Supramolecular three-armed star polymers via cyclodextrin host–guest self-assembly

Abstract

Three-armed star polymers with a cyclodextrin core and polyacrylamide arms were prepared via inclusion complex formation. A novel adamantyl-functionalized chain transfer agent was utilized in the reversible addition–fragmentation chain transfer (RAFT) polymerization of N,N-dimethylacrylamide and N,N-diethylacrylamide to afford guest-functionalized polymers. In combination with a three-pronged β-cyclodextrin core, supramolecular self-assembly was exploited for the formation of star-shaped architectures. This was demonstrated via a combination of dynamic light scattering (DLS) and 2D rotating frame nuclear Overhauser effect spectroscopy (ROESY) in D2O. Furthermore, turbidity measurements in the case of PDEAAm showed a rise in the LCST of the system. The complex formation was shown to be reversible, as DLS at elevated temperatures (70 °C) indicated a complete disassembly of the star polymers.