Thermal Protection Laminate

Abstract

The laminate may include one or more thermal insulation layers, each having a thermal conductivity of 0.05 W / m K or less, where the laminate has a thickness of 500 μm or less and a thickness of 0.10 mm 2 / s or less. The laminate may include an adhesive layer, where a rear surface of the laminate is at least partially defined by the adhesive layer or a liner layer removably disposed on the adhesive layer. The laminate may include a protective layer defining at least a portion of a front surface of the laminate, where the protective layer has a thermal conductivity at least 3.5 times the thermal conductivity of each of the insulating layers.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 231,127, filed August 9, 2021, which is incorporated by reference in its entirety.

[0002] A. Field of the Invention The present invention relates generally to laminates for thermal protection of systems such as, but not limited to, aircraft and spacecraft. [Background technology]

[0003] background B. Description of Related Art Systems such as aircraft, spacecraft, missiles, rockets, artillery shells, or other projectiles may include components that are exposed to high temperatures and require protection from high temperatures. Conventional insulating materials such as foams, polymers, and elastomers may provide some thermal protection but still face limitations. For example, polymer foams have low thermal conductivity, which reduces heat transfer, while their thermal diffusivity, i.e., the thermal conductivity of a material divided by its density and specific heat capacity, tends to be higher than other insulating materials. The higher the thermal diffusivity (meaning the higher the thermal conductivity relative to the specific heat capacity and density of the material), the faster the temperature of such polymer foams tends to rise with continued heating, such that heat propagates faster. Other polymeric and elastomeric materials may have lower thermal diffusivities than polymeric foams, but tend to have higher thermal conductivities. In addition, heat concentrated in one portion of such conventional insulating materials may not be distributed over its entire surface, accelerating heat transfer through the thickness of the material to the surface of the component it is designed to protect. Thus, conventional insulating materials may not provide the desired level of thermal protection in some applications.

[0004] Furthermore, in some systems, the insulating material may be subject to severe spatial constraints. Because conventional insulating materials are typically relatively thick and / or stiff, such constraints may limit the amount of conventional insulating material that may be included in a system, further limiting the thermal protection provided by the material or rendering such materials unusable in the system. Compounding these constraints, polymers, elastomers, and foams often have relatively high coefficients of thermal expansion, making the spatial constraints more restrictive when these materials are heated. Summary of the Invention

[0005] Thus, there is a need in the art for materials that provide better thermal protection than traditional insulating materials, including applications with tight space constraints. Some of the laminates of the present invention have relatively low thermal conductivity and thermal diffusivity, respectively, such as a thermal conductivity of 0.05 watts per meter Kelvin (W / m K) or less (e.g., 0.025 W / m K or less) and a thermal conductivity of 0.15 millimeters per second (mm 2 / s) or less (for example, 0.10 mm 2 This need in the art is addressed by including one or more insulating layers having a thermal diffusivity of 1000 .mu.m / s or less. Each such insulating layer may be relatively thin, e.g., 254 micrometers thick or less, and / or flexible such that the laminate may be usable in limited spaces, allowing the laminate to provide excellent thermal protection in systems that are subject to severe space constraints. Additionally, each of the insulating layers may have a relatively low coefficient of thermal expansion, such as 40 μm / m·K or less, further facilitating the usability of the laminate in limited spaces. One suitable material for each of the insulating layers is a layer of polymer aerogel, such as polyimide aerogel.

[0006] In addition, some laminates may include one or more adhesive layers, with at least a portion of the rear surface of the laminate defined by a first of the adhesive layers (or a liner layer disposed on the first adhesive layer and removable from the adhesive layer to expose it) that can adhere the laminate to a surface for thermal protection. The first adhesive layer may, for example, comprise a pressure sensitive adhesive, allowing the laminate to be easily applied to a surface.

[0007] Also disclosed is a method of making a layer of polymeric aerogel suitable for use in at least some of the laminates of the present invention. The method may include the steps of: (a) providing a monomer or combination of monomers to a solvent to form a solution; (b) polymerizing the monomers in the solution to form a polymeric gel matrix; and (c) subjecting the polymeric gel matrix to conditions sufficient to remove liquid from the polymeric gel matrix to form an aerogel having a polymeric matrix that includes an open-cell structure. Step (b) may further include adding a curing agent to the solution to reduce the solubility of the formed polymer in the solution and to form macropores, mesopores, and / or micropores in the gel matrix, the formed macropores, mesopores, and / or micropores containing liquid from the solution. The process may include the step of casting the polymeric gel matrix in step (b) onto a support such that a layer of the polymeric gel matrix is ​​constructed on the support, where the aerogel in step (c) is in the form of a film.

[0008] The porous structure of the aerogel, including the amount and volume of macroporous, mesoporous, and microporous cells, can be controlled primarily by controlling the polymer / solvent dynamics during the formation of the polymer gel matrix. As an example, a curing agent can be added to the solution in step (b) to reduce the solubility of the polymer formed in the solution and to form macropores in the gel matrix, the formed macropores containing liquid from the solution. Such a curing agent can be, for example, 1,4-diazabicyclo[2.2.2]octane. Alternatively, adding a curing agent such as triethylamine to the solution in step (b) to improve the solubility of the polymer formed in the solution will result in the formation of a relatively small number of macropores in the gel matrix. In another example, when forming a polyimide aerogel, increasing the ratio of hard amines (e.g., p-phenylenediamine (p-PDA)) in the polymer backbone over softer diamines (e.g., 4,4'-oxydianiline (4,4'-ODA)) can favor the formation of macropores over smaller mesopores and micropores.

[0009] More details regarding monomers, solvents, and processing conditions are provided below, but in general terms, the following can be adjusted to control the pore structure of the aerogel: (1) the polymerization solvent; (2) the polymerization temperature; (3) the polymer molecular weight; (4) the molecular weight distribution; (5) the copolymer composition; (6) the amount of branching; (7) the amount of crosslinking; (8) the branching method; (9) the crosslinking method; (10) the method used to form the gel; (11) the type of catalyst used to form the gel; (12) the chemical composition of the catalyst used to form the gel; (13) the amount of catalyst used to form the gel; (14) the temperature of gel formation; (15) the type of gas flowing over the material during gel formation; (16) the rate at which gas flows over the material during gel formation; (17) the atmospheric pressure during gel formation; (18) the removal of dissolved gas during gel formation; (19) the presence of solid additives in the resin during gel formation; (20) the time of the gel formation step; (21) the substrate used in gel formation; and (22) the steps of any solvent exchange steps. (23) the composition of the solvent used in each step of any solvent exchange process; (24) the time used in each step of any solvent exchange process; (25) the residence time of the part in each step of the solvent exchange process; (26) the flow rate of any solvent exchange solvent; (27) the type of flow of any solvent exchange solvent; (28) the agitation rate of any solvent exchange solvent; (29) the temperature used in each step of any solvent exchange process; (30) the ratio of the volume of any solvent exchange solvent to the volume of the part; (31) the drying method; (32) the temperature at each step of the drying process; (33) the pressure at each step of the drying process; (34) the composition of the gas used in each step of the drying process; (35) the gas flow rate during each step of the drying process; (36) the temperature of the gas during each step of the drying process; (37) the temperature of the part during each step of the drying process; (38) the presence of an enclosure around the part during each step of the drying process; (39) the type of enclosure around the part during drying; and / or (40) the solvent used in each step of the drying process.

[0010] Some of the laminates of the present invention have opposing front and rear surfaces and include one or more, optionally multiple, insulation layers. In some laminates, each of the insulation layers has a thermal conductivity of 0.05 Watts per meter Kelvin (W / m K) or less. In some laminates, each of the insulation layers has a thermal conductivity of 0.15 mm 2 / s (mm 2 2 / s) or less. In some laminates, each of the insulating layers has a thickness of 254 micrometers (μm) or less.

[0011] In some laminates, at least one of the insulation layers includes a layer of polymer aerogel. In some laminates, for at least one of the insulation layers, the layer of polymer aerogel includes an open cell structure and / or includes micropores, mesopores, and / or macropores. In some laminates, for at least one of the insulation layers, the layer of polymer aerogel has a pore volume, and at least 10%, at least 50%, at least 75%, or at least 95% of the pore volume is composed of micropores, composed of mesopores, composed of macropores, or composed of micropores and / or mesopores. In some laminates, for at least one of the insulation layers, the layer of polymer aerogel has an average pore size of 2.0 nm to 50 nm. In some laminates, for at least one of the insulation layers, the layer of polymeric aerogel has an average pore size of 50 nm to 5,000 nm, optionally 100 nm to 500 nm, and / or a median pore size of 50 nm to 5,000 nm, optionally 250 to 600 nm. In some laminates, for at least one of the insulation layers, the layer of polymeric aerogel comprises at least 90% by weight of an organic polymer and / or at least 90% by weight of a polyimide, polyamide, polyaramid, polyurethane, polyurea, and / or polyester. In some laminates, for at least one of the insulation layers, the layer of polymeric aerogel comprises at least 90% by weight of a polyimide. In some laminates, for at least one of the insulation layers, the layer of polymeric aerogel has a thickness of 75 to 200 μm, optionally about 165 μm. In some laminates, for at least one of the insulation layers, the layer of polymeric aerogel has a decomposition temperature of 400° C. or more, 450° C. or more, or 500° C. or more, and / or the layer of polymeric aerogel has a thermal expansion coefficient of 40 μm / m·K or less. In some laminates, for at least one of the insulation layers, a plurality of fibers are dispersed or embedded in the layer of polymeric aerogel.

