SusChEM: Carbonylative Polymerization of Heterocycles and Heteroalkenes

University Of Akron, Akron OH

Investigators

Abstract

The Chemical Catalysis Program supports the efforts of Professor Li Jia of the University of Akron for the investigation of the transition metal-catalyzed carbonylative polymerization of heterocycles (e.g., aziridines and epoxides) and heteroalkenes (containing carbon-oxygen and carbon-nitrogen double bonds). The research encompasses two major objectives: 1) a comprehensive understanding of the mechanism of the cobalt-catalyzed carbonylative polymerization of aziridines and 2) the development of a novel class of zwitterionic nickel (Ni) and palladium (Pd) catalysts for the carbonylative polymerization of epoxides and aldehydes. The mechanistic study utilizes a combination of complementary experimental approaches, including in situ infrared spectroscopy, synthesis of model compounds for catalyst resting states, and a kinetic study of the catalytic process. The novel zwitterionic Ni and Pd catalysts are rationally designed on the basis of the existing mechanistic knowledge obtained from known cobalt catalysts. The polymerization reactions developed in this project are powerful tools for the synthesis of polyamides and polyesters. Polyamides are specialty polymers with applications in antifouling coatings and as physical crosslinkers in high-performance thermoplastic elastomers. The polyesters are environmentally-degradable plastics for commodity applications. This project falls under the SusChEM initiative as it utilizes non-petroleum based starting materials (e.g., CO) as well as some non-precious metal catalysts (e.g., nickel) for the production of potential commodity-scale products. The Chemical Catalysis Program supports the efforts of Professor Li Jia of the University of Akron for the investigation of a catalytic polymerization reactions. Carbon monoxide serves as the raw material for the polymers (plastics) produced by the catalytic polymerizations; carbon monoxide can be obtained from biomass and from the conversion of carbon dioxide (a greenhouse gas). These chemical processes are more environmentally sustainable than those that rely on fossil feedstock. The products of the polymerization are also aimed to benefit the environment. One type of the polymers can be used as an antifouling coating and can potentially replace the tin and copper biocides currently applied to marine vessels to prevent marine fouling. Another polymer product can be used as an ingredient for recyclable thermoplastic rubbers that replace the non-recyclable thermoset rubbers. The polyesters produced by the present catalytic polymerization are "green" plastics that degrade into harmless substances in the environment. The graduate, undergraduate, and high school students will gain important environmental perspectives as well as experience in industrially-relevant areas of research.