PARALINKED AROMATIC POLY(AMIC ETHYL ESTER)S - PRECURSORS TO RODLIKE AROMATIC POLYIMIDES .1. SYNTHESIS AND IMIDIZATION STUDY

The synthesis and characterization of several para-linked aromatic poly(amic ethyl ester)s are described. These substituted polyamides are precursors to rodlike aromatic polyimides. The poly(amic ethyl ester)s are based on 2,5-bis(ethoxycarbonyl)terephthalic acid and several substituted 1,4-diaminobenzene and noncoplanar 4,4'-diaminobiphenylene derivatives. Depending on the degree and type of substitution, the precursors are soluble to high concentrations in solvents such as DMF or NMP without the addition of inorganic salts. In addition to the characterization of the precursor polyamides, a detailed chemical and thermal study of the imidization process is presented, based on dynamic and isothermal TGA measurements and FT-IR spectroscopy investigations.