Contamination fluoropolymer

Fig. 2.10. Chemical state images obtained with the Escascope in Fig. 2.9, from a contaminated fluoropolymer [2.29]. (A) image in contribution to C Is from C-F bonding, (B) image in contribution to C Is from C-C bonding.

Figure 10. Chemical state images obtained with the ES-CASCOPE in Figure 9, from a contaminated fluoropolymer [1. ]...

Fluorine contamination has been reported in various environments and applications in the past. It has shown up in plasma processing [10-18], as crosscontamination from storage in contaminated containers or with contaminated samples [14,18], and modification of aluminum deposited on fluoropolymer substrates and other polymers having fluorine-based plasma treatments has also been observed [19-21]. Fluorocarbon lubricants have also been noted to modify the oxide structures on aluminum alloys [22,23], and the degradation of AI2O3 catalytic supports has been associated with fluoride conversion during reactions with fluorocarbons [24]. Alloy oxide modification has also been well noted in the presence of fluorine compounds not of the fluorocarbon family [25]. 

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

In the chemical processing industry, for example, fluoropolymers are selected for their resistance to chemical attack. They serve as linings for carbon steel vessels, and for piping and other fluid handling components. They provide durable, low maintenance, and economical alternatives to exotic metal alloys. In these applications, fluoropolymers also offer thermal stability for use at high temperatures. And because they do not react with process streams, they help prevent contamination of products. 

Products of the degradation of molten fluoropolymers are highly corrosive, often containing hydrofluoric acid. The parts of the machine that come in contact with molten fluoropol5miers must be constructed from corrosion-resistant metals that are significantly more expensive than lower grades of steel. Corrosion of process surfaces can result in the contamination of the finished product and deterioration of its physical properties. 

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 fluoropol5mier 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 fluoropol5mier is heated above 300°C.Fi... 

Much more expensive, but similarly long-lasting and with very good resistance to dirt contamination, UV radiation and chemical attacks, are fluoropolymer foils with reinforcement nets made of glass fibres (refs... 

Corporation (Golden, CO). The reactor, 1.22m wide by 2.44 m, consisted of a fiberglass-reinforced plastic I-beam frame. A transparent fluoropolymer film, treated to accept adhesives, formed the front and back windows of the reactor. The film windows were attached to the reactor frame with foam tape coated on both sides with an acrylic adhesive. The catalyst, titanium dioxide (Degussa P25), was coated onto a structured, perforated polypropylene tubular packing commonly used in oil-water separators. The Ti02 was suspended in water as a slurry and sprayed onto the tubular supports with a new paint sprayer until the supports were opaque. Fluid modeling of airflow flnough the reactor showed that a 5.1 cm PVC manifold, located at the inlet and outlet of flie reactor, would provide an even flow distribution. Small (0.6 cm) holes, drilled into flie manifold at one inch intervals, provided the even flow distribution required for efficient contact of the contaminated air with the catalyst. 

Polyvinylidene fluoride n. (-H2CCF2-) . Thermoplastic fluorocarbon polymer derived from vinylidene fluoride. It is a fluoropolymer with alternating CFi2 and CF2 groups. PVDF is an opaque white resin. Extremely pure, it is superior for non-contaminating applications. In film form it is characterized by superior weather and UV resistance. Abbreviation is PVDF. 

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