The nano-SiO2／acrylate resin composite latex was synthesized by in situ emulsion polymerization of methyl methacrylate(MMA)and butyl acrylate(BA)in the presence of nano—SiO2 particles

which were modified by silane coupling agent 3-(trimethoxysilyl)propyl methacrylate．The surface properties and dispersibility of nano-SiO2 after modification

chemical structure

Zeta potential and diameter distribution of the composite latex prepared and thermal stability of the hybrid film formed bY the composite latex were investigated by Fourier transform infrared spectrometer(FT-IR)

transmission electron microscopy(TEM)

Zeta meter

Zeta Plus apparatus(dynamic light scattering method)and thermogravimetric analysis(TGA)

respectively．After modification with silane coupling agent

silane was grafted onto the surface of nano—SiO2 to form the organic layers

which were able to efficiently prevent the silica nanoparticles from aggregation in the in situ emulsion polymerization system and improve the compatibility of silica nanoparticles with the acrylate monomers．The nano—SiO2／acrylate resin composite latex prepared had the properties of silica nanoparticles and pure acrylate latex but was not simply a combination．Strong chemical bonding tethered the silica and acrvlate chains to form the core／shell structural composite latex．Consequently

the hybrid film formed by the composite latex exhibited a better thermal properties than the pure acrylate latex film．