WO2019185207A1 - Hydrophobic organic aerogels based on epoxy-isocyanate polymer network - Google Patents

Hydrophobic organic aerogels based on epoxy-isocyanate polymer network Download PDF

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Publication number
WO2019185207A1
WO2019185207A1 PCT/EP2019/050540 EP2019050540W WO2019185207A1 WO 2019185207 A1 WO2019185207 A1 WO 2019185207A1 EP 2019050540 W EP2019050540 W EP 2019050540W WO 2019185207 A1 WO2019185207 A1 WO 2019185207A1
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Prior art keywords
group
hydrophobic organic
gel
organic aerogel
methyl
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PCT/EP2019/050540
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French (fr)
Inventor
Belen DEL SAZ-OROZCO RODRIGUEZ
Ilaria DE SANTO
Asta SAKALYTE
Elisabet TORRES CANO
Fouad Salhi
Original Assignee
Henkel Ag & Co. Kgaa
Henkel IP & Holding GmbH
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Application filed by Henkel Ag & Co. Kgaa, Henkel IP & Holding GmbH filed Critical Henkel Ag & Co. Kgaa
Priority to CN201980022179.1A priority Critical patent/CN111902472A/en
Publication of WO2019185207A1 publication Critical patent/WO2019185207A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/003—Polymeric products of isocyanates or isothiocyanates with epoxy compounds having no active hydrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/08—Processes
    • C08G18/16—Catalysts
    • C08G18/18—Catalysts containing secondary or tertiary amines or salts thereof
    • C08G18/20—Heterocyclic amines; Salts thereof
    • C08G18/2081—Heterocyclic amines; Salts thereof containing at least two non-condensed heterocyclic rings
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
    • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
    • C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
    • C08G18/7664—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups
    • C08G18/7671—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing alkylene polyphenyl groups containing only one alkylene bisphenyl group
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/74—Polyisocyanates or polyisothiocyanates cyclic
    • C08G18/76—Polyisocyanates or polyisothiocyanates cyclic aromatic
    • C08G18/7657—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings
    • C08G18/7692—Polyisocyanates or polyisothiocyanates cyclic aromatic containing two or more aromatic rings containing at least one isocyanate or isothiocyanate group linked to an aromatic ring by means of an aliphatic group
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
    • C08G18/78—Nitrogen
    • C08G18/7806—Nitrogen containing -N-C=0 groups
    • C08G18/7818—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative groups
    • C08G18/7831—Nitrogen containing -N-C=0 groups containing ureum or ureum derivative groups containing biuret groups
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
    • C08G18/78—Nitrogen
    • C08G18/7875—Nitrogen containing heterocyclic rings having at least one nitrogen atom in the ring
    • C08G18/7887—Nitrogen containing heterocyclic rings having at least one nitrogen atom in the ring having two nitrogen atoms in the ring
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
    • C08G18/70—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the isocyanates or isothiocyanates used
    • C08G18/72—Polyisocyanates or polyisothiocyanates
    • C08G18/77—Polyisocyanates or polyisothiocyanates having heteroatoms in addition to the isocyanate or isothiocyanate nitrogen and oxygen or sulfur
    • C08G18/78—Nitrogen
    • C08G18/79—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates
    • C08G18/791—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates containing isocyanurate groups
    • C08G18/792—Nitrogen characterised by the polyisocyanates used, these having groups formed by oligomerisation of isocyanates or isothiocyanates containing isocyanurate groups formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2110/00—Foam properties
    • C08G2110/0091—Aerogels; Xerogels
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G2350/00—Acoustic or vibration damping material
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2201/00—Foams characterised by the foaming process
    • C08J2201/04—Foams characterised by the foaming process characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation
    • C08J2201/05—Elimination by evaporation or heat degradation of a liquid phase
    • C08J2201/0502—Elimination by evaporation or heat degradation of a liquid phase the liquid phase being organic
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/02—Foams characterised by their properties the finished foam itself being a gel or a gel being temporarily formed when processing the foamable composition
    • C08J2205/024—Organogel, i.e. a gel containing an organic composition
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/02—Foams characterised by their properties the finished foam itself being a gel or a gel being temporarily formed when processing the foamable composition
    • C08J2205/026—Aerogel, i.e. a supercritically dried gel
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/02—Foams characterised by their properties the finished foam itself being a gel or a gel being temporarily formed when processing the foamable composition
    • C08J2205/028—Xerogel, i.e. an air dried gel
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/04—Foams characterised by their properties characterised by the foam pores
    • C08J2205/042—Nanopores, i.e. the average diameter being smaller than 0,1 micrometer
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2363/00—Characterised by the use of epoxy resins; Derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2375/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers

Definitions

  • the present invention relates to hydrophobic organic aerogel obtained by reacting an isocyanate compound and an epoxy compound in a presence of a solvent.
