Shaken Not Stirred: Perfluoropyridine-Polyalkylether Prepolymers

Abstract

The purpose of this work was to employ perfluoropolyalkylethers (PFPAEs) with perfluoropyridines (PFPs) to form telechelic oligomers for use in low-temperature materials. Since perfluoropyridines are very regioselective, various nucleophiles were utilized, starting with an arsenal of PFPAEs such as oligo(hexafluoropropylene oxide) methylene alcohol (Krytox Methylene alcohols), Mach I perfluoroether diol, and Fluorolink E10H. Each reaction was completely successful with PFP using bases such as sodium hydride or the preferred cesium carbonate. Various solvents could be utilized (tetrahydrofuran (THF) or acetonitrile), but dimethylformamide (DMF) was the favored option. Further exploration was accomplished with mechanochemical synthesis, and the majority of the reactions were shortened from their 48 to 72 h reactions to approximately 1 min in good to moderate yields. Finally, Fluorolink E10-H-based bis(perfluoropyridine)-PFPAE was then copolymerized with Bisphenol A, Bisphenol AF, 1,1,1-tris(4-hydroxyphenyl) ethane, and PEG 2000 forming novel materials, which were further characterized with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).