[0012] Some laminates include one or more, optionally multiple adhesive layers, coupled to the insulation layer. In some laminates, a first of the adhesive layers defines at least a portion of the rear surface of the laminate. The first adhesive layer, in some embodiments, comprises a pressure sensitive adhesive, which optionally comprises a silicone, an acrylic, and / or a rubber. Each of the adhesive layers has a thickness of 50 μm or less, optionally 15-35 μm, in some laminates. In some laminates having multiple insulation layers and multiple adhesive layers, at least one of the adhesive layers is disposed between adjacent insulation layers.

[0013] Some laminates include a protective layer coupled to the thermal insulation layer. The protective layer, in some laminates, defines at least a portion of the front surface of the laminate. In some laminates, the protective layer has a thickness of 12 to 200 μm and / or a thermal conductivity at least 3.5 times the thermal conductivity of each of the thermal insulation layers. The protective layer, in some laminates, includes molybdenum and optionally has a thickness of 12 to 77 μm. In some laminates, the protective layer includes graphite and optionally has a thickness of 35 to 127 μm. In some laminates, the protective layer includes a polyimide layer and optionally has a thickness of 51 μm or less. In some such laminates, the protective layer includes an aluminum layer disposed on the polyimide layer and defining at least a portion of the front surface of the laminate, the aluminum layer optionally having a thickness of 500 nanometers or less. In some laminates, the protective layer includes carbon black particles dispersed in the polyimide layer and / or the protective layer has a surface resistivity of 10 5 ~10 12 In some laminates having multiple adhesive layers, a second of the adhesive layers is disposed between and in contact with the protective layer and one of the insulating layers.

[0014] Some laminates include a liner layer removably disposed on the first adhesive layer, the liner layer defining at least a portion of the rear surface of the laminate. The liner layer, in some laminates, includes a polymer film.

[0015] Some laminates have a flammability rating of UL94 VTM-0. Some laminates have a thickness of 500 μm or less. Some laminates are arranged in a roll such that a portion of the front surface of the laminate faces a portion of the rear surface of the laminate.

[0016] Some systems include a surface and one of the laminates of the present invention. In some systems, a first adhesive layer of the laminate is disposed on the surface. In some systems, the surface includes a metal, optionally including aluminum, molybdenum, and / or stainless steel, or a polymer. Some systems include a vehicle including the surface. In some systems, the vehicle is an aircraft or spacecraft. Some systems include a missile, rocket, artillery shell, or other projectile including the surface.

[0017] The term "aerogel" generally refers to a class of materials produced by forming a gel, removing a mobile interstitial solvent phase from the pores, and then replacing it with a gas or gas-like material. By controlling the gel and evaporation system, density, shrinkage, and pore collapse can be minimized. Aerogels of the invention can include macropores, mesopores, and / or micropores. In preferred aspects, a majority (e.g., greater than 50%) of the pore volume of the aerogel can be composed of macropores. In other alternative aspects, a majority of the pore volume of the aerogel can be composed of mesopores and / or micropores, such that less than 50% of the pore volume of the aerogel is composed of macropores. In some embodiments, aerogels of the invention have low bulk densities (about 0.75 g / cm 3 Less than about 0.01 g / cm 3 ~0.5g / cm 3 ), high surface area (typically about 10 m 2 / g~1,000m 2 / g or more, preferably about 50m 2 / g~1000m 2 / g), high porosity (greater than or equal to about 20%, preferably greater than about 85%), and / or relatively large pore volume (greater than or equal to about 0.3 mL / g, preferably greater than or equal to about 1.2 mL / g).

[0018] The presence of macropores, mesopores, and / or micropores in the aerogels of the present invention can be determined by mercury intrusion porosimetry (MIP) and / or gas physisorption experiments. MIP tests can be used to measure mesopores and macropores (i.e., American Standard Testing Method (ASTM) D4404-10, Standard Test Method for Determination of Pore Volume and Pore Volume Distribution of Soil and Rock by Mercury Intrusion Porosimetry). Gas physisorption experiments can be used to measure micropores (i.e., ASTM D1993-03 (2008) Standard Test Method for Precipitated Silica - Surface Area by Multipoint BET Nitrogen).

[0019] The "decomposition temperature" of a material is the temperature at which 2%, 5%, or 10% of a sample of the material will decompose when heated in an environment elevated to that temperature. The decomposition temperature can be measured by placing a sample in a thermogravimetric analyzer (TGA), heating the sample from ambient temperature in the TGA (e.g., at a rate of 10°C / min), and recording as the decomposition temperature the temperature at which the mass of the sample is 2%, 5%, or 10% lower than its initial mass.

[0020] The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically. Two items that are "coupled" may be integral to one another, or may be connected to one another through one or more intermediate components or elements.

[0021] The terms "a" and "an" are defined as one or more, unless this disclosure expressly requires otherwise.

[0022] The term "substantially" is defined as being largely, but not necessarily entirely, what is specified, as will be understood by those of skill in the art (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees, and substantially parallel includes parallel). In any disclosed embodiment, the terms "substantially," "approximately," and "about" may be substituted with "within [a percentage]" of what is specified, where the percentage is 0.1%, 1%, 5%, or 10%.

[0023] The term "and / or" means and, or, or. By way of example, A, B, and / or C includes: A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. In other words, "and / or" operates as an inclusive or.

[0024] The terms "comprise" (and any form of including, such as "comprises" and "comprising"), "have" (and any form of including, such as "has" and "having"), "include" (and any form of including, such as "includes" and "including"), and "contain" (and any form of including, such as "contains" and "containing") are open-ended linking verbs. As a result, an apparatus that "comprises," "has," "includes," or "contains" one or more elements has those one or more elements, but is not limited to having only those one or more elements. Similarly, a method that "comprises," "has," "includes," or "contains" one or more steps has those one or more steps, but is not limited to having only those one or more steps.

[0025] Any aspect of any of the apparatus and methods may consist of or consist essentially of any described elements, features, and / or steps, rather than comprise / have / include / contain. Thus, in any of the claims, the phrases "consisting of" or "consisting essentially of" may be used in place of any of the preceding open-ended linking verbs to modify the scope of a given claim from one that would otherwise use an open-ended linking verb.

[0026] Unless expressly prohibited by the nature of this disclosure or the embodiments, features of one embodiment may be applied to other embodiments even if not described or illustrated.

[0027] Some details relating to the aforementioned aspects and others are set forth below. [Brief description of the drawings]

[0028] The following drawings are presented by way of example, and not by way of limitation. For purposes of brevity and clarity, not all features of a given structure are always shown in every figure in which the structure appears. Identical reference numbers do not necessarily refer to identical structures. Rather, the same reference numbers may be used to refer to similar features or features with similar functionality, as well as non-identical reference numbers.

[0029] [Figure 1] FIG. 1 is a cross-sectional view of a first embodiment of a laminate of the present invention having an adhesive layer attaching the laminate to a surface. [Diagram 2] FIG. 2 is a cross-sectional view of a second embodiment of a laminate of the present invention having a liner layer removably disposed on the adhesive layer of the laminate, the liner layer defining at least a portion of the rear surface of the laminate. [Diagram 3] FIG. 3 is a perspective view of a roll of the laminate of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Detailed Description A. Thermal Protection Laminates and Systems Incorporating Same Referring to FIG. 1, a first embodiment 10a of a laminate of the present invention is shown attached to a surface 46, the laminate having opposing front and rear faces 26a and 26b. The laminate 10a may include one or more insulation layers 14 and one or more adhesive layers 18, for example, any one or more of 1, 2, 3, 4, 5, 6, 7, 8, or 9 insulation layers, or between any two of 1, 2, 3, 4, 5, 6, 7, 8, or 9 adhesive layers. A first one of the adhesive layers 18 may define at least a portion (e.g., at least a majority, including up to all) of the rear face 26b, such that the first adhesive layer can adhere the laminate 10a to the surface 46 when placed on the surface. In addition, the laminate 10a may include a protective layer 22 that defines at least a portion (e.g., at least a majority, including up to all) of the front face 26a. However, the adhesive layer 18 is optional. By way of illustration, a laminate of the invention that does not include such a first adhesive layer may be bonded to a surface (e.g., 46) via mechanical force, for example, by wrapping such a laminate around the surface. Moreover, any recitation of a "first," "second," or "third" adhesive layer in a claim does not, by itself, require more than a single adhesive layer.

[0031] As shown, the laminate 10a includes two insulation layers 14, three adhesive layers 18, and one protective layer 22, with substantially all of the front surface 26a and rear surface 26b defined by the protective layer and the first adhesive layer, respectively. However, in other embodiments, the laminate may include a single insulation layer 14 and / or a single adhesive layer 18, and / or omit the protective layer 22. Additionally, in some embodiments, the laminate 10a need not have an adhesive layer 18 defining at least a portion of its rear surface 26b.