  • the aerogels according to the present invention are hydrophobic high-performance materials (lightweight, with low thermal conductivity, low shrinkage, and high mechanical properties).
  • Aerogels are three-dimensional, low-density assemblies of nanoparticles derived from drying wet- gels by exchanging the pore-filling solvent to a gas, usually with a supercritical fluid. By these means, the capillary forces exerted by the solvent due to evaporation are minimized, and structures with large internal void space are achieved. The high porosity and small pore size of these materials is reason for their very low thermal conductivity, which makes aerogels extremely attractive materials for thermal insulating applications.
  • aerogels are lightweight materials with a very low thermal conductivity. Therefore, aerogels are known for being good insulating materials due to their nanostructure. Thus, thickness of the insulating layer can be reduced while obtaining similar insulating properties. Aerogels are environmentally friendly because they are air filled, and furthermore, they are not subject to ageing.
  • Thermal insulation is important in many different applications in order to save energy and reduce costs. Examples of such applications are construction, transport and industry. For some applications, it is possible to use a thick insulating panel to reduce the heat transfer. However, other applications may require thinner insulating panels/layers because of size limitations. For the thin insulating panels/layers the thermal conductivity of the material has to be extremely low in order to get the same insulating properties than with thicker insulating panels/layers. Additionally, in some cases and depending on the application, high mechanical properties may also be required.
  • aerogels are inorganic aerogels, mainly based on silica, although different organic aerogels have also been described in the literature.
  • Inorganic silica aerogels provide high thermal insulating properties; however, they are fragile and have poor mechanical properties. These low mechanical properties are generally attributed to the well-defined narrow interparticle necks.
  • the fragility of silica could be solved by different methods, by crosslinking aerogels with organic polymers or by post-gelation casting of a thin conformal polymer coating over the entire internal porous surface of the preformed wet-gel nanostructure.
  • Inorganic silica aerogels represent the most traditional type and offer the best thermal insulating performance. However, these materials are brittle, dusty and easy air-borne, and therefore, cannot withstand mechanical stress. Because of that, sometimes they are classified as hazardous materials. In addition, due to their brittleness, they are not suitable for some applications where mechanical properties are required.
  • organic aerogels described in the literature were based on phenol-formaldehyde resins.
  • organic aerogels are not fragile materials. They are based on polymeric networks of different nature, formed by the cross-linking of monomers in solution to yield a gel that is subsequently dried to obtain a porous material.
  • Considerable number of organic aerogels are based on materials prepared using multifunctional isocyanates.
  • Various isocyanate monomers can be used to prepare polyimide aerogels (by reaction with anhydrides), polyamide aerogels (by reaction with carboxylic acids), polyurethane aerogels (by reaction with hydroxylated compounds), polycarbodiimide aerogels or polyurea aerogels (by reaction with aminated compounds or with water as catalyst).
  • Polyurethane aerogels can be obtained by reacting of cyclic ether based resins with polyisocyanates and subsequently dried by supercritical drying. These aerogels show low thermal conductivity and good mechanical properties. However, these materials are not usually hydrophobic. Both inorganic and organic aerogels are generally hydrophilic. To improve hydrophobicity of an aerogel, the surface of the aerogel can be hydrophobized by using a modification solution wherein surface groups can be replaced by hydrophobic groups, typically, trimethylsilyl (TMS). The TMS groups are most often introduced through trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDZ), or hexamethyldisiloxane (HMDSO) hydrophobization agents.
