(193bc) Nearly Precise Ionomers Designed for Ion Transport

Controlling the sequence of ionic groups in ionomers produces better defined nanoscale morphologies and allows new insights into the ionic conductivity. In this study, a series of nearly precise polyester-based carboxylate ionomers with different ion contents were synthesized by polymerizing diol and dianhydride monomers followed by neutralizing the carboxylic acid groups with lithium or sodium cations. This new synthetic route provides possible access to scalable production. By X-ray scattering, the nearly precise ionomers exhibit well-defined microstructures similar to the truly precise ionomers in contrast to the fully random polymers. The ionic conductivity of nearly precise ionomers, as measured by broadband dielectric spectroscopy, increases with the ion contents in the ionomer. The ionic conductivity was also measured under humid environment, where the ionic groups become hydrated so as to significantly improve the ionic conductivity.