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 determinations 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-vinylnaphthalene 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 polycondensation catalysts and the nature of the heterogeneous polymerization environment at 300 °C.