Palladium‐catalyzed phosphonation of SEBS block copolymer

Abstract

Phosphonic acid-bearing styrene-ethylene/butylene-styrene (SEBS) block copolymer was synthesized by bromination and subsequent palladium-catalyzed phosphonation of SEBS. The phosphonated block copolymer was characterized by spectroscopic, thermal, and conductivity measurements. The new polymer shows good ionexchange capacity of $0.7 meq/g and proton conductivity of around 2-4 mS/cm (at room temperature and 100% relative humidity) which is in good agreement with literature value of other phosphonated materials. This value was obtained despite a relatively low degree of phosphonation, demonstrating the ability of the phase separated nature of block copolymers to promote proton conductivity. V V C 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5431-5441, 2008

Phosphonic acid‐based amphiphilic diblock copolymers derived from ROMP

“…1 and 2, respectively). In particular, 31 P NMR and FTIR were the most informative techniques. Disappearance of the phosphonate ester peak at 4.16 ppm in 1 H NMR was observed after cleavage.…”

“…Methylene peaks were not observed in DMF-d 7 :D 2 O because of micellization of the polymer. The insets are corresponding 31 P NMR spectra of the respective polymers. MS800/12 instrument with polarized light (824 nm) and a measuring angle of 90 relative to the incident beam.…”

“…26 Phosphonic acid-based polymers have also found several applications such as chelating agents for heavy metal salts, 27,28 ion-exchange resins, 29 and fuel cell membranes. [30][31][32] In this study, we present an approach for the synthesis of phosphonic acid type block copolymers derived from ROMP using ''Grubbs' third generation catalyst'' [(H 2 -Imes)(3-Br-py) 2 -(Cl) 2 Ru ¼ CHPh]. Block copolymer components, monomers 2 and 3, were synthesized by a nucleophilic exchange reaction and Mitsunobu coupling, respectively, using easily accessible starting material exo-oxabicyclo-[2.2.1]hept-5-ene-2,3-dicarboximide, 1 (Scheme 1).…”

In situ modification of Nafion® membranes with phospho-silicate for improved water retention and proton conduction

“…the incorporation of inorganic oxide particles along with acidic characteristics has the potential to increase the durability, water retention capacity and proton conduction of PFSA membranes at elevated conditions. The phospho-silicate containing particles are particularly promising candidates due to the presence of thermally and chemically stable hygroscopic silicate along with acidic phosphate groups, which are known to retain their proton conductivity at higher temperatures [10][11][12]. Moreover, hydrogen ions more strongly bind to the non-bridging oxygen in phosphate in comparison to Si-OH.…”

A synthesis study of phosphonated PSEBS for high temperature proton exchange membrane fuel cells

“…It is difficult to achieve high molecular weight polymers by the polymerization method, due to the aggregation of phosphonic acid groups . The chemical grafting method appears to be convenient and advantageous to produce thermally stable phosphonated membranes . Several polymers such as polystyrene, poly(phenylene oxide), polyimide, and polysulfone, have been subjected to functionalization with phosphonic acid group and were used to fabricate high temperature PEM .…”