The dianhydride monomer 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride and two diamine monomers, 4,4'-diamino-3,3'-biphenyldiol (HAB) and 2,4-diaminophenol dihydrochloride (DAP), were used to synthesize a series of poly(hydroxyl amic acid). Further functionalization by grafting acrylate groups yields the corresponding poly(acrylate amic acid) that underwent a crosslinking reaction on exposure to UV-light and was used as a negative-tone photosensitive polyimide (PSPI). The analysis of chemical composition and molecular weight of these poly(amic acid)s determined by nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy, and get permeation chromatography revealed that the molecular weight of the poly(hydroxyl amic acid) increased with the molar content of HAB in the feedstock, because HAB exhibited higher polymerization reactivity than DAP. Moreover, the degree of grafting acrylate groups onto poly(hydroxyl amic acid) was determined by H-NMR spectroscopy. The photoresist was formulated by adding 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl) butanone (IRG369) and isopropylthioxanthone as a photoinitiator, tetra(ethylene glycol) diacrylate as a crosslinker, and tribromomethyl phenyl sulfone as a photosensitizer. The PSPI precursor exhibited a photosensitivity of 200 mJ/Cm-2 and a contrast of 1.78. A pattern with a resolution of 10 pm was observed in an optical micrograph after thermal imidization at 300 degrees C. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114:2395-2402, 2009