Masaaki Yamabe

Novel phosphonated perfluorocarbon polymers

Abstract The copolymerization or terpolymerization of dimethyl perfluoro(3-vinyloxypropyl)phosphonate with tetrafluoroethylene and perfluoro(propyl vinyl) ether yields new perfluorocarbon polymers bearing phosphono groups. A new method for the synthesis of perfluorovinyloxy-substituted perfluoroalkylphosphonic acid derivatives have been also developed by the transformation reactions of corresponding carboxylic esters, involving the facile formation of CF–P bonds by the reaction of perfluoroalkyl iodides with tetraethyl diphosphite. Some of the fundamental properties of these polymers are described.

Progress of fluoropolymers on coating applications: Development of mineral spirit soluble polymer and aqueous dispersion

Fluoro-olefine vinyl ether copolymer (FEVE) has been well known as highly durable polymer for paints industry. FEVE has been widely used for ambient temperature curable solvent-borne paints. In this report, recent developments of FEVE copolymer are reported for mild-solvent paint system and water-borne paint system. Firstly, mineral spirit soluble FEVE copolymers are mentioned for both 1-component and crosslinkable 2-component mild-solvent paint systems. Secondly, FEVE aqueous dispersion polymers are mentioned for non-crosslinkable 1-component latex paint system, crosslinkable 2-component emulsion paint system with isocyanate as containing high OH value and for 1-component crosslinkable emulsion paint system containing carboxyl functionality reactive with hydrazide.

Synthesis and properties of perfluorocarboxylated polymers

Abstract Copolymerization of tetrafluoroethylene and perfluorovinyl ether having carboxylated group in the side chain was investigated. A series of new perfluorocarboxylated polymers with various functional group contents were synthesized by radical polymerization procedure and their structures were examined by IR, NMR spectrometry, osmometry, and X-ray diffraction analysis.

Synthesis of fluorinated difunctional monomers

Abstract In order to obtain fluorinated difunctional monomers for fluoropolyurethanes, we synthesized novel fluorinated aliphatic diisocyanates [OCNCH 2 (CF c2 ) n CH 2 NCO] from corresponding diols [HOCH 2 CH 2 (CF 2 ) n CH 2 CH 2 OH]. Oxidation of the diols with chromium trioxide-sulfuric acid gave α, α, ω, ω-tetrahydroperfluoroalkylene dicarboxylic acids in high yields. Then treating the acids with phosphorus pentachloride afforded corresponding dicarboxyl chlorides, which are easily converted to dicarboxyl azides with hydrazoic acid-pyridine complex. Finally, on Curtius rearangement of the azides, the end products, α, α, ω, ω-tetrahydroperfluoroalkylene diisocyanates were obtained in 53% (n=4) and 19% (n=6) yields from the starting diols.

SYNTHESIS OF PERFLUORINATED VINYL ETHERS HAVING ESTER GROUP

Abstract A new efficient and convenient synthetic process of perfluorinated vinyl ethers containing an ester group was developed by pyrolysis in the presence of α-trifluoromethyl moiety without loss of –COF functional group followed by alcoholysis in high yield.

A new synthetic route to perfluoroalkylphosphonates involving facile formation of the CF–P linkage

A new synthetic route to perfluoroalkylphos-phonates which involves the facile formation of CF–P bonds is reported.

Copolymerization of tetrafluoroethylene and ethylene in fluorinated organic solvents

Copolymerization of tetrafluoroethylene and ethylene was investigated in trichlorotrifluoroethane and trichlorofluoromethane solvents. The high solubility of the monomers in these solvents made polymerization under reduced pressures possible. Trichlorofluoromethane acted as an effective chain transfer agent to regulate the molecular weight. Kinetic studies showed that bimolecular and unimolecular termination prevailed at low and high polymer concentrations, respectively.

Synthesis of Fluorinated Dicarboxylic Acids and Their Derivatives.

New fluorinated dicarboxylic acids, 3, 3, 4, 4, 5, 5, 6, 6-octafluorooctanedioic acid [2 a] and 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8-dodecafluorodecanedioic acid [2 b], having a methylene group between perfluoroalkylene and each carboxyl group, were synthesized in high yields, by the oxidation of corresponding diols[1] with CrO3/H2SO4 (Jones reagent). Oxidation of [1] with other oxdizing reagents such as nitric acid and KMnO4 did not virtually give[2].These dicarboxylic acids are useful not only as monomers of fluorinated polycondensation polymers, but also as precursors of other difunctional monomers such as bis(carboxyl chlorides)[3]and diisocyanates [4].

Synthesis and characterization of perfluorocarboxylate polymers

Abstract Perfluorocarboxylated polymers have recently become increasingly important as base material for ion exchange membranes with excellent electrolytic performance in chlor-alkali process. The polymers were synthesized by copolymerization of tetrafluoroethylene and functional perfluorovinylether such as CF 2 =CFO(CF 2 ) 3 COOCH 3 and CF 2 =CFOCF 2 CF(CF 3 )O(CF 2 ) 3 COOCH 3 . Copolymerization was conducted in bulk or solution system in trichlorotrifluoroethane with the use of radical initiator including azobisisobutyronitrile. By controlling monomer feed ratio, copolymers having various vinylether contents up to 35 mole% were obtained. Reactivity ratios of tetrafluoroethylene and perfluorovinylethers were 7.00 and 0.14, respectively. Resulting copolymers were partially crystalline or amorphous depending upon vinylether contents. The copolymers had thermal decomposition temperature as high as 320°C and melt viscosity of c.a. 10 4 poise at 200 – 230°C. Characterization of these new copolymers are reported based on the measurement of I.R, NMR, Xray spectra and viscoelastic behavior.

The reaction of 1,2-diiodo-tetrafluoroethane with sulfur trioxide

Abstract As an extension of our studies on the reaction of I(CF 2 CF 2 ) n I (n = 2 and 3) with sulfur trioxide 1) , the reaction of 1,2-diiodo-tetrafluoroethane with sulfur trioxide was studied. 1,2-Diiodo-tetrafluoroethane was reacted with an excess of sulfur trioxide at reaction temperature ranging from 0°C to 115°C. The products were not the expected iododifluoroacetyl fluoride and/ or oxalyl fluoride, but thermally stable derivatives with polysulfate structures. These derivaties could be converted nearly quantitatively into iododifluoroacetyl fluoride and ethyl iododifluoroacetate by potassium fluoride and by ethanol, respectively. The possible structures of these derivatives will be discussed based on these results and 19 F-NMR studies.