Patent ID: 7838600
Filing Date: 2010-11-23
Classification: C08F,C08G,C08L

Abstract:
1. A process for preparing diblock and triblock copolymers comprising the steps of: (a) performing radical polymerization of N-vinyl-2-pyrrolidone in the presence of a radical initiator, a chain transfer agent and an alcoholic solvent to form hydroxy-terminated poly (N-vinylpyrrolidone) wherein said hydroxy-terminated poly (N-vinylpyrrolidone) is isolated by dissolution and precipitation and (b) performing ionic polymerization of monomers or comonomers selected from the group consisting of 3,6-dimethyl-1,4-dioxane-2,5-dione, ε-caprolactone and γ-caprolactone in the presence of a base and a macroinitiator wherein said macroinitiator is the hydroxy-terminated poly (N-vinylpyrrolidone) formed in step (a) thereby preparing said diblock and triblock copolymers, wherein said copolymers self-assemble in polymeric micelles or stabilized nanoparticles in aqueous solution.