A soluble polyimide was synthesized from 2,2'-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BPADA) and 3,3'-dimethyl-4,4-diaminodiphenylmethane (DMMDA) by a two-step method, and it had good solubility both in strong bipolar solvents and in common low-boiling-point solvents. The BPADA-DMMDA polyimide was dissolved in chloroform (CHCl3) and cast onto a glass substrate in a humid atmosphere. The BPADA-DMMDA/CHCl3 solution easily formed honeycomb films. Some affecting factors, such as the polymer solution concentration, atmospheric humidity, and solvent volatility, were tested. (C) 2007 Wiley Periodicals, Inc.