Trifluoroethylene

Poly(l-Chloro-l,2,2-Trifluoroethylene). Poly(l-chloro-l,2,2-trifiuoroethylene consists of linear chains in which the predominant repeating unit is... 

Typical piezoelectric materials are ceramic crystals and copolymers, such as poly(vinyHdene fluoride-i o-trifluoroethylene),... 

As part of his elegant and comprehensive examination ot the competition between [2+2] and [2+4] reactions of fluorinated ethylenes, Bartlett found that trifluoroethylene s [2+4] reaction with butadiene competed somewhat with its [2+2] cycloaddirion [66] (equation 62). 

Propagation reactions involving the fluoro-olefins, vinyl fluoride (VF)6Q 7 vinylidene fluoride (VF2)69 7""74 and trifluoroethylene (VF3),75 show relatively poor rcgiospccificity. This poor specificity is also seen in additions of small... 

Particularly relevant is the case of some copolymers of PVDF. Already small amounts (5-20% by mol) of a fluorolefinic comonomer (vinyl fluoride (VF) [89-90], trifluoroethylene [91-93], tetrafluorethylene [94, 95]) can force the polymers to a melt crystallization in the piezoelectric P form. (We recall that the homopolymer crystallizes in the non-piezoelectric a form, by melt crystallization). 

Sodium cyanide, reaction with chioro-trifluoroethylene to form 3-chloro-2,2,3-trifluoropropionic add, 40, 11... 

Ethylene trifluoroethylene (Tefzel) (ETFE) has good mechanical properties from cryogenic levels to 350°F (177°C). It has an upper continuous working temperature limit of 300°F (149°C). 

Agopovich, J. W. et al., J. Amer. Chem. Soc., 1983, 105, 5048 After ozonisation of trifluoroethylene in chlorotrifluoromethane solution at —95°C, the reactor must only be allowed to warm slightly (to —88°C) during subsequent cryogenic distillation. When allowed to warm towards ambient temperature the reactor exploded violently. The residue from distillation is peroxidic and probably sensitive to sudden temperature increases. 

The closest physical realization of the system examined above would be a polymer such as poly(vinyl fluoride) doped into poly(ethylene) (observing the r resonance) or poly(trifluoroethylene) doped into poly(tetra-fluorethylene), observing H. Neither of these systems is likely to be sufficiently miscible, and there is the possibility of significant proportions of head-to-head linkages, which would dominate the experimental M2 because of the proximity of the spins on adjacent backbone atoms. 

In table I we present the molar Kerr constants and mean square dipole moments of three fluorinated polymers, poly (trifluoroethylene) (PFjE), polylvinylidene fluoride) (PVF2) and poly(fluoromethylene) (PFM), dissolved in p-dioxane. The results show the sensitivity of mK to the degree and type of fluorination varying over an order of magnitude and also changing sign. Calculations of mK and for comparison are in progress (5). 

Method of gasketing flat gaskets vinylidene-difluoride, ethylenechloro-trifluoroethylene (ECTFE), Halar, Ryton PPS O-rings ... 

However, crystallization occurs when x > 1 and such behavior is not required in the elastomers. Consequently, it is necessary to synthesize co-oligomers from various fluorinated monomers such as vinylidene fluoride (VDF), trifluoroethylene... 

In the presence of equimolar quantities of propene the yield of trifluoroethylene is sharply reduced and a cyclopropane derivative is formed. The overall rate of decomposition is unaffected. Fishwick et al.13S attribute the much lower reactivity of 1,1,2,2-tetrafluoroethyltrimethylsilane (cf. the trifluorosilane derivative) to electron release by methyl to silicon which makes the silicon less electropositive and less receptive to attack by fluorine. 

Watts and Goldstein reported the solvent and concentration dependence of 2/H-f °f vinyl fluoride in cyclohexane and DMF. Smith and Ihrig 61 62> extended those results to other solvents and also measured the solvent dependence of 2/H-f the isomeric difluoroethylenes and trifluoroethylene (Table 23). The... 

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