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A. Stolarzewicz, D. Neugebauer, J. Grobelny, Z. Grobelny



Polymerization of oxiranes in the presence of potassium hydride


Polimery 1998, No 7-8, 443


DOI: dx.doi.org/10.14314/polimery.1998.443


Summary

The potassium hydride/18-crown-6 system was found to promowe anionic polymerization of oxiranes at room temperature to yield, e.g., poly(butoxymethyl oxirane)s with Mw /Mn < 1.1 and with each macromolecule hydroxy-terminated (after hydrolysis) on both ends. No chain transfer re action on the monomer was found to occur. Methyloxirane (or propylene oxide, PO) was found to polymerize with side reactions occurring; Mw /Mn was 1.8. A polymerization mechanism was suggested to explain the formation of dipotassium propylene glycol as the major product at the initial stage. In the presence of dicyclohexane-18-crown-6, the rate of polymerization of PO was the same. However, the molecular weight of the resulting polymer was twice as high.


Keywords: anionic polymerization of oxiranes, initiation with potassium hydride, effect of crown ethers


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