  • TMS trimethylchlorosilane
  • HMDZ hexamethyldisilazane
  • HMDSO hexamethyldisiloxane
  • An alternative, and more direct route to obtain open-porous, hydrophobic materials is to use precursors that contain chemically bound hydrophobic groups, for example, methyltri(m)ethoxysilane (MTMS/MTES) or dimethyldimethoxysilane (DMDMS).
  • MTMS/MTES methyltri(m)ethoxysilane
  • DDMS dimethyldimethoxysilane
  • crosslinking is another method used to improve water resistance of an aerogel by the substitution of hydrophilic groups and the formation of three- dimensional network.
  • cross-linker increases the production cost.
  • Surface coating by formation of rigid and hydrophobic layers on the surfaces of aerogels can also be used to improve both the compressive strength and water resistance of aerogels.
  • all these approaches are disadvantageous because of an additional step in the material preparation process after the gel formation.
  • Figure 1 illustrates the improved hydrophobicity of the aerogels according to the present invention.
  • Figure 2 illustrates the contact angle (Q) measurement.
  • the present invention relates to a hydrophobic organic aerogel obtained by reacting an isocyanate compound having a functionality from 2 to 6 and an epoxy compound having a functionality from 2 to 6 in a presence of a solvent, wherein said isocyanate compound is selected from the group consisting of
  • a is an integer from 1 to 30;
  • b is an integer from 1 to 30;
  • c is an integer from 1 to 30;
  • X represents a substituent, or different substituents and are selected independently from the group consisting of hydrogen, halogen and linear or branched C1 -C6 alkyl groups, attached on their respective phenyl ring at the 2-position, 3-position or 4-position, and their respective isomers
  • R 1 is selected from the group consisting of a single bonded -0-, -S-, -C(O)-, -S(O)2-, -S(P03)-, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted C7-C30 alkylaryl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group and a substituted or unsubstituted C1-C30 heteroalkyl group from and
  • R 2 is selected independently from the group consisting of alkyl, hydrogen and alkenyl
  • Y is selected from the group consisting of and d is an integer from 0 to 3; and mixtures thereof;
  • epoxy compound is selected from the group consisting of
  • e 1 , e 2 , e 3 are same or different and independently selected from 1 to 12; f , f 2 , f 3 are same or different and independently selected from 1 to 12; g 1 , g 2 , g 3 are same or different and independently selected from 1 to 26; h 1 , h 2 , h 3 are same or different and independently selected from 0 to 6, provided that h 1 +h 2 +h 3 is at least 2; i 1 , i 2 , i 3 are same or different and independently selected from 0 to 25; j 1 , j 2 , j 3 are same or different and independently selected from 1 to 26; k 1 , k 2 , k 3 are same or different and independently selected from 0 to 6, provided that k 1 +k 2 +k 3 is at least 2; and I 1 , I 2 , I 3 are same or different and independently selected from 0 to 25;
  • R 3 represents a substituent or different substituent and is selected independently from the group consisting of hydrogen, halogen and linear or branched C1-C15 alkyl or alkenyl groups, attached to their respective phenyl ring at the 3-, 4- or 5-position and their respective isomers and m is an integer from 1 to 5; wherein n and o are same or different and independently selected from 1 to 10;
  • p is an integer from 1 to 5;
  • the present invention also relates to a method for preparing a hydrophobic organic aerogel according to the present invention comprising the steps of: 1 ) dissolving an epoxy compound into a solvent and adding an isocyanate compound and mixing; 2) adding a catalyst if present, and mixing; 3) letting the mixture to stand in order to form a gel; 4) washing said gel with a solvent; and 5) drying said gel by supercritical or ambient drying.
  • the present invention encompasses a thermal insulating material or an acoustic material comprising a hydrophobic organic aerogel according to the present invention.
  • the present invention also encompasses use of a hydrophobic organic aerogel according to the present invention as a thermal insulating material or acoustic material.
  • aerogel is meant herein a synthetic porous, low-density material derived from a gel, in which a gas has replaced the liquid component of the gel. Due to their porosity and density, these materials generally present low thermal conductivity.
