Stabilization of fluoropolymers

A method for the production of a melt-fabricatable fluoropolymer, by the conversion of a fluoropolymer bearing carboxylic acid groups and prepared as an aqueous dispersion using a dispersion polymerisation process which employs a dispersing agent whose dispersion-stabilising effect is removable by heating the dispersion to a temperature of 190.degree. C. to 240.degree. C. and an initiator which yields carboxylic acid groups on the fluoropolymer, which method comprises, after preparing an aqueous dispersion of the fluoropolymer using dispersion polymerisation, converting the carboxylic acid groups on the fluoropolymer in the aqueous dispersion to carboxylate anion groups using a base and then heating the comodified fluoropolymer dispersion to a temperature of 190.degree. C. to 240.degree. C. to cause simultaneously:

• (1) substantial removal of carboxylate anion groups, thereby to yield stable groups in their place, and
• (2) isolation of the melt-fabricatable fluoropolymer from the dispersion by coagulation of the fluoropolymer dispersion.