We synthesized an AB(2)-type monomer, 4-{4-[di(4-aminophenyl)methyl]-phenoxy}phthalic acid, which contained one phthalic acid group and two aminophenyl. functionalities. The direct self-polycondensation of the AB(2)-type monomer in the presence of triphenylphosphite as an activator afforded a hyperbranched poly(ether imide) with a large number of terminal amino groups. This polymer was characterized with H-1 NMR and IR spectroscopy. The degree of branching of the hyperbranched poly(ether imide) was approximately 56%, as determined by a combination of model compound studies and an analysis of H-1 NMR spectroscopy integration data. The terminal amino groups underwent functionalization readily. The solubility and thermal properties of the resulting polymers depended on the nature of the chain end groups. In addition, the hyperbranched poly(ether imide) was grafted with polyhedral oligomeric silsesquioxane (POSS). Transmission electron microscopy analysis revealed that the grafted POSS molecules aggregated to form a nanocomposite material. (C) 2003 Wiley Periodicals, Inc.