Methods and compositions for producing graphene polyurethane foams

Abstract

A method for producing a polyurethane foam is provided herein. The method includes dispersing turbostratic graphene in a polymerization solution. The polymerization solution includes a first component for polymerizing to obtain a polymer. The method includes adding a second component for polymerizing with the first component to chemically convert the polymerization solution to a polyurethane foam. Also provided herein is a polyurethane foam including turbostratic graphene and a polymer formed from the polymerization of a polyol and an isocyanate. Also provided herein is a turbostratic graphene dispersion including turbostratic graphene and a solvent for dispersing the turbostratic graphene.

Description

[Technical Field]

[0001] Technical Field FIELD OF THE INVENTION

[0001] Embodiments disclosed herein relate to polyurethane foams, and more particularly to compositions and methods for producing graphene polyurethane foams. [Background technology]

[0002] introduction

[0002] Polyurethane foams are used in a variety of applications. Adding graphene to ingredients for producing polyurethane foams can provide various benefits. However, graphene dispersions in ingredients may not have high concentrations of conventional graphene. Turbostratic graphene offers various advantages over conventional graphene due to its turbostratic properties. For example, turbostratic graphene has fewer layers of graphene than conventional graphene, which allows for a higher concentration of graphene in the graphene dispersion.

[0003]

[0003] Furthermore, due to the low yield of graphene produced by chemical methods, it has not previously been possible to produce turbostratic graphene dispersions in high concentrations. However, turbostratic graphene can be produced in large quantities by Joule heating of a carbon feedstock. Summary of the Invention [Problem to be solved by the invention]

[0004]

[0004] Therefore, there is a need for new methods for producing polyurethane foams, and new polyurethane foams comprising turbostratic graphene. Additionally, there is a need for turbostratic graphene dispersions that can be used to produce polyurethane foams. There is also a need for high-concentration turbostratic graphene dispersions that can be used as masterbatches, which can make the dispersions easier to store. [Means for solving the problem]

[0005] overview According to some embodiments, there is a method for producing a polyurethane foam. The method includes dispersing turbostratic graphene in a polymerization solution. The polymerization solution includes a first component for polymerization to obtain a polymer. The method also includes adding a second component for polymerization with the first component to chemically convert the polymerization solution to a polyurethane foam.

[0006] The method may provide that the first component is a monomer or a polymer.

[0007] The above method may provide that the second component is a monomer or a polymer.

[0008]

[0008] The above method may provide that the turbostratic graphene is dispersed in the polymerization solution by at least one of the group including sonication, shear mixing, stirring, shaking, vortexing, milling, ball milling, and grinding.

[0009] The above method may provide that the first component is a polyol and the second component is an isocyanate.

[0010]

[0010] The above method may provide that the polyol is at least one of the group comprising petroleum-based polyols and bio-derived polyols.

[0011]

[0011] The above method may provide that the petroleum-based polyol is produced from at least one of the group including mineral oil, paraffinic oil, naphthenic oil, crude oil, kerosene, aliphatic oil, aromatic oil, petroleum, diesel oil, motor oil, and turbine oil.

[0012]

[0012] The above method may provide that the bio-derived polyol is produced from at least one of the group including vegetable oil, seed oil, soybean oil, rapeseed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, olive oil, grapeseed oil, linseed oil, castor oil, fish oil, algae oil, and mustard oil.

[0013]

[0013] The above method may provide that the isocyanate is at least one of the group including methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), p-phenylene diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CDI), and tolidine diisocyanate (TODI).

[0014]

[0014] The method may also include dispersing the turbostratic graphene in a solvent before dispersing it in the polymerization solution.

[0015]

[0015] The method may also include heating the solvent while dispersing the turbostratic graphene in the solvent.

[0016]

[0016] The above method may provide that the solvent comprises at least one of the group comprising an aqueous solvent, an alcoholic solvent, an organic solvent, and an oil-based solvent.

[0017]

[0017] The above method may provide that the aqueous solvent is a water-surfactant solution.

[0018]

[0018] The aqueous solvent may be sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), lithium dodecyl sulfate (LDS), sodium deoxycholate (DOC), sodium taurodeoxycholate (TDOC), cetyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB), pluronic F87, polyvinylpyrrolidone (PVP), polyoxyethylene (40) nonylphenyl ether (CO-890), Triton X-100, Tween 20, Tween 80, polycarboylate (H14N), sodium cholate, tetracyanoquinodimethane (TCNQ), pyridinium tribromide, N,N'-dimethyl-2,9-diazaperopyrenenium dication, N,N'-dimethyl-2,7-diazapyrene, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt, 1-pyrenemethylamine hydrochloride, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt hydrate, 1-pyrenecarboxylic acid, 1-aminopyrene, 1-aminomethylpyrene, 1-pyrenecarboxylic acid 13. The method of claim 12, wherein the carboxylic acid is at least one of the group comprising 1-pyrene butyric acid, 1-pyrene butanol, 1-pyrenesulfonic acid hydrate, 1-pyrenesulfonic acid sodium salt, 1,3,6,8-pyrenetetrasulfonetetraacid tetrasodium salt, 6,8-dihydroxy-1,3-pyrene disulfonic acid disodium salt, 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt, perylene bisimide boraamphiphile, tetrabutylammonium hydroxide (TBA), 9-anthracenecarboxylic acid.

[0019]

[0019] The method may provide that the aqueous solvent is at least one of the group comprising a water-surfactant solution, a water-pluronic solution, and a water-dihydrolevoglucosenone solution.

[0020]

[0020] The above method may provide that the alcoholic solvent is at least one of the group including methanol, ethyl alcohol, isopropyl alcohol, butanol, pentanol, ethylene glycol, propylene glycol, and glycerol.

[0021]

[0021] The method may provide that the organic solvent is at least one of the group comprising toluene, N-methyl-2-pyrrolidone (NMP), xylene, benzene, 1,2-dichlorobenzene (DCB), and dimethylformamide (DMF).

[0022]

[0022] The above method may provide that the organic solvent is at least one of the group including seed oil, soybean oil, rapeseed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, olive oil, grapeseed oil, linseed oil, castor oil, fish oil, algae oil, mustard oil.

[0023]

[0023] The above method may provide that the concentration of the turbostratic graphene dispersed in the solvent is between 1 and 15 mg / mL.

[0024]

[0024] The above method may provide that the turbostratic graphene has graphene layers that are oriented in directions that are offset from one another.

[0025]

[0025] In the above method, turbostratic graphene is 200 to 300 m 2 / g.

[0026]

[0026] The method may provide that the turbostratic graphene has between 1 and 5 layers of graphene.

[0027]

[0027] The method may provide that the turbostratic graphene has a particle size between 5 nm and 2000 nm.

[0028]

[0028] The method may provide that the turbostratic graphene has an oxygen content between 0.1% and 5% by atomic ratio.

[0029]

[0029] The method may also include heating the polymerization solution while dispersing the turbostratic graphene.

[0030]

[0030] Turbostratic graphene polyurethane foam can be produced by the above method.

[0031]

[0031] According to some embodiments, there is a polyurethane foam comprising turbostratic graphene, the polyurethane foam also comprising a polymer formed from the polymerization of a polyol and an isocyanate.

[0032]

[0032] The above polyurethane foam may provide that the turbostratic graphene increases the compressive strength of the polyurethane foam compared to polyurethane foam that does not have turbostratic graphene.

[0033]

[0033] The polyurethane foam may be provided such that the turbostratic graphene reduces the average pore size of the polyurethane foam compared to polyurethane foam not having turbostratic graphene.

