Investigation on performance of polyurethane by adding of Titanium dioxide Nanoparticle.

Dispersion of nanotitan particles in polyurethane (PU) resin plays an important role to achievement better mechanical and physical properties. In this study nanocomposite coating was performed by incorporating nanotitania pigment with rutile and anatase phase in polyurethane to different loading level (0.1, 0.5, 1.0 and 2.0% by weight). Dispersion of nanoparticles in PU matrix was done by using ultrasonication mixing machine (2 h) and rotary mixer (3 h) and also again UT mixing machine (1 h) and finally gas removing. After addition of the appropriate amount of hardener, prepared nanocomposite coating was investigated by applying on steel and glass substrate and after 2weeks time for curing, exposing them to UV weathering, salt spray, scratch and hardness testing. The dispersion quality and surface morphology of nanocomposite coating was evaluated by using different analytical techniques. Dispersion quality of nanocomposite was investigated using optical microscopy. Dry film thickness (DFT) of samples was mostly in the range 90 µm. Roughness after exposing of naoncomposites on UV radiation and salt spray measurement by atomic force microscopy (AFM) topography and analysis by this apparatus and mechanical behavior also by using hardness and scratch test and also by colorimetry measurements, surface degradation of PU nanocomposite coatings was characterized by color changing, defined as the color measurement, after being exposed to accelerated weathering conditions.