Synthesis and unimolecular micellar behavior of amphiphilic star-shaped block copolymers obtained via the Passerini three component reaction†
A series of new amphiphilic star-shaped block copolymers with hydrophobic cores and hydrophilic shells was synthesized, using the Passerini three component step-growth polymerization (Passerini-3CP). The degree of polymerization of the Passerini hydrophobic cores (20, 10 and 5 repeating units) was controlled and the chain ends were quantitatively functionalized with different sized PEG-aldehydes and/or PEG-isocyanides via another Passerini reaction. The encapsulation and phase transfer properties of the star-shaped block copolymers were followed visually and by using UV/VIS-spectroscopy, using Orange II and Para Red dyes as guest molecules. The investigated polymers showed a unimolecular micellar behavior, as shown by dynamic light scattering (DLS) and the mentioned encapsulation experiments.