[0032] Each of the insulating layers 14 can reduce heat transfer for thermal protection of the surface 46. For example, each of the insulating layers 14 can have a thermal conductivity of less than or equal to any one of 0.06, 0.05, 0.045, 0.040, 0.035, 0.030, 0.025, 0.020, 0.015, or 0.010 Watts per meter·Kelvin (W / m·K), or between any two (e.g., less than or equal to 0.025 W / m·K), and / or a thermal conductivity of less than or equal to 0.30, 0.20, 0.15, 0.125, 0.10, 0.09, 0.08, 0.07, 0.06, or 0.05 millimeters per second (mm 2 / s) or between any two (for example, 0.15 mm 2 / s or less or 0.10 mm 2 / s or less). As used herein, the thermal conductivity of a layer or laminate is measured according to ASTM C518 and the specific heat capacity of a layer or laminate, i.e., the value required to determine the thermal diffusivity of a layer or laminate, is measured according to either ASTM E1269 or ASTM C1784, both measurements being made at 25°C.

[0033] In addition, each of the insulating layers 14 may be heat resistant and / or have a low coefficient of thermal expansion so that the laminate 10a can withstand heating during use and expansion in applications where the laminate is subject to severe space constraints. For example, each of the insulating layers 14 may have a decomposition temperature of any one or more of, or between any two of, 400, 425, 450, 475, 500, 525, 550, 575, or 600° C. (e.g., 450° C. or more), and / or a coefficient of thermal expansion (e.g., in at least one direction) of any one or less of, or between any two of, 40, 35, 30, 25, 20, 15, 10, or 5 μm / m·K (e.g., 40 μm / m·K or less).

[0034] To achieve such properties, at least one (up to and including each) of the insulating layers 14 may include a layer of polymeric aerogel, such as one that includes at least 90% by weight of an organic polymer, such as polyimide, polyaramid, polyurethane, polyrea, and / or polyester (e.g., polyimide). Each polymeric aerogel layer may have micropores, mesopores, and / or macropores. Any one or more of, or between, 10%, 25%, 50%, 75%, or 95% of the pore volume of each aerogel layer may be composed of micropores, mesopores, and / or macropores (e.g., micropores, mesopores, micropores and mesopores, or macropores). The mean pore size and / or median pore size of each aerogel layer can be any one or more of 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 800, 1,000, 2,000, 3,000, 4,000, or 5,000 nm, or between any two (e.g., the mean pore size can be 100-500 nm and the median pore size can be 250-600 nm). The materials and fabrication process for the layers of polymeric aerogel are described in further detail in Sections B and C below.

[0035] In some embodiments, for at least one (e.g., each) of the insulation layers 14, the aerogel layer can include reinforcing fibers, which can be dispersed throughout the aerogel layer (e.g., as chopped fibers or discontinuous fibers not arranged in a sheet) or embedded in the aerogel layer (e.g., as a woven, nonwoven, or unidirectional sheet of fibers), optionally such that the volume of the fibers is any one or more of 0.1%, 10%, 20%, 30%, 40%, or 50% of the volume of the aerogel layer, or between any two. However, the aerogel layer need not include fibers (e.g., to promote flexibility).

[0036] Suitable fibers include glass fibers, carbon fibers, aramid fibers, thermoplastic fibers, thermoset fibers, ceramic fibers, basalt fibers, rock wool fibers, steel fibers, cellulose fibers, etc. The fibers used for reinforcement have an average filament cross-sectional area of ​​7, 15, 30, 60, 100, 200, 300, 400, 500, 600, 700, or 800 μm. 2 or between any two of; for example, for fibers having a circular cross-section, the average diameter of the fibers can be any one or more of 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 μm, or between any two (e.g., 5-24 μm, such as 10-20 μm or 12-15 μm).

[0037] Non-limiting examples of thermoplastic polymers that may be used for the polymeric reinforcing fibers include polyethylene terephthalate (PET), polycarbonate (PC), polybutylene terephthalate (PBT), poly(1,4-cyclohexylidenecyclohexane-1,4-dicarboxylate) (PCCD), glycol modified polycyclohexyl terephthalate (PCTG), poly(phenylene oxide) (PPO), polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polymethyl methacrylate (PMMA), polyethyleneimine or polyetherimide (PEI), and and derivatives thereof, thermoplastic elastomers (TPE), terephthalic acid (TPA) elastomers, poly(cyclohexanedimethylene terephthalate) (PCT), polyethylene naphthalate (PEN), polyamide (PA), polysulfone sulfonate (PSS), sulfonate of polysulfone, polyether ether ketone (PEEK), polyether ketone (PEKK), acrylonitrile butyldiene styrene (ABS), polyphenylene sulfide (PPS), copolymers thereof, polyesters or derivatives thereof, polyamides or derivatives thereof (e.g., nylon), or mixtures thereof.

[0038] Non-limiting examples of thermoplastic polymers that may be used as materials for the polymeric reinforcing fibers include unsaturated polyester resins, polyurethanes, polyoxybenzyl methylene glycol anhydrides (e.g., Bakelite), urea formaldehyde, diallyl phthalate, epoxy resins, epoxy vinyl esters, polyimides, cyanate esters of polycyanurates, dicyclopentadiene, phenols, benzoxazines, copolymers thereof, or mixtures thereof.

[0039] Each of the insulation layers 14 may include a layer of polymeric aerogel, but in other embodiments, at least one of the insulation layers (up to and including each) may be any suitable insulating material, such as a layer of fiber or a layer of fiber (e.g., fiberglass) attached (e.g., via an adhesive, such as a silicone adhesive) to an overlying layer, such as a stainless steel, aluminum, graphite, molybdenum, glass, or polymer overlying layer. At least one of the insulation layers 14 (up to and including each) may also include a layer of fiber laminated to the layer of polymeric aerogel, optionally such that the layer of fiber is disposed closer to the front surface 26a of the stack 10a than the layer of aerogel. The fibers of the fiber layer may be any of those previously described for the aerogel fiber reinforcement (e.g., fiberglass and / or basalt fiber) and may be arranged in a variety of fibrous structures. For example, the fibers may form a fiber matrix, such as a felt, batting lofty batting, mat, woven fabric, or nonwoven fabric. The fibers may be oriented in one direction or all directions.

[0040] In some embodiments, the fibers used as reinforcement in the aerogel layer or fiber layer are 5 μm or less. 2 ~40,000μm 2 and / or an average length of 20 mm to 100 mm.

[0041] To enable use of the laminate 10a in applications having tight space constraints, each of the insulating layers 14 (e.g., aerogel layers) can be relatively thin. For example, the thickness 30 of at least one (e.g., each) of the insulating layers 14 (e.g., aerogel layers) can be equal to or less than any one of 510, 475, 450, 425, 400, 375, 350, 325, 300, 275, 250, 225, 200, 175, 150, 125, 100, or 75 μm, or between any two, preferably equal to or less than 254 μm (e.g., between 75 and 200 μm, such as about 165 μm).

[0042] As the outer-facing surface of the laminate 10a, the protective layer 22 can further promote the ability of the laminate to mitigate heat transfer therethrough in addition to providing physical protection to the other layers of the laminate. For example, the protective layer 22 can have a higher thermal conductivity than each of the insulating layers 14, e.g., at least 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, or 30 times (e.g., at least 3.5 times or at least 10 times) the thermal conductivity of each of the insulating layers, to promote heat distribution across the front surface 26a, thereby reducing heat concentration within the laminate 10a. Additionally or alternatively, the density of the protective layer 22 can be higher than each of the insulating layers 14, e.g., at least 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, or 50 times the density of each of the insulating layers, which can promote the thermal diffusivity of the laminate 10a.

[0043] The protective layer 22 may comprise any material suitable for this purpose. For example, the protective layer 22 may comprise a polyimide layer (e.g., comprising at least 90% polyimide by weight). Such a polyimide layer may optionally provide a surface resistivity of the protective layer 22 of 10 5 ~10 12It may optionally include a conductive filler, such as carbon black, dispersed in the polyimide such that the resistance is Ω / square. Additionally or alternatively, the protective layer 22 may include an aluminum layer disposed on the polyimide layer and defining at least a portion (e.g., at least a majority, including up to all) of the front surface 26a; for example, the aluminum layer may be vacuum deposited onto the polyimide layer and relatively thin (e.g., having a thickness of no more than any one of 500, 450, 400, 350, 300, 250, 200, 150, or 100 nm, or between any two). The protective layer 26 may also include graphite and / or a metal (e.g., a metal foil) such as molybdenum, aluminum, stainless steel, steel, carbon steel, copper, brass, Monel®, superalloys (e.g., Hastelloy®, Inconel®, Waspaloy®, Rene 41®, Incoloy®, SPS® MP98T, CMSX single crystal alloys, etc.), and the like.

