Phthalonitrile-carbon fiber composites produced by vacuum infusion process:

High-temperature carbon fiber-reinforced plastics based on phthalonitrile resins are obtained for the first time by vacuum infusion process. For this purpose, formulations based on low-melting bis(3-(3,4-dicyanophenoxy)phenyl) phenyl phosphate monomer in combination with 1,3-bis(3,4-dicyanophenoxy)benzene and 4-[3-(prop-2-yn-1-yloxy)phenoxy]benzene-1,2-dicarbonitrile were developed. Resin viscosities η ≤ 600 mPa·s were suitable for VIP and at the same time the thermal and mechanical properties of the cured matrices were in high level featured to phthalonitriles (HDT ≥ 420℃, E ≥ 5.1 GPa). CFRP samples were manufactured by vacuum infusion process with carbon fabric and demonstrated thermal stability over 400℃ and a change of mechanical properties by less than 10% at 300℃. Present results sufficiently extend the application field of phthalonitriles as matrices for complex-shape high temperature composite parts in aerospace or high-temperature composite tooling for PEEK-like thermoplastics processing.