[0034]

[0034] The polyurethane foam may be provided with turbostratic graphene, which increases the thermal insulation properties of the polyurethane foam compared to polyurethane foam that does not have turbostratic graphene.

[0035]

[0035] The polyurethane foam may provide that the turbostratic graphene increases the thermal insulation of the polyurethane foam by at least 60%.

[0036]

[0036] The polyurethane foam may provide that the turbostratic graphene increases the sound absorption of the polyurethane foam compared to polyurethane foam that does not have turbostratic graphene.

[0037]

[0037] The polyurethane foam has a viscosity of 20 to 95 kg / m 3 It may be provided that the density is between .gtoreq..times ...

[0038]

[0038] The polyurethane foam may be provided with turbostratic graphene having graphene layers oriented in directions that are offset from one another.

[0039]

[0039] The polyurethane foam has a turbostratic graphene content of 200 to 300 m. 2 / g.

[0040]

[0040] The polyurethane foam may be provided such that the turbostratic graphene has between 1 and 5 layers of graphene.

[0041]

[0041] The polyurethane foam may be provided such that the turbostratic graphene has a particle size between 5 nm and 2000 nm.

[0042]

[0042] The polyurethane foam may be provided such that the turbostratic graphene has an oxygen content between 0.1% and 5% in atomic ratio.

[0043]

[0043] The polyurethane foam may provide that the turbostratic graphene is produced from at least one of the group including petroleum coke, tire carbon black, carbon black, metallurgical coke, plastic ash, plastic powder, powdered coffee, anthracite, coal, corn starch, pine bark, polyethylene microwax, wax, chemplex 690, cellulose, naptenic oil, asphaltene, gilsonite, and carbon nanotubes.

[0044]

[0044] The polyurethane foam may provide that turbostratic graphene is produced by Joule heating of carbon powder.

[0045]

[0045] The polyurethane foam may provide that turbostratic graphene is produced by Joule heating of carbon-based pills.

[0046]

[0046] The polyurethane foam may provide that turbostratic graphene is produced from a carbon feedstock by Joule heating the carbon feedstock to a temperature between 2800°C and 3000°C.

[0047]

[0047] The polyurethane foam may provide that the polyol is at least one of the group comprising petroleum-based polyols and bio-derived polyols.

[0048]

[0048] The polyurethane foam may be provided in such a manner that the isocyanate is at least one of the group including methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), p-phenylene diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CDI), and tolidine diisocyanate (TODI).

[0049]

[0049] The polyurethane foams can be used in automobile seating, bedding, furniture, flooring, road materials, or building construction.

[0050]

[0050] The polyurethane foam can be used as a urethane coating, adhesive, sealant, epoxy, or elastomer.

[0051] According to some embodiments, there is a kit for producing a polyurethane foam comprising turbostratic graphene. The kit also includes a polymerization solution for conversion to the polyurethane foam. The polymerization solution includes a first component for polymerization to obtain a polymer.

[0052] The kit may also include a second component for polymerizing with the first component.

[0053]

[0053] The kit may provide that the first component is a monomer or a polymer.

[0054]

[0054] The kit may provide that the second component is a monomer or a polymer.

[0055]

[0055] The kit may provide that the first component is a polyol and the second component is an isocyanate.

[0056]

[0056] The kit may provide that the polyol is at least one of the group including petroleum-based polyols and bio-derived polyols.

[0057]

[0057] The above kit can produce turbostratic graphene polyurethane foam.

[0058]

[0058] According to some embodiments, there is a turbostratic graphene dispersion comprising turbostratic graphene, the turbostratic graphene dispersion also comprising a solvent for dispersing the turbostratic graphene.

[0059]

[0059] The turbostratic graphene dispersion may provide that the concentration of turbostratic graphene in the solvent is between 1 mg / mL and 15 mg / mL.

[0060]

[0060] The turbostratic graphene dispersion may provide that the turbostratic graphene has graphene layers that are oriented in directions that are offset from one another.

[0061]

[0061] The turbostratic graphene dispersion may provide that the turbostratic graphene is graphene having 5 or less layers.

[0062]

[0062] The above turbostratic graphene dispersion may provide that the solvent for dispersing the turbostratic graphene is a polyol solution for converting it into a polyurethane foam.

[0063]

[0063] The above turbostratic graphene dispersion may provide that the solvent for dispersing the turbostratic graphene is an isocyanate solution for conversion into polyurethane foam.

[0064]

[0064] The above-mentioned turbostratic graphene dispersion may provide that the solvent for dispersing the turbostratic graphene is at least one of the group including an aqueous solvent, an alcohol-based solvent, an organic solvent, and an oil-based solvent.

[0065]

[0065] The turbostratic graphene dispersion may provide that the aqueous solvent is a water-surfactant solution.

[0066]

[0066] The turbostratic graphene dispersion may be provided such that the concentration of turbostratic graphene in the aqueous solvent is between 1 and 5 mg / mL.

[0067]

[0067] The above turbostratic graphene dispersion may provide that the aqueous solvent is at least one of the group including a water-surfactant solution, a water-pluronic solution, and a water-dihydrolevoglucosenone solution.

[0068]

[0068] The turbostratic graphene dispersion may be prepared by mixing an aqueous solvent containing sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), lithium dodecyl sulfate (LDS), sodium deoxycholate (DOC), sodium taurodeoxycholate (TDOC), cetyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB), pluronic F87, polyvinylpyrrolidone (PVP), polyoxyethylene (40) nonylphenyl ether (CO-890), Triton X-100, Tween 20, Tween 80, polycarboylate (H14N), sodium cholate, tetracyanoquinodimethane (TCNQ), pyridinium tribromide, N,N'-dimethyl-2,9-diazaperopyrenenium dication, N,N'-dimethyl-2,7-diazapyrene, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt, 1-pyrenemethylamine hydrochloride, 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt hydrate, 1-pyrenecarboxylic acid, 1-aminopyrene, 1-aminomethylpyrene, 1-pyrenecarboxamide The compound may be at least one of the group comprising 1,3,6,8-pyrenetetrasulfonetetraacid, 1-pyrenebutyric acid, 1-pyrenebutanol, 1-pyrene sulfonic acid hydrate, 1-pyrene sulfonic acid sodium salt, 1,3,6,8-pyrenetetrasulfonetetraacid tetrasodium salt, 6,8-dihydroxy-1,3-pyrene disulfonic acid disodium salt, 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt, perylene bisimide bora amphiphile, tetrabutylammonium hydroxide (TBA), 9-anthracenecarboxylic acid.

[0069]

[0069] The above turbostratic graphene dispersion may provide that the alcohol-based solvent is at least one of the group including methanol, ethyl alcohol, isopropyl alcohol, butanol, pentanol, ethylene glycol, propylene glycol, and glycerol.

[0070]

[0070] The turbostratic graphene dispersion may be provided such that the concentration of turbostratic graphene in the alcohol-based solvent is between 1 and 50 mg / mL.

[0071]

[0071] The turbostratic graphene dispersion may be provided such that the concentration of turbostratic graphene in the alcohol-based solvent is 6.3% w / w or less.

[0072]

[0072] The above turbostratic graphene dispersion may provide that the organic solvent is at least one of the group including acetone, toluene, N-methyl-2-pyrrolidone (NMP), xylene, benzene, 1,2-dichlorobenzene (DCB), dimethylformamide (DMF), and methyl ethyl ketone (MEK).

[0073]

[0073] The turbostratic graphene dispersion may be provided such that the concentration of turbostratic graphene in the organic solvent is between 1 and 100 mg / mL.

