as dispersants for titanium oxide nanopowder

Abstract Trisilanol isobutyl polyhedral oligomeric silsesquioxane (POSS) was used to disperse nanosized titanium dioxide (TiO 2 ) particles in polypropylene (PP). The silanol groups of the POSS cage were bound to the surface of the TiO 2 particles, creating a layer of isobutyl POSS that improved compatibility with the PP matrix. POSS was an effective dispersant both when applied in a chemical pretreatment of TiO 2 and when simply added to the blend during melt compounding. The average particle size of TiO 2 was reduced from 70 nm for neat TiO 2 to 50 nm for the POSS/TiO 2 blend to 33 nm for TiO 2 chemically treated with POSS. Additionally, the POSS coating improved the color of the material and reduced the catalytic effect of TiO 2 on thermooxidative degradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008