Characterization of carboxylated poly(butyl acrylate) latices produced by a semibatch process

Several carboxylated poly(butyl acrylate) latices prepared by a semibatch emulsion polymerization process were characterized in this study. A significant amount of polyelectrolyte was found in the latex product containing 10% AA, designated as AA10. On the other band, latices containing 0.1% AA (AAO.1), 0.1% MAA (MAAO.1), and 10% MAA (MAA10) showed very low levels of polyelectrolyte in water. Based on the critical flocculation concentration data, it can be concluded that incorporation of 10% AA or 10% MAA into the emulsion polymers can greatly improve the chemical stability of the latex products, especially at higher pH. The data of the pH and conductometric titration experiments show that the MAA unit can be distributed more uniformly in the latex particles in comparison with the AA unit. This result is further confirmed by determination of the T-g's of the emulsion polymers by means of thermally stimulated current (TSC). (C) 1996 John Wiley & Sons, Inc.