title: Dielectric relaxations of polyether-based polyurethanes containing ionic liquids as antistatic agents.
abstract: Dielectric properties of polyurethanes containing poly(propylene oxide) (PO) and poly(ethylene oxide) (EO) units are discussed, along with the results of direct current (DC) measurements and broadband electrical spectroscopy (BES) studies. The dielectric properties of polyether-containing polyurethanes (PUs) are compared to those of PUs containing 1000 ppm of ionic liquids (ILs) as antistatic agents. The effects of the chemical environment of these ILs, including anion-fixed polymers (PU-AF), cation-fixed polymers (PU-CF), and a simple mixture of IL with the PUs (PU-IL), are compared and discussed on the basis of ion mobility. DC measurements suggest that the charge current is attributed not only to the electrode polarization but also to continuous dielectric relaxation. BES studies elucidate that both fast and slow relaxations are taking place in EO-rich domains in pristine PU and PU-AF. The activation energies of the slow relaxation and of the ionic conductivity are similar, suggesting that the ionic conductivity of these materials is attributed to the ion exchange reaction in EO/ion complexes. In contrast, only fast relaxations are observed in the domains mostly comprised of ion-depleted EO in the PUs containing "free" anions, i.e., PU-CF and PU-IL. This suggests that [Tf2N](-) ligands are weakly interacting with the EO chains and contribute effectively to the ion conduction. Thus, enhanced ionic conductivity is observed in PU-CF and PU-IL, yielding sufficient antistatic effects. Taking into account its long shelf life, arising from the lack of IL bleed-out, PU-CF is concluded to be the most promising candidate.
authors.affiliation: Global Innovation Research Organization, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan. ohnoh@cc.tuat.ac.jp and Department of Biotechnology, Tokyo University of Agriculture and Technology, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsurumaki
authors.affiliation: Section of Chemistry for Technology, Department of Industrial Engineering, University of Padua, Via Marzolo 1, in Department of Chemical Sciences, I-35131 Padova (PD), Italy and IENI-CNR, via Marzolo 1, Padova, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Bertasi
authors.affiliation: Section of Chemistry for Technology, Department of Industrial Engineering, University of Padua, Via Marzolo 1, in Department of Chemical Sciences, I-35131 Padova (PD), Italy.
authors.forename: Keti
authors.initials: K
authors.lastname: Vezzù
authors.affiliation: Section of Chemistry for Technology, Department of Industrial Engineering, University of Padua, Via Marzolo 1, in Department of Chemical Sciences, I-35131 Padova (PD), Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Negro
authors.affiliation: Section of Chemistry for Technology, Department of Industrial Engineering, University of Padua, Via Marzolo 1, in Department of Chemical Sciences, I-35131 Padova (PD), Italy and IENI-CNR, via Marzolo 1, Padova, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Di Noto
authors.affiliation: Global Innovation Research Organization, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan. ohnoh@cc.tuat.ac.jp and Department of Biotechnology, Tokyo University of Agriculture and Technology, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohno