Synthesis and thermal properties of poly(arylene ether ketone)s containingphthalazinone moieties

A series of novel poly(arylene ether ketone)s were synthesized from the rea ction of hydroquinone and 4-(4-(4-hydroxyphenyl)-2,3-phthalazin-1-one with 4,4'-difluorobenzophenone in N-cyclohexylpyrrolidinone containing anhydrous potassium carbonate. The polymers exhibited high glass transition temperat ures together with excellent thermooxidative stability. The chain structure of these polymers was studied by means of differential scanning calorimetr y (DSC), wide-angle X-ray diffraction techniques (WAXD), and matrix-assiste d laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-M S). The experimental results indicated that these "asmade" copoly(aryleneke tone)s containing hydroquinone moieties exhibited a block chain structure w ith segments which mainly consisted of hydroquinone and 4,4'-difluorobenzop henone. These chain segments resulted in crystallites in the polymers altho ugh they are thermodynamically unstable. The polymers showed thermal proper ties comparable to commercial PEEK, but the conditions for synthesis are mu ch milder. The glass transition temperatures and solubilities of the copoly (arylene ketone)s tended to increase with increasing phthalazinone moiety c ontent, while the crystallite melting points and crystallinity appeared to decrease. (C) 1999 John Wiley & Sons, Inc.