Using ultrasound-assisted dispersion and in situ emulsion polymerization to synthesize TiO2/ASA (acrylonitrile-styrene-acrylate) nanocomposites

In this study, TiO2/acrylonitrile-styrene-acrylate (ASA) nanocomposites with different loading content of TiO2 were prepared via in situ emulsion polymerization. Before the polymerization, TiO2 nanoparticles were dispersed in the reaction monomer by ultrasonic to reduce the agglomeration of TiO2. A series of characterization were taken to study the properties of the nanocomposites. The result of Wide angle X-ray diffraction (WAXD) analysis indicated that the crystal form of TiO2 remained unchanged after the in situ emulsion polymerization. Interestingly, the introduction of TiO2 induced a significant improvement in the impact toughness of TiO2/ASA nanocomposites, which increased dramatically by about 10 kJ/m2 compared with neat ASA. And we attributed this improvement to the better dispersibility of TiO2 in ASA matrix which is proved by Transmission Electron Microscopy (TEM) analysis. In addition, the solar reflectance of the nanocomposites was related to the addition of TiO2 nanoparticles. The more the TiO2 nanoparticle was added, the higher the solar reflectance of the nanocomposite was. Moreover, the outdoor temperature test just proved the result of the solar reflectance.