Broader Impact: Education

1
New Insights in Polyolefin Blend
MiscibilityJeffery L. White, Oklahoma State
University, DMR-0611474
Broader Impact Education The PIs 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