Polymerization of fluorinated monomers

Supercritical Carbon Dioxide - Refers to carbon dioxide that has been heated to above its critical temperature and pressure. Supercritical CO2 is a potent solvent for a great many organic substances. It is also a suitable medium for polymerization of fluorinated monomers. 

There is an important categoiy of free-radical emulsion polymerizations where the hydrophobic polymer does not dissolve in its own monomer [3-6] or is only sparingly soluble in its own monomer [3]. Some examples of these kinds of polymerizations are the emulsion polymerization of fluorinated monomers (e.g. tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), 1,2-difluoroethylene) [4,5] and acrylonitrile [6]. The polymers formed by these polymerizations all have significant industrial importance, particularly as engineering polymers (e.g. Teflon, aciylonitrile-butadiene-styrene copolymer (ABS)). As a result much of the research into these processes remains outside the public domain. 

Properties Wh. powd. m.w. 431.10 dens. 0.6-0.7 g/cc b.p. 125 C anionic Toxicology ACGIH TLV 0.1 mg/m in air LD50 (oral, rat) 430 mg/kg, (skin, rabbit 4300 mg/kg LC50 (inh., rat, 4 h) 980 mg/m toxic by inhalation and skin contact skin and eye irritant confirmed carcinogen experimental reproductive effects TSCA listed Hazardous Decomp. Prods. Heated to decomp., emits toxic fumes of F and NH3 Uses Surfactant, emulsifier for emulsion polymerization of fluorinated monomers photographic chem. 

FLUORAD Fluorochemical Surfactant FC-126 Is an anionic fluorochemical surface active agent particularly useful as an emulsifier in the polymerization of fluorinated monomers where its surface activity and the highly fluorinated nature of micelles formed in aqueous media combine to give this unique utility. FC-126 is classified as an ammonium perfluoro-alkane carboxylate. It shows excellent surface activity in alkaline media. 

Both dJorofluorocarbons (CFCs) and carbon dioxide appear to be very good solvents for amorphous, low-melting fluoropolymers. Since environmental restrictions have limited the use of CFCs drastically, carbon dioxide has become a highly viable alternative solvent for the production of amorphous fluoropolymers [59]. Examples of polymerization of fluorinated monomers in a homogeneous reaction medium of SCCO2 are the polymerization of fluorinated acrylates (see, for example Refs. 59-61, fluoroalkyl-derivatized styrene [62], fluorinated vinyl and cyclic ethers [63], and the telomerization of 1,1-difluoroethylene [64]. Other options to run a... 

This section describes polymerization of fluorinated monomers in carbon dioxide above its eritieal temperature and pressure. Supercritical CO2 has been used as an environmentally friendly solvent to replace noxious organic solvents. The critical state for a pure substanee is the state of temperature and pressure at which the... 

Geng and coworkers reported synthesis of polyfluorene by Kumada catalyst-transfer condensarimi polymerization of fluorine monomer 38 (Scheme 46). Polymerization of 38 was carried out in the presence of nickel acetylacetonate/ l,3-bis(diphenylphosphino)propane [Ni(acac)2/dppp] at 0°C, yielding polyfluorene with COTitrolled molecular weight and low polydispersity [134]. 

Uses Surf. tens, reducer for aq. sol ns. surfactant for descaling baths, glass polishing baths, metal surf, treatment, acidic metal scouring baths emulsifler tor polymerization of fluorinated monomers such as PVDF and PTFE... 

Uses Surfactant for emulsion polymerization of fluorinated monomers exc. surface activity in alkaline media... 

Larichev, R., Wilmington, B., Aqueous polymerization of fluorinated monomer using hydrogen containing branched fluoroether surfactant EP 2367862, 2011. 

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