New Macromolecular Architectures and Functions Through Macromolecular Recognition by Cyclodextrins

Abstract

Cyclodextrins(CDs) were found to form inclusion complexes not only with polyethylene glycol) (PEG) but also polypropylene glycol) (PPG), poly(methyl vinyl ether) (PMVE), and poly(oxytrimethylene) (POT) to give crystalline compounds in high yields. The complex formation is highly selective. α-CD formed complexes with PEG and POT, although it did not form complexes with PPG and PMVE. γ-CD formed complexes with PMVE, although α- and β-CD did not form complexes with PMVE. The complexes are stoichiometric compounds and characterized by IR, ¹H NMR, ¹³C NMR, ¹³C CP/MAS NMR, ¹³C PST/MAS NMR spectra and X-ray, thermal, and elemental analyses. CDs were also found to form inclusion complexes with hydrophobic polymers, such as oligoethylene and polyisobutylene. α-CD formed complexes with oligoethylene of molecular weight less than 1000. β-CD and γ-CD formed complexes with polyisobutylene (PIB), although α-CD did not form complexes with PIB of any molecular weight. The yield of the complex with β-CD decreased with increasing the molecular weight of PIB. In contrast, the yield of the complex with γ-CD with PIB increased with increasing the molecular weight. The chain length selectivities are reversed.