Improving the Creep Stability of High-Density

ABSTRACT: Acicular titania nanoparticles with average dimensions of 15 60 nm2 were produced by hydrother-mal crystallization of TiOCl2. Titania particles were surface-functionalized with octadecylsilane to obtain an organo-philic surface. High-density polyethylene (HDPE) nanocom-posites were prepared by melt compounding with 2, 3, and 5 vol % concentrations of untreated and surface-functional-ized titania nanoparticles. Quasi-static mechanical tensile tests evidenced slight increments of both the elastic modulus and stress at yield, which were accompanied by a marked reduction of the strain at break at high filler contents. The introduction of titania nanoparticles induced a substantial reduction of the creep compliance of the HDPE matrix and of its creep rate, especially at long loading times. Untreated titania nanoparticles were more effective in reducing the creep compliance than the functionalized ones. VC 2009 Wile