Adjustable crystalline stereocomplexes from enantiopure gradient polycarbonates

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• 作者：Ye Liu ; Keke He ; Weimin Ren ; Rongrong Li ; Xiaobing Lu
• 关键词：crystalline polycarbonates ; gradient stereocomplex ; polymer assembly ; cocrystallization
• 刊名：SCIENCE CHINA Chemistry
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：59
• 期：11
• 页码：1415-1420
• 全文大小：1,106 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Chinese Library of Science
  Chemistry
  
• 出版者：Science China Press, co-published with Springer
• ISSN：1869-1870
• 卷排序：59

文摘

Stereoselective interaction was observed in the mixture of enantiopure gradient polycarbonate (denoted as PCOPC-g-PCPC, originated from the enantioselective terpolymerization of CO₂, 3,4-epoxytetrahydrofuran (COPO) and cyclopentene oxide (CPO)) and various isotactic polycarbonates with opposite configuration in chloroform solution. The resultant crystalline stereocomplexes exhibit enhanced thermal stability and new crystalline behaviors, significantly distinct from their parent polymers. It was found that the cocrystallization selectively occurred between (R)-PCOPC (CO₂/COPO copolymer) and (S)-PCOPC-enriched segment in the gradient terpolymer (S)-PCOPC-g-PCPC, while (R)-PCPC (CO₂/CPO copolymer) selectively complexed with (S)-PCPC-enriched segment. No stereocomplexation was observed between (S)-PCOPC-g-PCPC and (S)-PCOPC or (S)-PCPC. This study is beneficial to finding new routes to prepare various semicrystalline materials having a wide variety of physical properties and degradability.