SYNTHESIS AND CHARACTERIZATION OF NEW SOLUBLE AROMATIC POLYIMIDES FROM 3,4-BIS(4-AMINOPHENYL)-2,5-DIPHENYLFURAN AND AROMATIC TETRACARBOXYLIC DIANHYDRIDES

New soluble polyimides with inherent viscosities of 0.2-0.6 dL/g were synthesized from 3,4-bis(4-aminophenyl)-2,5-diphenylfuran and various aromatic tetracarboxylic dianhydrides by the conventional two-step method which involved ring-opening polyaddition and subsequent cyclodehydration. Almost all of the polyimides were generally soluble in a wide range of organic solvents such as N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidone, m-cresol, o-chlorophenol, and pyridine. The polyimide prepared from pyromellitic dianhydride was crystalline, whereas the other polyimides were amorphous. All the polyimides have glass transition temperatures in the range of 281-344-degrees-C and showed no appreciable weight loss up to 410-degrees-C in both air and nitrogen atmospheres.