A new aromatic diamine, with an isopropylidene and bromo-substituted arylene ether structure, 3,3 ' ,5,5 ' -tetrabromo-2,2-bis [4-(4-aminophenoxy)phenyl]propane, was synthesized by the nucleophilic substitution reaction of p-chloronitrobenzene with 3,3 ' ,5,5 ' -tetrabromobisphenol A, followed by a catalytic reduction of the resulting dinitro compound. Novel aromatic polyimides with inherent viscosities ranging from 0.53 to 2.1 dL/g were then obtained by a one-step or two-step polymerization process with this diamine and various aromatic dianhydrides. These bromine-containing polyimides showed typical amorphous diffraction patterns and were readily soluble at room temperature in N-methyl-2-pyrrolidone, N,N ' -dimethylformamide, N,N ' -dimethylacetamide, and even in less polar solvents such as chloroform, tetrahydrofuran, and pyri dine. They also dissolved in dimethyl sulfoxide, m-cresol, o-chlorophenol,or concentrated sulfuric acid with heating. Class-transition temperatures were 272-303 degreesC, depending on the nature of the dianhydride moiety. Thermogravimetric analysis showed that all the polymers were thermally stable, with 10% weight loss occurring between 465 and 499 degreesC in nitrogen and between 457 and 492 degreesC under atmospheric conditions. The bulky bromine substituents not only increased the solubility but also compensated for the loss of thermal properties caused by the flexible ether linkage.