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 polymides 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°C and showed no appreciable weight loss up to 410°C in both air and nitrogen atmospheres.