Patent ID: 8314206
Filing Date: 2012-11-20
Classification: C08L

Abstract:
1. A method of purifying PS-b-PXVP from a solution comprising dissolved PS-b-PXVP and a dissolved lithium salt, where “X” is 2 or 4, comprising: providing a solution comprising dissolved PS-b-P2VP, dissolved PS-b-P4VP, and a dissolved lithium salt, the solution comprising a carbon-containing liquid solvent, the carbon-containing liquid solvent being soluble in liquid water; combining the carbon-containing liquid solvent having the dissolved PS-b-P2VP, dissolved PS-b-P4VP, and a dissolved lithium salt with liquid water and precipitating a first precipitate therefrom, the first precipitate having greater concentration PS-b-P2VP and PS-b-P4VP and lower concentration of lithium than was in the solution; dissolving the first precipitate in an organic liquid solvent that can form an azeotrope with water; combining the organic liquid solvent having the dissolved first precipitate with liquid water and forming an aqueous liquid phase and an organic liquid phase therefrom; separating the organic liquid phase from the aqueous liquid phase; and after the separating, boiling away liquid from the organic liquid phase to leave a resultant precipitate, the first precipitate having more water than any water in the resultant precipitate, the resultant precipitate having greater concentration PS-b-P2VP and PS-b-P4VP and lower concentration of lithium than was in the solution.