SYNTHESIS AND CHARACTERIZATION OF AROMATIC POLY(ETHER SULFONE IMIDE)SDERIVED FROM SULFONYL BIS(ETHER ANHYDRIDE)S AND AROMATIC DIAMINES

Two sulfonyl group-containing bis(ether anhydride)s, 4,4'-[sulfonylbis (1,4-phenylene)dioxy] diphthalic anhydride (IV) and ,4'-[sulfonylbis(2 ,6-dimethyl-1,4-phenylene)dioxy] diphthalic anhydride (Me-IV), were pr epared in three steps starting from the nucleophilic nitrodisplacement reaction of the bisphenolate ions of 4,4'-sulfonyldiphenol and 4,4'-s ulfonylbis (2,6-dimethylphenol) with 4-nitrophthalonitrile in N,N-dime thylformamide (DMF). High-molar-mass aromatic poly(ether sulfone imide )s were synthesized via a conventional two-stage procedure from the bi s(ether anhydride)s and various aromatic diamines. The inherent viscos ities of the intermediate poly(ether sulfone amic acid)s were in the r anges of 0.30-0.47 dL/g for those from IV and 0.64-1.34 dL/g for those from Me-IV. After thermal imidization, the resulting two series of po ly(ether sulfone imide)s had inherent viscosities of 0.25-0.49 and 0.3 9-1.19 dL/g, respectively. Most of the polyimides showed distinct glas s transitions on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (T-g) were recorded between 2 23-253 and 252-288 degrees C, respectively. The results of thermogravi metry (TG) revealed that all the poly(ether sulfone imide)s showed no significant weight loss before 400 degrees C. The methyl-substituted p olymers showed higher T-g's but lower initial decomposition temperatur es and less solubility compared to the corresponding unsubstituted pol ymers. (C) 1998 John Wiley & Sons, Inc.