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Influence of the kind of crown ether on the heterogeneous polymerization of propylene oxide in the presence of potassium hydride

✍ Scribed by Andrzej Stolarzewicz; Dorota Neugebauer

Publisher
John Wiley and Sons
Year
1998
Tongue
English
Weight
271 KB
Volume
199
Category
Article
ISSN
1022-1352

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✦ Synopsis

The influence of 12-crown-4, 15-crown-5, 18-crown-6, dicyclohexano-18-crown-6 and dicyclohexano-24-crown-8 on the propylene oxide polymerization with potassium hydride was studied. The highest reaction rate was obtained in the presence of 18-crown-6 or dicyclohexano-18-crown-6. The use of dicyclohexano-18-crownd was found to enhance the molecular mass of polymers more than other ligands. The observed effects were related to the heterogeneity of the reaction mixture and the structure of the crown ether complexes with the potassium cation.

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✍ Pengfei Yang; Xuwei Zhu; Yanhong Yu; Yong mei Xia; Tianduo Li πŸ“‚ Article πŸ“… 2009 πŸ› John Wiley and Sons 🌐 English βš– 258 KB

## Abstract The anionic polymerization of propylene oxide was investigated with potassium __t__‐butoxide as an initiator, and the solvent hexamethyl phosphoric triamide was used in controlling experiments. The relative molar mass limit of the products was determined as about 2700, and the Cο£ΎC doubl