Synthesis,characterization,and properties of novel UV-resistant poly(urethane-imide)/POSS nanocomposite

In this study, a series of hybrid nanocomposites composed of poly(urethane-imide) (PUI), fluoroethylene vinyl ether copolymers, and octa-aminophenyl polyhedral oligomeric silsesquioxane (POSS) were successfully prepared. Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), contact angle analysis, thermogravimetric analysis (TGA), and dynamic mechanical analysis were used to characterize the hybrid nanocomposites, which were found to have excellent thermostability, mechanical strength, and ultraviolet (UV) resistance. The SEM results showed that POSS nanoparticles, at low content level, could disperse homogeneously in the PUI matrix. The TGA results confirmed that the thermostability of the hybrid nanocomposites was significantly improved by the addition of POSS. Moreover, the UV-resistant property of the nanocomposites was evaluated based on the change in mechanical property and weight loss caused by the UV radiation. POSS (5 wt%) achieved the highest efficiency in enhancing the UV resistance of the nanocomposites. After UV radiation, the tensile modulus of the nanocomposite without POSS decreased to 187 MPa, and the mass loss was 7.26%. In contrast, the tensile modulus of the nanocomposite containing 5 wt% POSS increased from 412 MPa to 444 MPa, and the mass loss was only 3.76%.