Emulsion Polymerization of Acrylic Monomers Stabilized by Poly(Ethylene Oxide)

Abstract

The stability of acrylic latices stabilized by poly(ethylene oxide) (PEO) is governed by the bridging flocculation process during polymerization. The final latex particle size increases with increasing concentration of initiator, PEO, or NaCl. The total scrap formed during the reaction increases rapidly with increasing NaCl concentration due to the ionic strength effect. It is shown that the final latex particle size decreases rapidly with an increase in the agitation speed. The amount of total scrap formed during polymerization is generally greater at a higher agitation speed. These results suggest that the fraction of the particle surface covered by PEO and the ratio of the thickness of the PEO adsorption layer to that of the electric double layer of the latex particles should play an important role in determining the final latex particle size and colloidal stability.