[0074]

[0074] The turbostratic graphene dispersion may provide that the concentration of turbostratic graphene in the organic solvent is 11% w / w or less.

[0075]

[0075] The above turbostratic graphene dispersion may provide that the oily solvent is at least one of the group including vegetable oil, seed oil, soybean oil, rapeseed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, olive oil, grapeseed oil, linseed oil, castor oil, fish oil, algae oil, mustard oil, mineral oil, and naphthenic oil.

[0076]

[0076] The turbostratic graphene dispersion may be provided such that the concentration of turbostratic graphene relative to the oily solvent is between 1 and 100 mg / mL.

[0077]

[0077] The turbostratic graphene dispersion may be provided such that the concentration of turbostratic graphene in the oily solvent is 11% w / w or less.

[0078]

[0078] The turbostratic graphene dispersion may be provided as a masterbatch in which the turbostratic graphene dispersion is concentrated to between 5 and 10 times the concentration required for producing polyurethane foam.

[0079]

[0079] The turbostratic graphene dispersion may be provided in which the solvent is a polyol.

[0080]

[0080] The turbostratic graphene dispersion may be provided by heating the polyol while dispersing the graphene.

[0081]

[0081] The turbostratic graphene dispersion may be provided by stirring the polyol while dispersing the graphene.

[0082]

[0082] The turbostratic graphene dispersion may be provided in which the solvent is an isocyanate.

[0083]

[0083] According to some embodiments, there is a polyurethane foam comprising graphene, the polyurethane foam also comprising a polymer formed from the polymerization of a polyol and an isocyanate, the polyol being made from an oil.

[0084]

[0084] The polyurethane foam may provide that the graphene is at least one of the group including turbostratic graphene, very few layer graphene, few layer graphene, multilayer graphene, and graphene nanoplatelets.

[0085]

[0085] The polyurethane foam may be provided with turbostratic graphene having graphene layers oriented in directions that are offset from one another.

[0086]

[0086] The polyurethane foam has a turbostratic graphene content of 200 to 300 m. 2 / g.

[0087]

[0087] The polyurethane foam may be provided such that the turbostratic graphene has 1 to 5 layers of graphene.

[0088]

[0088] The polyurethane foam may be provided such that the turbostratic graphene has a particle size between 5 nm and 2000 nm.

[0089]

[0089] The polyurethane foam may provide that the polyol is made from at least one of the group comprising petroleum-based oils and biologically derived oils.

[0090]

[0090] The polyurethane foam may provide that the petroleum-based oil is at least one of the group including mineral oil, paraffinic oil, naphthenic oil, crude oil, kerosene, aliphatic oil, aromatic oil, petroleum, diesel oil, motor oil, and turbine oil.

[0091]

[0091] The polyurethane foam may be provided in which the biologically derived oil is at least one of the group including vegetable oil, seed oil, soybean oil, rapeseed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, olive oil, grapeseed oil, linseed oil, castor oil, fish oil, algae oil, and mustard oil.

[0092]

[0092] The polyurethane foam may be provided in which the isocyanate is at least one of the group including methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), p-phenylene diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CDI), and tolidine diisocyanate (TODI).

[0093] According to some embodiments, there is a method for producing a polyurethane foam. The method includes dispersing graphene in oil. The method also includes chemically converting the oil into a polyol. The method also includes adding an isocyanate to chemically convert the polyol into a polyurethane foam.

[0094]

[0094] The method may provide that the graphene is at least one of the group comprising turbostratic graphene, very few layer graphene, few layer graphene, multilayer graphene, and graphene nanoplatelets.

[0095]

[0095] The above method may provide that the turbostratic graphene has graphene layers that are oriented in directions that are offset from one another.

[0096]

[0096] In the above method, turbostratic graphene is 200 to 300 m 2 / g.

[0097]

[0097] The method may provide that the turbostratic graphene has between 1 and 5 layers of graphene.

[0098]

[0098] The method may provide that the turbostratic graphene has a particle size between 5 nm and 2000 nm.

[0099]

[0099] The above method may provide that the polyol is made from at least one of the group comprising petroleum-based oils and bio-derived oils.

[0100]

[0100] The above method may provide that the petroleum-based oil is at least one of the group including mineral oil, paraffinic oil, naphthenic oil, crude oil, kerosene, aliphatic oil, aromatic oil, petroleum, diesel oil, motor oil, and turbine oil.

[0101]

[0101] The above method may provide that the biologically derived oil is at least one of the group including vegetable oil, seed oil, soybean oil, rapeseed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, olive oil, grapeseed oil, linseed oil, castor oil, fish oil, algae oil, and mustard oil.

[0102]

[0102] The above method may provide that the isocyanate is at least one of the group including methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), p-phenylene diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CDI), and tolidine diisocyanate (TODI).

[0103]

[0103] Further aspects and features will become apparent to those skilled in the art upon review of the following description of several representative embodiments.

[0104] BRIEF DESCRIPTION OF THE DRAWINGS

[0104] The drawings included herein are intended to illustrate various examples of the articles, methods, and apparatuses herein. [Brief explanation of the drawings]

[0105] [Figure 1A]

[0105] A transmission electron microscope (TEM) image of turbostratic graphene according to one embodiment. [Figure 1B]

[0106] 1 is a high-resolution TEM image of turbostratic graphene, showing an area 105 where 3-4 or more layers of graphene are detected stacked on a flat sheet, according to one embodiment. [Figure 1C]

[0107] 1 is a high-resolution transmission electron microscopy (HRTEM) of turbostratic graphene according to one embodiment. [Figure 1D]

[0108] 1D is a representative selected area electron diffraction (SAED) of the structure shown in FIG. 1C illustrating the turbostratic properties of graphene according to one embodiment. [Figure 1E]

[0109] 1E is an intensity profile of the SAED in FIG. 1D according to one embodiment. [Figure 1F]

[0110] 1 is an X-ray photoelectron spectroscopy (XPS) spectrum of a representative sample of turbostratic graphene produced by Joule heating, according to one embodiment. [Figure 2A]

[0111] 1 is a flowchart illustrating a method for manufacturing polyurethane foam (PUF). [Figure 2B]

[0112] Comparison of the physical properties of turbostratic graphene-based PUF composites (TGPU) and PUF composites with conventional graphene (XGPU), showing the relative changes to a PUF without any additives (standard PU). [Figure 3]

[0113] 10 is an image of foam pore size as a function of additive material, according to one embodiment. [Figure 4]

[0114] 4A-4C are images of polyurethane foam of Batch H before and after compression with a 100 g load, according to one embodiment. PUF without additives is shown before compression 405 and after compression. [Figure 5]

[0115] 1 is a graph showing the thermal conductivity of four polyurethane foams according to one embodiment. [Figure 6]

[0116] 1 is an image of an apparatus for measuring the sound absorption properties of four polyurethane foams according to one embodiment. [Figure 7]

[0117] 1 is a turbostratic graphene-oil dispersion before storage and after 3 weeks of storage according to one embodiment. [Figure 8]

[0118] 1 is a flowchart showing a method for producing a polyurethane foam. DETAILED DESCRIPTION OF THE INVENTION

[0106] Detailed Description

[0119] Various devices or processes are described below to provide examples of each claimed embodiment. The embodiments described below are not intended to limit any claimed embodiment, and any claimed embodiment may include processes or devices different from those described below. A claimed embodiment is not limited to a device or process having all the features of any one device or process described below, nor is it limited to features common to some or all of the devices described below.

