Process for enriching the difunctional content of (per) fluopolyether mixtures
AssigneeSolvay Specialty Polymers Italy S.P.A.
InventorsClaudio Adolfo Pietro Tonelli, Roberto Valsecchi, Fabrizio Mutta
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Abstract
The present invention relates to a process for increasing the content of bifunctional species in mixtures of non functional, mono- and bifunctional (per)fluoropolyethers which comprises the adsorption of a (per)fluoropolyether mixture onto an adsorbing stationary phase, a first desorption step with a supercritical fluid only and a second desorption step with the supercritical fluid and a mixture of a polar solvent.
Claims12
A process for increasing the content of bifunctional species in mixtures of non functional, mono- and bifunctional (per)fluoropolyethers which comprises the following steps:
- (a) adsorbing a mixture (M) of non functional, mono- and bifunctional (per)fluoropolyethers having a first average functionality (F1) onto an adsorbing stationary phase;
- (b) desorbing mixture (M) with a supercritical fluid to recover a (per)fluoropolyether mixture (M′) having a second average functionality (F2) lower than functionality (F1);
- (c) desorbing the remaining mixture (M) with the supercritical fluid in admixture with a polar solvent to recover a (per)fluoropolyether mixture (M″) having a third average functionality (F3) higher than functionality (F1).
Dependencies are inferred from the claim text.