Preparation of biphenyl perfluorocyclobutyl (BP-PFCB) polyethylene glycol (PEG) copolymers by the formation of fluorinated arylene vinylene ether (FAVE)

A series of biphenyl perfluorocyclobutyl (BP-PFCB) polyethylene glycol (PEG) copolymers were prepared by nucleophilic addition the hydroxyl end groups of PEG to trifluorovinyl ether (TFVE) end groups of biphenyl perfluorocyclobutyl (BP-PFCB) oligomers. Upon addition, copolymers are linked through a new fluorinated arylene vinylene ether (FAVE) bond. Resulting copolymers were characterized by ATR-FTIR, H-1, and F-19 NMR analysis. Gel permeation chromatography (GPC) showed a number-average molecular weights (M(n)s) of polymers from 9000 to 16,000. A moderated increase in Mns was observed compared to corresponding oligomers. Differential scanning calorimetry (DSC) thermograms revealed glass transition temperatures (T(g)s) from -25 to 127 degrees C. All copolymers showed one copolymer-specific T-g. All T(g)s were compared to the theoretical values calculated from the Fox equation. Comparisons showed T(g)s became more agreeable at the lowest and highest PEG weight fractions. Thermal gravimetric analysis (TGA) studies showed a two-stage degradation in nitrogen and air that corresponded to copolymer weight percent. The onsets of degradations were from 343 to 360 degrees C for copolymers in air and from 333 to 343 degrees C for copolymers in nitrogen.