Ring-opening polymerization of ethylene carbonate using ionic liquids as catalysts
writer：Zhou, Jiancheng; Cheng, Ling; Wu, Dongfang
keywords：polymer synthesis; ionic liquid; polycarbonate; ring-opening polymerization
source：期刊
specific source：E-POLYMERS
Issue time：2011年
The ring-opening polymerization of ethylene carbonate was examined usingionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF(4)) and 1-butyl-3-methylimidazolium chlorozincate ([bmim]Cl-(ZnCl(2))(x)), as polymerization catalysts. It was shown that the polymerization was accompanied with decarboxylation and chain cleavage reaction. As the reaction time increased, the monomer conversion increased and the content of ethylene carbonate units in the resultant polymer decreased, while the polymer molecular weight increased at first, reached a maximum and then decreased. It was also found that not only the polymerizing activity of the [bmim]Cl-(ZnCl(2))(x) but also its performance for suppressing the decarboxylation and chain cleavage increased with the molar fraction of ZnCl(2). It was deduced that the catalytic performance of ionic liquids mainly depended on their inorganic anions and that the larger the amountof these anions in the reaction system, the better the catalytic performance. The polymerizing activity of ionic liquids was much higher than conventional catalysts often used for the polymerization of ethylene carbonate.