The role of itaconic and fumaric acid in the emulsion copolymerization of methyl methacrylate and n-butyl acrylate

The effect of itaconic (IA) and fumaric (FA) acids, in the emulsion copolymerization of methyl methacrylate (MMA) with n-butyl acrylate (BA) is presented in this work. The effect of functional monomers on the overall conversion, on the colloidal properties of the latexes as well as on the distribution of the carboxylic groups (buried, particle surface and serum) was examined. The effect of the pH on the partitioning of IA and FA on the copolymerizations was also examined in order to better understand the role of these functional monomers. The carboxylic groups present in the cleaned latexes were analyzed using conductimetry and manual titration with a solution of sodium hydroxide in methanol. The results of these analyses showed that it was possible to determine the distribution profile of the carboxylic groups in the latexes (buried, particle surface and serum). It was demonstrated that IA and FA were distributed differently throughout the three phases of the emulsion, with these differences depending on the solubility of the corresponding monomer.