From fluoropolymers

Prevedouros et al (2006) estimate PFCA point source emissions from fluoropolymer manufacturing to contribute with approximately 60 % to the total PFCAs used. The substance distribution upon entry is 23 % to air, 65% to water and 12 % to soils [Prevedouros et al (2006)]. 

The potential hazards associated with the liberation of COF 3 from fluoropolymers has been described in Section 13.1.6. In particular, the thermal decomposition of... 

Fluoropolymers are chemically stable and inert or relatively unreactive. Reactivity, generally, decreases as fluorine content of the polymer increases. Fluorine induces more stability than chlorine. Fluoropolymers can produce toxic products if overheated. Precautions should be taken to exhaust any degradation fragments produced during the processing and fabrication of parts from fluoropolymers. 

Goodman, J. Andrews, S. Fluoride contamination from fluoropolymers in semiconducfor manufacture. Solid State Technol., June 1990. 

Figure la shows the experimental set-up for measurement of outgassed species from fluoropolymers on exposure to 157 nm. The exposure source is a LAMBDA PHYSIK OPTex UV excimer laser (Wavelength 157 nm, Power 0.8 mJ/pulse, Rep. Rate 30 Hz, Pulse duration 5-10 ns FWHM, laser intensity 2 MW/cm2) where a vacuum chamber was connected via CaF2 lens. A PFEIRRER... 

Outgassed Species from Fluoropolymers for F2 lithography on Exposure to 157 nm... 

Extrusion is one of the most popular processes for fabricating parts from fluoropolymers. Fiber and filament account for a relatively small share of all fluoropolymers extrusion. The principal end products are wire insulation, tubing, film, and sheet. Fluo-ropolymer films are widely used in release, surface protection, and packaging. Sheet and profile extrusions account for a small share of fluoropol5uners consumption. 

It is sometimes necessary to bond the fluoro-polymer parts to themselves or to other materials. Of course these polymers are known for their nonstick properties and must be rendered adherable. Machining and treatment for adhesion are two examples of finishing techniques routinely applied to fluo-ropolymer parts. This chapter describes a number of techniques commonly used to finish parts made from fluoropolymers. 

Dehalogenation - Loss of a halogen atom (such as fluorine and chlorine) from a molecule is called dehalogenation. For example, alkaline metals like sodium can abstract fluorine atoms from fluoropolymers upon contact. 

Wafer Carrier - A basket, often made from fluoropolymers, for transportation of silicon wafers during the processing and shipping. 

Since an IPMC functions as a pathway for hydrated cations, its properties will be expected to affect the performance of an IPMC actuator. The membrane materials used in IPMCs have so far been limited to a few commercially available perfluorinated ionic polymers, such as Nafion, and the thickness of the IPMC has also been restricted to the available thickness of the commercial membrane [67]. However, IPMC actuators employing new ionic membranes have now been reported [68]. The membranes are prepared from fluoropolymers grafted with polystyrene sulfonic acid (PSSA). IPMCs assembled with these membranes have been shown to exhibit at least several times larger displacements than the Nafion-based IPMC with similar thickness. 

Firebrake ZB 415 with Dechlorane Plus gives flame-retardant properties superior to those of antimony oxide alone. Grade ZB 500 makes it possible to suppress fumes from fluoropolymers, and gives good flame-retardant properties to poly(ether ketone)s and polyfether sulphone)s. Other key applications are talc-reinforced PP replacing PVC. ABS, and PA 66 in electrical/electronic applications, and EVC cable compounds. 

Recovery/Removal and Recycling of Perfluorinated Acids from Fluoropolymers and Industrial Waste Streams In the last decade of the twentieth century, PFOS and PFOA as well as other fluorinated substances came under scrutiny because they are environmentally persistent and potentially bioaccumulative. Analytical developments resulted in the detection of these substances widespread in the environment [28]. Triggered by these environmental concerns, as well as by the high price of the fluorinated emulsifiers, methods were developed which allowed effective recovery and recycling of fluorinated emulsifiers from these industrial production processes. 

Emulsifier Recovery/Removal from Fluoropolymer Dispersions Fluo-ropolymer dispersions contain all of the fiuorinated emulsifier used during the polymerization step unless a part of it is lost during workup (e.g., up-concentration) and stabilization with nonionic nonfluorinated emulsifiers. In any event, some fiuorinated emulsifier always remains in the dispersion, as all of these steps cannot remove the fiuorinated emulsifier completely, even if they are applied several times, for example, by up-concentration via ultrafiltration with repeated dilution of the up-concentrated dispersion [26]. Although further processing of fluoropolymer dispersions usually destroys the bulk of the fiuorinated emulsifier, it is desirable to recover and reuse the expensive polymerization aid completely while keeping or even improving the quality of the dispersions. 

Like their H C counterparts, inverse-detected F C experiments are preferred to direct-detected C F experiments. In principle, H C correlated experiments can be readily adapted to collect F C chemical shift correlated 2D-NMR spectra by taking into account the differences between the C—F and C—H couplings when setting the coherence transfer delays and the different resonance frequencies of F and H. However, their application to the study of fluoropolymers is not widespread. In practice, many other factors must be considered in order to obtain good quality correlated 2D-NMR spectra from fluoropolymers. The high... 

Carbon Correlations Multiple bond F- C correlation experiments provide the additional spectral data needed to determine atomic connectivities and to obtain unambiguous assignments of F and C resonances from fluoropolymers. Results from 7cf correlation experiments (and also those from HETCQR) can... 

Fluoropolymers have evolved over six decades. New monomers have allowed the synthesis of new polymers with new methods of processing. Most newer perfluoropolymers have the same basic properties as polytetrafluoroethylene (PTFE) but they offer new methods of processing. These new techniques have greatly increased the range of parts that can be fabricated from fluoropolymers at reduced cost. Today, fluoropolymers are processed by methods almost identical to those used a half century ago as well as by state of the art molding technologies. 

Even though environmental stress cracking must be considered in designing parts from fluoropolymers, it is not considered an extensive problem for this family of plastics. Permeation variables have a strong influence on stress cracking. Different fluoropolymers... 

Perfluoropolymers, namely PFA and PTFE, have been the most frequently used plastics in high purity applications (Figs. 15.6 - 15.11). PVDF, ETFE, and ECTFE are used in lower-purity water systems or with less aggressive chemicals. Corrosive acids and bases are handled through perfluoropolymer tubes and components. A great deal of work has been concentrated by fluoropolymer manufacturers to eliminate various forms of impurities from fluoropolymers. 

ECTFE and PVDF are includedl l in the list of currently proposed material for wet-bench construction. Wet benches, the facilities in semiconductor plants where wet processing is carried out, typically use fluoropolymers for all surfaces that can affect fluid purity. Storage containers and sinks, along with all other plumbing, are constructed from fluoropolymers. Fabs are expensive to build and may easily cost over 2 billion to construct. Obtaining insurance for a fab... 

Goodman, J., and Andrews, S., Fluoride Contamination from Fluoropolymers in Semiconductor Manufacture, Solid State Technology, Jun. 1990. 

Other than inhalation of degradation products, fume fever may also be caused by fluoropolymer contaminated smoking material. It is prudent to ban tobacco products from fluoropolymer work areas. Local exhaust ventilation should be installed to remove the process effluents from the work areas. It has been suggested that no health hazards exist unless the fluoropolymer is heated above 300°C.f" ]... 

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