Macromolecular Characterization and Solution Behavior of Polymer Additives

Abstract : In the ARO project, several aspects of polymer rheology and microstructures were investigated by using a variety of physical techniques, including the development of a new magnet-enhanced optical falling needle/sphere rheometer. From studies of rheological properties and association behavior of mixtures of poly(isobutyl methacrylate-tert-butyl aminoethyl methacrylate) and an ionomer in solution, and of random copolymers of styrene with sodium-2- acrylamido-2-methylpropane sulphonate, it becomes clear that structures of associative polymers can best be approached by using well-defined block copolymers. Furthermore, the ionic interactions deserve special examination in view of ion cluster formation and long-range inhomogeneities which are present often because of processing procedures. A series of studies of block copolymers, including lightly sulfonated polystyrene-b-poly(tert butylstyrene) and triblock poly(oxyethylene-oxypropylene-oxyethylene) in nonpolar (xylene), polar (water) and water/o-xylene mixtures. The size, shape and aggregation number were determined by using laser light scattering- small angle x-ray scattering and transient electric birefringence techniques. Rheology of interacting polymers, Association behavior of polymer additives and of block, Copolymers