Miniemulsion polymerization: Applications and new materials

Stable miniemulsions were prepared with cationic (CTAB and CTMA(2)-tartrate ) and nonionic surfactants (Lutensol AT50 and SE3030). The dependence of th e latex particle sizes on the amount of the different surfactants showed th at ionic surfactants can be more efficiently employed for the synthesis of small particles than the nonionics. For encapsulation of pigments the chemi cal parameters of the miniemulsion, such as amount and type of the surfacta nt, have to be chosen so that the final size of the latex corresponds with the size of the pigments. The pigments themselves require a hydrophobic sur face in order to enable their embedding into the monomer phase. The success ful incorporation of the pigments into the latexes was verified by transmis sion electron microscopy, freeze-fracture electron microscopy, and the anal ytical ultracentrifuge.