PROCESS FOR THE FRACTIONATION OF POLYOXYALKYLENE BLOCK COPOLYMERS

摘要

A process for the fractionation of polyoxyalkylene block copolymers wherein the polydispersity of the polyether is reduced. The fractionation process, which removes lower molecular weight species such as polyoxyalkylene homopolymer, truncated polyoxyalkylene diblock polymers, or other reaction byproducts, comprises salt extraction and liquid phase separation to provide a product with a narrower molecular weight distribution, lower degree of unsaturation, and distinctly different physical characteristics compared to the starting material.