[0107]

[0120] The term "graphene" refers to a one-atom-thick planar sheet of sp2-bonded carbon atoms densely packed into a honeycomb crystal lattice, further comprising an intact ring structure of carbon atoms and aromatic bonds throughout at least most of the internal sheet, and lacking significant oxidative modification of the carbon atoms. Graphene can be distinguished from graphene oxide in that it contains a lower degree of oxygen-containing groups such as OH, COOH, and epoxides. The term "graphene monolayer" refers to graphene that is a single layer of graphene. The term "very few-layer graphene" refers to graphene that is between one and three layers of graphene. The term "few-layer graphene" refers to graphene that is between two and five layers of graphene. The term "multilayer graphene" refers to graphene that is between two and ten layers of graphene.

[0108]

[0121] The term "turbostratic graphene" refers to graphene with little order between the graphene layers. Other terms that can be used include misoriented, twisted, rotated, rotationally defective, and weakly bonded. The rotational stacking of turbostratic graphene promotes reduced interlayer bonding and increases lattice spacing, thereby providing superior physical properties compared to competing graphene structures on a weight-for-weight basis. Small differences in the stacking direction of adjacent layers can result in significant differences in the performance characteristics of the product. One obvious and important performance advantage of turbostratic graphene is that the multilayer graphene structure is easily separated into several individual graphene layers, which do not tend to recombine. The turbostratic nature of graphene can be observed and confirmed by Raman spectroscopy, transmission electron microscopy (TEM), selected-area electron diffraction (SAED), scanning transmission electron microscopy (STEM), and X-ray diffraction (XRD) analysis.

[0109]

[0122] One method for producing large quantities of turbostratic graphene is by Joule heating of carbon powder or carbon-based pills. Turbostratic graphene can be produced from carbon pills by Joule heating to temperatures between 2800 and 3000°C. The synthesis of graphene from carbon pills primarily produces few-layer turbostratic graphene. Turbostratic graphene is a misaligned set of graphene layers. Therefore, the graphene layers are not AB stacked but are misaligned relative to each other. The graphene layer configuration in turbostratic graphene allows for easier dispersion of graphene powder in liquids. This easier dispersion of graphene allows for the production of better graphene composites.

[0110]

[0123] The Joule heating synthesis method and compositions thereof are described in the Patent Cooperation Treaty application of Tour et al., having an international publication date of March 12, 2020, and having International Publication Number WO2020 / 051000A1, which is incorporated herein by reference in its entirety.

[0111]

[0124] The graphene layers of turbostratic graphene are stacked randomly, unlike the AB-stacked graphene found in other types of bulk graphene. The turbostratic properties of the disclosed graphene allow it to be more easily dispersed at higher concentrations and remain dispersed for extended periods, such as days to years. Turbostratic graphene can be dispersed at concentrations of 1 mg / mL (1 g / L) to 15 mg / mL (15 g / L), depending on the medium. In contrast, conventional graphene can be dispersed down to as little as 1 mg / mL (1 g / L). Turbostratic graphene dispersions can be used to fabricate turbostratic graphene polyurethane foams (TGPUFs). For example, dispersions of turbostratic graphene in water, oil, or polyol can be used to fabricate TGPUFs. In some embodiments, turbostratic graphene is dispersed directly in the medium, and in some embodiments, a second additive medium is used to facilitate the dispersion of the turbostratic graphene.

[0112]

[0125] 120~150m 2 / g, turbostratic graphene has a 2 / g.

[0113]

[0126] Compared to conventional graphene, which has a grain size of 4 to 6 microns, turbostratic graphene can have a grain size between 5 nm and several microns.

[0114]

[0127] Referring to Figure 1A, a transmission electron microscope (TEM) image of turbostratic graphene is shown, according to one embodiment. A 200 nm scale bar is provided at the bottom left of the image to indicate the scale of the image. Referring to Figure 1B, a high-resolution TEM image of turbostratic graphene is shown. The high-resolution image shows a region 105 where 3-4 or more layers of graphene are detected stacked on a flat sheet, according to one embodiment.

[0115]

[0128] As shown in Figures 1A and 1B, turbostratic graphene has between 1 and 5 graphene layers that are not AB stacked. In contrast, conventional graphene has more than 5 AB-stacked graphene layers, typically more than 10 AB-stacked graphene layers. The energy required to exfoliate AB-stacked graphite or graphene into few-layer graphene is much greater than that required for turbostratic graphene. AB-stacked graphite or graphene can be exfoliated, for example, using high-energy sonication and harsh chemical methods. Due to the larger number of AB-stacked graphene layers, conventional graphene is more difficult to disperse at higher concentrations, and the composites have a higher weight per unit volume because the numerous graphene layers sandwiched between the outer layers do not contribute to the composite's improvement.

[0116]

[0129] 1C, high-resolution transmission electron microscopy (HRTEM) of turbostratic graphene produced from a pill is shown, according to one embodiment. Inset image 115 shows a high-magnification image of the edge of the sheet showing the three graphene planes.

[0117]

[0130] Methods for synthesizing graphene by Joule heating of carbon pills and their compositions are described in the Patent Cooperation Treaty application of Mancevski having an international filing date of October 13, 2020, and having international application number PCT / CA2020 / 051368, which is incorporated herein by reference in its entirety.

[0118]

[0131] Referring to Figure ID, a representative selected area electron diffraction (SAED) of the structure shown in Figure 1C is shown, illustrating the turbostratic nature of graphene, according to one embodiment. The arcs 110 are observed as overlapping rings of distinct bright spots. Each circularly arranged spot in the 60-degree arc 120 represents an individual sublayer or sheet with a different angular orientation (up to 53°) relative to a reference (0° spot) located to the right of the arc. The dashed squares on the pattern are expanded on the right side of Figure ID, showing the contribution of each individual spot 125.

[0119]

[0132] Referring to Figure 1E, an intensity profile of the SAED in Figure 1D is shown, according to one embodiment. The distance for surface 130 is shown as 0.35 nm, surface 100 is shown as 0.21 nm, and surface 110 is shown as 0.12 nm. These distances are calibrated against an SAED standard of aluminum metal.

[0120]

[0133] High-purity graphene and low-oxygen content turbostratic graphene means that composites made of turbostratic graphene can have fewer defects and impurities, and therefore a lower percentage of them in the composite, allowing for stronger interfacial interactions between the graphene and the polymer matrix. Additionally, low-oxygen content graphene can improve interactions with non-polar (hydrophobic) polymer matrices.

[0121]

[0134] The high-resolution transmission electron microscope (HRTEM) image of a representative sheet of Joule-heated graphene in Figure 1C shows the turbostratic nature of graphene. The sheet structure in the center of the image has dimensions of approximately 500 × 700 nm and is composed of several stacked layers of graphene. The inset shows a higher magnification image of the edge of the sheet, revealing three graphene planes. Wrinkles 140 and corrugations 145 are observed at the edge of the central structure, which are characteristic of two-dimensional materials.

[0122]

[0135] The SAED in Figure 1D shows the turbostratic nature of the central sheet, with multiple distinct bright spots observable within a 60° arc 120. The arc 120 is visually indicated using a curved arrow between two white lines defining the beginning and end of the arc. Each bright spot results from electron diffraction of a single graphene layer or several graphene layers in the same orientation. To illustrate the turbostratic nature of the graphene sheet in the image in Figure 1C, the angular orientation of selected bright spots was calculated relative to one arbitrary spot selected as 0° (located to the right of the 60° arc 120) (Gupta et al., Twist-Dependent Raman and Electron Diffraction Correlations in Twisted Multilayer Graphene, J. Phys. Chem. Lett., 2020, 11, 8, 2797-2803).

