Perfluoropolymers films

Arcella V, Ghielmi A, and Tommasi G. High performance perfluoropolymer films and membranes. In Li NN, DrioU E, Ho WSW, and Lipscomb GG, eds. Annals of the New York Academy of Sciences vol. 984 Advanced Membrane Technology. New York The New York Academy of Sciences, 2003, pp. 226-244. 

Levyt" has described a process for orienting perfluoropolymer films. Tables 6.20 and 6.21 (see Table 6.22 for resin composition) present the properties of PFA and FEP as a function of stretch ratio. A stretch ratio of 0 was indicative of as-cast unstretched film. Note that in the absence of any stretch in the transverse direction, with an increase in the stretch ratio TD modulus increased significantly, while creep decreased and shrinkage reached a constant level. In effect, stretching the film makes it stronger in many ways. 

Arcella V, Ghiehni A and Tommasi G (2003), High Performance Perfluoropolymer Films and Membranes , Ann New York Acad Sci, 984,226-244. 

Arcella V, Ghiehni A, Tommasi G (2003) Fligh performance perfluoropolymer films for membranes. Ann N Y Acad Sci 984 226-244... 

ETFE copolymers can be readily fabricated by a variety of melt-processing techniques.19 They have a wide processing window, in the range 280 to 340°C (536 to 644°F) and can be extruded into films, tubing, and rods or as thin coating on wire and cables. Injection molding of ETFE into thin sections is considerably easier than injection molding of melt-processible perfluoropolymers because the former has... 

Aqueous dispersions of these two melt-processible perfluoropolymers are processed in a way similar to PTFE dispersion. FEP dispersions can be used for coating fabrics, metals, and polyimide films. They are very well suited for bonding seals and bearings from PTFE to metallic and nonmetallic components and as nonstick and low-friction coatings for metals.16 FEP can be fused completely into a continuous film in approximately 1 min at 400°C (752°F) or 40 min at 290°C (554°F).17 PFA is used to coat various surfaces, including glass fabric, glass, and metals. 

R.R. Tiwari, Z.P. Smith, H. Lin, B.D. Freeman, D.R. Paul, Gas permeation in thin films of high free-volume glassy perfluoropolymers. Part I. Physical aging, Polymer 55 (2014)5788-5800. 

Similar to perfluoropolymers (see Sec. 11.6.1), ETFE and ECTFE can be foamedf using carbon dioxide. ECTFE resin was formed into a film and placed in the pressure vessel. The vessel was pressurized with carbon dioxide to 6.9 MPa, then heated to 220°C and held at this temperature for 1 hour. Heating the vessel raised the gas pressure to 18 MPa, which was released by venting. The vessel was eooled to room temperature and the film was removed. The appearance of the film turned opaque from transparent due to foaming it had a void eontent of 56%. 

Carbon, fluorine, and hydrogen are the major elements that form the perfluorinated and partially fluori-nated fluoropolymers. The presence of fluorine is the main reason that these plastics have many special properties, which surpass those of most polymers. The desirable properties span across mechanical, tribological, electrical, and thermal characteristics of these polymers in addition to chemical resistance. Increased fluorine content of the fluoropolymers enhances these properties. Consequently, perfluoropolymers should be sought out when ultimate chemical resistance, electrical properties, etc., are required. This chapter concentrates on presenting the key properties of fluoropolymers. Properties of fluoroplastics films can be found in Ch. 6 and Appendix VI. 

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