Comb-type fluorine-containing polymer electrolyte membranes

Abstract

Using a hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane (D4 H) with 2.2.3.3-tetrafluoropropyl acrylate and vinyltriethoxysilane at a 1:3:1 ratio of the initial compounds in the presence of platinum catalysts, a new D4 RR' type fluorine-containing methylorganocyclosiloxane was obtained. Via a ring-opening co-polymerization reaction of D4 R,R' type methylorganocyclotetrasiloxane in a solution, in the presence of catalysts, anhydrous powder-like potassium hydroxide, or tetramethylammonium fluoride, new comb-type siloxane matrices with pendant ethyl tetrafluopropionate side groups and cross-linkable triethoxysilane moieties were obtained. The synthesized comb-type polymers were analysed with FTIR, 1 H, 13 C, and 29 Si NMR spectroscopy as well as the DSC and GPC methods. Sol-gel reactions of polymers doped with lithium trifluoromethanesulfonate (triflate) and lithium bis(trifluoromethanesulfonyl)imide were studied and solid polymer electrolyte membranes were obtained. The ion conductivity of the membranes was determined via electrical impedance spectroscopy.