[0123]

[0136] Referring to Figure 1F, an X-ray photoelectron spectroscopy (XPS) spectrum of the turbostratic graphene sample of Figure 1C produced by Joule heating of a pill is shown, according to one embodiment. The top graph 150 shows a survey scan, and the bottom graph 155 shows a high-resolution scan and assignment of the carbon edges.

[0124]

[0137] This XPS shows high-purity turbostratic graphene and a low oxygen content. Survey scan 150 shows a turbostratic graphene sample composed of over 98% carbon (atomic ratio). Other elements detected include oxygen and sulfur, but in small amounts (1.2% and 0.4%, respectively). The low oxygen content is characteristic of the Joule heating process and is much lower than that observed in the chemical production of graphene by exfoliation of graphite (>10%, atomic ratio, also measured by XPS) (Al-Gaashaniab et al., XPS and structural studies of high-quality graphene oxide and reduced graphene oxide prepared by different chemical oxidation methods, Ceramics International, 2019, 45, 11, 14439-1444). The high-resolution spectrum of the carbon edge 155 shows carbon peaks that deconvolute into four major peaks, confirmed by a similar analysis of carbon materials in the literature (Lesiak et al., C sp2 / sp3 hybridizations in carbon nanomaterials - XPS and (X)AES study, Applied Surface Science, 2018, 452, 223-231). The most prominent peak, located at 284.45 eV (approximately 80% of the carbon atoms), is assigned to carbon atoms with sp2 hybridization (C=C). Other peaks indicate the presence of carbon atoms with sp3 hybridization and C-O bonds (C-OH and C=O). The high content of sp2 hybridization (nearly 80%) indicates that most of the carbon atoms in the sample are arranged in a 2D structure.

[0125]

[0138] Due to the high purity of graphene and low oxygen content of the present disclosure, composites made with turbostratic graphene have fewer defects and impurities and therefore require a lower percentage in the composite for it to perform well than conventional composites.

[0126]

[0139] Conventional production of turbostratic graphene grown by chemical vapor deposition (CVD) and other atomic deposition methods is slow and may not be able to produce more than a few layers of graphene on a substrate; therefore, the large yields required for producing turbostratic graphene composites have not been possible with conventional methods. An advantage of turbostratic graphene produced by Joule heating is that graphene can be produced in large quantities, such as grams to kilograms, in powder form. This high yield allows Joule-heated turbostratic graphene to be used with composite materials.

[0127]

[0140] Turbostratic graphene can be used as an additive to make polyurethane foam composites by adding between 0.01 wt% and 5 wt% of turbostratic graphene to polyurethane foam components, such as either polyol or isocyanate, before mixing the polyurethane foam components. The examples herein show the use of 0.063 wt% turbostratic graphene in the foam material, but any concentration between 0.01 wt% and 5 wt% turbostratic graphene can be used.

[0128]

[0141] Turbostratic graphene polyurethane foam is presented, which offers various advantages over graphite nanoplatelet (GNP) materials, AB-stacked graphene, and polyurethane foam with carbon nanoparticles.

[0129]

[0142] In one embodiment, 120 m of conventional graphene 2 / g~150m 2 / g, turbostratic graphene is 200m 2 / g~300m 2 / g.

[0130]

[0143] In one embodiment, turbostratic graphene can have a particle size between 5 nm and 200 nm when produced from a carbon black feedstock, or between 100 nm and over 2000 nm when petroleum coke or coffee grounds are used as the feedstock. In comparison, conventional turbostratic graphene has a particle size between 4 and 6 microns.

[0131]

[0144] In one embodiment, the turbostratic graphene dispersion can have a concentration between 1 mg / mL (1 g / L) and 15 mg / mL (15 g / L). In comparison, conventional graphene dispersions can have a concentration of only up to 1 mg / mL (1 g / L).

[0132]

[0145] In one embodiment, turbostratic graphene can have a low oxygen content between 0.1% and 5% atomic percent. In comparison, conventional graphene typically has a higher oxygen content of 10% or more atomic percent. If desired, the oxygen content of turbostratic graphene can be increased by intentionally introducing oxygen content after the turbostratic graphene is produced.

[0133]

[0146] In one embodiment, the concentration of turbostratic graphene in the turbostratic graphene polyurethane foam may be between 0.01 wt% and 5 wt%. The improved dispersion properties of turbostratic graphene and the smaller number of graphene layers allow for an increased concentration of graphene in the polyurethane foam, and therefore the turbostratic graphene polyurethane foam weighs less per unit volume than polyurethane foam with conventional graphene. [Example]

[0134] Example 1 - Preparation of Polyurethane Foam

[0147] Here, we provide a polyurethane foam (PUF) containing turbostratic graphene, which is fabricated and tested. One method for fabricating turbostratic graphene is by resistive (ohmic) Joule heating, hence the name Joule-heated graphene. Results are compared with PUFs fabricated without additives, with a carbon black (CB) additive, and with conventional graphene. The turbostratic graphene-based PUFs had better mechanical properties than either the additive-free PUFs or the PUFs with other types of graphene.

[0135]

[0148] 2A , a flowchart illustrating a method 200 for producing polyurethane foam is shown, according to one embodiment. Method 200 includes dispersing turbostratic graphene in a polymerization solution at 210. Optionally, method 200 includes heating the polymerization solution while dispersing the turbostratic graphene at 211. The polymerization solution includes a first component for polymerizing to obtain a polymer. Method 200 also includes adding a second component for polymerizing with the first component at 215 to chemically convert the polymerization solution to a polyurethane foam. Optionally, method 200 includes dispersing turbostratic graphene in a solvent at 205 before dispersing the turbostratic graphene in the polymerization solution at 210. Optionally, method 200 includes heating the solvent while dispersing the turbostratic graphene at 206.

[0136]

[0149] In some embodiments, the first component is a polyol and the second component is an isocyanate. In some embodiments, the first component is an isocyanate and the second component is a polyol. The polymerization solution is a solution that can be converted into a polyurethane foam. In some embodiments, the first component is a monomer or polymer. In some embodiments, the second component is a monomer or polymer.

[0137]

[0150] Referring to Figure 2B, a comparison of the physical properties of turbostratic graphene-based PUF composites (TGPU) and PUF composites with conventional graphene (XGPU) is shown, demonstrating the improvement in physical properties relative to PUF without any additives (standard PU).

[0138]

[0151] In one embodiment, the commercially available Flex Foam-iT! Polyurethane Foam kit can be used to manufacture the PUF. This kit includes two parts: Part A is a methylene diphenyl diisocyanate (MDI)-based isocyanate material, and Part B is a polyol material. Typically, the material in Part B is a petroleum-based polyol, but it can also be a bio-based polyol or a combination of a petroleum-based polyol and a bio-based polyol.

[0139]

[0152] An example of the fabrication of turbostratic graphene PUF (PUF / TG) is described as Batch H. Turbostratic graphene is produced from a carbon feedstock of 30% bark and 70% petroleum coke prepared in the form of a carbon-based compressed pill. The carbon is converted to turbostratic graphene by Joule heating. First, 20 mg of turbostratic graphene is mixed with 20 g of Part B polyol (0.1%) by heating the polyol to 80-100 °C until the polyol solution becomes less viscous. Then, 20 mg of turbostratic graphene is added, followed by sonication until the mixture becomes uniformly black. In the next step, 11.5 g of Part A is mixed with the dispersion of Part B and turbostratic graphene for 15-30 seconds, poured into a mold, and cured at room temperature for 2 hours. The amount of turbostratic graphene in the resulting PUF / TG is 0.063 wt%. PUFs with conventional graphene (PUF / XG) and PUFs with carbon black (PUF / CB) are also fabricated by the same method, replacing turbostratic graphene with conventional graphene and carbon black, respectively.

