The Naval Research Laboratory (NRL) has developed a new class of PEEK™-like phthalonitrile (PN) resins for use in a variety of applications due to their ease of processability when in a melt-state followed by curing to produce high-temperature, high-char polymeric thermosets. The PN resins, where n < 1, were initially designed to fabricate polymer matrix composites (PMC) by cost effective manufacturing methods such as resin transfer molding, a type of out of autoclave (OOA) processing. The resin formulations are indefinitely stable under ambient conditions and can be prepared to various viscosities and gel times for use in all commercial resin processes. Phthalonitrile-based PMCs exhibit high thermal and oxidative stability approaching 500 °C (930 °F) in air, have low water absorption, retain structural integrity in a fire environment, and show thermal properties that exceeds Navy expectations for composite ship and aircraft applications.

PN composite fire properties outperform widely used epoxy composites.


  • Resins processed from a melt state with low viscosities reduces overall manufacturing costs of finished products.
  • Resins cure via addition reaction, yielding void-free finished products due to no off-gassing.

Application Areas

  • Commercial:
    • Lightweight, high temperature PMCs as parts in areas of automotive, marine, and aerospace:
      • engine components, brake pads, exhaust systems, bearings, structural components, sporting goods, battery casings (Li-ion, etc.).
  • Military:
    • Ship structures above and below deck, radomes, electronic devices, pressurized vessels, UAV structural components, light armor, high-speed weapons and fuselage, chemical- fire- and oil-proof coatings.


  • “Improved Synthesis of Oligomeric Phthalonitriles and Studies Designed for Low Temperature Cure,” J. Poly. Sci., Part A: Poly. Chem., 52 (2014) 1662–1668.
  • “Improved Synthesis and Properties of Aryl Ether-Based Oligomeric Phthalonitrile Resins and Polymers,” Polymer, 67 (2015) 185–191.
  • PEEKTM is a trademark of Victrex PLC.

Licensing and Collaboration Opportunities
US Patent Nos. 6,756,470; 6,891,014; 7,452,959; 7,511,113; 8,039,576; 8,222,403; 8,288,454; 8,362,239; 8,530,607; 8,569,399; 8,735,532; 8,859,712; 8,921,510; 8,946,321; 8,969,434; 8,981,036 and US Patent Publication Nos. US20110263775A1 are available for license to companies with commercial interest. Collaborative research and development is available under a Cooperative Research and Development Agreement (CRADA).

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