Block‐Selected Molecular Recognition and Formation of Polypseudorotaxanes between Poly(propylene oxide)‐Poly(ethylene oxide)‐Poly(propylene oxide) Triblock Copolymers and α‐Cyclodextrin

Although a poly(propylene oxide) (PPO) chain was previously thought to be impenetrable to α-cyclodextrin, the middle poly(ethylene oxide) (PEO) block of PPO-PEO-PPO triblock copolymers can be selectively recognized and included by α-cyclodextrin to form polypseudorotaxanes (see schematic representation), even though it is flanked by two PPO blocks.