Effect of alkalinization on carboxylated latices prepared with various amount of a non-ionogenic hydrophilic comonomer 2-hydroxyethyl methacrylate

Six latices of carboxylated styrene/butyl acrylate copolymers with 0–25% of 2-hydroxyethyl methacrylate (HEMA) were prepared by semicontinuous non-seeded emulsion polymerization and investigated by photon correlation spectroscopy and viscometry. Although HEMA is non-ionogenic, it profoundly affects the latex behavior after alkalinization: both methods revealed that HEMA promotes an increase in hydrodynamic dimensions of dispersed particles. The increase in viscosity due to incorporation of 10% of HEMA into the copolymers can make more than one order of magnitude at high volume fractions.