title: Synthesis and evaluation of novel proton exchange membranes containing the semisquaric Acid group.
abstract: We focus our attention here on semisquaric acid, which is known to show high acidity, as a new proton dissociating group for proton exchange membranes (PEMs). The introduction of a squaric acid group into aromatic polymers was conducted by the reaction of lithiated aromatic polymers and diisopropoxy squarate, followed by treatment with hydrochloric acid. A resulting polyphenylsulfone membrane with the squaric acid group introduced (PPSf-SQ, IEC = 4.1 meq·g(-1) ) showed proton conductivity of 1.0 × 10(-1) S·cm(-1) at 80 °C under 95% relative humidity, which indicates that the semisquaric acid has the potential to become an alternative proton-conducting group for PEMs.
authors.affiliation: Sumitomo Chemical Co., Ltd., Tsukuba Research Laboratory, 6 Kitahara, Tsukuba, Ibaraki, 300-3294, Japan. yoshimurak2@sc.sumitomo-chem.co.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshimura
authors.forename: Lanny S
authors.initials: LS
authors.lastname: Liebeskind