  • gel is meant herein is a solid, jelly-like soft material, having a substantially dilute cross- linked system, which exhibits no flow when in the steady state.
  • the present invention relates to a hydrophobic organic aerogel obtained by reacting an isocyanate compound and an epoxy compound.
  • the reaction of isocyanate with epoxy groups allows preparing a polymeric network with a high cross-linking degree because of the polymerization mechanism of epoxy resins.
  • the high cross-linking degree results in lower pore size and better mechanical properties compared to the material having a lower cross-linking degree. Given the reactivity of these functional groups, the resulting aerogels may have different connectivity.
  • the resulting nanoporous network may include polyurethane (b), polyisocyanurate (c) and polyoxazolidone (d), as well as polyurea (a) in a lesser extent.
  • Hydrophobic organic aerogels according to the present invention have high cross-linking degree, lower pore size and better mechanical properties than less cross-linked aerogels.
  • the present invention relates to a hydrophobic organic aerogel obtained by reacting an isocyanate compound having a functionality from 2 to 6 and an epoxy compound having a functionality from 2 to 6 in a presence of a solvent.
  • a hydrophobic organic aerogel according to the present invention has improved hydrophobicity and good water resistance properties. Furthermore, the hydrophobic organic aerogels according to the present invention are lightweight with low thermal conductivity, they have low shrinkage, and good mechanical properties.
  • a hydrophobic organic aerogel is obtained by reacting an isocyanate compound and an epoxy compound.
  • Suitable isocyanate compound for use in the present invention is an aliphatic or aromatic isocyanate, selected from the group consisting of
  • a is an integer from 1 to 30;
  • b is an integer from 1 to 30;
  • c is an integer from 1 to 30;
  • X represents a substituent, or different substituents and are selected independently from the group consisting of hydrogen, halogen and linear or branched C1 -C6 alkyl groups, attached on their respective phenyl ring at the 2-position, 3-position or 4-position, and their respective isomers
  • R 1 is selected from the group consisting of a single bonded -0-, -S-, -C(O)-, -S(O)2-, -S(P03)-, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted C7-C30 alkylaryl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group and a substituted or unsubstituted C1-C30 heteroalkyl group from and
  • R 2 is selected independently from the group consisting of alkyl, hydrogen and alkenyl
  • Y is selected from the group consisting of and d is an integer from 0 to 3;
  • said isocyanate compound is selected from the group consisting of 3,5-bis(6- isocyanatohexyl)-6-(6-isocyanatohexylimino)-1 ,3,5-oxadiazinane-2,4-dione, 1 ,3-bis[p-( ⁇ p-[3,5-bis(3- isocyanatotolyl)-2,4,6-trioxo-1 ,3,5-triazinan-1-yl]phenyl ⁇ methyl)phenyl]-5-(3-isocyanatotolyl)-1 ,3,5- triazinane-2,4,6-trione, 4,4’-diphenylmethane diisocyanate, 1 ,3,5-tris(6-isocyanatohexyl)-1 ,3,5- triazinane-2,4,6-trione, 1 ,3-bis(6-isocyanatohexyl)-1-(6-isocyanatohexyl
  • Examples of commercially available isocyanate compound for use in the present invention are but not limited to Desmodur N3300, Desmodur N3400, Desmodur N3600, Desmodur N3900, Desmodur N3200, Desmodur 44V, Desmodur RE, Desmodur IL from Covestro; Wannate HT 100 from Wanhua; Diphenylmethane 4,4'-diisocyanate (MDI) from Merck; and VORASTAR HB 6042 from the Dow Chemical Company.
  • a hydrophobic organic aerogel according to the present invention has an isocyanate compound content from 0.2 to 56 % by weight of the total weight of the reaction mixture (including solvent) preferably from 0.3 to 45% and more preferably from 0.5 to 35%.
  • the content of the isocyanate compound is more than 56%, aerogels with high density and high thermal conductivity will be obtained. These are not desired properties for the aerogels according to the present invention.
