Properties of polypropylene/TiO2 nanocomposites: The melt rheology, tensile strength and electrical characteristics.

Abstract

Titanium dioxide (TiO₂) in rutile crystal form with and without modification by 1 wt% of 3-glycidoxypropyl-trimethoxy silane were mixed with isotactic polypropylene (PP) at 180^oC to prepare nanocomposites. Investigation of melt rheology of nanocomposites showed the relative melt viscosity increased with increasing levels of original TiO₂ (ORT) and modified TiO₂ (MRT). Tensile test of samples revealed that mechanical properties of PP/MRT nanocomposites have significantly improved in comparison with PP/ORT nanocomposites. The maximum value of tensile strength and Young’s modulus of PP/MRT reached 42 MPa and 979 MPa, respectively, at 2 wt% of MRT. The investigation of accelerated weathering test of nanocomposites revealed the retention in tensile strength of PP/ORT and PP/MRT nanocomposites are higher than that of pure PP. The electrical properties of PP/ORT and PP/MRT nanocomposites were also studied. The results showed that both MRT and ORT decreased electric insulation of PP. However, electric insulation of PP/ORT nanocomposites is still higher than that of PP/MRT nanocomposites.