Abstract
Two new fluorinated copolymers synthesized by grafting ω-hydroxyl pyrazolic (Trip) and triazolic (Trit) tripods onto poly(chlorotrifluoroethylene-alt-2-iodoethyl vinyl ether) copolymer (poly(CTFE-alt-IEVE) are reported.These copolymers were prepared in two steps: the ω-hydroxy nitrogenous heterocycles reacted with iodine atomsof poly(CTFE-alt-IEVE) copolymer followed by the deprotection of the benzyl group. The chemical structuresof tripod monomers and resulting copolymers were characterized by nuclear magnetic resonance and infraredspectroscopies, elemental analysis, and mass spectrometry. The first analysis allowed one to determine the degreeof grafting that reached 80 and 19% for copolymers bearing pyrazole and triazole, respectively. Membraneswere processed in pellet form by compressing these copolymers. Thermal properties of the membranes,examined by thermogravimetric analysis and differential scanning calorimetry, showed that such copolymerswere thermally stable up to 200°C under air, and exhibited glass transition temperatures ranging between 31and 47°C. The temperature dependence of conductivity led to a simple Arrhenius behavior for both copolymers.Poly(CTFE-alt-IEVE)-dep-Trit19% and poly(CTFE-alt-IEVE)-dep-Trip80% copolymers had a maximum protonconductivity of 1.3 10−3 and 5.91 10−5mS/cm respectively at 180°C under quasi-anhydrous conditions. CyclicVoltammetry (CV) study illustrated that the electrochemical stability d