Synthesis and characterization of negative-type photosensitive hyperbranched polyimides with excellent organosolubility from an A2+B3 monomer system

A series of photosensitive hyperbranched polyimides (HB-PIs) were prepared through facile end-group modifications of the fully imidized polymer. A triamine, 1,3,5-tris(4-aminophenoxy)benzene, and a dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, were condensed with a dropwise addition method in a molar ratio of 1/2 to afford an anhydride-terminated poly(amic acid) precursor, which was then end-capped by 4-aminophenol and chemically imidized to yield a phenol-terminated HB-PI. The modifications of the terminal phenol groups of the polyimide by acyl chloride compounds (acryloyl chloride, methylacryloyl chloride, and cinnamoyl chloride) gave the target polymers. The photosensitive HB-PIs showed good thermal properties and excellent solubility even in low-boiling-point solvents at room temperature, such as acetone, 1,1,2-trichloroethane, tetrahydrofuran, and chloroform. Photosensitive property studies revealed good photolithographic properties with a resolution greater than 3 mum and a sensitivity of 650-680 mJ/cm(2). (C) 2004 Wiley Periodicals, Inc.