United States of America As Represented by the Administrator of Nasa

The United States of America As Represented by the Administrator of the

Keith L Gordon

Emilie J Siochi

Cheol Park

Jin Ho Kang

Roberto J Cano

Brian W Grimsley

Michael W Czabaj

Joycelyn S Harrison

Peter T Lillehei

Robert G Bryant

Godfrey Sauti

Dennis C Working

Sharon E Lowther

Timothy F Scott

Russell W Smith

Scott R Zavada

Various embodiments provide multi-layered self-healing materials, capable of repairing puncture damage. The multi-layered self-healing materials, capable of repairing puncture damage of the various embodiments may be constructed by sandwiching a reactive (e.g., oxygen sensitive) liquid monomer formulation between two solid polymer panels, such as a polymer panel of Barex 210 IN (PBG) serving as the front layer panel and a polymer panel of Surlyn&#xae; 8940 serving as the back layer panel. The various embodiments may provide methods to produce multi-layered healing polymer systems. The various embodiments may provide a two-tier, self-healing material system that provides a non-intrusive capability to mitigate mid to high velocity impact damage in structures.

Multi-layered self-healing material system towards impact mitigation

One aspect of the present invention is a puncture healing polymer blend comprising a self-healing first polymer material having sufficient melt elasticity to snap back and close a hole formed by a projectile passing through the material at a velocity sufficient to produce a local melt state in the first polymer material. The puncture healing polymer blend further includes a non-self-healing second material that is blended with the first polymer material. The blend of self-healing first polymer material and second material is capable of self-healing, and may have improved material properties relative to known self-healing polymers.

Puncture healing engineered polymer blends

Methods are provided to produce new mechanoresponsive healing systems. Additionally, various embodiments provide a two tier self-healing material system concept that provides a non-intrusive method to mitigate impact damage in a structure ranging from low velocity impact damage (e.g., crack damage) to high velocity impact damage (e.g., ballistic damage.) The various embodiments provide the mechanophore linked polymer PBG-BCB-PBG. The various embodiments provide methods for synthesizing PBG-BCB-PBG.

Methods of making mechanoresponsive healing polymers

A composite comprising a combination of a self-healing polymer matrix and a carbon fiber reinforcement is described. In one embodiment, the matrix is a polybutadiene graft copolymer matrix, such as polybutadiene graft copolymer comprising poly(butadiene)-graft-poly(methyl acrylate-co-acrylonitrile). A method of fabricating the composite is also described, comprising the steps of manufacturing a pre-impregnated unidirectional carbon fiber preform by wetting a plurality of carbon fibers with a solution, the solution comprising a self-healing polymer and a solvent, and curing the preform. A method of repairing a structure made from the composite of the invention is described. A novel prepreg material used to manufacture the composite of the invention is described.

Puncture-healing thermoplastic resin carbon-fiber-reinforced composites and method of fabricating the same

Mechanoresponsive healing polymers

Puncture-healing thermoplastic resin carbon-fiber reinforced composites

Metamaterials or artificial negative index materials (NIMs) have generated great attention due to their unique and exotic electromagnetic properties. One exemplary negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly (benzimidazole) (PBI). The doped PBI showed a negative dielectric constant at megahertz (MHz) frequencies due to its reduced plasma frequency and an induction effect. The magnitude of the negative dielectric constant and the resonance frequency were tunable by doping concentration. The highly doped PBI showed larger absolute magnitude of negative dielectric constant at just above its resonance frequency than the less doped PBI.

Negative dielectric constant material based on ion conducting materials

Some implementations provide a composite material that includes a first material and a second material. In some implementations, the composite material is a metamaterial. The first material includes a chiral polymer (e.g., crystalline chiral helical polymer, poly-&#x3b3;-benzyl-L-glutamate (PBLG), poly-L-lactic acid (PLA), polypeptide, and/or polyacetylene). The second material is within the chiral polymer. The first material and the second material are configured to provide an effective index of refraction value for the composite material of 1 or less. In some implementations, the effective index of refraction value for the composite material is negative. In some implementations, the effective index of refraction value for the composite material of 1 or less is at least in a wavelength of one of at least a visible spectrum, an infrared spectrum, a microwave spectrum, and/or an ultraviolet spectrum.

Doped chiral polymer metamaterials

Puncture-healing thermoplastic resin carbon-fiber-reinforced composites

Metamaterials or artificial negative index materials (NIMs) have generated great attention due to their unique and exotic electromagnetic properties. One exemplary negative dielectric constant material, which is an essential key for creating the NIMs, was developed by doping ions into a polymer, a protonated poly(benzimidazole) (PBI). The doped PBI showed a negative dielectric constant at megahertz (MHz) frequencies due to its reduced plasma frequency and an induction effect. The magnitude of the negative dielectric constant and the resonance frequency were tunable by doping concentration. The highly doped PBI showed larger absolute magnitude of negative dielectric constant at just above its resonance frequency than the less doped PBI.

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Hampton, VA, United States of America

Keith L Gordon