Effect of molecular structures of Gemini and polymerizable emulsifiers on cationic emulsion copolymerization of styrene and butyl acrylate

In order to understand the effect of molecular structures of emulsifiers on the cationic emulsion copolymerization of styrene (St) and butyl acrylate (BA) in details, hexadecyl trimethyl ammonium bromide (CTAB), methacryloxy ethyl hexadecyl dimethyl ammonium bromide (DMHB), ethanediyl bis(hexadecyl dimethyl ammonium bromide) (G16-2-16), and maleic acid diethyl bis(hexadecyl dimethyl ammonium bromide) (P16-8-16) were used as emulsifiers. TEM photos, instantaneous conversions, and colloidal features, such as the particle size, surface charge density, and glass transition temperature (Tg), were measured. Compared with polymerizable emulsifiers (DMHB and P16-8-16), non-polymerizable emulsifiers (CTAB and G16-2-16) produced more uniform nanospheres. In the reactions with polymerizable emulsifiers, higher reaction rates, lower surface charge densities, and lower Tg were observed. Compared with the single-chain emulsifiers, the double-chain emulsifiers resulted in lower reaction rates, bigger particle sizes, better monodispersities, and higher surface charge densities.