A one-pot strategy for the synthesis and functionalization of hyperbranched polytriazoles

Herein we report a one-pot strategy for the synthesis and functionalization of hyperbranched polytriazoles by means of the Huisgen 1,3-dipolar cycloaddition of an AB₂-type monomer containing an alkyne and two azide groups. The AB₂ monomer is synthesized starting from dimethyl 5-hydroxyisophthalate in four steps with an overall yield of 58%, and the synthesis and purification are straightforward. The synthesis of end-capped hyperbranched polytriazoles (HBPTs) can be achieved via the Huisgen cycloaddition of the AB₂ monomer using only heat, followed by functionalization with either sulfonic acid (-SO₃H) or pentafluorophenyl (-Ph-F₅) end groups. The resulting functional hyperbranched polytriazoles, HBPT-Ph-SO₃H and HBPT-Ph-F₅, are characterized by ¹H NMR and FT-IR spectroscopies as well as gel-permeation chromatography. The film is fabricated simply by blending the two polymers, and the ion exchange capacity and ion conductivity are measured.