Perfluoroalkoxy polymers stabilization

End groups are stabilized by treating the PFA with methanol, anmionia, amines, and elemental fluorine that produces CFj end groups [73-77]. The polymer is recovered, dried, and melt-extruded into cubes for melt fabrications processes. Perfluoroalkoxy is also available in bead (as-polymerized), dispersion and fine powders forms. 

PFA polymers are fully fluorinated and melt processible. They have chemical resistance and thermal stability comparable to polytetrafluoroethylene (PTFE). Melt viscosity of PFA is over one million times lower than PTFE. Perfluoroalkoxy resins are in general copolymers of tetrafiuoroethylene with one or more of perfluoroalkyl vinyl ether comonomers. Commercial examples of the latter include perfluoromethyl vinyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), and perfluoropropyl vinyl ether (PPVE). PFA resins are specified by ASTM Method D3307, which also provides procedures or references to other ASTM methods for the measurement of resin properties. Commercial PFA resins offered by major manufacturers have been listed in Tables 6.1 through 6.7. 

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