POLYMETHYLALUMINIUM OXIDE AND STEREOREGULAR POLYMERIZATION OF PROPYLENE-OXIDE

Date

1993-05-01

Author

OKTEM, Z
SARI, A
ALYURUK, K

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Polymethylaluminium oxide (PMAO) was prepared by reacting trimethylaluminium (AlMe3) with water in dilute dioxane solution. Several PMAO samples with different degrees of polymerizations (DP) were prepared (1 less-than-or-equal-to DP less-than-or-equal-to 7) either by changing reaction conditions or by fractionating the products. PMAO with DP about unity was found to be trimeric in dilute dioxane solutions but, in higher dielectric solvents, it partially dissociated into free ions. Electrical conductance measurements showed that the initially present ion-pairs were converted into another type of ion-pairs (solvent-bound ion-pairs) with a lower dissociation constant as the solution was aged. Catalytic activities of several PMAO samples in the stereoregular polymerization of propylene oxide were studied. Only a slight improvement of the stereoregular yield was observed by increasing the DP of the used catalyst. It was concluded that the methylaluminium oxide repeating units are the active species in the stereoregular polymerization and catalytic activity cannot be ascribed either to the presence of an ''undetected impurity'' or an ''unidentified unique structure of PMAO''.

Subject Keywords

Organic Chemistry, General Physics and Astronomy, Polymers and Plastics

URI

https://hdl.handle.net/11511/66798

Journal

EUROPEAN POLYMER JOURNAL

DOI

https://doi.org/10.1016/0014-3057(93)90121-u

Collections

Department of Chemistry, Article

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Citation Formats

Z. OKTEM, A. SARI, and K. ALYURUK, “POLYMETHYLALUMINIUM OXIDE AND STEREOREGULAR POLYMERIZATION OF PROPYLENE-OXIDE,” EUROPEAN POLYMER JOURNAL, pp. 637–643, 1993, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66798.