Processes for polyether polyol purification and preparation

Abstract

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.

Dependencies are inferred from the claim text.