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 ...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(CO_2/COPO copolymer) and(S)-PCOPC-enriched segment in the gradient terpolymer(S)-PCOPC-g-PCPC, while(R)-PCPC(CO_2/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.展开更多
基金supported by the National Natural Science Foundation of China (21134002, 21504011)the Specialized Research Fund for the Doctoral Program of Higher Education (20130041130004)the Chang Jiang Scholars Program (T2011056) from Ministry of Education of the People’s Republic of China
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(CO_2/COPO copolymer) and(S)-PCOPC-enriched segment in the gradient terpolymer(S)-PCOPC-g-PCPC, while(R)-PCPC(CO_2/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.