[0140]

[0153] Another example of PUF fabrication is described as Batch R. Turbostratic graphene is produced from a carbon feedstock of 30% bark and 70% petroleum coke prepared in the form of a carbon-based compressed pill. The carbon is converted to turbostratic graphene by Joule heating. 20 mg of turbostratic graphene is first dispersed in 20 ml of benzene and sonicated until the turbostratic graphene is fully dispersed. Next, the graphene / benzene slurry is dispersed in 11.5 g of Part A (MDI) and mixed with a magnetic stirrer until the mixture is uniformly black. In the next step, 20 g of Part B (polyol) is mixed with the Part A and graphene / benzene dispersion for 15–20 seconds and then poured into a Pyrex mold where it is cured at room temperature for 2 hours. The amount of turbostratic graphene in the PUF is 0.063%. PU / XG and PU / CB foams are fabricated using the same method, replacing the turbostratic graphene with conventional graphene and carbon black, respectively.

[0141]

[0154] Turbostratic graphene can also be dispersed in toluene, N-methyl-2-pyrrolidone (NMP), or xylene instead of benzene. Alternative liquid dispersants compatible with Part A materials (isocyanate-containing compounds such as MDI) and Part B materials (polyols) can also be used.

[0142]

[0155] The physical properties of the foam produced in Example Batch H are shown in Table 1.

[0143] [Table 1]

[0144]

[0156] As a benchmark, the density of foam for automotive applications is 42 kg / m 3 The density for the cushion and backrest of automobile seats is 20-95 kg / m 3 should be within the range.

[0145]

[0157] When graphene-like materials are added, the foam cell count increases and the foam cell size decreases. The foam cell size of a PUF with 50% petroleum-based polyol and 50% bio-based polyol is in the range of 200-600 microns, while the cell size of a foam with 1% graphite nanoplatelet (GNP) additive is below 200 microns.

[0146]

[0158] Referring to Figure 3, an image of foam pore size as a function of additive material is shown, according to one embodiment. The pore sizes are shown for PUF305 with no additives, PUF310 with 0.063% carbon black, PUF315 with 0.063% conventional graphene, and PUF320 with 0.063% turbostratic graphene. A representative cell 325 for PUF305 with no additives has a circumference of 2.761 mm and an area of ​​0.606 mm. 2 and a radius of 0.439 mm. A representative cell 330 of PUF 310 with 0.063% carbon black has a circumference of 2.251 mm and an area of ​​0.403 mm. 2 The typical cell 335 of the PUF 315 with 0.063% conventional graphene has a perimeter of 1.477 mm and an area of ​​0.174 mm. 2 The first representative cell 340 of the PUF 320 with 0.063% turbostratic graphene has a perimeter of 1.263 mm and an area of ​​0.127 mm 2 and the radius is 0.201 mm. The second representative bubble 345 of the PUF 320 with 0.063% turbostratic graphene has a perimeter of 0.848 mm and an area of ​​0.057 mm. 2 and the radius is 0.135 mm.

[0147]

[0159] Referring to Figure 4, images of polyurethane foam from Batch R before and after compression with a 2 kg load are shown, according to one embodiment. A PUF without any additives is shown before 405 and after 410 compression. A PUF with 0.063% carbon black is shown before 415 and after 420 compression. A PUF with 0.063% conventional graphene is shown before 425 and after 430 compression. A PUF with 0.063% turbostratic layering is shown before 435 and after 440 compression.

[0148]

[0160] The compressive strength of four PUFs produced in Example Batch R according to one embodiment is measured, as shown in Table 2. The thickness of each foam is measured and compared to the compressed thickness using a 2 kg load. The compressive strength (kPa) and relative compressive strength between foams were calculated from the measured pre-load thickness and compressed thickness of each foam.

[0149] [Table 2]

[0150]

[0161] As shown in Table 2, adding turbostratic graphene to the PUF increases the compressive strength of the foam by 262%. Conventional graphene increases the compression by 78%.

[0151]

[0162] The compressive strength of four PUFs produced in Example Batch H, according to one embodiment, is measured, as shown in Table 3. The thickness of each foam is measured and compared to the compressed thickness using a small 100 g mass load. The compressive strength (kPa) and relative compressive strength between foams were calculated from the measured pre-load thickness and compressed thickness of each foam.

[0152] [Table 3]

[0153]

[0163] As shown in Table 3, the addition of turbostratic graphene contributes to a change in compressive strength of over 40%, which is much greater than conventional graphene.

[0154]

[0164] Referring to Figure 5, a graph showing the thermal conductivity of four polyurethane foams is shown, according to one embodiment. The thermal conductivity of the four PUFs is measured by placing them on a hot plate set at 100°C. To avoid issues where each foam has a slightly different thickness, a thermocouple probe is inserted 1 cm from the bottom of each foam. Foam temperatures are recorded every 15 seconds for two minutes.

[0155]

[0165] As shown in Table 4, the change in temperature (dT) after heating the PUF at 100° C. for 2 minutes is measured according to one embodiment.

[0156] [Table 4]

[0157]

[0166] The addition of turbostratic graphene increases the thermal insulation of the foam by 61% compared to the baseline additive-free PUF, in contrast to the increase in thermal conductivity seen with conventional graphene and carbon black.

[0158]

[0167] The amount of turbostratic graphene in the PUF can be increased or decreased to use the packing effect to change the thermal conductivity of the PUF.

[0159]

[0168] Referring to Figure 6, an image of an apparatus for measuring the sound absorption properties of four polyurethane foams is shown, according to one embodiment. The sound absorption properties of the four PUFs are measured using a Styrofoam box, inside which a device such as a smartphone is placed to generate sound at three specific frequencies in the range useful to the automotive industry: 1600 Hz, 2000 Hz, and 2500 Hz, as shown at 605. A sample of the PUF is placed in an opening in the lid of the box, as shown at 610, and a second device, such as a second smartphone, is placed on top of the PUF. The second smartphone has sound analysis software that records the dB value of the sound.

[0160]

[0169] The sound absorption properties of PUF are shown in Table 5.

[0161] [Table 5]

[0162]

[0170] The sound absorption quality of PUFs is highly dependent on the sound frequency and can be improved by adding carbon-based additives. PUFs with 0.063% turbostratic graphene content attenuated sound frequencies above 2 kHz. Acoustically, turbostratic graphene was comparable to conventional graphene-based foams.

[0163] Example 2 - Turbostratic graphene dispersion

[0171] In one embodiment, turbostratic graphene is first dispersed in a liquid to break down the weak surface forces that hold the graphene powder together. The turbostratic graphene dispersion can be further diluted with various materials typically used for the production of PUFs and masterbatches, such as polyols and isocyanate-containing compounds. Due to the turbostratic nature of graphene, turbostratic graphene particles in the 5 nm to 2000 nm size range disperse with low energy, remain dispersed, and do not agglomerate even after days or even years. The turbostratic graphene-liquid dispersion can be diluted or further mixed with other materials typically used in the production of polyurethane foams, and does not agglomerate after the production of masterbatches, such as polyol masterbatches or isocyanate-containing masterbatches.

[0164]

[0172] In general, the turbostratic graphene dispersions are four times more concentrated than the most concentrated conventional graphene dispersions produced by liquid-phase exfoliation of conventional graphite, and more than ten times more concentrated than many reported values ​​for graphene nanoplatelets (GNPs).

