Monomeric and Polymeric Fluoroalkyl Sulfonyl Fluorides, Sulfonate Salts and Sulfonic Acids for Use as Electrolytes and Coatings

Abstract

Monomeric and polymeric fluoroalkyl sulfonyl fluorides, sulfonate salts and sulfonic acids have qualities desirable for use as electrolytes in alternative energy sources such as fuel cells and solid polymer electrolyte lithium batteries. Since the nature of the fluoroalkyl group affects the properties of these compounds, new monomeric and polymeric fluoroalkyl sulfonyl fluorides, sulfonate salts and sulfonic acids were prepared in this work. Simple compounds prepared in this work were: the fluoroalkyl sulfonyl fluorides, sulfonate salts and sulfonic acid CHF (OCF₂CF2SO₂ F)₂ CF₂(OCF₂CF₂SO₂F) ₂ CH₂(OCF₂CF₂SO3Na) ₂ CF₂(OCF₂CF₂SO3 ) ₂Ca , CF₂(OCF₂CF₂SO3H) ₂ prepared by means of electrochemical fluorination; FC (CF3 ) ₂OCH₂CH₂OCF₂CF₂SO₂F prepared using the adduct of hexafluoroacetone and silver fluoride; CH₃OCF₂CF₂SO₂F prepared as a substrate for free-radical substitution reactions of fluorinated species; and the pentafluorosulfur lithium sulfonate salts SFsCHFSO₃Li and SFsCF₂SO₃Li. Novel compounds containing both alcohol and fluoroalkyl sulfonyl functional groups were prepared: the chlorohydrin ClCH₂CH (OH) CH₂OCF₂CF₂SO₂F; the benzyl ethers HOCH₂CH (OCH₂C6Hs) CH₂OCF₂CF₂SO₂F and C6HsCH₂OCH₂CH (OH) CH₂OCF₂CF₂SO₂F as a product mixture; and the diol HOCH₂CH (OH) CH₂OCF₂CF₂SO₂F. The diol was found to be a useful synthon for the preparation of two polymeric fluoroalkyl sulfonyl fluorides: the polyester [C (O)CF₂CF₂CF₂ C (O) OCH₂CH (CH₂OCF₂) CF₂SO₂F] O]n by reaction with perfluoroglutaric anhydride and a polyurethane formed with 1,6-diisocyanohexane. Other polymeric compounds prepared were: the sulfonyl fluoride, sulfonate salt and sulfonic acid [OCH₂CH (CH₂OCF₂CF₂SO₂F)]n, [OCH₂CH (CH₂OCF₂CF₂SO₃Na)]n, and [OCH₂CH (CH₂OCF₂CF₂SO₃H)]n prepared by homopolymerization of the epoxide OCH₂CHCH₂OCF₂CF₂SO₂F; a cross-linked copolymer of the same epoxide; and the fluoroalkyl sulfonyl fluoride polyacrylat [-CH₂-CH-(CO₂CH₂CH₂CF₂CF₂OCF₂CF₂SO₂F)]n prepared from the acrylate ester H₂C=CHC (O) OCH₂CH₂CF₂SO₂F. ¹H, ¹⁹F and ¹³C nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry, melting point or boiling point, elemental analysis, contact angles, optical clarity, refractive index, and specific conductivity were among the techniques used to characterize the compounds.