The effects of TiO2 nanoparticles on physical and thermal properties of polyurethane foam and sandwich panel

flexible polyurethane foam (PU) and monolithic polyurethane sandwich panel samples reinforced with different weight percent of TiO2 nanoparticles (0.25, 0.5, 0.75, 1, 1.5 and 2) have been successfully prepared. The effects of TiO2 nanoparticles on the physical and thermal properties of mentioned samples were examined. In order to observe morphological structure of polyurethane (PU) samples, scanning electron microscopy (SEM) were used. Research results showed that by increasing TiO2 nanoparticles to 2 wt.%, the density of foam and sandwich panel increased to 32.2% and 62.6%, respectively in comparison with pure sample and amount of water absorption decreased to 45% and 58.8%, respectively. The results of UV analysis showed that the maximum amount of UV rays absorption in PU foam reinforced with 2 wt.% of TiO2 nanoparticles equals to 3.21 at wavelength of 450 nm. Investigation results of TGA analysis showed that the presence of TiO2 nanoparticles caused improvement thermal stability of PU nanocomposites. By increasing TiO2 nanoparticles to 1 and 2 wt.%, the degradation temperature at weight loss equals to 10 wt.% of PU increased 14.5 ºC in comparison with pure sample. Also the degradation temperature of weight loss equals to 50 wt.% of samples reinforced with 1 and 2 wt.% of TiO2 nanoparticles increased 1 and 3 ºC, respectively.