SYNTHESIS AND PROPERTIES OF POLYIMIDES, POLYAMIDES AND POLY(AMIDE-IMIDE)S FROM ETHER DIAMINE HAVING THE SPIROBICHROMAN STRUCTURE

A novel spirobichroman unit containing dietheramine, 6,6'-bis(4-amino- phenoxy) -4,4,4',4',7,7'-hexamethyl-2,2'-spirobichroman (3), was prepa red by the nucleophilic substitution of roxy-4,4,4',4',7,7'-hexamethyl -2,2'-spirobichroman with p-chloronitrobenzene in the presence of K2CO 3 followed by hydrazine catalytic reduction of the intermediate dinitr o compound. A series of polyimides were synthesized from diamine 3 and various aromatic dianhydrides by a conventional two-stage procedure t hrough the formation of poly( amic-acid)s followed by thermal imidizat ion. The intermediate poly(amic-acid)s had inherent viscosities of 1.0 0-2.78 dL/g. All the poly (amic-acid)s could be thermally cyclodehydra ted into flexible and tough polyimide films, and some polyimides were soluble in polar solvents such as N-methyl-2-pyrrolidone (NMP), N,N-di methylacetamide (DMAc), and N,N-dimethylformamide (DMF). These polyimi des had glass transition temperatures (T-g) in the range of 236-256 de grees C, and 10% weight loss occurred up to 450 degrees C. Furthermore , a series of polyamides and poly( amide-imide)s with inherent viscosi ties of 0.71-2.29 dL/g were prepared by direct polycondensation of the diamine 3 with various aromatic dicarboxylic acids and imide ring-con taining dicarboxylic acids by means of triphenyl phosphite and pyridin e. All the polyamides and poly(amide-imide)s were readily soluble in p olar solvents such as DMAc, and tough and flexible films could be cast from their DMAc solutions. These polymers had glass transition temper atures in the range of 137-228 degrees C and 10% weight loss temperatu res in the range of 419-443 degrees C in air and 404-436 degrees C in nitrogen, respectively. (C) 1997 John Wiley & Sons, Inc.