Polyimide Ionomer Nanocomposite for Aerospace Structures and Part Fabrication

We propose to modify thermoplastic polyimides by reducing molecular weight, incorporating ionic terminations and nanoparticulate clay to deliver new composite materials with exceptional properties. A clay nanomer will be combined with thermoplastic ionomerically terminated polyimides to produce melt fabricable nanocomposites. Ionomeric polyimides have not previously been available to the composite formulator, and it is expected that constructions using this material will exhibit superior physical properties below its Tg. Ionic bonding diminishes at thermoplastic processing temperatures, and combined with low molecular weight polyimides provides lower melt viscosity to assist in manufacturing large shaped parts, structures and laminates by conventional extrusion, injection molding, hot-gas welding and filament bonding methods. Nanoparticulate blends with high polymers are known to demonstrate enhanced physical properties. Expected improvements are increased modulus; tensile strength; impact, abrasion and ablation resistance; and resistance to mono-atomic oxygen. Improved properties include decreased thermal expansion coefficient, flammability and gas diffusion rate. Ionomers are known to be self-healing toward high-energy projectile impacts, making this type of material useful as space armor. Improved gas diffusion rate may enhance containment vessels for liquefied propellant and fuel storage. The result of this research will be a high performance polymer economically processable with conventional equipment.