Synthesis of Adamantyl Polyphosphazene-Polystyrene Block Copolymers, and β-Cyclodextrin-Adamantyl Side Group Complexation

Hydrophobic block copolymers with adamantyl polyphosphazene and polystyrene blocks were synthesized via the controlled cationic living polymerization of a phosphoranimine at ambient temperature. beta-Cyclodextrins (beta-CDs) were then complexed with the adamantyl side groups in aqueous media to generate amphiphilic block copolymers. These underwent micelle formation in ail aqueous environment. The micellar behavior of these complexes was monitored using fluorescence techniques, transmission electron microscopy (TEM), and dynamic light scattering. The critical micelle concentration of the adamantyl polyphosphazene-polystyrene block copolymer complexes was 0.925 mg/L. TEM imaging revealed spherically shaped micelles. A mean diameter of 193 run was measured by dynamic light scattering. It was possible to control micelle formation by changing the amount of beta-CD in the aqueous medium at constant block copolymer concentration.