Maleic anhydride-terminated fluorinated polyimides with changeable refractive indices

Fluorinated aromatic polyimides have been intensively applied as waveguide materials due to their excellent thermal stability, high transparency, high glass transition temperature T_g, low optical losses and low absorption for water. This paper investigates novel fluorinated polyimides synthesized from the cocondensation of 4,4´-diaminodiphenylenether (ODA), 2,2´-bis-(3,4-dicarboxyphenyl)-hexafluoroproane dianhydride (6FDA) and maleic anhydride (MA) . The chemical structure of MAPIs were characterized by ¹H NMR and FT-IR spectroscopy and their chemical and thermal properties were investigated by DSC, TGA . The refractive indices of their cured films were directly measured at different temperature.