Purity of double hydrophilic block copolymers revealed by capillary electrophoresis in the critical conditions.

Block copolymers enable combining properties of different polymers; double hydrophilic block copolymers are innovative examples. Size-exclusion chromatography (SEC or GPC) has a quasi-monopoly in separation-based characterization methods for polymers, including block copolymers. However, in terms of purity determination (unintended homopolymers present in the copolymers), SEC resolution proves insufficient except for the extreme compositions for which the second block is much larger than the first one.