This project focuses on the design, synthesis, and catalytic conversion of cyclic esters derived from renewable resources into useful, sustainable polymeric materials. An interdisciplinary approach will be taken that integrates chemical synthesis and structural definition of new monomers, catalysts, and polymers, mechanistic studies of polymerization catalysis via synergistic use of experimental and theoretical methods, and characterization of the properties of new and useful multiblock polymeric materials. An approach aimed at uncovering important and detailed mechanistic information concerning metal alkoxide systems will also be pursued. Finally, expansion and further development of all-renewable and degradable polylactide-polymenthide-polylactide thermoplastic elastomers will be augmented with new efforts to develop these materials for specific applications.
With this award, the Organic and Macromolecular Chemistry Program is supporting the research of Professors William Tolman and Marc Hillmyer of the Department of Chemistry at the University of Minnesota, Twin Cities. The jointly directed research efforts of Professors Tolman and Hillmyer address the challenge of transforming traditional chemical and materials processing, production, and disposal methods and contribute to sustainable technology development by providing fundamental insights into catalysis of renewable cyclic ester polymerizations. The findings from this research will be useful to future industrial efforts to develop new and useful polymeric materials that are environmentally friendly, renewable, and biodegradable. Through interdisciplinary student training in synthesis, polymer chemistry, and catalysis, dissemination of research findings through publications and lectures at conferences, and other activities aimed at informing the public, the research program will impact efforts to develop sustainable technologies for the benefit of society.
," 2/1/09-7/31/12, fourteen students and postdoctoral research associates were trained in catalysis and polymer chemistry. Ten articles were published, one patent was filed, and an Honors Undergraduate and a Ph.D. thesis were completed. Broader impact contributions included development and staffing of an exhibit on "Sustainable Polymers" at the Minnesota State Fair’s EcoExperience (>300,000 annual visitors), co-organization and co-presentation of the "Energy and U Show" to more than 3000 K-12 students per year, involvement in Regional Junior and High School Science Bowl competitions, and meetings with underrepresented minority students at Annual North Star STEM Alliance receptions. In addition, the PIs developed and co-taught for the first time a new course "Green Chemistry" (CHEM 4601) to over 40 undergraduate senior chemistry majors (spring, 2011). The research supported by the grant focused on the design, synthesis, and catalytic conversion of cyclic esters derived from renewable resources into useful, sustainable polymeric materials. Our general approach integrated chemical synthesis and structural definition of new monomers, catalysts, and polymers, mechanistic studies of polymerization catalysis via synergistic use of experimental and theoretical methods, and characterization of the properties of new and useful multiblock polymeric materials. For example, we developed new indium catalysts that were effective at polymerizing D,L-lactide, a renewable monomer derived from corn, to polylactide in a stereoselective manner. We also developed a new method for evaluating the detailed chemical steps involved in cyclic ester polymerizations that provided new insights into how changes in a catalyst influence the polymerization rate. A series of new monomers were developed from plant-derived feedstocks (menthol, carvone, limonene), and these monomers were polymerized to yield new and useful polymers. Multiblock copolymers were also prepared using plant-derived monomers, and these new materials were found to have excellent properties as pressure sensitive adhesives and thermoplastic elastomers. Finally, an improved method for converting bio-derived carboxylic acids to olefins useful as chemical feedstocks was developed.