[0044] Like the thermally conductive layer 14, the protective layer 22 can be relatively thin. For example, the thickness 38 of the protective layer 22 can be up to any one of 300, 250, 200, 150, 100, 85, 70, 55, 40, 25, or 12 μm, or between any two (e.g., between 12 and 200 μm). Different thicknesses can be advantageous for different protective layer materials. For example, when the protective layer 22 comprises a polyimide (with or without a filler and / or an aluminum layer), the thickness 38 can be advantageously up to any one of 51, 40, 30, or 20 μm, or between any two (e.g., about 25 μm). The molybdenum protective layer 22 may advantageously have a similar or larger thickness 38, such as up to any one of 77, 70, 60, 50, 40, 30, 20, or 12 μm, or between any two (e.g., 12-77 μm). As another example, the graphite protective layer 22 may advantageously have a larger thickness 38, such as up to any one of 127, 120, 110, 100, 90, 80, 70, 60, 50, 40, or 30 μm, or between any two (e.g., 35-127 μm).

[0045] As shown, the laminate 10a includes a protective layer 22, although in other embodiments, the laminate may not have a protective layer. In such other embodiments, one of the insulating layers 14 may define at least a portion (e.g., at least a majority, including up to all) of the front surface 26a of the laminate 10a.

[0046] If the laminate 10a includes multiple insulation layers 14 and / or one protective layer 22, the laminate may include multiple adhesive layers 18, with a first adhesive layer defining at least a portion of the rear surface 26b to enable adhesion to the surface 46 as described above, and the remaining adhesive layers bonding the insulation layers and / or protective layers together. To do so, each of the adhesive layers 18 other than the first adhesive layer may be disposed between and in contact with other adjacent ones of the laminate layers (e.g., between two of the insulation layers 14 and / or between one of the thermally conductive layers and the protective layer 22). As shown, a second one of the adhesive layers 18 is disposed between and in contact with the protective layer 22 and one of the insulation layers 14, and a third one of the adhesive layers is disposed between and in contact with two of the insulation layers. To promote adhesion without adding substantial thickness to the laminate 10a, the thickness 34 of at least one (e.g., each) of the adhesive layers 18 can be equal to or less than any one of 50, 45, 40, 35, 30, 25, 20, 15, or 10 μm, or between any two (e.g., 15-35 μm).

[0047] At least one of (up to and including each of) the adhesive layers 18 may include a pressure-sensitive adhesive, such as those including silicone, acrylic, and / or rubber. Such a pressure-sensitive adhesive, when used for the first adhesive layer 18, may allow the laminate 10a to be quickly applied to a surface 46 (e.g., by simply pressing the laminate 10a against the surface) for its thermal protection. However, at least one of the adhesive layers 18 may include different types of adhesives, such as fluoropolymer films, polyimide films, and B-stage epoxies; examples include commercially available adhesives such as FEP Film, Pyralux® HT, and Pyralux® GPL from DuPont™, and TSU510S-A from Toyochem Co., LTD. (Tokyo, Japan). With such other adhesives, adhesion may be achieved by stacking the layers of laminate 10a (e.g., 14, 18, 22) and, optionally, applying heat and / or pressure (e.g., with a press) to the stack such that the temperature exceeds the glass transition temperature of adhesive layer 18. In some embodiments having multiple adhesive layers 18, some of the adhesive layers (e.g., the first adhesive layer) may comprise a pressure sensitive adhesive and others (e.g., other than the first adhesive layer) may comprise another type of adhesive, such as those listed above.

[0048] The composition of adhesive layer 18 may mitigate the risk of delamination, such as by heat resistance. For example, at least one (e.g., each) of adhesive layers 18 may have a decomposition temperature of any one or more of, or between any two of, 350, 375, 400, 425, 450, or 500° C. In addition, at least one (e.g., each) of adhesive layers 18 may have a glass transition temperature or melting point of any one or more of, or between any two of, 100, 150, 175, 200, 225, 250, or 275° C.

[0049] The above-described configuration allows the laminate 10a to provide thermal protection in high temperature environments. For example, the thermal diffusivity of the laminate 10a may be 0.15, 0.125, 0.10, 0.09, 0.08, 0.07, 0.06, 0.05, or 0.04 mm 2 / s, or between any two (for example, 0.10 mm 2 / s or less, for example, 0.075 mm 2 / s or less), thereby reducing the propagation of heat therethrough. Surprisingly, the thermal diffusivity of the stack 10a can be lower than the thermal diffusivity of each of the insulating layers 14, even when the stack includes a protective layer 22 that has a higher thermal conductivity than each of the insulating layers.

[0050] By way of example, the thermal conductivity of the laminate 10a can be any one or less, or between any two of: 0.025, 0.030, 0.035, 0.040, 0.045, 0.050, 0.055, or 0.060 W / m·K, and / or the specific heat capacity of the laminate can be any one or more, or between any two of: 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.90, 1.00, 1.10, 1.20, 1.25, 1.30, 1.35, or 1.40 J / g K.

[0051] Additionally, the flammability rating of the laminate 10a may be UL94 VTM-0 such that it will withstand combustion. Systems in which such thermal protection is advantageous include, for example, vehicles, particularly spacecraft such as aircraft and rockets, that are exposed to high temperature environments. The surface 46 to which the laminate 10a is attached may be the surface of a vehicle, such as an aircraft or spacecraft, or may be the surface of a missile, rocket, artillery shell, or other projectile, and may include, for example, metals (e.g., aluminum, stainless steel, molybdenum, steel, carbon steel, copper, brass, Monel®, superalloys, etc.) and / or polymers (e.g., fiber-reinforced polymers, such as those reinforced with carbon, aramid, and / or glass fibers). In some embodiments, the surface 46 may include titanium and / or nickel. Thus, the laminate 10a may provide thermal protection to the surface 46.

[0052] Additionally, while the overall thickness 42 of the laminate 10a may be 0.50 inches or less, the laminate may advantageously be relatively thin as previously discussed, for example, less than or equal to any one of 2540, 2000, 1500, 1000, 500, 400, 300, or 200 μm, or between any two (e.g., less than or equal to 1000 μm or less than or equal to 500 μm). Such thinness may enable the laminate 10a to be used in small spaces, such as those common in vehicles such as aircraft and spacecraft, while still providing the thermal protection previously discussed. Thus, the laminate 10a may provide better thermal protection in size-constrained applications than conventional insulating materials that may not be able to meet the size constraints or may sacrifice thermal protection to meet the size constraints.

[0053] 2, a second laminate 10b is shown that is substantially similar to laminate 10a, with the primary exception that laminate 10b includes a liner layer 50. As shown, laminate 10b has not yet been attached to surface 46. To protect first adhesive layer 18 prior to attachment to surface 46 (e.g., against contaminants that may impair its adhesion), liner layer 50 may be removably disposed on first adhesive layer 18 such that at least a portion (e.g., at least a majority, including up to the entirety) of rear surface 26b of laminate 10b is defined by the liner layer. Liner layer 50 may include, for example, a polymeric film or a paper sheet, and may be removed from first adhesive layer 18, for example, by peeling it from laminate 10b.

[0054] Additionally, with reference to FIG. 3, the laminate (e.g., 10a or 10b) may be flexible. Illustratively, the laminate 10b may be placed in a roll 54 having an inside diameter 58 of 10 cm, 8 cm, 5 cm, 4 cm, 2 cm, or 1 cm or between any two of them without undergoing permanent deformation. Such flexibility, even if not to the level of this example, may be provided by the materials of the insulation layer, adhesive layer, and other (if present) layers of the laminate and / or the relatively small thicknesses of those layers (e.g., as described above). When in the roll 54, a portion of the front surface 26a of the laminate may face a portion of its rear surface 26b.

[0055] B. Polymer aerogel layer material The layers of the polymer aerogel can include organic materials, inorganic materials, or mixtures thereof. Organic aerogels can be made from polyacrylates, polystyrenes, polyacrylonitriles, polyurethanes, polyureas, polyimides, polyamides, polyaramids, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehyde, resorcinol formaldehyde, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, agarose, and the like. In certain embodiments, the aerogel is a polyimide aerogel.

[0056] Polyimides are a type of polymer that have many desirable properties. Polyimide polymers contain nitrogen atoms in the polymer backbone, where the nitrogen atoms are linked to two carbonyl carbons, somewhat stabilized by adjacent carbonyl groups. The carbonyl group contains a carbon, called the carbonyl carbon, which is double-bonded to an oxygen atom. Polyimides are usually thought of as AA-BB type polymers, since two different classes of monomers are usually used to produce polyimide polymers. Polyimides can also be prepared from AB type monomers. For example, aminodicarboxylic acid monomers can be polymerized to form AB type polyimides. Monoamines and / or monoanhydrides can be used as end-capping agents, if desired.

[0057] One class of polyimide monomers is usually diamines, or diamine monomers. It should be understood that diamine monomers can also be diisocyanates, and isocyanates can be substituted for amines in this description, where appropriate. As known to those skilled in the art, there are other types of monomers that can be used in place of diamine monomers. The other types of monomers are called acid monomers, and are usually in the form of dianhydrides. In this description, the term "diacid monomers" is defined to include dianhydrides, tetraesters, diester acids, tetracarboxylic acids, or trimethylsilyl esters, all of which can be reacted with diamines to produce polyimide polymers. Dianhydrides should be understood to be tetraesters, diester acids, tetracarboxylic acids, or trimethylsilyl esters, which can be substituted where appropriate. As known to those skilled in the art, there are other types of monomers that can be used in place of diacid monomers.

