Abstract Pyromellitic dianhydride (1) was reacted with L-alanine (2) to result [N, N′- (pyromellitoyl)-bis-l-alanine diacid](3). This compound (3) was converted to N, N′- (pyromellitoyl)-bis-l-alanine diacyl chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacyl chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic aromatic diols furnish a series of new PEI s and Co-PEI s ...