Amphiphilic copolymers from miniemulsified systems

Abstract

The polymerization process of two monomers with different polarities was carried out in direct or inverse miniemulsions using the monomer systems acrylamide/methyl methacrylate and acrylamide/styrene. The monomer, which is insoluble in the continuous phase, is miniemulsified in the continuous phase of water or cyclohexane in order to form stable, small droplets with a low amount of surfactant. The monomer with the opposite hydrophilicity dissolves in the continuous phase (and not in the droplets). Starting from those two dispersion situations, the locus of initiation (in one of the two phrase or at the interface) was found to have a great influence on the reaction products and the quality of the obtained copolymers. One important criterion for the quality of the formed copolymer was a minimal content of the homopolymers, which was checked by using the GPC as a separation device. The quality of the formed copolymer with respect to the copolymer composition and its blockiness was analyzed by NMR. The analysis of the colloidal behavior of the particles formed by the copolymers was a third point of analytical interest.