A MECHANISTIC STUDY ON THE STEREOREGULAR POLYMERIZATION OF PROPYLENE-OXIDE BY THE PRUITT-BAGGETT CATALYST

1994-01-01
TAKROURI, F
ALYURUK, K
The structures of the Pruitt-Baggett adduct (PBA) and the Pruitt-Baggett catalyst (PBC) were studied in some detail. PBC extensively ionizes in acetonitrile (K(d)=3.48 x 10(-3) mol l-1 at 25-degrees-C) producing an anionic fragment composed of seven Fe atoms and a cationic fragment with two Fe atoms. Hittorf electrolysis showed that the anionic fragments exclusively bore the high molecular weight stereoregular poly(propylene oxide)s (K-polymers). However, study of the polymerization in the presence of anion and cation scavengers and in different dielectric media supported a previous conclusion that neither free anions nor cations were solely responsible for the stereoregular polymerization, but together with a monomer molecule they combine to yield catalytically active monomer-bound ion pairs. The study of the product showed that K-polymers were connected to each other with Fe atoms. However, these chains could be freed by extracting the Fe residues with hydrochloric acid. A mechanism for the stereoregular polymerization of propylene oxide that is consistent with the present and already published data was suggested.

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Citation Formats
F. TAKROURI and K. ALYURUK, “A MECHANISTIC STUDY ON THE STEREOREGULAR POLYMERIZATION OF PROPYLENE-OXIDE BY THE PRUITT-BAGGETT CATALYST,” POLYMER, pp. 1518–1525, 1994, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/65523.