[0058] Since one diacid monomer has two anhydride groups, a different diamino monomer can react with each anhydride group, and thus the diacid monomer can be located between two different diamino monomers. The diamine monomer contains two amine functional groups; therefore, after the first amine functional group is linked to one diacid monomer, the second amine functional group is still available to link to another diacid monomer, which then links to another diamine monomer, and so on. In this way, the polymer backbone is formed. The resulting polycondensation reaction product forms a polyamic acid.

[0059] Polyimide polymers are usually formed from two different types of monomers, and different variants of each type of monomer can be mixed. Thus, one, two, or more diacid monomers can be included in the reaction vessel, as can one, two, or more diamino monomers. If long polymer chains are desired, the total molar amount of diacid monomers is kept approximately the same as the total molar amount of diamino monomers. Since multiple types of diamines or diacids can be used, the various monomer constituents of each polymer chain can be varied to produce polyimides with different properties. For example, a single diamine monomer AA can be reacted with two diacid comonomers B1B1 and B2B2 to produce polyimides of the general formula (AA-B1B1): x -(AA-B2B2) y where x and y are determined by the relative incorporation of B1B1 and B2B2 into the polymer backbone. Alternatively, diamine comonomers A1A1 and A2A2 can be reacted with a single diacid monomer BB to form a polymer chain of the general formula (A1A1-BB): x -(A2A2-BB) y In addition, two diamine comonomers A1A1 and A2A2 can be reacted with two diacid comonomers B1B1 and B2B2 to form a polymer chain of the general formula (A1A1-B1B1): w -(A1A1-B2B2) x -(A2A2-B1B1) y -(A2A2-B2B2) zwhere w, x, y, and z are determined by the relative incorporation of A1A1-B1B1, A1A1-B2B2, A2A2-B1B1, and A2A2-B2B2 into the polymer backbone. More than two diacid comonomers and / or more than two diamine comonomers can also be used. Thus, one or more diamine monomers can be polymerized with one or more diacids, and the general formula of the polymer is determined by varying the amount and type of monomers used.

[0060] There are many examples of monomers that can be used to make polymeric aerogels, including polyamic acid amide polymers. In some embodiments, the diamine monomer is a substituted or unsubstituted aromatic diamine, a substituted or unsubstituted alkyl diamine, or a diamine that can contain both aromatic and alkyl functional groups. A non-limiting list of possible diamine monomers includes 4,4'-oxydianiline (ODA), 3,4'-oxydianiline, 3,3'-oxydianiline, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, diaminobenzanilide, 3,5-diaminobenzoic acid, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 1,3-bis-(4-aminophenoxy)benzene, 1,3-bis-(3-aminophenoxy)benzene, 1,4-bis-(4-aminophenoxy)benzene, 1,4-bis-(3-aminophenoxy)benzene, 2,2-bis[4-( 4-aminophenoxy)phenyl]-hexafluoropropane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 4,4'-isopropylidenedianiline, 1-(4-aminophenoxy)-3-(3-aminophenoxy)benzene, 1-(4-aminophenoxy)-4-(3-aminophenoxy)benzene, bis-[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]sulfone, bis(4-[4-aminophenoxy]phenyl)ether, 2,2'-bis-(4-aminophenyl)-hexafluoropropane (6F-diamine), 2,2'-bis-(4-phenoxyaniline)isopropylidene, meta-phenylenediamine, para-phenylenediamine, 1,2-diaminobenzene, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,6-diaminopyridine, bis(3-aminophenyl)diethylsilane, 4,4'-diaminodiphenyldiethylsilane, benzidine, dichlorobenzidine, 3,3'-dimethoxybenzidine, 4,4'-Diaminobenzophenone, N,N-bis(4-aminophenyl)-n-butylamine, N,N-bis(4-aminophenyl)methylamine, 1,5-diaminonaphthalene, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4-aminophenyl-3-aminobenzoate, N,N-bis(4-aminophenyl)aniline, bis(p-beta-amino-t-butylphenyl)ether, p-bis-2-(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,3-bis(4-aminophenoxy)benzene, m-xylenediamine, p-xylenediamine, 4,4'-diaminodiphenyl ether phosphine oxide, 4,4'-diaminodiphenyl N-methylamine, 4,4'- Diaminodiphenyl N-phenylamine, amino-terminated polydimethylsiloxane, amino-terminated polypropylene oxide, amino-terminated polybutylene oxide, 4,4'-methylenebis(2-methylcyclohexylamine), 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, and 4,4'-methylenebisbenzenamine, 2,2'-dimethylbenzidine, (also known as 4,4'-diamino-2,2'-dimethylbiphenyl (DMB)), bisaniline-p-xylidene, 4,4'-bis(4-aminophenoxy)biphenyl, 3,3'-bis(4 In certain embodiments, the diamine monomer is ODA, 2,2'-dimethylbenzidine, or both.

[0061] A non-limiting list of possible dianhydride ("diacid") monomers includes hydroquinone dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride), 2,2-bis(3,4-diphenylsulfonyl)dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)bis(phthalic anhydride), ... dicarboxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, bis(3,4-dicarboxyphenyl)sulfoxide dianhydride, polysiloxane-containing dianhydrides, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-benzophenonetetraearboxylic dianhydride, naphthalene-2,3,6,7-tetracarboxylic dianhydride, naphthalene-1,4,5,8-tetracarboxylie(c arboxylie) dianhydride, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane, 2,6-dichloro Include naphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, phenanthrene, 8,9,10-tetracarboxylic dianhydride, pyrazine-2,3,5,6-tetracarboxylic dianhydride, benzene-1,2,3,4-tetracarboxylic dianhydride and thiophene-2,3,4,5-tetracarboxylic dianhydride.In certain embodiments, the dianhydride monomer is BPDA, PMDA or both.

[0062] In some aspects, the molar ratio of anhydride to total diamine is 0.4:1 to 1.6:1, 0.5:1 to 1.5:1, 0.6:1 to 1.4:1, 0.7:1 to 1.3:1, or especially 0.8:1 to 1.2:1. In further aspects, the molar ratio of dianhydride to polyfunctional amine (e.g., triamine) is 2:1 to 140:1, 3:1 to 130:1, 4:1 to 120:1, 5:1 to 110:1, 6:1 to 100:1, 7:1 to 90:1, or especially 8:1 to 80:1. Monoanhydride groups can also be used. Non-limiting examples of monoanhydride groups include 4-amino-1,8-naphthalic anhydride, endo-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, citraconic anhydride, trans-1,2-cyclohexanedicarboxylic anhydride, 3,6-dichlorophthalic anhydride, 4,5-dichlorophthalic anhydride, tetrachlorophthalic anhydride, 3,6-difluorophthalic anhydride, 4,5-difluorophthalic anhydride, tetrafluorophthalic anhydride, maleic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, 2,2-dimethylglutaric anhydride. These include 3,3-dimethylglutaric anhydride, 2,3-dimethylmaleic anhydride, 2,2-dimethylsuccinic anhydride, 2,3-diphenylmaleic anhydride, phthalic anhydride, 3-methylglutaric anhydride, methylsuccinic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, 2,3-pyrazinedicarboxylic anhydride, or 3,4-pyridinedicarboxylic anhydride. In particular, the monoanhydride group may be phthalic anhydride.

[0063] In another embodiment, the polymer composition used to prepare the layer of the polymeric aerogel comprises a polyfunctional amine monomer having at least three primary amine functional groups. The polyfunctional amine may be a substituted or unsubstituted aliphatic polyfunctional amine, a substituted or unsubstituted aromatic polyfunctional amine, or a polyfunctional amine containing a combination of an aliphatic and two aromatic groups, or a combination of an aromatic and two aliphatic groups.A non-limiting list of possible polyfunctional amines includes propane-1,2,3-triamine, 2-aminomethylpropane-1,3-diamine, 3-(2-aminoethyl)pentane-1,5-diamine, bis(hexamethylene)triamine, N',N'-bis(2-aminoethyl)ethane-1,2-diamine, N',N'-bis(3-aminopropyl)propane-1,3-diamine, 4-(3-aminopropyl)heptane-1,7-diamine, N',N'-bis(6 ... (aminohexyl)hexane-1,6-diamine, benzene-1,3,5-triamine, cyclohexane-1,3,5-triamine, melamine, N-2-dimethyl-1,2,3-propanetriamine, diethylenetriamine, 1-methyl or 1-ethyl or 1-propyl or 1-benzyl-substituted diethylenetriamines, 1,2-dibenzyldiethylenetriamine, lauryldiethylenetriamine, N-(2-hydroxypropyl)diethylenetriamine , N,N-bis(l-methylheptyl)-N-2-dimethyl-1,2,3-propanetriamine, 2,4,6-tris(4-(4-aminophenoxy)phenyl)pyridine, N,N-dibutyl-N-2-dimethyl-l,2,3-propanetriamine, 4,4'-(2-(4-aminobenzyl)propane-1,3-diyl)dianiline, 4-((bis(4-aminobenzyl)amino)methyl)aniline, 4-(2-(bis(4-aminophenethyl)amino)ethylene Examples of suitable polyoxypropylene triamines include N,N,N',N'-tetrakis(4-aminophenyl)-1,4-phenylenediamine, polyoxypropylene triamines, octa(aminophenyl) polyhedral oligomeric silsesquioxanes, or combinations thereof. A specific example of a polyoxypropylene triamine is JEFFAMINE® T-403 from Huntsman Corporation, The Woodlands, TX USA. In certain embodiments, the aromatic polyfunctional amine may be 1,3,5-tris(4-aminophenoxy)benzene or 4,4',4''-methanetriyltrianiline.In some embodiments, the multifunctional amine contains three primary amine groups and one or more secondary and / or tertiary amine groups, for example, N',N'-bis(4-aminophenyl)benzene-1,4-diamine.

