Solvay Solexis S.p.a.

Evasio Deregibus

Valeri Kapeliouchko

Stefano Ferrero

Alberto Mirigliani

Omar Ligabue

A process for preparing a fluoropolymer dispersion that is substantially anionic fluorinated surfactant free includes adding to a fluoropolymer dispersion a nonionic surfactant having a cloud point (CP) between 40 and 80&#xb0; C. in a concentration of 1.5% to 50% by weight of the fluoropolymer, heating the dispersion up to a temperature Tin a range of CP&#xb1;10&#xb0;C., decanting the dispersion in a reactor at Tuntil obtaining a lower aqueous phase containing a concentrated fluoropolymer dispersion and an upper aqueous phase substantially not containing the fluoropolymer dispersion, washing the decanted dispersion with a solution of water and nonionic surfactant having a concentration of the nonionic surfactant of 0.5% to 50% by weight of the fluoropolymer, removing the upper aqueous phase from the upper part of the reactor, and discharge and recovery of the fluoropolymer dispersion.

Process for preparing fluoropolymer dispersions

An elimination process of fluorinated anionic sufactants from exhausted gaseous streams, wherein the gaseous stream is put into contact with aqueous solutions having in the range from 3.5 to 13.8, the aqueous solution density being lower than 1.05 g/cm, wherein the concentration in the aqueous solution of the fluorinated anionic surfactant removed by the gaseous stream is lower than or equal to 70 ppm.

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Alessandria, Italy

Evasio Deregibus