Preparation of nano titanium dioxide reinforced rigid polyurethane foam

By power ultrasonic, nano titanium dioxide particles were dispersed into polyaryl-polymethylene-isocyanate (PAPI), and rigid polyurethane foams (RPU) reinforced by nano TiO2 were prepared by polymerization PAPI with polyether polyol. SEM was employed to observe structures of TiO2-filled polyurethane foam and showed that nano TiO2 particles had been dispersed uniformly in foam. Results of mechanic test show that nano TiO2 particles in low loading fraction can increase the compress strength and impact strength of rigid polyurethane foam. But addition of nano TiO2 led to the rapid accretion of viscosity of PAPI, which made the foam reaction difficult and contributed to the impact strength decrease in addition of 10% nano TiO2.