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.Potential Commercial ApplicationsImitec will initiate quantitative commercialization test results to support the market assessments during Phase I, to be completed during a Phase II. mechanical properties (tensile strength, modulus, elongation); processing conditions, (e.g. thermoforming and extrusion temperatures) and electrical properties (dielectric strength, dielectric constant, dissipation factor). Market development will be directed toward applications where reduced material cost, enhanced material physical properties, and the processing advantages of using conventional industrial equipment supply significant economic opportunities. Specific current applications are: High strength, lightweight, contoured, shelter and radiation shields in space using highly filled material, for example boron for shielding against high energy heavy metal ions. Energy absorbing, self-healing space armor to protect satellite system components from particles and debris in a low earth orbit environment. Lamination adhesives to fabricate piezoelectric transducers and flexible high density circuits. Aerospace wire insulation systems for both military and commercial aviation. On-site composite manufacture and repair of industrial structures, vessels and processing equipment. Low gas diffusion rate composite tanks for liquified propellants usable on launch vehicles to reduce weight. Water sluices, intake manifolds and valves for power plants made from biological growth inhibiting polyimide ionomers by ATP (Automatic Tow Placement) filament winding and injection molding methods.
