Haruhisa Miyake

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.

The Design and Development of Flemion Membranes

Salt brine electrolysis using perfluorinated ion exchange membranes is now recognized worldwide as the most energy saving process for the production of chlorine and caustic alkali. Membranes are based on perfluorinated polymers having functional groups.

Advances in Flemion Membranes for Chlor-Alkali Production

Updated advances of Asahi Glass’s membrane cell technology are described. Design concepts and advantages of the AZEC-F2 electrolyzer, basic properties and commercial experiences of Flemion 890 series (sulfonate base) membranes, features and economics of Fx-50 (a membrane for production of 50% caustic soda) are introduced.

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 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.