Fluorinated Pyridine Aryl Ether Polymers with Defined Microstructures, Diverse Architectures, and Tunable Thermal Properties

By utilizing the unique regioselective nucleophilic aromatic substitution (SNAr) of pentafluoropyridine with bisphenols, a series of 4-substituted tetrafluoropyridine (TFP) aryl ether monomers were prepared in nearly quantitative yields from a facile, base-promoted methodology. Sequential regioselective SNAr of TFP monomers with bisphenols afforded linear amorphous, solution-processable fluorinated pyridine aryl ether polymers as well as networks. Room-temperature kinetic experiments using 19F NMR revealed high-molecular-weight polymers with nearly quantitative conversions. By the nature of the bisphenol substitution and its electronic effects, the polymer microstructure was tuned for a broad range of glass transition temperatures for optically transparent materials. This work will provide insights into synthetic routes toward TFP monomers, step-growth polymerization kinetics, molecular weight determination, and thermal properties.