writer：WEIZHONG YUAN, JIE REN
keywords：a-cyclodextrin (a-CD), block copolymers, host–guest systems, star-block, copolymer, star polymers, supramolecular inclusion complexes
source：期刊
Issue time：2009年

A series of star-block poly(L-lactide)-b-poly(ethylene oxide) (SPLLA-b-PEO) copolymers were synthesized by ring-opening polymerization (ROP) and DCC chemistry. The inclusion complexes of SPLLA-b-PEO copolymers and a-cyclodextrin (a-CD) were prepared with two different methods. FTIR, 1H NMR, WAXD, DSC, and TGA indicate that a-CD only can be threaded onto PEO blocks in inclusion complexes of a-CD-SPLLA-b-PEO1.1K-a, a-CD-SPLLA-b-PEO2K-a, and a-CD-SPLLA-b-PEO5Ka formed without heating and ultrasonication, and can be threaded onto both PLLA and PEO blocks in inclusion complexes of a-CD-SPLLA-b-PEO1.1K-b, a-CD-SPLLAb-PEO2K-b, and a-CD-SPLLA-b-PEO5K-b formed with heating and ultrasonication. Namely, a-CDs can be threaded onto PEO blocks and the flanking bulky PLLA blocks of star-block copolymers to form stable  polyseudorotaxanes with heating method and ultrasonication to conquer the activation energy barrier of the inclusion complexation between bulky PLLA and a-CD and the effect of the steric hindrance of star-block copolymers. With the alteration of preparing methods, the inclusion complexes of a-CD with the outer PEO block or PEO and PLLA blocks were obtained successfully.