Abstract:

Four acrylic copolymers (MMA/BA/HEMA/AA) containing various amount of AA were prepared by solution polymerization. The soap-free water-solubilized colloidal dispersions were obtained by dispersing the copolymer in water through seif-emulsion of the partly neutralized AA in the copolymer. TEM showed that the particles of the colloidal dispersions are spherical and of monodispersion, and the particle size decreases with increasing AA content ranging from 30 nm to 90 nm. It was found by conductometric titration that most —COO~- locates on the particle surface and the surface —COO~- increases with increasing AA content, resulting in the enhancement of zeta-potential. All these results are consistent with the facts that the electrolyte-resistance (expressed as C.C.C. value) and the storage stability (expressed as apparent viscosity) of the colloidal dispersions increase with increasing AA content.

Key words: Acrylic copolymer, Soap-free water-solubilized polyacrylics, Stability of colloidal dispersion