Indexed by:
Journal Papers
First Author:
Wan Zhao-Qian
Co-author:
Ren Wei-Min,Yang Shuai,Li Ming-Ran,Gu Ge-Ge,Lu Xiao-Bing
Date of Publication:
2019-10-08
Journal:
Angewandte Chemie (International ed. in English)
Included Journals:
PubMed
Document Type:
J
ISSN No.:
1521-3773
Key Words:
copolymerization,crystallinity,isomerization,smart materials,unsaturated polyesters
Abstract:
An aliphatic polyester has been prepared from ethylene oxide and maleic anhydride that undergoes reversible transformation between amorphous (Tg =18 °C) and crystalline (Tm =124 °C) states through cis-trans isomerization of the C=C bonds in the polymer backbone without any change in either the molecular weight or dispersity of the polymer. A similar transformation was also observed in chiral unsaturated polyesters formed from enantiopure terminal epoxides, such as epichlorohydrin, phenyl glycidyl ether, and (2,3-epoxypropyl)benzene. These unsaturated polyesters with 100 % E-configuration in the crystalline state were prepared by quantitative isomerization of their Z-configuration analogues in the presence of a catalytic amount of diethylamine, while in the presence of benzophenone, irradiation with 365 nm UV light resulted in the transformation of about 30 % trans-alkene to cis-maleate form, thereby affording amorphous polyesters.© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Translation or Not:
no
