Facile and Efficient Incorporation of Methacrylate Groups into Poly(amic acid) via an Acid-Catalyzed One-Pot Esterification

Abstract Herein, we report a one-pot esterification of poly(amic acid) (PAA) using 2-vinyloxyethyl methacrylate (VEMA) under acidic conditions. A model reaction afforded the corresponding hemiacetal ester in 94% yield. Applying this method to PAA enabled direct introduction of methacrylate-functionalized hemiacetal groups at room temperature. (+)-Camphorsulfonic acid provided stable esterification without gelation, achieving 71% conversion after storage at 5 °C for 7 days. This method offers a simple route to negative-tone alkali-developable PSPI materials.