Preparation and Characterization of Polypseudorotaxanes Based on Biodegradable Poly(l-lactide)/Poly(ethylene glycol) Triblock Copolymers
Preparation and Characterization of Polypseudorotaxanes Based on Biodegradable Poly(l-lactide)/Poly(ethylene glycol) Triblock Copolymers
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DOI：
10.1021/ma035200k
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发表时间：
2003-11
期刊：
影响因子：
5.5
通讯作者：
H. Choi;T. Ooya;S. Sasaki;N. Yui;Y. Ohya;T. Nakai;T. Ouchi
中科院分区：
文献类型：
--
作者：
H. Choi;T. Ooya;S. Sasaki;N. Yui;Y. Ohya;T. Nakai;T. Ouchi
合成了一种A-−-B-−A型三嵌段共聚物，包括聚乳酸-L-丙交酯和聚乙二醇，并研究了其与环糊精(α-CD)的络合作用。尽管聚乳酸嵌段含有大量的甲基作为侧链，但得到了稳定的聚乳酸-−-−-聚乳酸三嵌段共聚物以及聚乳酸，并经1HNMR、固体13C CP/MAS核磁共振、FT-IR和X-射线光谱确证。从结果中推测，客体分子进入了疏水CD空腔，它们在聚乙二醇单嵌段和聚乳酸嵌段中都形成了稳定的假紫杉烷。α-CD与聚乙二醇嵌段形成包合物；此外，它们与聚乳酸部分的末端嵌段形成非常粘连的假紫杉烷。限制在CD通道中的共聚物失去了原有的结晶性能，但由于共聚物的长链性质，与CDS形成了通道型疏水晶体结构。这种聚合物包裹体是一种复杂的包裹体。
A variation of A−B−A-type triblock copolymers consisting of poly(l-lactide) (PLLA) and poly(ethylene glycol) (PEG) was synthesized and examined for complexation with α-cyclodextrins (α-CDs). Although the PLLA block has bulky methyl groups as side chains, stable polypseudorotaxanes of PLLA−PEG−PLLA triblock copolymers as well as PLLA were obtained and confirmed by 1H NMR, solid-state 13C CP/MAS NMR, FT-IR, and X-ray spectroscopies. From the results, it was hypothesized that the guest molecules threaded into the hydrophobic CD cavities, and they form stable pseudorotaxanes in both PEG and PLLA blocks. The α-CDs slide over the flanking bulky PLLA blocks to form an inclusion complex with PEG block; in addition, they form very stick pseudorotaxanes with the end-blocks of PLLA parts. The copolymers confined to the CD channels lost their original crystalline properties but formed a channel-type hydrophobic crystalline structure with CDs due to long chain nature of the copolymers. Such a polymeric inclusion compl...