SYNTHESIS AND EVALUATION OF NOVEL POLYIMIDES DERIVED FROM SPIROBICHROMAN DIETHER ANHYDRIDE

A spirobichroman structure-containing diether anhydride (SBCDA), oxy)- 4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman dianhydride, was prepare d by the nucleophilic nitrodisplacement of 4-nitrophthalonitrile with the phenolate ion of oxy-4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman , followed by alkaline hydrolysis of the intermediate tetranitrile and dehydration of the resulting tetraacid. A series of high molecular we ight poly(ether imide)s with inherent viscosities between 0.45 and 1.2 8 dL/g were synthesized from SBCDA and various aromatic diamines via a conventional two-stage procedure that included ring-opening polyaddit ion in N,N-dimethylacetamide (DMAc) to give poly(amic acid)s, followed by thermal cyclization to poly(ether imide)s. The intermediate poly(a mic acid)s had inherent viscosities of 0.70-1.50 dL/g. Except for the poly(ether imide) obtained from p-phenylenediamine, the other poly(eth er imide)s were soluble in various organic solvents and could be solut ion-cast into transparent, flexible, and tough films. These poly(ether imide)s had glass transition temperatures in the range 175-262 degree s C and showed no significant decomposition below 420 degrees C, with 10% weight loss being recorded above 446 degrees C in nitrogen or air. (C) 1997 John Wiley & Sons, Inc.