Advanced copolymer and terpolymer systems are being studied under a coordinated research program in the Polymer Science Laboratories at the University of Southern Mississippi. In this report we described second year efforts in synthesis, characterization, and rheology to develop polymers with significantly improved efficiency in mobility control and conformance as compared to conventional systems. Key features of these microstructually tailored systems allow triggered response to environmental stimuli including pH, ionic strength, electrolyte concentration, and shear. Ampholytic and/or hydrophobic interactions between polymer chains can be designed for desired reological response. The polymers have potential to circumvent problems inherent in traditional EOR polymers where molecular weight must be compromised to allow sufficient permeation without plugging of the porous reservoir network. Most conventional polymers fail in high calcium, barium, or sodium concentrations, precluding use in high salinity fields or off-shore. By contrast, these advanced polymer systems would maintain high viscosities or behave as virtual gels under low shear conditions and at elevated electrolyte concentrations. At high fluid shear rates, associates would deaggregate yielding low viscosity solutions, reducing problems of shear degradation or face plugging during injection. Other promising polymer systems developed during the past year are polymeric surfactants with potential for use in higher salt, higher temperature reservoirs for mobilization of entrapped oil. Since 1978, DOE-sponsored research projects in our laboratories have been directed at establishing unifying concepts regarding interrelationships between tailored polymer structures and fluid behavior under controlled salinity, pH, concentration, shear, and flow through porous media. We have demonstrated that nearly every significant behavioral characteristic of polymer solutions in mobility control can be related to macromolecular architecture and hydrodynamic volume. These include: ? concentrations required for mobility control ? viscosity in the presence of electrolytes ? phase stability as a function of ionic strength and temperature ? adsorption to porous media ? network pore clogging ? sweep efficiency and slug dispersion ? shear thinning effects ? G molecular associations ? polymer/surfactant interactions