Purification of poly ether ketone ketone by centrifugal filtration

A method for the manufacture of polyether ketone ketone (PEKK), comprising the steps of:

• (i) reacting 1,4-bis(4-phenoxybenzoylbenzene) and/or diphenylether with at least one difunctional aromatic acyl chloride, in a reaction solvent and in presence of a Lewis acid, to obtain a product mixture comprising a PEKK-Lewis acid complex;
• (ii) contacting the obtained product mixture with a protic solvent so as to form a dispersion that comprises a liquid phase comprising Lewis acid and a second phase comprising PEKK;
• and
• (iii) separating the second phase of the dispersion from the liquid phase, so as to recover a crude PEKK and an effluent containing Lewis acid,
• wherein step (iii) comprises a step of centrifugal filtration,
• wherein the method comprises after step (iii) further one or more steps of washing the crude PEKK, and subjecting the resulting mixture to a further solid/liquid separation, wherein the one (or more) washing step is (are) performed in a centrifugal filtration device, without removing the crude PEKK between subsequent steps.