SYNTHESIS AND PROPERTIES OF POLY(ETHER IMIDE)S DERIVED FROM 4,4'-(1,5-NAPHTHYLENEDIOXY)DIPHTHALIC ANHYDRIDE AND VARIOUS AROMATIC DIAMINES

A naphthalene unit-containing bis(ether anhydride), 4,4'-(1,5-naphthyl enedioxy)-diphthalic anhydride, was prepared in three steps starting f rom the nucleophilic nitro-displacement reaction of 1,5-dihydroxynapht halene and 4-nitrophthalonitrile in N,N-dimethylformamide (DMF) soluti on in the presence of potassium carbonate. High-molar-mass aromatic po ly(ether imide)s were synthesized using a two-stage polymerization pro cess from the bis(ether anhydride) and ten aromatic diamines. The inte rmediate poly(ether amic acid)s had inherent viscosities of 0,66-1,27 dL/g. The films of poly(ether imide)s derived from some diamines, such as p-phenylenediamine, benzidine, and bis[4- (4-aminophenoxy)phenyl] ether, crystallized and embrittled during the thermal imidization proc ess. The other poly(ether imide)s were amorphous materials and could b e fabricated into transparent, flexible, and tough films. These poly(e ther imide) films had yield strengths of 111-125 MPa, tensile strength s of 96-150 MPa, elongations to break of 10-38%, and initial moduli of 1,6-2,4 GPa. All of these polymers were insoluble in organic solvents , except for that derived from 2,2-bis[(4-aminophenoxy)phenyl]propane. Their T-g's were recorded in the range of 226-265 degrees C by DSC. T hermogravimetric analysis (TG) showed that all the polymers were stabl e up to 535 degrees C in both air and nitrogen atmosphere.