Loading patent…
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsJuan M. Vazquez, Roberto J. Cano, Brian J. Jensen, Erik S. Weiser
Estimating the term…
A fully imidized, solvent-free polyimide foam having excellent mechanical, acoustic, thermal, and flame resistant properties is produced. A first solution is provided, which includes one or more aromatic dianhydrides or derivatives of aromatic dianhydrides, and may include one or more aromatic diamines, dissolved in one or more polar solvents, along with an effective amount of one or more blowing agents. This first solution may also advantageously include effective amounts respectively of one or mores catalysts, one or more surfactants, and one or more fire retardants. A second solution is also provided which includes one or more isocyanates. The first and second solutions are rapidly and thoroughly mixed to produce an admixture, which is allowed to foam—in an open container, or in a closed mold—under ambient conditions to completion produce a foamed product. This foamed product is then cured by high frequency electromagnetic radiation, thermal energy, or a combination thereof. Alternatively, the process is adapted for spraying or extrusion.
A random copolymeric polyimide foam prepared by combining components comprising one or more aromatic dianhydrides, one or more aromatic diamines, and one or more isocyanates, said foam further comprising both random molecular weight imide units and random molecular weight copolymeric units prepared by the reaction of the isocyanates with the random molecular weight imide units.
A random copolymeric polyimide foam prepared by combining components comprising one or more aromatic dianhydrides, one or more aromatic diamines, and one or more isocyanates, said foam further comprising both random molecular weight imide units and random molecular weight copolymeric units prepared by the reaction of the isocyanates with the random molecular weight imide units, and said foam having a density of from about 0.2 pounds/ft3 to 0.8 pounds/ft3.
Dependencies are inferred from the claim text.