4-Aminophenoxy phthalonitrile (APPH) has been synthesized and utilized to catalyze the curing of resorcinol-based phthalonitrile monomer, 1,3-bis(3,4-dicyanophenoxy) benzene (BDB), and bisphenol-A-based phthalonitrile monomer, 2,2-bis[4-(3,4-dicyanophenoxy)phenyl propane (BDPP). Fourier transform infrared spectroscopy (FT-IR) showed that polytriazine structures have been formed during polymerization, and the introduction of APPH facilitated curing reaction. The prepared BDB and BDPP resins show outstanding thermal stability, high modulus and high glass transition temperature (T-g) which were further improved with increase in APPH content. Postcuring effects on thermal and dynamic mechanical properties were evaluated using thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). (C) 2013 Elsevier B.V. All rights reserved.