Stuart Cooper was finishing his PhD when I arrived at Princeton. His thesis advisor, Arthur Tobolsky, proposed that I continue Stuart's work. I didn't feel that there was much future in block copolymers and choose instead to pursue thesis research in melt rheology. About 10 years later I saw the light and a good fraction of the research in our group since then has focused on these facinating polymers. I will review some of our past work on the interaction of fast polymerization and phase separation during the formation of polyurethanes. Phase mixing during polymerization is important for our current work in which we substitute polyols derived from soybean oil for the typical polyether polyols used to make polyurethane foam. Atomic force microscopy on compressed foams was used to image the phases. These images as well as differential scanning calorimetry, dynamic mechanical analysis, infrared and small angle x-ray scattering demonstrate that these soybased polyols can interact with the hard segements.