ISOLATION, SPECTRA, STRUCTURE, AND RING-OPENING POLYMERIZATION OF STRAINED MACROCYCLIC ARYL(ETHER KETONE) DIMER

Macrocyclic arylene ether ketone dimer was isolated from a mixture of cyclic oligomers obtained by the nucleophilic substitution reaction of bisphenol A and 4,4'-difluorobenzophenone and easily polymerized to h igh molecular weight linear poly(ether ketone). The cyclic compound wa s characterized by FTIR, H-1- and C-13-NMR, and single-crystal x-ray d iffraction. Analysis of the spectral and crystal structure reveals ext reme distortions of he phenyl rings attached to the isopropylidene cen ter and of the turning points of the molecular polygons. The release o f the ring strain on ring-opening combined with entropical difference between the linear polymer chain and the more rigid macrocycle at temp eratures of polymerization may be the proposed motivating factors in t he polymerization of this precursor to high molecular weight poly(ethe r ketone). (C) 1997 John Wiley & Sons, Inc.