AQUEOUS 2-PHASE SYSTEMS FROM CYCLODEXTRIN POLYMERS AND HYDROPHOBICALLY-MODIFIED ACRYLIC POLYMERS

In this study, a copolymer of N,N-dimethylacrylamide and hydroxyethyl- methacrylate was synthesized and hydrophobically modified with about 2 mole % of adamantyl groups. The mixing of this modified copolymer wit h water-soluble beta-cyclodextrin polymers reveals thickening properti es. Inclusion complexes formation between adamantyl groups and beta-cy clodextrin cavities are responsible of intermolecular associations. Ab ove a given total polymer concentration a phase separation occurs, giv ing a gel phase topped by a liquid phase. We have stated the phase dia gram by analysis of the two phases in equilibrium. It has been observe d that the two polymers are present in both phases and that the gel ph ase is more concentrated than the other one. This phase behavior is an original complex coacervation phenomenom which is due to the specific attractive interactions of the two different macromolecules: inclusio n complexes formed between the two neutral polymers.