Styrenic surfmers in emulsion polymerization of acrylic monomers. 3. Surface analysis

Styrenic block-copolymer polymerizable surfactants;ants, when engaged in em ulsion polymerization of core-shell acrylic latexes, are forming copolymers containing a large majority of monomer units. These copolymers can be extr acted, and analyzed, after extensive washing of the particles by ultrafiltr ation. Owing to the restricted mobility of the polymer inside the particles , direct H-1 NMR analysis, in normal water-with water suppression-of the la tex itself in its initial serum, gives selective detection of the water-sol vated species and allows to estimate both the amount of surfmer remaining a t the surface of the particle and their conformation, thus allowing to dete rmine what part of it participates in the steric and electrosteric stabiliz ation.