Controlled variation of monomer sequence-distribution in the synthesis of aromatic poly(ether ketone)s

Lim, K. J. C., Cross, P., Mills, P. and Colquhoun, H. M. (2016) Controlled variation of monomer sequence-distribution in the synthesis of aromatic poly(ether ketone)s. High Performance Polymers, 28 (8). pp. 984-992. ISSN 1361-6412 doi: 10.1177/0954008315612140

Abstract/Summary

The effects of varying the alkali metal cation in the high-temperature nucleophilic synthesis of a semi-crystalline, aromatic poly(ether ketone) have been systematically investigated, and striking variations in the sequence-distributions and thermal characteristics of the resulting polymers were found. Polycondensation of 4,4'-dihydroxybenzophenone with 1,3-bis(4-fluorobenzoyl)benzene in diphenylsulfone as solvent, in the presence of an alkali metal carbonate M2CO3 (M= Li, Na, K, or Rb) as base, affords a range of different polymers that vary in the distribution pattern of 2-ring and 3-ring monomer units along the chain. Lithium carbonate gives an essentially alternating and highly crystalline polymer, but the degree of sequence-randomisation increases progressively as the alkali metal series is descended, with rubidium carbonate giving a fully random and non-thermally-crystallisable polymer. Randomisation during polycondensation is shown to result from reversible cleavage of the ether linkages in the polymer by fluoride ions, and an isolated sample of alternating-sequence polymer is thus converted to a fully randomised material on heating with rubidium fluoride.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/43742
Identification Number/DOI	10.1177/0954008315612140
Refereed	Yes
Divisions	Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > NMR (CAF) Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Thermal Analysis (CAF) Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Xray (CAF)
Publisher	Sage
Download/View statistics	View download statistics for this item