Partially imidized poly[(amic ester)‐alt‐imide]: A novel polyimide pregursor

Partial imidization of poly[(amic ester)‐alt‐(amic acid)], a precursor for the “strictly alternating” copolyimides, was performed via selective chemical imidization of amic acid units in the copolymer precursor. The resulting, poly[(amic ester)‐alt‐imide], showed superior properties such as an excellent solution stability, good processibility and improved optical transparency, which are essential for the use as a precursor for the polyimide.