Synthesis of (Sty-co-BA-AA) latexes including ZnO and TiO₂ nanoparticle by miniemulsion polymerization

Herein, it is reported that synthesis of poly(styrene-co-butyl acrylate) latexes containing ZnO and TiO₂ nanoparticles was carried out using miniemulsion polymerization. The synthesized latexes and films cast from them were characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy energy dispersive X-ray (SEM-EDAX), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Stress–strain and DMA analysis was performed for the mechanical analysis of the films prepared from latexes. The particle sizes of the latexes were about 60 nm for pure latex and latex only containing ZnO and TiO₂, while the particle size for latex containing nanoparticle mixture was measured as 120 nm. XRD, SEM-EDAX, and TEM analysis results showed that the nanoparticles were well dispersed in latex. When the mechanical analysis results were compared, latex films including 2% ZnO nanoparticles were found to be stronger. DMA analysis showed that the glass transition temperature (T_g) values of the polymers were between 0 and 10°C and the nanoparticles were not effective in changing the T_g values. Latex films were exposed to 254 nm UV light to determine their yellowing. According to the colorimetric measurement, ZnO nanoparticle-embedded films were found to be more resistant to yellowing.