[0064] Non-limiting examples of capping agents or groups include amine, maleimide, nadimide, acetylene, biphenylene, norbornene, cycloalkyl, and N-propargyl, and those derived from reagents including 5-norbornene-2,3-dicarboxylic anhydride (nadic anhydride, NA), methylnadic anhydride, hexachloronadic anhydride, cis-4-cyclohexene-1,2-dicarboxylic anhydride, 4-amino-N-propargylphthalimide, 4-ethynylphthalic anhydride, and maleic anhydride, among others.

[0065] The characteristics or properties of the final polymer are greatly influenced by the selection of monomers used to produce the polymer. Factors to consider when selecting monomers include the properties of the final polymer, such as flexibility, thermal stability, coefficient of thermal expansion (CTE), coefficient of hydraulic expansion (CHE), and any other properties that are particularly desirable, as well as cost. In many cases, certain important properties of a polymer for a particular application can be identified. Other properties of the polymer may be less important or have a wide range of acceptable values; therefore, many different monomer combinations may be used.

[0066] In some examples, the backbone of the polymer may include a substituent. The substituent (e.g., oligomer, functional group, etc.) may be directly attached to the backbone or may be linked to the backbone through a linking group (e.g., tether or flexible tether). In other embodiments, compounds or particles may be incorporated (e.g., mixed and / or encapsulated) into the polyimide structure without being covalently attached to the polyimide structure. In some examples, the incorporation of compounds or particles may be performed during the polyamic reaction process. In some examples, the particles may aggregate, thereby producing polyimides with domains containing different concentrations of non-covalently bound compounds or particles.

[0067] Specific properties of polyimides can be influenced by incorporating certain compounds into the polyimide. The choice of monomer is one way to influence specific properties. Another way to influence properties is by adding compounds or property-modifying moieties to the polyimide.

[0068] C. Preparation of polymer aerogel layers Polymeric aerogel films that may be used in at least some of the laminates of the present invention are commercially available. Non-limiting examples of such films include Blueshift AeroZero® rolled film (available from Blueshift Materials, Inc. (Spencer, Massachusetts)) and Airloy® film (available from Aerogel Technologies, LLC), with Blueshift AeroZero® rolled film being preferred in some aspects.

[0069] Additionally, and in addition to the processes described below, polymer aerogels (such as films, stock shapes, or monoliths) can be made using methods described in WO 2014 / 189560 to Rodman et al., WO 2017 / 0355829 to Sakaguchi et al., WO 2018 / 078512 to Yang et al., WO 2018 / 140804 to Sakaguchi et al., and WO 2019 / 006184 to Irvin et al., WO 2019 / 029191 to Ejaz et al., WO 2017 / 0121483 to Poe et al., and / or U.S. Pat. No. 9,963,571 to Sakaguchi et al., all of which are incorporated by reference in their entireties.

[0070] The following provide non-limiting steps that may be used to make layers of polymeric aerogel suitable for use in the laminates of the invention. These steps may include: (1) preparation of the polymer gel, (2) optional solvent exchange, (3) drying the polymer solution to form the aerogel, and (4) bonding the polymeric aerogel film onto a substrate.

[0071] 1. Polymer gel formation The first stage in the synthesis of an aerogel can be the synthesis of a polymerized gel. For example, if a polyimide aerogel is desired, at least one acid monomer can be reacted with at least one diamino monomer in a reaction solvent to produce a polyamic acid. As previously mentioned, many acid monomers and diamino monomers may be used to synthesize a polyamic acid. In one aspect, the polyamic acid is contacted with an imidization catalyst in the presence of a chemical dehydrating agent to produce a polymerized polyimide gel via an imidization reaction. "Imidization" is defined as the conversion of a polyimide precursor to an imide. Any imidization catalyst suitable for driving the conversion of a polyimide precursor to a polyimide state is suitable. Non-limiting examples of chemical imidization catalysts include pyridine, methylpyridine, quinoline, isoquinoline, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), triethylenediamine, lutidine, N-methylmorpholine, triethylamine, tripropylamine, tributylamine, other trialkylamines, 2-methylimidazole, 2-ethyl-4-methylimidazole, imidazole, other imidazoles, and combinations thereof. Any dehydrating agent suitable for use in forming imide rings from amic acid precursors is suitable for use in the methods of the present invention. Preferred dehydrating agents include at least one compound selected from the group consisting of acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, trifluoroacetic anhydride, phosphorus trichloride, and dicyclohexylcarbodiimide.

[0072] In one aspect of the invention, one or more diamino monomers and one or more polyfunctional amine monomers are premixed in one or more solvents and then one or more dianhydrides (e.g., diacid monomers) are added in successive small amounts at predetermined time increments while monitoring the viscosity. The desired viscosity of the polymerization solution can range from 50 to 20,000 cP, or particularly from 500 to 5,000 cP. Non-crosslinked aerogels can be prepared by carrying out the reaction with incremental additions of dianhydrides while monitoring the viscosity. For example, a triamine monomer (23 equivalents) can be added to the solvent to obtain a 0.0081 molar solution. A first diamine monomer (280 equivalents) can be added to the solution, followed by a second diamine monomer (280 equivalents). The dianhydrides (552 equivalents total) can then be added in successive small amounts at predetermined time increments while monitoring the viscosity. The dianhydrides can be added until the viscosity reaches 1,000 to 1,500 cP. For example, a first portion of the dianhydride can be added, the reaction can be stirred (e.g., 20 minutes), a second portion of the dianhydride can be added, and then a sample of the reaction mixture can be analyzed for viscosity. After stirring for an additional period of time (e.g., 20 minutes), a third portion of the dianhydride can be added and a sample can be taken for viscosity analysis. After further stirring for a desired period of time (e.g., 10 hours to 12 hours), the monoanhydride (96 equivalents) can be added. After reaching the target viscosity, the reaction mixture can be stirred for a desired period of time (e.g., 10 hours to 12 hours) or until the reaction is deemed complete.

[0073] The reaction temperature for gel formation can be determined by routine experimentation depending on the starting materials. In preferred embodiments, the temperature can be any one or more of 15°C, 20°C, 30°C, 35°C, 40°C, and 45°C, or between any two thereof. After a desired time (e.g., about 2 hours), the product can be isolated (e.g., filtered), and then the nitrogen-containing hydrocarbon (828 equivalents) and the dehydrating agent (1214 equivalents) can be added. The addition of the nitrogen-containing hydrocarbon and / or dehydrating agent can be done at any temperature. In some embodiments, the nitrogen-containing hydrocarbon and / or dehydrating agent is added to the solution at 20°C to 28°C (e.g., room temperature) and stirred at that temperature for a desired time. In some examples, the solution temperature is increased to 150°C after the nitrogen-containing hydrocarbon and / or dehydrating agent is added.

[0074] Reaction solvents can include dimethyl sulfoxide (DMSO), diethyl sulfoxide, N,N-dimethylformamide (DMF), N,N-diethylformamide, N,N-dimethylacetamide (DMAc), N,N-diethylacetamide, N-methyl-2-pyrrolidone (NMP), 1-methyl-2-pyrrolidinone, N-cyclohexyl-2-pyrrolidone, 1,13-dimethyl-2-imidazolidinone, diethylene glycol dimethoxy ether, o-dichlorobenzene, phenol, cresol, xylenol, catechol, butyrolactone, hexamethylphosphoramide, and mixtures thereof. Reaction solvents and other reactants can be selected based on compatibility with the materials and methods applied; that is, whether the polymerized polyamic acid amide gel is cast onto a support film, injected into a moldable part, or cast into a shape for further processing into a workpiece. In certain embodiments, the reaction solvent is DMSO.

[0075] With the above in mind, the introduction of macropores into the aerogel polymer matrix, as well as the amount of such macropores present, can be carried out in the manner outlined. In one non-limiting manner, the formation of macropores, as opposed to small mesopores and micropores, can be controlled primarily by controlling the polymer / solvent dynamics during gel formation. In this way, the pore structure can be controlled, and the amount and volume of macroporous, mesoporous, and microporous cells can be controlled. For example, a curing additive that reduces the solubility of the polymer produced during polymerization, such as 1,4-diazabicyclo[2.2.2]octane, can produce a polymer gel containing more macropores compared to another curing additive that improves the solubility of the resulting polymer, such as trimethylamine. In another specific non-limiting example, when producing polyimide aerogels, the ratio of rigid amines (e.g., p-phenylenediamine (p-PDA)) to more flexible diamines (e.g., -ODA) incorporated into the polymer backbone can be increased to favor the production of macropores over small mesopores and micropores.

