Fluoropolymers tetrafluoroethylene, synthesis

None of fluoropolymers or their decomposition products poses any threats to the ozone layer. None are subject to any restrictive regulations under the Montreal Protocol and the US Clean Air Act. Reacting HF with chloroform produces the main fluori-nated ingredient of tetrafluoroethylene synthesis CHCIF2. It has a small ozone depleting potential but is excluded from the Montreal Protocol regulation... 

The first reactions of fluorinated olefins in C02 reported by DeSimone et al. involved the free-radical telomerization of 1,1 -difluoroethylene29 and tetrafluor-oethylene.30 This work demonstrated the feasibility of carrying out free-radical reactions of highly electrophilic species in solvents other than expensive fluorocarbons and environmentally detrimental chlorofluorocarbons. The work has since been more broadly applied to the synthesis of tetrafluoroethylene-based, nonaqueous grades of fluoropolymers,31,32 such as poly(tetrafluoroethylene-co-peduoropropylvinyl ether) (Scheme 2). These reactions were typically carried out at between 20 and 40% solids in C02 at initial pressures of between 100 and 150 bars, and 30-35°C (Table 10.1). 

Romack, T. J. DeSimone, J. M. Synthesis of Tetrafluoroethylene-Based, Non-aqueous Fluoropolymers in Supercritical Carbon Dioxide. Macromolecules 1995, 28, 8429-8431. 

Fluorinated surfactants have been used for decades as processing aids during aqueous emulsion polymerization synthesis of fluoropolymers such as poly (tetrafluoroethylene). The function of the fluorosurfactant is to solubilize both the fluorinated monomer(s) as well as the growing fluoropolymer. Historically, the... 

The first part of the book deals with definitions and fundamental subjects surrounding the polymerization of fluoropol)miers. Basic subjects such as the identification of fluoropolymers, their key properties, and some of their everyday uses are addressed. The main monomer, tetrafluoroethylene, is extremely flammable and explosive. Consequently, safe polymerization of this monomer requires special equipment and technology. Molecular forces within these polymers are reviewed and coimected to macro properties. Monomer and polymer synthesis techniques and properties are described. Part One ends with a detailed list of advertised commercial grades of fluoroplastics. 

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