TABLE OF CONTENTS Fluorinated ionomers are produced in relatively small volumes. For the economics of manufacture it is therefore important to integrate the manufacture with that of similar, larger volume products. For perfluorinated ionomers, at least the monomer synthesis can be integrated with that of other vinyl ether monomers such as perfluoro propyl vinyl ether (PPVE) or perfluoro methyl vinyl ether (PMVE). For partially fluorinated ionomers, there is the possibility of radiation grafting certain monomers on commercially available fluoropolymer films such as fluorinated ethylene propylene (FEP) copolymer. While this approach may lead to attractive economics, the oxidative stability of the products obtained has been poor.
Perfluorinated ionomers are derived from melt-processable precursor polymers that are obtained by the copolymerization of tetrafluoroethylene (TFE) and a perfluorinated vinyl ether containing a sulfonyl halide or carboxylic ester functional group. The ether linkage is required to give the vinyl group sufficient activity to allow the incorporation of a high percentage of the functional monomers. The alkyl groups ?R F used in the vinyl ethers CF 2=CF ?O ?R F are shown in Table 3.1. The molecular weight (MW) of the vinyl ether monomers is given and it is used as a short form to identify and distinguish them.
| MW | ?R F | Polymer Name | Company |
|---|---|---|---|
| 446 |
 | Nafion Flemion Aciplex (now) | DuPont Asahi Glass Asahi Chemicals |
| 496 |
 | Aciplex (old) | Asahi Chemicals |
| 422 |
 | Nafion Aciplex | DuPont |
