Perfluoropolyether (PFPE)-Based Vitrimers with Ionic Conductivity

• Published in: Macromolecules Vol. 52; no. 5; pp. 2148 - 2155
• Main Authors: Lopez, Gérald, Granado, Lérys, Coquil, Gaël, Lárez-Sosa, Andrés, Louvain, Nicolas, Améduri, Bruno
• Format: Journal Article
• Language: English
• Published: American Chemical Society 12.03.2019
• Subjects: Chemical Sciences; Polymers
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.8b02493

Ion-conducting low-T g perfluoropolyether (PFPE)-based vitrimers were obtained via thermally initiated polyaddition and in situ N-alkylation in the presence of a fluorinated cross-linker. Both reactions were quantified by differential scanning calorimetry (DSC) employing the Vyazovkin method (74 ± 1 kJ mol–1 for the polyaddition and 140 kJ mol–1 for the N-alkylation). The viscous flow activation energy was found to be 161 ± 23 kJ mol–1, in good correlation with the activation energy calculated by DSC for the N-alkylation. The creep behavior at elevated temperature is typical of a viscoelastic liquid and the relaxation times range from 2.5 h at 170 °C to 4 min at 210 °C. The topology freezing transition temperatures found via thermal creep experiment and relaxometry were in absolute agreement (ca. 110 °C). The network is stable under acidic and basic environments and can recover its mechanical properties after two recyclings. Three samples were prepared by varying the cross-linker loading, and the most stable displays a T d 5% of 293 °C under nitrogen and a water contact angle of 136°. Ionic conductivities for these nondoped materials range from 0.5 × 10–6 to 1.1 × 10–6 S cm–1 at 27 °C.