Broader Impact : Education

1. New Insights in Polyolefin Blend MiscibilityJeffery L. White, Oklahoma State University, DMR-0611474 Broader Impact: Education The PI’s group moved from NCSU to OSU as this renewal was just beginning. Dr. Marcin Wachowicz began as a postdoctoral fellow December 1, 2005. Since that time, Rosimar Rovira, a Ph.D. student from Puerto Rico, has worked on the project from the standpoint of some unique polymer syntheses, and a summer undergraduate student (Drew Cooper, a chemistry major at Notre Dame) has also joined for the summer of 2006. With respect to Mr. Cooper, the PI is providing an REU-type experience from grant funds, even though OSU is not hosting an REU program this summer. During the first full year of the renewal, approximately 7 seminars were given in the state to four-year institutions regarding this NSF project. Faculty there were appreciative, as most smaller institutions are not able to provide any significant polymer instruction. Broader Impact: Outreach using I-Pod Science Podcasting The PI, pictured on the I-Pod below, is generating science education “movies” that can be accessed as Podcasts using any computer or hand-held video I-Pod. In this way, the multitude of rural schools throughout the state can access real-time teaching aids, “browse” a variety of topics which they might like to see in a personal visit by the PI, and learn how science influences daily life.

2. New Insights in Polyolefin Blend MiscibilityJeffery L. White, Oklahoma State University, DMR-0611474 During the first funding period, our group established the relationship between configurational entropy, i.e., what conformational energy modes a polymer chain can access, and miscibility. In the second funding period, we are seeking techniques to (1) strictly quantify these effects, and (2) establish relationships between physical properties of new blends and how their chains rearrange on very slow timescales. To this end, the figure (right) shows a quantitative model for chain conformational dynamics on the frequency scale of 1-10 Hz. Our work is the only work to study this slow motion regime (believed to be most important for mechanical properties) for both blend chains simultaneously but specifically, and without any solvent or labeling. The main conclusion for the polyisobutylene and polypropylene blend shown is that mixing effects are not additive by composition, but rather generate new dynamic regimes promoting miscibility (see reference). dS/S T (K) Sample chain rearrangement data (5-10 Hz frequency) for the hhPP chains in a solid PIB/hhPP blend extracted from pure CODEX NMR experiments over a wide temperature range (200-300 K). Experimental points and theoretical fits (solid line) are indicated. Positive intensity corresponds to the density of chain motion in the selected frequency range. The approach is applicable to any polymer blend for which a 13C NMR signal is available. From the model, an activation energy for chain reorientation = 78 kJ/mole is extracted. Model details can be provided on request, as well as the control experiments for the pure polymers. Macromolecules, 2005, 38, 10466 (December 13 issue) entitled “Factors That Allow Non-Polar Macromolecules to Form Miscible Blends”