ИСТИНА

Modern aircrafts consist of carbon fiber reinforced plastics up to 50 % mass for civil ones and 70 % for fighters. Nowadays the most common matrices are epoxy and BMI resins with upper limit of operating temperatures up to 250 °C. Development of polymer matrices stable at temperatures up to 450 °C would allow replacement of aluminum alloys by CFRP in parts operating at elevated temperatures. For aerospace industries jet engine compressor blades or supersonic aircraft body parts could be of the greatest interest in terms of application of such materials. CFRP operating temperatures are determined by thermal stability of the polymer matrix. Thermosets derived from phthalonitrile resins cured in the presence of aromatic amines are known as the most heat-resistant polymers demonstrating stability up to 500 °C. The main disadvantage of these resins was poor processability due to high melting points of uncured phthalonitrile monomers (170–200°C) which resulted in high processing temperatures during CFRP manufacturing. This set up special requirements for auxiliary materials, and quick gelation occurring at temperatures >200 °C limited sizes and shapes of the produced items. The development of low-melting siloxane- and phosphate- bridged phthalonitrile monomers [1-3] allowed to obtain phthalonitrile resins suitable for cost-effective injection methods for composite manufacturing [4, 5]. The reported composites demonstrated moderate mechanical properties which retained at 300 ℃. In the current report we describe resin formulations based on the aforementioned monomers and CFRP manufacturing with detailed characterization of the obtained materials.