Clickable perfluorocyclobutyl aryl ether polymers bearing azido groups: synthesis and post-functionalization

Abstract

A novel class of clickable perfluorocyclobutyl (PFCB) aryl ether polymers containing azido groups (APFCB polymers) is reported. The thermal cyclopolymerization reaction of 2-methyl-1,4-bis(1,2,2-trifluorovinyloxy)benzene was first optimized by DSC, GPC and 19F NMR, and the matrix polymer (PFCB-Me) with high average molecular weights (Mw = 13.61 × 104 g/mol) and molecular weight distributions (Mw/Mn = 1.68) was obtained. Then, a series of APFCB polymers with tunable azido contents were successfully prepared from the PFCB-Me polymer by bromination and azidation. Post-functionalization of APFCB polymers with sulfonate functionality was accomplished by Cu(I)-catalyzed azide-alkyne cycloaddition click chemistry. The prepared polymers were characterized by FT-IR and NMR spectra, while the thermal properties and solubility were also investigated. The APFCB polymers exhibit glass transition temperatures in the range of 67 °C to 73 °C and good solubility in common organic solvents. This work suggests that the designed APFCB polymers may be a promising versatile platform for developing new functional PFCB aryl ether polymers.