Low Temperature, In Situ Polymerization of Vinyl Acetate in Silica Containing Emulsion Gels

Vinyl acetate (VAc) was polymerized to about 90% conversion in 9 h at 40°C from the colloidal microstructure of the VAc/fumed silica/cetyltrimethylammonium bromide (CTAB) system. The glass transition ( T g ) of poly(vinyl acetate) (PVAc) polymerized in these emulsion gels with silica was higher ( T g = 41 ° C ) than those of PVAc made from bulk polymerization at 60°C ( T g = 31 ° C ) and the weight average molar mass ( M w ) was also larger ( M w about 300 kg/mol) than those from bulk polymerization ( M w = 125 kg / mol ). Increased M w , T g , and lowered processing temperature for these composites could facilitate new applications for PVAc.