pH-responsive pseudorotaxane between comblike PEO-grafted triblock polymer and α-cyclodextrin

The pH-responsive inclusion complexation of comblike triblock polymer, P2VP- b -PPEOMA- b -P2VP, with α-cyclodextrin (α-CD) was studied. The triblock polymer was prepared by reversible addition–fragmentation chain transfer polymerization (RAFT) and formed inclusion complexes (ICs) after selective threading of the PEO segment of the triblock polymer through the cavities of α-CD units. For comparison, PPEOMA homopolymer was prepared, and the inclusion complexation with α-CD was also studied. The formed ICs were characterized by XRD and 1 H NMR. The results revealed that P2VP- b -PPEOMA- b -P2VP can form ICs with α-CD even when forming micelles, and the introduction of P2VP had a great influence on the solution property and the stoichiometry of EO to CD of the inclusion complexes depending on the concentration and the pH of the solution.