Thiophene monomer structures containing different hetero aromatic rings (containing five-member/six-member, varying electronegativity, functional groups) were designed and synthesized. The influence of structural components of the side chain on the thermal stability of the polymers of the above monomers was analyzed using thermogravimetric analysis. The results show that thiophene-containing hetero aromatic side chains linked through six-member ring show high thermal stability. © 2009 Springer Science+Business Media, LLC.