Aromatic diamine monomers, including o-phenylenediamine (oPD), p-phenylenediamine (oPD), 4,4'-diaminodiphenylenemethane (DADPM) and benzidine (BZN), were polymerized by chemical oxidation using sodium persulfate, potassium persulfate, and ammonium persulfate as oxidant catalysts. Aluminium-triflate (Al(OTf)(3)) was also used for the first time as a co-catalyst under various polymerization conditions. The homopolymers obtained are characterized by FT-IR, H-1 and C-13 NMR, GPC, WAXD, DSC and TGA. The yield, solubility, structure and molecular weight of the polymers are significantly dependent on the oxidative catalyst and polymerization conditions. The polymers show different molecular structures, good thermal stability and decompose above 400 degrees C in nitrogen. (C) 2012 Elsevier Ltd. All rights reserved.