A method for the manufacture of polyether ketone ketone (PEKK), including: (i) providing a 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex; (ii) purifying said 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex; (iii) reacting said 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex with at least one difunctional aromatic acyl chloride in a reaction solvent and optional additional Lewis acid to obtain a product mixture including a PEKK-Lewis acid complex; and (iv) decomplexing the PEKK-Lewis acid complex to obtain a PEKK polymer. Further, a composition including at least 40 wt. % of 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex and an anhydrous aprotic solvent or solvent mixture, characterized in that it includes less than 1 wt. %, preferably less than 0.5 wt. % and in particular less than 0.1 wt. % of molecules including xanthydrol groups and its use for the manufacture of polyether ketone ketone.

A method for the manufacture of polyether ketone ketone (PEKK), including: providing a 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex; purifying said 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex; reacting said 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex with at least one difunctional aromatic acyl chloride in a reaction solvent and optional additional Lewis acid to obtain a product mixture including a PEKK-Lewis acid complex; and decomplexing the PEKK-Lewis acid complex to obtain a PEKK polymer. Also, a composition including at least 40 wt. % of 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex and an anhydrous aprotic solvent or solvent mixture, wherein the composition includes less than 1 wt. %, preferably less than 0.5 wt. % and in particular less than 0.1 wt. % of molecules comprising xanthydrol groups. And, the use of the composition for the manufacture of polyether ketone ketone.

A method for the manufacture of polyether ketone ketone (PEKK), including: (i) providing a 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex; (ii) purifying said 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex; (iii) reacting said 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex with at least one difunctional aromatic acyl chloride in a reaction solvent and optional additional Lewis acid to obtain a product mixture including a PEKK-Lewis acid complex; and (iv) decomplexing the PEKK-Lewis acid complex to obtain a PEKK polymer.

Further, a composition including at least 40 wt. % of 1,4-bis(4-phenoxybenzoyl)benzene-Lewis acid complex and an anhydrous aprotic solvent or solvent mixture, characterized in that it includes less than 1 wt. %, preferably less than 0.5 wt. % and in particular less than 0.1 wt. % of molecules including xanthydrol groups and its use for the manufacture of polyether ketone ketone.

The invention relates to a process for purification of a polyether polyol which is prepared by ring-opening polymerization of an alkylene oxide in the presence of an initiator having a plurality of active hydrogen atoms and a composite metal cyanide complex catalyst, has a number average molecular weight of at most 10,000 g/mol and contains ultra-high molecular weight (UHMW) components having molecular weights of at least 3 times the number average molecular weight, said process comprising filtering the polyether polyol with a membrane having an average pore size of from 0.5 to 80 nm to produce a permeate comprising a purified polyether polyol containing a reduced amount of UHMW components. Further, the invention relates to a process for preparing a polyether polyol from the purified polyether polyol; and to a process for preparing a polyurethane foam.