Synthesis and characterization of phthalazinone-based poly(aryl ether ketone) derived from 4,4'-dichlorobenzophenone

As distinguished from the conventional preparation of poly(aryl ether ketone)s utilizing 4,4'-difluorobenzophenone, a novel synthetic method of high molecular weight poly(phthalazinone ether ketone) derived from 4,4'-dichlorobenzophenone was studied. Reaction conditions to get high molecular weight polymer were investigated in details. Experimentally, sulfolane was chosen as the reaction media and high molecular weight polymer could be obtained in 78 hr at 210 degrees C. The cyclic oligomers in the polymer product reduced to below 3.0% when the concentration of the reactant is 1.61.7g/ml. Fourier transform infrared (FT-IR), 1H NMR, and elemental analysis were used to confirm the structure of the obtained polymer. The amorphous polymer showed reasonable solubility in selective solvent, such as chloroform and N-methyl-2-pyrrolidone, and tough, flexible, and transparent thin film can be readily prepared from their N-methyl-2-pyrrolidone solution. The obtained polymer showed high glass transition temperature (Tg) up to 261 degrees C detected by differential scanning calorimetry (DSC), and the temperature of 5% weight loss under nitrogen higher than 500 degrees C detected by thermal gravimetric analysis (TGA), indicating its excellent thermal stability. Copyright (C) 2011 John Wiley & Sons, Ltd.