1,2,3-Triazolium-Based Poly(ionic liquid)s Obtained Through Click Chemistry Polyaddition

A series of four 1,2,3-triazolium-based poly(ionic liquid)s (TPILs) is synthesized from the polyaddition of different tailor-made alpha-azide-omega-alkyne monomers by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), followed by quaternization with methyl iodide and subsequent anion exchange with lithium bis(trifl uoromethylsulfonyl) imide. Whereas the chemical structures of the bis(trifl uoromethylsulfonyl) imide counter anion and the N-3 methyl group are common to all TPILs, the structural features of the repeating units, i.e., triethylene glycol or undecanoyl spacers with either ester or ether linkages, are varied and compared. Their impact on the physical and ion-conducting properties of the obtained TPILs is established based on H-1 NMR, DSC, thermogravimetric analysis (TGA), and broadband dielectric spectroscopy (BDS) characterization techniques. Most importantly, the replacement of an ether by an ester group at the C-4 position of the 1,2,3-triazolium ring significantly decreases the thermal stability and ionic conductivity of TPILs, whereas the chemical nature of the triethylene glycol or undecanoyl spacers has little influence on the materials properties.