ECTFE chemical resistance

Fluoroplastic FPs have superior heat and chemical resistance, excellent electrical properties, but only moderate strength. Variations include PTFE, FEP, PFA, CTFE, ECTFE, ETFE, and PVDF. Used for bearings, valves, pumps handling concentrated corrosive chemicals, skillet linings, and as a film over textile webs for inflatables such as pneumatic sheds. Excellent human-tissue compatibility allows its use for medical implants. 

Ethylene chlorotrifluoroethylene (Halar) (ECTFE) has excellent chemical resistance to most chemicals including caustic. ECTFE can be used from -105°F (-76°C) to 302°F 150°C). To obtain good extrusion characteristics, this polymer is usually compounded with a small amount of extrusion aid. 

It is difficult to make a comparison because each material can be sensitive to different chemicals but, generally, within the service temperatures range, the chemical resistance increases with the amount of fluorine, or halogen total for PCTFE and ECTFE. 

In the chemical process industry it is often used in chlorine/caustic environment in cell covers, outlet boxes, lined pipes (see Figure 4.25), and tanks. In the pulp and paper industries pipes and scrubbers for bleaching agents are lined with ECTFE. Powder-coated tanks, ducts, and other components find use in semiconductor and chemical process industries (see Figure 4.26). Monofilament made from ECTFE is used for chemical-resistant filters and screens.58... 

Halar ECTFE (ethylenechlorotrifluoroethylene) This material is an alternating copolymer of ethylene and chlorotrifluroethylene. This fluoropolymer withstands continuous exposure to extreme temperatures and maintains excellent mechanical properties across this entire range (from cryogenic temperatures to 180°C). It has excellent electrical properties and chemical resistance, having no known solvent at 121°C. It is also nonbuming and radiation-resistant. Its ease of processing affords a wide range of products. 

Copolymers of ethylene with tetrafluoroethylene (ETFE) and chlorotrifluoroethylene (ECTFE) are mechanically stronger than perfluoropolymers, with some reduction in their chemical resistance and continuous use temperature and an increase in the coefficient of friction. 

As in the case of ETFE, ECTFE terpolymers (same termonomers) have better mechanical, abrasion, and radiation resistance than those of PTFE and other perfluoropolymers. Dielectric constant of ECTFE is 2.5-2.6, and it is independent of temperature and frequency. Dissipation factor is 0.02 and much larger than ETFE s. ECTFE is resistant to most chemicals except for hot polar and chlorinated solvents. It does... 

This chapter has been divided based on the fluorine content of fluoropolymers, that is, perfluorinated and partially fluorinated. In general, resistance of polymers to chemicals of all types increases with an increase in their fluorine content. Therefore, the chemical resistance of ETFE, ECTFE, and PVDF is generally inferior to that of perfluorinated polymers such as PFA and FEP. 

The chemical resistance of ECTFE is outstanding. It is resistant to most of the common corrosive chemicals encountered in industry. Included in this list of chemicals are strong mineral and oxidizing acids, alkalies, metal etchants, liquid oxygen, and practically all organic solvents except hot amines (aniline, dimethylamine, etc.). No known solvent dissolves or stress cracks ECTFE at temperatures up to 250°F (120°C). 

This simplified structure shows the ratio of the monomers being 1 1 and strictly alternating, which is the desirable proportion. Commonly known by the trade name, Halar , ECTFE is an expensive, melt-processible, semicrystalline, whitish semiopaque thermoplastic with good chemical resistance... 

Partially fluorinated materials include ECTFE (ethylene trifluoroethylene), ETEE (ethylene tetrafluoroethylene), and PVDE (polyvinylidene fluoride). The partially fluorinated materials have higher mechanical properties but lower temperature ratings (<300°E/149°C), and chemical resistance. 

Partially fluorinated materials are ECTFE, ETFE, and PVDF. These materials have higher mechanical properties but lower temperature (<300°F/150°C) and chemical resistance. Fluoropolymer linings can cost 5-20 times more than thermoset linings so they are typically restricted to elevated temperature environment. 

Chemical resistance in ECTFE is excellent. ECTFE is resistant to mineral acids, oxidizing acids, inorganic bases, and all solvents it is not resistant to hot amines [86]. 

ECTFE is resistant to most chemicals except hot polar and chlorinated solvents. It does not stress crack dissolve in any solvents and has better barrier properties to SOj, Clj, HCl, and water than FEP and PVDF. 

Ethylene chloro-trifluoroethylene (ECTFE) is a partially fluorinated melt processable polymer that is intermediate in performance between fully fluorinated polymers (PTFE) and PVDF. It has excellent chemical resistance to oxidizing chemicals and is used in chemical piping apphcahons for severe environments. 

ECTFE polymers are melt processible. Commercial ECTFE is a copolymer of tetrafluoroethylene and chlorotrifiuoroethylene. They have lower chemical resistance and thermal stability than perfiuorinated polymers. ECTFE exhibits excellent... 

Chlorotrifluoroethylene-ethylene copolymers (ECTFE) contain about 50 mole % chlorotrifluoroethylene. These copolymers are generally similar to the tetrafluoroethylene-ethylene copolymers (section 7.9) in that they are melt-processable and have high impact strength and good chemical resistance. Comparative values for some properties are given in Table 7.1. The temperature range of useful performance is from about — 80°C to 170°C. Chlorotrifluoroethylene-ethylene copolymers find use in injection mouldings for chemical process equipment and cable insulation. 

This fluoropolymer has excellent chemical resistance. See Chapter 6 for more information about adhesion treatment of ECTFE. ... 

Even though potential memory exists in all TPs, polyolefins, neoprenes, silicones, and other cross-linkable TPs are example of plastics that can be given memory either by radiation or by chemically curing. Fluorocarbons, however, need no such curing. When this phenomenon of memory is applied to fluorocarbons such as TFE, FEP, ETFE, ECTFE, CITE, and PVF2, interesting high-temperature or wear-resistant applications become possible. 

---