The allure of "molecular videos": In-situ infrared spectroscopy of polymerization processes

In-situ infrared spectroscopy permits the real-time elucidation of polymerization kinetics and mechanisms for a wide range of polymerization processes. Both near- and mid-infrared spectroscopy have been utilized for the investigation of living ionic polymerizations. The essential determination of pseudo-first-order polymerization kinetics that are consistent with living mechanisms and monomer conversion profiles facilitated the discovery of novel block and star copolymers. Real-time determination of polymerization rates for stable free radical polymerizations of styrene and 2-vinyl naphthalene has provided significant insight regarding nitroxide mediation in free radical polymerization processes. Free radical alternating copolymerization of norbornenes with maleic anhydride was also investigated and in-situ mid-infrared spectroscopic analysis has been vital for mechanistic studies of this copolymerization process. In addition, mid-infrared spectroscopy of melt phase polyester polymerizations via acidolysis allowed the identification of suitable poly-condensation catalysts and the nature of the heterogeneous polymerization environment at 300 °C.