PREPARATION AND CHARACTERIZATION OF AQUEOUS DISPERSIONS OF OIL-COATED POLY(ACRYLlC ACID) PARTICLES

ABSTRACT

A system consisting of a 5% aqueous dispersion of poly(acrylic acid) particles protected from aqueous environnement by a silicon oil layer coating and stabilized by emulsifying agents has been designed. The influence of formulation parameters on the Theological properties of the system are described. The formulated dispersion has been shown to undergo large viscosity changes from a liquid state up to a semi-solid consistency when the preparation is diluted or subjected to pH increases. The microstructure of the gelified system consisted of a close packing of deformable poly(acrylic acid) swollen particles, as shown by rheological dynamic oscillatory experiments.