Perflouroelastomer composition having improved processability

A process for preparation of an uncured perfluoroelastomer composition comprising the steps of

• A) preparing a perfluoroelastomer having a plurality of carbonyl-containing functional groups selected from the group consisting of carboxyl endgroups, carboxylate endgroups, carboxamide endgroups, and mixtures thereof by copolymerizing a monomer mixture comprising a) a perfluoroolefin monomer and b) a perfluorovinyl ether monomer selected from the group consisting of perfluoro(alkyl vinyl) ethers, perfluoro(alkoxy vinyl) ethers, and mixtures thereof at a pressure of from 4-10 MPa, in the presence of a persulfate free radical initiator, in a polymerization mixture, wherein i) the feed ratio of monomer to initiator is controlled so that the ratio of the radical flux to the polymerization rate, R.sub.i /R.sub.p, is from about 10 to 50 millimoles per kilogram, and ii) less than 5 mole percent of a sulfite or bisulfite reducing agent, based on the millimoles of persulfate initiator, is present in the polymerization mixture;
• B) isolating said perfluoroelastomer having a plurality of carbonyl-containing functional groups;
• and
• C) heating said isolated perfluoroelastomer having a plurality of carbonyl-containing functional groups at a temperature of at least 250.degree. C. for a time sufficient to at least partially decarboxylate the perfluoroelastomer.