(5cb) Design of Novel Polymeric Materials

Polymers are used in a
plethora of applications: packaging, medical devices, membranes, fuel cells,
adhesives, rubber elastomers, fibers, coatings, building materials, automotive
materials, and etc.  These applications require control over various polymer
properties such as mechanical properties, chemical compatibility, transport (or
prevention of transport) of small molecules, adhesion, conductivity,
biocompatibility, and many others.  A single polymer is unlikely to have the
properties required for a desired application.  Rather, combining more than one
polymer is a powerful way to take advantage of the diversity of properties that
polymers have.  Various strategies can be employed to create polymer mixtures:
binary blending, synthesis of copolymers, and designing polymeric surfactants
to compatibilize immiscible polymers. 

I have worked
previously in two areas of interest related to the design of polymeric
materials.  First, during the course of my graduate work at the University of
California, Berkeley, advised by Prof. Nitash P. Balsara in Chemical
Engineering, I utilized block copolymer surfactants to create microstructured
mixtures of immiscible polymers.  The block copolymers exhibited both repulsive
and attractive interactions with the immiscible polymers, which were
manipulated in order to control the structure of the resulting material. Thermodynamically
stable microstructured materials were prepared with as little as 1 vol. % of
the block copolymer surfactant added to the mixture.^1-3

Second, my postdoctoral
research focuses on the area of renewable materials under the guidance of Prof.
Marc A. Hillmyer at the University of Minnesota, Department of Chemistry.  Presently,
the majority of polymers are synthesized from petroleum-derived feedstocks. 
The world supply of petroleum is finite, and in the future it will be necessary
to turn to sustainable alternative resources for plastics raw materials.  We
have chosen to prepare composites prepared from two renewable materials:
polylactide, a biodegradable polymer derived from starch sources such as corn,
and soybean oil, an abundant and inexpensive triglyceride oil. Polylactide is
one of most commonly studied polymers derived from a renewable resource.  However,
the brittleness of the polymer is one of the main impediments to its use in
many traditional petroleum-based polymer applications.  The incorporation of
soybean oil into polylactide allows for the reduction of its brittleness and
thus broadens the potential applications of this material. 

1. Ruegg, M. L.;
Reynolds, B. J.; Lin, M. Y.; Lohse, D. J.; Balsara, N. P.  ?Minimizing the
Concentration of Diblock Copolymer Needed to Organize Blends of Weakly
Segregated Polymers by Tuning Attractive and Repulsive Interactions?,
Macromolecules, 2007, 40, 1207-1217.

2. Ruegg, M. L.;
Reynolds, B. J.; Lin, M. Y.; Lohse, D. J.; Krishnamoorti, R.; Balsara, N. P.  ?Effect of Pressure on a
Multicomponent A/B/A-C Polymer Blend with Attractive and Repulsive
Interactions?, Macromolecules, 2007, 40, 355-365.

3. Ruegg, M. L.;
Reynolds, B. J.; Lin, M. Y.; Lohse, D. J.; Balsara, N. P.  ?Microphase and
Macrophase Separation in Multicomponent A/B/A-C Polymer Blends with Attractive
and Repulsive Interactions?, Macromolecules 2006, 39, 1125-1134.