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 7–8 hr at 210°C. The cyclic oligomers in the polymer product reduced to below 3.0% when the concentration of the reactant is 1.6–1.7 g/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 (T_g) up to 261°C detected by differential scanning calorimetry (DSC), and the temperature of 5% weight loss under nitrogen higher than 500°C detected by thermal gravimetric analysis (TGA), indicating its excellent thermal stability. Copyright © 2011 John Wiley & Sons, Ltd.

Soluble and heat-resistant polymers have great potential for use as processable, high-temperature polymeric materials. In this study, four types of new poly(arylene ether s-triazine)s containing alkyl-, aryl- and chloro-substituted phthalazinone moieties in the main chain were prepared through direct solution polycondensation of 2,4-bis(4-fluorophenyl)-6-phenyl-s-triazine with each of methyl-, phenyl- and chloro-substituted phthalazinones. A key feature of these polymers is the incorporation of phthalazinone and side groups into the poly(arylene ether s-triazine) backbone to endow them with good solubility while maintaining other attractive properties. The polymers were obtained in high yields, and had inherent viscosities ranging from 0.38 to 0.55 dL g⁻¹. Their structure was characterized using Fourier transform infrared and NMR spectra and elemental analysis. The polymers were almost amorphous, and soluble in N-methyl-2-pyrrolidone, pyridine, N,N-dimethylacetamide, hot N,N-dimethylformamide and sulfolane. Tough and nearly transparent films obtained by direct solution casting exhibited good mechanical properties. The resulting polymers displayed glass transition temperatures ranging from 255 to 265 °C and thermal decomposition temperatures for 10% mass loss ranging from 476 to 599 °C, according to differential scanning calorimetry and thermogravimetric analysis, respectively. The reactivity of substituted phthalazinones in nucleophilic displacement reactions and the effect of the side groups on the physical properties of the polymers were also investigated. The results obtained revealed that such s-triazine-containing polymers possessed good solubility while maintaining acceptable thermal stability and high mechanical strength with the incorporation of alkyl-, aryl- and chloro-substituted phthalazinone moieties into their backbones, which makes them an attractive series of high-performance structural materials. Copyright © 2010 Society of Chemical Industry