FUMED SILICA AS STABILIZER OF PRECURSOR EMULSIONS USED TO PREPARE POLYMER LATEXES

Introducing small amounts of fumed silica into mixtures of organic liq uids, which contain ethylene glycol dimethylacrylate (EGDMA), a hydroc arbon (such as decane), and one of the following monomers: allylchlori de (AC), 3,4-dichloro-1-butene (DCB), or methyl methacrylate (MMA), en abled their dispersion into an aqueous solution of surfactant with the generation of stable emulsions. Such emulsions cannot be generated in the absence of fumed silica. Functionalized polymer latexes of poly ( AC-EGDMA), poly (DCB-EGDMA), and poly(MMA-EGDMA) could, thus, be prepa red through the polymerization of the emulsions. The chloride units in the poly(AC-EGDMA) or in the poly(DCB-EGDMA) were subsequently conver ted to quaternary ammonium salts. The resulted polymer-supported quate rnary ammonium salt together with RuCl3, 4-N-methylmorpholine N-oxide (NMO) and ammonium persulfate were employed in the catalytic oxidation of toluene to benzoic acid. Furthermore, the presence of fumed silica in the emulsions enabled the preparation of latexes containing rather uniformly distributed inorganic particle clusters of submicrometer si ze. Polymer-inorganic blends of NaY zeolite-(SiO(x))n/P(MMA-EGDMA), ze olite (4A)-(SiO(x))n/P(MMA EGDMA), TiO2-(SiO(x))n/P(MMA-EGDMA), CuO-(S iO(x))n/P(MMA-EGDMA), and Cu-(SiO(x))n/P(MMA-EGDMA) were thus obtained .