Fractionation of water-soluble polymers.

摘要

A solution is formed of a water soluble polymer containing acid groups in a blend of a polar solvent, water and base in an amount sufficient to neutralise at least 10% but not more than 90% molar of the acid groups and the solvent, the base and the amount of at least one of the base and the solvent are selected to cause phase separation of the solution into an aqueous phase containing a higher molecular weight polymeric fraction and an organic phase containing a lower molecular weight polymeric fraction.