Synthesis and characterization of two new vinyl groups containing alkoxysilanes and their uses in the vinyl acetate/2-ethylhexylacrylate copolymer latexes

The incorporation of alkoxysilanes into latex systems is of major interest in the field of colloidal science. Two novel vinyl-containing alkoxysilanes, 3-(trimethoxysilyl) propylthiomethacrylate (TMSPTM) and methacryloxyethyl triethoxysilylpropylcarbamate (METESPC) were prepared by the condensation reaction of methacryloyl chloride (MC) with (3-mercaptopropyl)-trimethoxysilane (MPTMS) and addition reaction of 2-hydroxyethyl methacrylate (HEMA) with (3-isocyanatopropyl) triethoxysilane (ICPTES), respectively. Then these monomers were copolymerized with vinyl acetate and 2-ethylhexylacrylate (VAc/2-EHA) by seeded emulsion polymerization, and copolymer latexes were obtained. One kind of vinyl-containing alkoxysilane, the triethoxyvinylsilane (TEVS) has been used as coupling reagent for comparison of the effects of alkoxysilane types on the latexes. The structural elucidation of monomers was carried out by FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The VAc/2-EHA copolymer latexes with TMSPTM or MPTMS were also characterized by FT-IR. The thermal stability of copolymers was respectively studied by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The morphologies of the latexes were characterized with scanning electron microscopy (SEM).

. SEM micrographs of (A) VAc/2-EHA, (B) VAc/2-EHA/TMSPTM (C) VAc/2-EHA/METESPC and (D) VAc/2-EHA/TEVS copolymers.Figure optionsDownload as PowerPoint slideHighlights
► Two novel vinyl-containing alkoxysilanes were prepared.
► As the organosilane increases, the particle size and viscosity of latexes increase.
► Films of the copolymer latexes show excellent water resistance.