Overview of selected Recent Research Projects

Research into feasibility of versatile and facile strategies for generating nanostructured hybrid glass/organic polymer materials with enhanced benefits via molecular level mixing of the hybrid components in the liquid state to afford novel structures, morphologies and properties that are impossible to produce using conventional methods. The self-organized structures ranging from nanometer to micrometer length scales are thermodynamically stable because the inorganic phases are mixed at the molecular level (i.e. form a single phase) during processing. This research was initiated under NSF funding and recently extended under joint NSF-EPSCor Nanotechnology Cluster and DOE funding to include advanced NMR and MD simulations with Dr. Todd Alam of Sandia National Laboratory.

Research in the rheology and phase behavior of novel nanostructured polymer blends was recently initiated under NSF funding. Here we are investigating molecular level blending of reactive polymers to provide an alternative and economical route to producing novel polymer blends with special structures and improved properties that are impossible to achieve using conventional polymer blending methods reported in the literature. The intrinsic molecular-level blending and compatibilization allows the formation of nanstructured polymer blends such as PP/PA6 blends with interesting, stable interpenetrating or co-continuous morphologies that can be controlled during processing. The phase separation kinetics of PP/PA6 blends as influenced by different processing conditions is being investigated in order to obtain a better understanding of the relationship between blend morphology, processing and properties.

Research into the Medium range Order in Polymeric Phosphate glasses was initiated under multi-year NSF funding (see the review article by Dr. otaigbe and Beall in Trends in Polymer Science, copy attached). Applications of theses interesting materials include high-powered laser fusion systems, biomaterials, storage materials for nuclear wastes, and as a component in load-bearing organic-inorganic hybrid cimposites. Most recently, this program on glassy phosphate polymers was extended under joint DoE and NSF International Supplemental funding to include neutron scattering with Dr. Chun Loong of Argonne National Laboratory , solid-state NMR with Dr. Marek Pruski of U.S. Dept. of energy-Ames laboratory and Dr. Wiench of the Polish Academy of Sciences, and study of the polyphosphate chain dynamics through high performance liquid chromatography with Dr. Brain Sales of Oak Ridge National Laboratory. This work was recently extended to include computational MD simulations with Drs. Todd Alam and Randy Cygan of Sandia National Laboratory.

Research into advanced polymer bonded magnets with enhanced magnetic properties for high temperature and aggressive environments was initaited under joint multi-year funding from NSF and Arnold Engineering Co. (a leading U.S. manufacturer of magnets). This work was recently extended to include Dr. Stuart Gabrielson of Brunel University in England.

Research into rheology of block copolymers and molecular polymer composites was initiated under NSF supplemental funding. In this work, melts and solutions of the block copolymers in both homogeneous and heterogeneous (micro-phase separated) states are characterized in terms of nonlinear properties such as non-Newtonian viscosity and first normal stress coefficient in steady shear flow, and linear properties such as in-phase and out-of phase viscosities are obtained in oscillatory shear flows.

Research into Gas Atomization of Polymers, Atomistic Simulation and Modeling of Ultra Fine Polymer Particles was initiated under joint ISU and Huntsman Chemical Company funding. This work was in collaboration with Dr. I. Anderson of Ames Laboratory. This program on polymer atomization was extended to include computer modeling and molecular dynamics simulation with Dr. Don Noid et al. of the Computational Chemistry Group at Oak Ridge National Laboratory. Two U.S. patents awards for this process were issued and four journal papers published. A number of companies have expressed strong interests in licensing this technology. This work was recently extended under an industry grant to include Dr. Bruce Klingensmith of Huntsman Chemical Corporation in Virginia and Dr. Robert Sutton of PPG Industries in Pennsylvania. Most recently, the polymer atomization program was extended under U.S. DoE funding to include generation of ultra-fine polymer particles of arbitrary size and composition in a joint effort with Dr. Michael Barnes of Oak Ridge National Laboratory. By combining this technique with interferometric (coherent) light scattering methods, we have been able for the first time to observe homogeneous blending of a two-component (immiscible) polymer system which ordinarily forms phase-separated structures.

Research into cyclomer technology-based processing methods was initiated to demonstrate feasibility of using ring-opening polymerizations (ROP) to make low-cost thermoplastic composites with enhanced properties such as light weight, high stiffness and strength, excellent crashworthiness and corrosion resistance [see the review article by Otaigbe in Trends in Polymer Science , 5, 17 (1997)]. This research program resulted in collaboration with Mr. Carl Johnson of Ford Motor Company in Michigan .

Research into developing new biodegradable plastics from natural renewable biopolymers derived from soybeans and corn was initiated under funding from American Soybean Association and Iowa Soybean Promotion Board. This work was in collaboration with Prof. Jay-lin Jane of the Department of Food Science and Human Nutrition, Iowa State University and Prof. Sam Huang of the University of Connecticut . Most recently, this project was extended through funding from Iowa Soybean Promotion Board to include feasibility of making thermosetting resins from BF3 .OEt2 catalyzed polymerization of modified soybean oils in a joint effort with Prof. Richard Larock of the Department of Chemistry, Iowa State University.

Research into novel inorganic-organic polymer hybrid systems was initiated to understand the dynamics of deformation and breakup of single drops of the dispersed phase in the continuous matrix polymer phase. This work was recently extended under joint ONR-NICOP and NSF international supplemental funding to include development of new flame-resistant, lightweight foam and quasicrystal-polyimide composites with Dr. Vladimir Yudin of the Institute of Macromolecular Compounds , Russia Academy of Sciences in Saint Petersburg and Prof. Valerie Sheares of the Dept. of Chemistry at ISU.