Calixarene-centered amphiphilic A2B2 miktoarm star copolymers based on poly(ε-caprolactone) and poly(ethylene glycol): Synthesis and self-assembly behaviors in water

Novel calixarene-centered amphiphilic A 2 B 2 miktoarm star copolymers composed of two PCL arms and two PEG arms with calix[4]arene as core moiety were synthesized by the combination of CROP and “click” chemistry. First, a heterotetrafunctional calix[4]arene derivative with two hydroxyl groups and two alkyne groups was designed as a macroinitiator to prepare calixarene-centered PCL homopolymers (C4-PCL) by CROP in the presence of Sn(Oct) 2 as catalyst at 110 °C. Next, azide-terminated PEG (A-PEG) was synthesized by tandem treating methoxy poly(ethylene glycol)s (mPEG) with 4-chlorobutyryl chloride and NaN 3 . Finally, copper(I)-catalyzed cycloaddition reaction between C4-PCL and A-PEG led to A 2 B 2 miktoarm star copolymer [C4S(PCL) 2 -(PEG) 2 ]. 1 H NMR, FT-IR, and SEC analyses confirmed the well-defined miktoarm star architecture. These amphiphilic miktoarm star copolymers could self-assemble into multimorphological aggregates in water. The calix[4]arene moieties with a cavity <1 nm on the hydrophilic/hydrophobic interface of these aggregates may provide potential opportunities to entrap guest molecules for special applications in supermolecular science. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010