Research

Waldow Group Research Projects

Our group has one main main research direction with many sub-projects and a second more focused project.  The frst area involves the compatibilization of polymer blends with added copolymers. This project uses a variety of techniques and approaches. The second area is the study of local segmental dynamics of copolymers in dilute solution.

Copolymer Compatibilization of Polymer Blends

Copolymers have often been used to compatibilize polymer blends through favorable interactions with the blend domains. One monomer of the copolymer will strongly interact with the phase rich in that same monomer and vice versa with the other monomer. We have traditionally studied two model polymer blend using polystyrene and polybutadiene with one model system having a low molecular weight allowing both the homogeneous and phase separated phased to be accessed. The other model system has molecular weights above their respective entanglement molecular weights restricting the accessible phase to only the phase separated region. We use 1) cloud point measurements, wide angle, dynamic, and static light scattering as well as small angle neutron scattering, 2) light microscopy (LM) and atomic force microscopy (AFM), 3) Monte Carlo simulations, and 4) anionic and controlled radical synthetic techniques.

Local Segmental Dynamics of Copolymers in Dilute Solution

My groups also studies local segmental dynamics of polybutadiene and PS/PB copolymers in dilute solution. This research is directed at understanding the cooperativity of local segmental transitions that take place especially in copolymer structures. C-13 spin-lattice (T_¹) relaxation is used to investigate these copolymer dynamics. These measurements have been measured using an upgraded Buker QE+ 300 MHz FT-NMR. We will be replacing our 300 MHz NMR with a new 500 MHz FT-NMR using both C-13 and deuterium spin lattice relaxation measurements.