Synthesis of new autophotosensitive semiaromatic hyperbranched polyimides with excellent mechanical properties and low birefringences

Abstract

A series of autophotosensitive semiaromatic hyperbranched polyimides (PIs) were prepared by (A2 + B3)-type method and endcapped with 2,6-dimethylaniline. The photosensitive hyperbranched PIs (PHBPIs) showed excellent solubility, excellent optical properties, and low birefringences in the range of 0.0022–0.0042 caused by their special hyperbranched structures and alicyclic chain segments reduced both intramolecular and intermolecular charge transfer complex effect. It also showed excellent mechanical properties with tensile modulus in the range of 1.37–1.60 GPa and good thermal stabilities. Photolithographic property of the polymer was examined by ultraviolet exposure. Scanning electron microscopic analysis revealed a highly resolved pattern with a line width of 8 μm.