poly(vinyl methyl ether)

1. Hydrogen Bonding in Polymer BlendsTimothy P. Lodge, University of Minnesota-Twin Cities, DMR 0804197 Although there are literally hundreds of different polymer materials available on the market, there is a great demand for improvements in property combinations, such as high strength, high flexibility, recyclability, water repellency, etc. To achieve these, a promising strategy is to blend different polymers, just as metals are blended in alloys such as brass. However, most polymer pairs do not mix, and thus strategies are required to stabilize the resulting materials. The introduction of hydrogen bonds between the different polymers is one such strategy. We have utilized model polymers in which one component accepts hydrogen bonds, while the other contains varying degrees of a hydrogen bond donor. By studying the flow properties of these materials, we are able to judge how many hydrogen bonds are necessary in order to achieve complete homogeneity in the resulting material. This information will ultimately be of great use in designing both formulations and processing conditions for advanced polymer blends. “Restoring Thermorheological Simplicity to Polymer Blends: How Many Hydrogen Bonds are Required?”, A. N. Gaikwad, A. Choperena, P. C. Painter, and T. P. Lodge, Macromolecules, 43, 4814-4821(2010). The green polymer (polyvinyl methyl ether) is a hydrogen bond acceptor, while the blue polymer (polystyrene) does not participate in hydrogen bonding. Thus the green/blue mixture has no hydrogen bonds, and shows complicated flow behavior. The red polymer (polyvinyl phenol), on the other hand, donates hydrogen bonds. By preparing random copolymers of red and blue, with differing fractions of red, the amount of hydrogen bonding in a blend can be systematically tuned. poly(vinyl methyl ether) polystyrene poly(vinyl phenol)

2. Broader Impact: Undergraduates doing Polymer Research Timothy P. Lodge, University of Minnesota-Twin Cities, DMR 0804197 Haidy Soto, an undergraduate at University of Texas-Pan American, participated in the summer REU program at Minnesota as part of the MRSEC-PREM partnership. Here she is presenting a poster on her work. Nakisha Newell is an undergraduate at Minnesota. She spent the spring semester as a UROP student, and joined the MRSEC REU program for the summer. Her work on polymer/ionic liquid phase diagrams should shortly lead to a publication. Dr. Hau-Nan Lee has gained valuable experience in mentoring undergraduates, including Nakisha and Sharon Chan (not shown), in their introduction to research.