[0165]

[0173] Turbostratic graphene dispersion in water, alcohol, solvent, or oil can be achieved using an ultrasonicator or shear mixer. For example, turbostratic graphene-water dispersion can be achieved by ultrasonication for 2-30 minutes or by shear mixing at 4000 rpm-5000 rpm for 15 minutes.

[0166]

[0174] In one embodiment, turbostratic graphene can be dispersed in a 1% water-pluronic (F-127) solution at various concentrations (1-5 mg / mL in water or 0.5% w / w). Other common water-compatible surfactants, such as common kitchen dishwashing liquid, dihydrolevoglucosenon (Cyrene), and other common water-compatible surfactants, can also be used in place of pluronic F-127. Other water-compatible surfactant / dispersant systems for graphene dispersions include sodium dodecyl sulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), lithium dodecyl sulfate (LDS), sodium deoxycholate (DOC), sodium taurodeoxycholate (TDOC), cetyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB), Pluronic F87, polyvinylpyrrolidone (PVP), polyoxyethylene(40) nonylphenyl ether (CO-890), Triton X-100, Tween 20, and Tween 80, Polycarboylate (H14N), Sodium Cholate, Tetracyanoquinodimethane (TCNQ), Pyridinium Tribromide, N,N'-Dimethyl-2,9-diazaperopyrenenium Dication, N,N'-Dimethyl-2,7-diazapyrene, 1,3,6,8-Pyrenetetrasulfonic Acid Tetrasodium Salt, 1-Pyrenemethylamine Hydrochloride, 1,3,6,8-Pyrenetetrasulfonic Acid Tetrasodium Salt Hydrate, 1-Pyrenecarboxylic Acid, 1-Aminopyrene, 1-Aminomethylpyrene Examples of suitable amines include 1-pyrenecarboxylic acid, 1-pyrenebutyric acid, 1-pyrenebutanol, 1-pyrene sulfonic acid hydrate, 1-pyrene sulfonic acid sodium salt, 1,3,6,8-pyrenetetrasulfonetetraacid tetrasodium salt, 6,8-dihydroxy-1,3-pyrene disulfonic acid disodium salt, 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt, perylene bisimide bora amphiphile, tetrabutylammonium hydroxide (TBA), and 9-anthracenecarboxylic acid.

[0167]

[0175] In one embodiment, turbostratic graphene can be dispersed at various concentrations (1-50 mg / ml or 6.3% w / w in alcohol) in alcohol, such as, but not limited to, methanol, ethyl alcohol, isopropyl alcohol, butanol, pentanol, ethylene glycol, propylene glycol, glycerol, and any combination thereof.

[0168]

[0176] In one embodiment, turbostratic graphene can be dispersed in various concentrations (1-100 mg / ml or 11% w / w in organic solvent) in organic solvents such as, but not limited to, acetone, toluene, N-methyl-2-pyrrolidone (NMP), xylene, benzene, 1,2-dichlorobenzene (DCB), dimethylformamide (DMF), and methyl ethyl ketone (MEK).

[0169]

[0177] 7, there is shown a turbostratic graphene-oil dispersion according to one embodiment before storage 705 and after three weeks of storage 710. The turbostratic graphene dispersion is maintained over the storage period in olive oil.

[0170]

[0178] In one embodiment, turbostratic graphene can be dispersed at various concentrations (1-100 mg / ml or 11% w / w in oil) in petroleum-based oils and vegetable oils such as seed oil, soybean oil, rapeseed oil, canola oil, peanut oil, cottonseed oil, sunflower oil, olive oil, grapeseed oil, linseed oil, castor oil, fish oil, algae oil, mustard oil, and combinations thereof. Other oils can include mineral oil, paraffinic oil, and naphthenic oil.

[0171]

[0179] In one embodiment, the turbostratic graphene dispersion can be present in water, alcohol, solvent, or oil. The turbostratic graphene dispersion can be used to produce masterbatches, such as isocyanate-containing masterbatches and polyol masterbatches. The turbostratic graphene dispersion is shear-mixed with an isocyanate-containing material or a polyol material to produce the masterbatch. Due to the dispersing ability of turbostratic graphene, the masterbatch can be diluted at least five times based on the batch. In another embodiment, the turbostratic graphene dispersion can be further concentrated by heating, evaporating a portion of the dispersing agent by distillation, centrifugation, or chemical means.

[0172]

[0180] In one embodiment, turbostratic graphene is used to prepare masterbatches, such as isocyanate-containing masterbatches and polyol masterbatches, by directly dispersing turbostratic graphene in an isocyanate or polyol material. Optionally, the directly dispersed isocyanate or polyol is maintained at room temperature. Optionally, the isocyanate or polyol is heated (80°C to 100°C) until a desired viscosity is reached to effectively disperse the turbostratic graphene.

[0173]

[0181] In some embodiments, the isocyanate may include, but is not limited to, methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 1,5-naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate (TMXDI), p-phenylene diisocyanate (PPDI), 1,4-cyclohexane diisocyanate (CDI), tolidine diisocyanate (TODI), and combinations thereof.

[0174]

[0182] In some embodiments, the polyol material may include petroleum-based polyols, and bio-derived polyols, and combinations thereof.

[0175]

[0183] The addition of turbostratic graphene to PUFs offers advantages not present when the PUF additive is GNPs. Due to the poor dispersion properties of GNPs, they tend to aggregate and increase the viscosity of the medium. These properties make it difficult to disperse GNPs in a polymer matrix without sacrificing the polymer matrix's performance properties. Furthermore, the increased viscosity makes it more difficult to pump the polyol and isocyanate from the storage tank through the dispersion nozzle.

[0176]

[0184] Due to the turbostratic properties of turbostratic graphene, it is advantageously more dispersible than other types of conventional graphene, such that individual graphene particles do not aggregate over days or months. These properties can advantageously facilitate the dispersion of turbostratic graphene into a polymer matrix, which can improve the performance properties of the polymer matrix. Furthermore, the viscosity of the turbostratic graphene-polyol dispersion and turbostratic graphene-isocyanate dispersion can advantageously facilitate pumping the turbostratic graphene-polyol dispersion and turbostratic graphene-isocyanate dispersion from a storage tank to a dispersion nozzle.

[0177]

[0185] In one embodiment, flexible polyurethane foam can be prepared using a one-shot method. This procedure involves mixing a turbostratic graphene dispersion, such as turbostratic graphene-toluene, with an isocyanate, such as MDI, at 1,000-1,500 rpm for 1-5 minutes to obtain a turbostratic graphene-MDI mixture. Optionally, the turbostratic graphene can be dispersed in a surfactant. Optionally, the turbostratic graphene can be dispersed in water, which is a blowing agent. Optionally, if dispersants, water, alcohol, oil, or solvents are undesirable in the final foam product, the turbostratic graphene dispersion can be treated to remove the dispersant by heating, distillation, or chemical methods. In one example, the turbostratic graphene concentration is 0.05% of the total weight of the polyol and MDI, and TG is introduced via a toluene dispersion. In one example, the turbostratic graphene concentration is 0.02% of the total weight of the polyol, MDI, and other chemicals, and the turbostratic graphene is introduced via a water dispersion where water is 4% of the total weight.

