Processable Fluoropolymers

Several observations could be made from these copolymerizations. High yields ofhigh-molecular-weight copolymer can readily be formed at incorporation levels well in excess of the 2-4 wt% PPVE desired in commercial products. For reactions done in the C02 system, even at high vinyl ether incorporations, melt- 

The first reactions of fluorinated olefins in CO2 reported by DeSimone et al. involved the fi ee-radical telomerization of 1,1 -difluoroethylene and tetrafluor-oethylene.3 This work demonstrated the feasibility of carrying out free-radical 

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This chapter is the fifth in a series of articles by these authors, entitled Processable Fluoropolymers with Low Dielectric Constants. ... 

Extrusion Guide for Melt Processible Fluoropolymers, Bulletin E-85783, E. I. Du Pont de Nemours Co., Wilmington, DE. 

Ebnesajjad, S., Fluoroplastics, Vol. 2, Melt Processible Fluoropolymers, Chapter 10, William Andrew Publishing, Norwich, NY, 2003. 

Summary of Properties of Selected Melt-Processible Fluoropolymers... 

Of the melt-processible fluoropolymers, which are the most suitable for tubing, PFA provides the extreme thermal and chemical resistance required in the pharmaceutical processing. PFA, however, does not have the physical strength of PTFE at elevated temperatures... 

Because of its high viscosity (10 °-10 poise at 380°C), PTFE cannot be fabricated by melt-processing techniques. Melt-processible fluoropolymers have been developed by copolymerization of TFE, and FEP, a copolymer of TFE and HFP, has a lower maximum continuous use temperature than PTFE (200° C vs. 260° C) because of the deterioration of mechanical properties. Whereas, PFA, a copolymer of TFE with PPVE or PEVE, offers thermal stability, melt-processibility, and a maximum continuous use temperature of 260°C. Both FEP and PFA are considered perfluoropolymers. 

Fluoropolymers. Melt processable fluoropolymers such as Teflon FEP, Tefzel ETFE, poly(vinylidene fluoride) (Kynar), and ethylene-chlorotrifluoroethylene copolymer (Halar) are suitable for wire insulation in special applications because they combine good physical properties with low flammability. They are used for instrumentation cable in process-control rooms, as well as for computer and aircraft wiring and in military applications. The... 

This section discusses the coating of surfaces using dispersions and powders of fluoropolymers. A majority of the dispersions consumed are PTFE based some FEP, PFA, PVDF material are also coated on different substrates. Powder coating resins are all melt processible fluoropolymers. Most of the parts used in the chemical processing industry are fabricated by powder coating which is covered in Ch. 8 of this volume. Liquid coatings are used in the rare cases in which powder cannot reach areas of a part with complex geometry. 

Manufacturing Parts from Melt-processible Fluoropolymers... 

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