Hydrophobically modified responsive polyelectrolytes

Thermally responsive latices composed of either linear or cross-linked copo lymers, as well as macroscopic hydrogels, have been prepared by copolymeriz ing N-isopropylacrylamide (NIPAAM) with acidic monomers (methacrylic acid) and with nonsoluble hydrophobic monomers. The hydrophobic monomers include methyl methacrylate, as well as fluorinated methacrylates. The product poly mers are polyelectrolytes showing thermal behavior typical of PNIPAAM. The dimensions of the latex particles have been studied by dynamic light scatte ring whereas the gels have been studied by swelling tests. The main topics of interest have been the effect of the chemical structure on the collapse of the polymers, on the one hand, and the effect of the topological structu re of the network on the properties of the gels, on the other hand. It has been shown that the polyelectrolyte nature of the gels is to a certain degr ee dependent on the homogeneity of the network structure. Also, the binding of low molar mass substances into the polymers has been studied.