Organic nano-titanium dioxides (TiO 2 ) were prepared with tetrabutyl titanate as precursor, hydrochloric acid as catalyst and γ -methacryloxpropyltrimethoxysilane (KH-570) as modifier, and the organic nano-TiO 2 /acrylate composite emulsions were synthesized by in-situ emulsion polymerization. The structure and properties of organic nano-TiO 2 and organic nano-TiO 2 /acrylate composite emulsions were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), dynamic light scattering (DLS), thermogravimetry (TG) and transmission electron microscopy (TEM). The results showed that KH-570 was grafted successfully to the surface of nano-TiO 2 , and the crystal of organic nano-TiO 2 was anatase form, the smallest particle diameter was 10.2 nm. The organic nano-TiO 2 was dispersed averagely in the polyacrylate matrix, the composite latex particles seemed like "strawberry" and the heat resistance of the composite latex films was improved with the addition of organic nano-TiO 2 .
Organic nano-silica was firstly synthesized by sol-gel method with methyl methacrylate (MMA) and butyl acrylate (BA) in the micelles as dispersing media, tetraethoxysilicate (TEOS) as precursor, hydrochloric acid as catalyst and methacryloylpropyl trimethoxysilane (A174) as modifier. Subsequently, the nano-silica/polyacrylate composite emulsions were directly prepared by in-situ emulsion polymerization under the action of the initiator. The structure and properties were characterized by Fourier transform infrared spectroscopy (FTIR), dynamic light-scattering (DSL), thermogracvimetry (TG) and transmission electron microscopy (TEM). The results showed that A174-modified nano-silica was successfully synthesized in the acrylate-based emulsions by the sol-gel method. The nano-silica was encapsulated by polyacrylate, and the composite latex particles exhibited an apparent core-shell structure. The A174 could improve the lipophilicity of nano-silica and increase the grafting efficiency of polyacrylate on nano-silica particles. The nano-silica/polyacrylate composite latex film had better thermal stability, and the composite latex particles had greater average size and broader size distribution in contrast to those of pure polyacrylate emulsions.
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