| 摘要 |
QM 35868 STABILISATION OF FLUOROPOLYMERS A method for the stabilisation and isolation of a fluoropolymer bearing carboxylic acid (-CO2H) 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 and an initiator (or initiator system) 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 (-CO2-) using a base and then heating the so-modified fluoropolymer dispersion to cause simultaneously: 1) substantial removal of carboxylate anion groups, thereby to yield stable groups in their place, and 2) isolation of the fluoropolymer from the dispersion by coagulation (agglomeration) of the fluoropolymer dispersion.
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