Aromatic polymers obtained by precipitation polycondensation, 2a) Synthesis of poly(ether ketone ether ketone ketone) (PEKEKK)

Abstract

A high molecular weight, linear aromatic poly(ether ketone ether ketone ketone) (PEKEKK) has been synthesized by electrophilic Friedel-Crafts acylation condensation of 1,4-diphenoxybenzophenone with terephthaloyl chloride. The syntheses were performed as precipitation polycondensations, and the polyketones were obtained in particle form. The viscosity (molecular weight), shape and size of these particles were found to be strongly dependent on the reaction conditions. For low monomer concentration, highly ordered needle-like particles were also obtained. The chemical structure of the polymers obtained was confirmed by 1H and 13C NMR spectroscopy, and para-substitution in aryl fragments of the main chain was identified. Analysis of the expanded 1H NMR spectra for the ring proton resonances reveals defect mefa- and ortho-structures. The amount and isomer ratio of these defect structures depend on the monomer concentration used.