[0178]

[0186] Next, the turbostratic graphene-MDI is mixed with a surfactant, catalyst, crosslinker, and blowing agent while stirring at 1,500 rpm for 10 seconds, and then a petroleum-based polyol, a bio-based polyol, or a combination thereof is added while stirring at 1,500 rpm for 10 more seconds. At 20 seconds, the mixed liquid is poured into a steel mold that was preheated to 60-80°C before pouring the mixture. The PUF mixture is held in the mold for 1-5 minutes before demolding. After demolding, the foam can be cured in an oven at 60-80°C for 1-2 hours.

[0179]

[0187] Another example of a PUF composite with turbostratic graphene is through the use of bio-based polyols. Bio-based polyols are typically triglyceride-based products such as castor oil or modified soybean oil, often referred to as natural oil polyols (NOPs). These have found use as partial replacements for petroleum-based polyols in applications such as furniture (stab stock applications), molded foams (typically automotive applications), and rigid foam applications (especially spray foam insulation). NOPs are typically derived by functionalizing unsaturated fatty acids in natural oils to introduce hydroxyl groups. Some examples of NOPS include Emery 14060 and 14090 polyols.

[0180]

[0188] The turbostratic graphene PUF composites and methods provided herein can be used in commercially available foam production kits that provide the components of Part A and Part B. Some examples of such kits include Flex Foam-iT! III by Smooth-On, Flex Foam-iT! 7FR flexible foam, and Foam-iT! 10 Slow rigid foam by Smooth-On.

[0181] Example 3 - PUF produced by polyol masterbatch

[0189] 8, a flow chart illustrating a method 800 for producing polyurethane foam is shown. Method 800 includes dispersing graphene in oil at 805. The method also includes chemically converting the oil into a polyol at 810. The method also includes adding an isocyanate at 815 to convert the polyol into a polyurethane foam.

[0182]

[0190] In one embodiment, graphene is dispersed in vegetable oil before chemically converting the graphene-oil dispersion into a polyol. The resulting polyol is used to produce graphene PUF composites. In some cases, turbostratic graphene can be used as the selected graphene, but the graphene is not limited to turbostratic graphene. In this process, polyurethane foam is produced from an isocyanate and a polyol, and graphene is pre-dispersed in a bio-polyol.

[0183]

[0191] Table 6 shows an example of the composition of a biopolyol prepared from oil with dispersed graphene, according to one embodiment.

[0184] [Table 6]

[0185]

[0192] In the composition of Table 6, turbostratic graphene is dispersed in soybean oil at a concentration of 0.074% by weight of the oil. The dispersion is typically sonicated for 2 to 15 minutes until a uniform, black solution is obtained. This dispersion can also be mixed using a shear mixing device. Next, 58.11 g of diethanolamine and 0.60 g of iodine are added to the above amount of turbostratic graphene-soybean oil dispersion while stirring. The mixture is stirred between about 90°C and about 113°C for 18 hours and then cooled to room temperature to yield about 368.54 grams of a dark liquid TG-soy polyol. This polyol is then reacted with 155.45 g of diphenylmethane diisocyanate (MDI) (where the turbostratic graphene concentration is 0.06% by total weight) to yield a solid turbostratic graphene-soy polyurethane material.

[0186]

[0193] Table 7 shows another embodiment of an oil-graphene dispersion for producing a polyol for conversion to a PUF, according to one embodiment.

[0187] [Table 7]

[0188]

[0194] In the composition of Table 7, turbostratic graphene is dispersed in corn oil at a concentration of 0.074% by weight of the oil. Hydrochloric acid is added to the turbostratic graphene-corn oil dispersion with stirring at room temperature. The mixture is heated to about 93°C and reacted at about 93°C for about 1 hour, followed by removal of water by distillation under reduced pressure at about 93°C. The mixture is added with the above-mentioned amount of diethanolamine and stirred between about 93°C and about 112°C for 40 hours, then cooled to room temperature to yield 368.54 grams of a dark liquid turbostratic graphene-corn oil polyol. This polyol is then reacted with the above-disclosed amount of diphenylmethane diisocyanate (MDI) (where the turbostratic graphene concentration is 0.06% by total weight) to yield a solid TG-corn polyurethane material.

[0189]

[0195] The resulting turbostratic graphene PUF composites can be used in automotive foams and other foam applications, including, but not limited to, bedding, furniture, flooring, and road filling and repair, as well as building construction. Other applications include urethane coatings, adhesives, sealants, epoxies, and elastomers. Other non-urethane applications, such as cement and concrete production and asphalt production, may also be included.

[0190]

[0196] Bio-based polyols may offer advantages over petroleum-based polyols. For example, bio-based polyols can be used as renewable resources instead of non-renewable resources such as petroleum. Petroleum polyols also generally require more energy to produce than bio-based polyols.

[0191]

[0197] While the foregoing description provides examples of one or more devices, methods, or systems, those skilled in the art will recognize that other devices, methods, or systems fall within the scope of the claims.

Claims

1. 1. A method for producing a polyurethane foam, comprising: Dispersing turbostratic graphene produced by resistive Joule heating in a polymerization solution, the polymerization solution comprising a first component for polymerizing to obtain a polymer; adding a second component to polymerize with the first component to chemically convert the polymerization solution to a polyurethane foam; A method comprising:

2. The method of claim 1 , wherein the first component is a monomer or a polymer.

3. The method of claim 1 , wherein the second component is a monomer or a polymer.

4. The method of claim 1 , wherein the first component is a polyol and the second component is an isocyanate.

5. The method of claim 4 , wherein the polyol is at least one of the group comprising petroleum-based polyols and bio-derived polyols.

6. 10. The method of claim 1, further comprising dispersing the turbostratic graphene in a solvent prior to dispersing in the polymerization solution.

7. 7. The method of claim 6, further comprising heating the solvent while dispersing the turbostratic graphene in the solvent.

8. The method of claim 6 , wherein the solvent comprises at least one of the group comprising aqueous solvents and organic solvents.

9. The method of claim 8, wherein the aqueous solvent is a water-surfactant solution.

10. 10. The method of claim 1, further comprising heating the polymerization solution while dispersing the turbostratic graphene.

11. 1. A method for producing a polyurethane foam, comprising: providing turbostratic graphene produced by resistive Joule heating; adding a polymer formed from the polymerization of a polyol and an isocyanate; A method for producing a polyurethane foam, comprising:

12. 12. The method of claim 11, wherein the turbostratic graphene has a grain size between 5 nm and 2000 nm.

13. 12. The method of claim 11, wherein the turbostratic graphene has an oxygen content between 0.1% and 5% atomically.

14. The method of claim 11 , wherein the turbostratic graphene is produced from carbon powder.

15. 12. The method of claim 11, wherein the turbostratic graphene is produced from heating a carbon feedstock to a temperature between 2800°C and 3000°C.

16. 12. Use of the polyurethane foam of claim 11 in automobile seating, bedding, furniture, flooring, road materials, or building construction.

17. 12. Use of the polyurethane foam of claim 11 as a urethane coating, adhesive, sealant, or elastomer.

18. providing turbostratic graphene produced by resistive Joule heating; adding the turbostratic graphene to a solvent for dispersing it in a solution containing a turbostratic graphene dispersion and a first component for polymerizing to obtain a polymer; Including, Polymerizing the first component into a polymer is accomplished by adding a second component to the solution to chemically convert the solution into a polyurethane foam. A method for producing turbostratic graphene dispersions for producing polyurethane foams.

19. 19. The method of claim 18, wherein the solvent for dispersing the turbostratic graphene is a polyol solution for conversion to polyurethane foam or an isocyanate solution for conversion to polyurethane foam.

20. 20. The method of claim 18, wherein the solvent for dispersing the turbostratic graphene is at least one of the group comprising an aqueous solvent and an organic solvent.

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