A porous metamaterial is disclosed, comprising a matrix (101) having a plurality of voids (103) therein, wherein a content of interest (104) is trapped within each of at least part of the voids (103), detached from the matrix (101), thereby providing a respective unit-cell (100) of the metamaterial, with an intended predetermined property associated with the presence of the content of interest (104) within the at least one void (103). A variety of applications of the disclosed metamaterials are presented, including armors having either non-Newtonian fluids or magnetic particles confined within the voids as a content of interest. Upon subjecting the magnetic particles to a rotating magnetic field, the magnetic particles spin within the voids and gain angular momentum, thereby improving the resistance of the armor against penetration. Systems and methods for manufacturing porous metamaterial units having contents of interest confined within voids therein, are also disclosed.

Articles are provided including at least one polyurethane prepared from: (a) about 1 equivalent of at least one polyisocyanate; (b) about 0.005 to about 0.35 equivalent of at least one polycaprolactone polyol; (c) about 0.01 to about 1.0 equivalent of at least one polyol selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-ethanediol, propanediol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecane diol, octadecanediol, cyclopentanediol, 1,4-cyclohexanediol, cyclohexanedimethanol, 1,4-benzenedimethanol, xylene glycol, hydroxybenzyl alcohol, dihydroxytoluene, bis(2-hydroxyethyl) terephthalate, 1,4-bis(hydroxyethyl)piperazine, N,N′,bis(2-hydroxyethyl)oxamide and mixtures thereof; and (d) about 0.01 to about 0.5 equivalent of at least one polyol selected from the group consisting of glycerol, tetramethylolmethane, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol, dipentaerythritol, tripentaerythritol, sorbitan, and mixtures thereof, each based upon the about 1 equivalent of the at least one polyisocyanate, wherein the article has a Gardner Impact strength of at least about 400 in-lb according to ASTM D-5420-04.

A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a low speed spool and a high speed spool; a rotor assembly coupled to the low speed spool; an electric machine rotatable with the low speed spool for extracting power from the low speed spool, for adding power to the low speed spool, or both; and an inter-spool clutch positioned between the low speed spool and the high speed spool for selectively coupling the low speed spool to the high speed spool.

A ballistic-resistant composite includes at least one layer that has a network of ballistic fibers and a resin matrix. The resin matrix includes maleic anhydride-grafted polypropylene (MA-g-PP).

An anti-ballistic protection system for protecting an interior space in a building. The ballistic barrier includes a laminated material having a plurality of layers of lightweight, flexible, ballistic resistant material such as woven sheets which are secured together into the laminate using a adhesive, heat weld, or stitching. The ballistic barrier is configured to be in a compact retracted state which can be deployed to provide a protective state to protect against kinetic ballistic projectiles. The system may include an automated control system operably configured to change the state of the ballistic barrier from the retracted state to the protective deployed state, such that upon sensing a threatening event or condition triggers a transition from the retracted state to the deployed protective state such that in the protective state. The ballistic barrier in the deployed state is configured to be resistant to penetration by high-speed ballistic projectiles such as a bullet fired from a gun or a shrapnel from a bomb to protect the interior space.

According to exemplary inventive practice, a personal armor system includes a textile-based layer not exceeding ½-half-inch thickness, and an elastomeric coating not exceeding ⅛-inch thickness. The textile-based layer includes a fiber reinforcement and a resin binder. The combined areal density of the textile-based layer and the elastomeric coating does not exceed 2.5 psf. According to a first mode of inventive practice, the elastomeric coating is essentially a strain-rate-sensitivity-hardening elastomer, and the areal density of the textile-based layer does not exceed 2.3 psf. According to a second mode of inventive practice, the elastomeric coating is essentially a microparticle-filled strain-rate-sensitivity-hardening elastomeric matrix material, and the areal density of the textile-based layer does not exceed 1.7 psf. The microparticles (e.g., spherical glass microparticles) do not exceed, by weight, 30 percent of the strain-rate-sensitivity-hardening elastomeric matrix material. The textile-based layer affords ballistic protection; the elastomeric coating affords protection against sharp/pointed objects.

The present invention provides process for producing a ballistic-resistant molded article, which molded article comprises: i) a plurality of layers of unidirectionally aligned polyolefin fibers, which layers are substantially absent a bonding matrix; and ii) a plurality of layers of adhesive, and which process comprises: a) providing a plurality of precursor sheets, each of said precursor sheets comprising i) at least one layer of unidirectionally aligned polyolefin fibers which layer is substantially absent a bonding matrix, and ii) at least one layer of adhesive; b) stacking said precursor sheets to form a stack, wherein the total amount of adhesive in the stack is from 5.0 to 12.0 wt. % based on the total weight of the stack; c) pressing the stack produced in step b) at a temperature of from 1 to 30° C. below the melting point of the polyolefin fibers and at a pressure of at least 8 MPa; and d) cooling the pressed stack produced in step c) to at least 50° C. below the melting point of the polyolefin fibers while maintaining pressure.

This technology relates materials that are stab, spike and ballistic resistant and to stab, spike and ballistic resistant composite articles incorporating uniaxially oriented, non-woven fabrics. A fabric layer having a non-uniform areal density is formed having thick areas and thin areas, the thick areas having a greater filament/tape concentration compared to the thin areas. In said thick areas, agglomerated tapes/filaments will protrude from the fabric layer surface. Additional layers are then adjoined with the non-uniform layer to form a panel that has stab, spike and ballistic resistance, with protrusions at least partially spacing the additional layers from full, direct contact with the surface of the non-uniform fabric layer to thereby enhance flexibility and stab, spike and ballistic resistance of the whole.

The present invention provides process for producing a ballistic-resistant molded article, which molded article comprises: i) a plurality of layers of unidirectionally aligned polyolefin fibers, which layers are substantially absent a bonding matrix; and ii) a plurality of layers of adhesive, and which process comprises: a) providing a plurality of precursor sheets, each of said precursor sheets comprising i) at least one layer of unidirectionally aligned polyolefin fibers which layer is substantially absent a bonding matrix, and ii) at least one layer of adhesive; b) stacking said precursor sheets to form a stack, wherein the total amount of adhesive in the stack is from 5.0 to 12.0 wt. % based on the total weight of the stack; c) pressing the stack produced in step b) at a temperature of from 1 to 30° C. below the melting point of the polyolefin fibers and at a pressure of at least 8 MPa; and d) cooling the pressed stack produced in step c) to at least 50° C. below the melting point of the polyolefin fibers while maintaining pressure.

Bonded polymeric film laminates comprising core polymer film layers individually coated on at least one side with a heat fusible polymer layer and fusion bonded together by the application of heat and pressure at a temperature at which each heat fusible polymer coating bonds together adjacent core polymer film layers, where the melting point or softening temperature of the heat fusible polymer is at least 3° C. below that of the core layer polymer, and the lamination temperature is at or above the melting point or softening temperature of the heat fusible coating polymer, where the heat fusible polymer coating layers are thinner than the core polymer film layers, where the coated core polymer film layers are uniaxially stretched by 2× to 40×, and the stretched coated core polymer film layers are cross-plied. Methods for forming the laminates, coated films from which the laminates are formed, and articles formed from the laminates are also disclosed.