Hydroxy-containing low molecular weight poly(2,6-dimethyl-1,4-phenylene oxide)(r PPO) and self-promoted hydroxycontaining phthalonitrile(HPPH) were prepared by redistribution reaction and the simple nucleophilic displacement of a nitro-substituent from 4-nitrophthalonitrile in a dipolar aprotic solvent respectively. The hydroxy-containing phthalonitriles modified by r PPO were prepared by mechanical blending without compatibilizer, followed by heating. The curing behavior was studied using dynamic rheological analysis, and the results showed that the r PPO-modified phthalonitrile exhibited a large processing window(over-67 °C) and complex viscosity(0.18-0.8 Pa·s) at moderate temperatures. After curing at 300 °C, the resulting polymers showed good thermal stability and high modulus as observed by thermogravimetric analysis(TGA) and dynamic mechanical analysis(DMA). The dielectric properties and the morphology of r PPO-modified phthalonitrile networks were studied by dielectric analysis and field-emission scanning electron microscopy(SEM).
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