Synthesis and characterization of polyetherimides via aromatic nitro displacement reaction

Two ether groups containing bisnitrophthalimide monomers 4,4’-Bis(4-nitrophthalimido phenoxy)diphenyl sulfone and 4,4'-bis (4-nitrophthalimido phenoxy)benzophenone were synthesized. The monomers were characterized by Fourier transform infrared (IR) spectroscopy and 1 H-NMR. The polyetherimides were prepared from bisnitrophthalimides by nucleophilic displacement of nitro group by bisphenolate ion. The polyetherimides were characterized by IR, 1 H-NMR, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, dielectric constants, solution viscosity and solubility. Polyetherimides were soluble in polar approtic solvents and improved solubility in common organic solvents is due to the presence of flexible groups in the polymer backbone. Polyetherimides exhibited good thermal stability and the temperature at which 10% weight loss occurs in the range 357—453°C in a nitrogen atmosphere. X-ray diffraction measurements revealed that these polyetherimides are amorphous.