[0076] The polymer solution may be cast onto a cast sheet, optionally covered with a support film, for a period of time. Casting may include spin casting, gravure coating, three-roll coating, roll-on knife coating, slot-die extrusion, dip coating, Mayer rod coating, or other techniques. In one embodiment, the cast sheet is a polyethylene terephthalate (PET) cast sheet. After time, the polymerized reinforced gel is removed from the cast sheet and prepared for the solvent exchange step. In some embodiments, the cast film may be heated stepwise to high temperatures to remove the solvent and convert the amic acid functional groups in the polyamic acid to imides by a dehydration cycloreaction, also called imidization. In some examples, the polyamic acid may be converted to polyimide in solution by the addition of a chemical dehydrating agent, a catalyst, and / or heat.

[0077] In some embodiments, polyimide polymers can be produced by preparing a polyamic acid polymer in a reaction vessel, then forming the polyamic acid into a sheet or film, followed by treatment with a catalyst or heat and catalyst to convert the polyamic acid into a polyimide.

[0078] Wet gels used to prepare aerogels may be prepared by any known gel-forming technique, for example, by adjusting the pH and / or temperature of a dilute metal oxide solution to the point where gelation occurs.

[0079] 2. Optional Solvent Exchange After synthesizing the polymer gel, in certain instances, it may be desirable to perform a solvent exchange, in which the reaction solvent is replaced with a more desirable second solvent. Thus, in one embodiment, a solvent exchange can be performed in which the polymer gel is placed inside a pressure vessel and submerged in a mixture containing the reaction solvent and the second solvent. A high pressure atmosphere is then created inside the pressure vessel, which forces the second solvent into the polymer gel and replaces some of the reaction solvent. Alternatively, the solvent exchange step may be performed without the use of a high pressure environment. It may be necessary to perform multiple solvent exchanges. In some embodiments, solvent exchange is not required.

[0080] The time required to perform a solvent exchange will vary depending on the type of polymer undergoing the exchange and the reaction solvent and second solvent used. In one embodiment, each solvent exchange can take 1-168 hours, or any period therebetween, including 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, or 23, 24, 25, 50, 75, 100, 125, 150, 155, 160, 165, 166, 167, or 168 hours. In another embodiment, each solvent exchange can take approximately 1-60 minutes, or about 30 minutes. Exemplary second solvents include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 3-methyl-2-butanol, 3,3-dimethyl-2-butanol, 2-pentanol, 3-pentanol, 2,2-dimethylpropan-1-ol, cyclohexanol, diethylene glycol, cyclohexanone, acetone, acetylacetone, 1,4-dioxane, diethyl ether, dichloromethane, trichloroethylene, chloroform, carbon tetrachloride, water, and mixtures thereof. In certain non-limiting embodiments, the second solvent may have a freezing point suitable for carrying out a supercritical or subcritical drying step. For example, at 1 atmosphere, tert-butyl alcohol has a freezing point of 25.5°C and water has a freezing point of 0°C. Alternatively, as described below, drying may be carried out without a supercritical or subcritical drying step, such as by evaporative drying techniques.

[0081] The temperature and pressure used in the solvent exchange step may be varied. The duration of the solvent exchange step can be adjusted by performing the solvent exchange at various temperatures or atmospheric pressures, or both, provided that the pressure and temperature within the pressure vessel do not cause either the first solvent or the second solvent to leave the liquid phase and become a gas, vapor, solid, or supercritical fluid. In general, higher pressures and / or temperatures decrease the amount of time required to perform the solvent exchange, and lower temperatures and / or pressures increase the amount of time required to perform the solvent exchange.

[0082] 3. Cooling and drying In one embodiment, after solvent exchange, the polymerized gel can be exposed to supercritical drying. In this example, the solvent in the gel can be removed by supercritical CO2 extraction.

[0083] In another embodiment, after the solvent exchange, the polymerized gel can be exposed to subcritical drying. In this example, the gel can be cooled below the freezing point of the second solvent and subjected to a freeze-drying or lyophilization process to produce an aerogel. For example, if the second solvent is water, the polymerized gel can be cooled below 0°C. After cooling, the polymerized gel can be subjected to a vacuum for a period of time to sublimate the second solvent.

[0084] In yet another embodiment, after the solvent exchange, the polymerized gel can be exposed to subcritical drying, optionally with heating, after most of the second solvent has been removed by sublimation. In this example, the partially dried gel material is heated to a temperature close to or above the boiling point of the second solvent for a period of time. The period can range from a few hours to a few days, with a typical period being about 4 hours. During the sublimation step, a portion of the second solvent present in the polymerized gel is removed, leaving a gel that may have macropores, mesopores, or micropores, or any combination thereof or all of such pore sizes. After the sublimation step is complete, or nearly complete, an aerogel is formed.

[0085] In yet another embodiment, after solvent exchange, the polymerized gel can be dried under ambient conditions, for example, by removing the solvent under a flow of gas (e.g., air, anhydrous gas, inert gas (e.g., nitrogen (N2) gas), etc.). Additionally, passive drying techniques can be used, such as simply exposing the gel to ambient conditions without an airflow.

[0086] Once cooled or dried, the films and stock shapes can be configured for use in the laminates of the present invention. For example, the films or stock shapes can be machined (e.g., by cutting or grinding) into the desired shape, such as square, rectangular, circular, triangular, irregular, random, etc. Also, as previously described, the films or stock shapes can be attached to a support material, such as with an adhesive. In an alternative embodiment, the support material can be incorporated into the matrix of the polymer aerogel, as described below.

[0087] 4. Incorporation of a reinforcing layer into the polymer aerogel matrix In addition to the above-mentioned method regarding the use of adhesives to bond the polymer aerogel to the support material, any embodiment of the present invention can include the incorporation of a support material into the polymer matrix to create a reinforced polymer aerogel without the use of adhesives. Of note, during the manufacture of non-reinforced polymer aerogels, a reinforced support film can be used as a carrier to support the gelled film during processing. During unwinding, the gelled film can be irreversibly pressed into the carrier film. Pressing the gelled film into the carrier film can provide substantial durability improvements. In another example, the polymer solution can be cast into the reinforcing or support material during the solution casting step described above.

[0088] Substrate selection and direct casting may allow for optimization (e.g., minimization) of the thickness of the resulting reinforced aerogel material. This process may also be extended to the production of fiber-reinforced polymer aerogels, with internally reinforced polyimide aerogels provided as an example. The process may include (a) forming a polyamic acid solution from a mixture of dianhydride and diamine monomers in a polar solvent such as DMSO, DMAc, NMP, or DMF; (b) contacting the polyamic acid solution with the chemical hardeners and chemical dehydrating agents listed above to initiate chemical imidization; (c) casting and infiltrating the polyamic acid solution onto a fiber support prior to gelation; (d) allowing the catalytic polyamic acid solution to gel around and into the fiber support during chemical imidization; (e) optionally performing a solvent exchange that may facilitate drying; and (f) removing the fugitive liquid phase contained within the gel by supercritical, subcritical, or ambient drying to obtain an internally reinforced aerogel. EXAMPLES

[0089] The present invention will be described in detail by way of specific examples.The following examples are provided for illustrative purposes only and are not intended to limit the present invention in any manner.Those skilled in the art will easily recognize various non-critical parameters that can be changed or modified to obtain essentially the same results.

[0090] Example 1 (Thermal Diffusivity of Exemplary Laminates) Four laminates were produced and the thermal diffusivity of each was measured. Each laminate had a single insulating layer of AeroZero® polyimide aerogel 165 μm thick. Laminate 1 had a Kapton® polyimide film protective layer defining its front surface and two 25 μm thick silicone pressure-sensitive adhesive layers, the first of which was disposed on the AeroZero® polyimide aerogel and defined the rear surface of laminate 1, and the second of which bonded the protective layer to the aerogel layer. Laminates 2 and 3 were substantially similar to laminate 1, except that their protective layers were layers of graphite and aluminum, respectively. Laminate 4 included only the AeroZero® aerogel layer defining the front surface of the laminate and a 25 μm thick silicone pressure-sensitive adhesive layer disposed on the aerogel layer and defined the rear surface of the laminate. As a comparison, the thermal diffusivity of a single 165 μm thick AeroZero® polyimide aerogel layer was also measured. The results are shown in Table 1 below.

[0091] Table 1: Thermal diffusivities of exemplary laminates TIFF2024533988000001.tif53128

[0092] Each laminate had a lower thermal diffusivity than the AeroZero® polyimide aerogel layer alone, which was surprising given that each laminate added to the AeroZero® polyimide aerogel layer one or more layers of materials with higher thermal conductivity than the AeroZero® polyimide aerogel layer, namely Kapton®, silicone, graphite, and / or aluminum.

