Description
The fluorinated ethylene propylene (Perfluoroethylene propylene copolymer; FEP) macromolecule consist mainly of a linear chain with the basic monomer unit [—(CF2 )3 —CF(CF3 )—]n.This translucent fluorocarbon is flexible and more workable than PTFE, and like PTFE it resists to all known chemicals except molten alkali metals, elemental fluorine, fluorine precursors, and concentrated perchloric acid. It withstands temperatures up to 200°C and may be sterilized by all known chemical and thermal methods. Certain carefully prepared films of FEP can be used as windows in equipment when necessary. The product has found extensive use as a pipe fitting liner as well as a liner in small vessels.
Chemical Properties
Similar to polytetrafluoroethylene but has a higher coefficient of friction.
Uses
Perfluoroethylene propylene copolymer can be used in wire and cable insulation, pipe linings, lining for processing equipment. Fibers are used for filtration screening and mist separators.
Production Methods
The elastomer is prepared by high-pressure, free-radical
aqueous emulsion polymerization. Fluorine is substituted
for hydrogen. The initiators are organic or inorganic peroxy
compounds, such as ammonium persulfate, and the emulsifying
agent is usually a fluorinated acid soap. Applications
include tubing, hose, and gaskets.
Definition
A copolymer of tetrafluoroethylene and hexafluoropropylene with properties similar to polytetrafluoroethylene resin. The repeating structure of the molecule is [–CF2–CF2–CF2CF(CF3)–]n.
