An improved synthetic method has been developed for oligomeric aromatic ether ketone-based phthalonitrile (PN) resins. A new curing additive was studied that lowers the cure temperature of the PN resin to around 150 degrees C and compared to the traditional high-temperature aromatic diamine. Mechanical and thermo-oxidative analyses of polymeric samples from both systems were determined and compared under various curing conditions. The PN polymer exhibited low water absorption regardless of the chosen cure system. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1662-1668