[0093] As part of these thermal diffusivity measurements, the thermal conductivity of each of the laminates and the AeroZero® polyimide aerogel layers was measured in accordance with ASTM C518, and the specific heat capacity was measured in accordance with ASTM E1269, each at 25° C. These thermal conductivity and specific heat capacity measurements, as well as the densities of the laminates and the AeroZero® polyimide aerogel layers, are shown in Table 2 below.

[0094] Table 2. Properties of exemplary laminates TIFF2024533988000002.tif36150

[0095] Example 2 Thermal Diffusivity of Exemplary Laminates and Insulation Materials Fourteen inventive laminate samples S1-S14 were prepared having the properties shown in Table 3 below.

[0096] (Table 3) Characteristics of the sample laminate TIFF2024533988000003.tif255153

[0097] A single 165 μm thick layer of AeroZero® polyimide aerogel and four comparative insulations C1-C4 were also prepared, having the properties shown in Table 4 below.

[0098] (Table 4) Characteristics of insulation materials TIFF2024533988000004.tif90160

[0099] The thermal diffusivities of the sample laminates S1-S14, the AeroZero® polyimide aerogel layer, and the comparative insulations C1-C4 were then measured. To that end, the thermal conductivity of the laminate or insulation was measured according to ASTM C518 and the specific heat capacity of the laminate or insulation was measured according to ASTM C1784 at 25° C. for each of the laminates and insulations, and these values, along with the density of the laminate or insulation (Tables 3 and 4), were used to calculate the thermal diffusivity of the laminate or insulation. These thermal diffusivities, as well as the thermal conductivity and specific heat capacity, are shown in Table 5 below.

[0100] Table 5: Thermal data of laminates S1-14 and insulation materials TIFF2024533988000005.tif111160

[0101] As shown in Table 5, the experiment of Example 2 produced the same results as Example 1: the thermal diffusivity of each of the laminates S1-14 was lower than that of the AeroZero® polyimide aerogel layer itself, even though each of the laminates S1-S14 included one or more layers with a higher thermal conductivity than the AeroZero® polyimide aerogel layer. Example 2 also showed another surprising result: Although the thermal conductivity of the fiberglass was slightly lower than that of the AeroZero® polyimide aerogel layer (compare AeroZero® aerogel and C4 in Table 5), the laminates S1-14, each of which included an AeroZero® polyimide aerogel layer, had significantly lower thermal diffusivity than the fiberglass-based insulations C1-C4.

[0102] The foregoing specification and examples provide a complete description of the structure and use of the exemplary embodiments. Although certain embodiments have been described above in some detail or in connection with one or more individual embodiments, those skilled in the art may make many modifications to the disclosed embodiments without departing from the scope of the present invention. Thus, it is not intended that the various exemplary embodiments of the apparatus and method be limited to the particular forms disclosed. Rather, they include all modifications and alternatives that fall within the scope of the claims, and embodiments other than those shown may include some or all of the features of the illustrated embodiments. For example, elements may be omitted or combined in a unitary structure and / or connections may be substituted. Furthermore, where appropriate, aspects of any of the embodiments described above may be combined with aspects of any other of the embodiments described above to form further embodiments having equivalent or different characteristics and / or functions and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or to several embodiments.

[0103] The claims are not intended to, and should not be construed as including, means-plus-function or step-plus-function limitations, unless such limitations are expressly recited in a given claim using the words "means" or "step," respectively.

Claims

1. One or more layers of insulation, each having a thermal conductivity of 0.05 watts per meter·Kelvin (W / m·K) or less; a protective layer coupled to the thermal insulation layer and defining at least a portion of the front surface of the laminate; A laminate comprising: the protective layer has a thickness of 12 to 200 μm and a thermal conductivity at least 3.5 times that of each of the thermal insulation layers; the protective layer comprises metal, graphite, and / or polyimide; the laminate comprises a thickness of 500 micrometers (μm) or less; and The laminate has a flow rate of 0.10 square millimeters per second (mm 2 / s).

2. a first adhesive layer bonded to the thermal insulation layer; At least a portion of the rear surface of the laminate a first adhesive layer; or a liner layer removably disposed on the first adhesive layer; It is stipulated by Preferably, the first adhesive layer comprises a pressure sensitive adhesive; and / or Preferably, the liner layer comprises a polymer film. The laminate according to claim 1.

3. The protective layer comprises molybdenum; Preferably, the protective layer contains molybdenum and has a thickness of 12 to 77 μm; the protective layer comprises graphite and has a thickness of 35 to 127 μm; the protective layer includes a polyimide layer and an aluminum layer disposed on the polyimide layer and defining at least a portion of the front surface of the laminate, the aluminum layer having a thickness of 500 nanometers or less; the protective layer comprises a polyimide layer and carbon black particles dispersed in the polyimide layer; and the surface resistivity of the protective layer is 10 5 to 10 12 Ω / square; and / or The protective layer includes a polyimide layer, and the thickness of the protective layer is 51 μm or less. The laminate according to claim 1.

4. a second adhesive layer bonded to the thermal insulation layer; wherein a second adhesive layer is disposed between and in contact with the protective layer and one of the thermal insulation layers; The laminate according to claim 1.

5. each of the adhesive layers comprises silicone, acrylic, and / or rubber; and / or each of the adhesive layers having a thickness of 50 μm or less; Preferably, the thickness of each of the adhesive layers is 15 to 35 μm. The laminate of claim 2.

6. at least one of the thermal insulation layers comprises a layer of polymer aerogel; 10. The laminate of claim 1, wherein preferably for at least one of the thermal insulation layers, the layer of polymer aerogel comprises an open-cell structure.

7. For at least one of the thermal insulation layers, the layer of polymer aerogel comprises micropores, mesopores, and / or macropores; Preferably, for at least one of the thermal insulation layers: The layer of polymer aerogel has a pore volume; and At least 10%, at least 50%, at least 75%, or at least 95% of the pore volume is made up of micropores; Preferably, for at least one of the thermal insulation layers: The layer of polymer aerogel has a pore volume; and At least 10%, at least 50%, at least 75%, or at least 95% of the pore volume is made up of mesopores; Preferably, for at least one of the thermal insulation layers: The layer of polymer aerogel has a pore volume; and At least 10%, at least 50%, at least 75%, or at least 95% of the pore volume is made up of macropores; or Preferably, for at least one of the thermal insulation layers: The layer of polymer aerogel has a pore volume; and At least 10%, at least 50%, at least 75%, or at least 95% of the pore volume is made up of micropores and / or mesopores; The laminate according to claim 6.

8. 7. The laminate of claim 6, wherein for at least one of the thermal insulation layers, the layer of polymeric aerogel has an average pore size of 2.0 nanometers (nm) to 50 nm.

9. For at least one of the thermal insulation layers, a layer of polymer aerogel is an average pore size between 50 nm and 5,000 nm; and / or Median pore size from 50nm to 5,000nm having Preferably, the average pore size is between 100 nm and 500 nm; and The median pore size is 250-600 nm. The laminate according to claim 6.

10. For at least one of the thermal insulation layers, the layer of polymer aerogel comprises at least 90% by weight of an organic polymer; or For at least one of the thermal insulation layers, the layer of polymer aerogel comprises at least 90% by weight of polyimide, polyamide, polyaramid, polyurethane, polyurea, and / or polyester; 7. The laminate of claim 6, wherein preferably for at least one of the thermal insulation layers, the layer of polymer aerogel comprises at least 90% by weight of polyimide.

11. For at least one of the thermal insulation layers, the layer of polymer aerogel has a thickness of 75 to 200 μm; 7. The laminate of claim 6, wherein the thickness of the layer of polymer aerogel is about 165 μm for at least one of the thermal insulation layers.

12. For at least one of the thermal insulation layers, the polymer aerogel layer has a decomposition temperature of 400°C or more, 450°C or more, or 500°C or more; For at least one of the thermal insulation layers, the thermal expansion coefficient of the polymer aerogel layer is 40 μm / m·K or less; and / or 10. The laminate of claim 6, wherein for at least one of the insulating layers, a plurality of fibers are dispersed or embedded in the layer of polymer aerogel.

13. the one or more insulation layers include two insulation layers; the laminate includes a third adhesive layer; and a third adhesive layer disposed between adjacent insulation layers; and / or 10. The laminate of claim 1, wherein the laminate has a flammability rating of UL94 VTM-0.

14. The laminate according to any one of claims 1 to 13, which is arranged in a roll shape so that a part of the front surface of the laminate faces a part of the rear surface of the laminate.

15. surface; and The laminate according to any one of claims 1 to 13. A system comprising: the laminate is disposed on the surface; Preferably, the surface comprises a metal, a polymer, or graphite; More preferably, the surface comprises a metal; and the metal comprises aluminum, molybdenum, stainless steel, steel, carbon steel, copper, brass, Monel®, and / or a superalloy; Preferably, the vehicle includes a surface; More preferably, the vehicle is an aircraft or spacecraft; and / or Preferably, the surface includes a missile, rocket, artillery shell, or other projectile, system.

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