Synthesis and characterization of perfluorocyclopentene-thioether polymers

Due to their unique properties and use in high performance materials, the ability to obtain fluorinated polymers utilizing straightforward synthetic methods remains of interest. In this study, we report the facile synthesis of new fluoropolymers via nucleophilic addition of a di-thiol to perfluorocyclopentene. Initially, model studies were completed with perfluorocyclopentene, benzenethiol and tetramethylsilane-protected benzenethiol to identify the optimal reaction conditions for the polymerization. These reaction conditions were then utilized to prepare perfluorocyclopentene-thioether polymers from perfluorocyclopentene and 4,4′-thiobisbenzenethiol. The isolated polymers had molecular weight distributions consistent with step-growth polymers and ¹⁹F NMR spectroscopy revealed that the addition of the nucleophile to perfluorocyclopentene was controlled. Analysis by DSC showed that the polymers were amorphous with glass transition temperatures around 65 °C. TGA in both air and nitrogen showed an initial degradation temperature around 370 °C, while the air analysis produced an additional plateau with a degradation temperature near 592 °C. This is the first known report of utilizing perfluorocyclopentene for the preparation of perfluorinated-thioether polymers. © 2024 Society of Industrial Chemistry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.