  • Suitable epoxy compound for use in the present invention is a long chain aliphatic epoxy compound or an aromatic epoxy compound.
  • Suitable epoxy compound for use in the present invention is selected from the group consisting of
  • e 1 , e 2 , e 3 are same or different and independently selected from 1 to 12; f , f 2 , f 3 are same or different and independently selected from 1 to 12; g 1 , g 2 , g 3 are same or different and independently selected from 1 to 26; h 1 , h 2 , h 3 are same or different and independently selected from 0 to 6, provided that h 1 +h 2 +h 3 is at least 2; i 1 , i 2 , i 3 are same or different and independently selected from 0 to 25; j 1 , j 2 , j 3 are same or different and independently selected from 1 to 26; k 1 , k 2 , k 3 are same or different and independently selected from 0 to 6, provided that k 1 +k 2 +k 3 is at least 2; and I 1 , I 2 , I 3 are same or different and independently selected from 0 to 25;
  • R 3 represents a substituent or different substituent and is selected independently from the group consisting of hydrogen, halogen and linear or branched C1-C15 alkyl or alkenyl groups, attached to their respective phenyl ring at the 3-, 4- or 5-position and their respective isomers and m is an integer from 1 to 5; wherein n and o are same or different and independently selected from 1 to 10;
  • p is an integer from 1 to 5;
  • said epoxy compound is selected from the group consisting of 2-[(3- ⁇ [2-hydroxy-3-( ⁇ 2-[(2- oxiranyl)methoxy]-4-pentadecylphenyl ⁇ methyl)-4-pentadecylphenyl]methyl ⁇ -2-[(2-oxiranyl)methoxy]- 4-pentadecylphenyl)methyl]-6-( ⁇ 2-[(2-oxiranyl)methoxy]-6-pentadecylphenyl ⁇ methyl)-3- pentadecylphenol, 2,3-bis ⁇ (E)-1 1-[(2-oxiranyl)methoxy]-8-heptadecenylcarbonyloxy ⁇ propyl (E)-12- [(2-oxiranyl)methoxy]-9-octadecenoate, 2- ⁇ [m-(8- ⁇ p-[(2- oxiranyl)methoxy]phenyl ⁇ pentadecyl)phenoxy]methyl ⁇ oxi
  • Examples of commercially available epoxy compound for use in the present invention are but not limited to Cardolite NC-547, Cardolite NC-514S and Cardolite NC-514 from Cardolite, Erisys GE35 from CVC thermosets, CER 4221 from DKSH, Vikoflex 7170 and Vikoflex 7190 from Arkema, Epiclon HP-5000, Epiclon HP-7200H and Epiclon HP-9500 from DIC Corporation, Jagroxy-505 from Jayant Agro-Organics Ltd., and KR-470, X-12-981 S, KR-517, KR-516, X-41-1059A and X-24-9590 from Shin Etsu.
  • a hydrophobic organic aerogel according to the present invention has an epoxy compound content from 0.7 to 60% by weight of the total weight of the reaction mixture (including solvent), preferably from 1 to 40% and more preferably from 1.5 to 20%.
  • a ratio of epoxy groups to isocyanate groups is 1 : 15 - 5: 1 , preferably 1 :8 - 3:1 and more preferably 1 :6 - 2:1.
  • a hydrophobic organic aerogel is obtained by reacting an isocyanate compound and an epoxy compound in a presence of a solvent.
  • Suitable solvent to be used in the present invention is a polar solvent, preferably polar aprotic solvent.
  • the solvent is selected from the group consisting of N,N-dimethylacetamide (DMAc), 1- methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), acetonitrile, acetone, methyl ethyl ketone (MEK), 4-methyl-2-pentanone (MIBK) and mixtures thereof.
  • DMAc N,N-dimethylacetamide
  • NMP 1- methyl-2-pyrrolidinone
  • DMSO dimethyl sulfoxide
  • MEK methyl ethyl ketone
  • MIBK 4-methyl-2-pentanone
  • solvents for use in the present invention are but not limited to N,N-dimethylacetamide, 1-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO) and acetonitrile from Merck Millipore, 4-methyl-2-pentanone (MIBK), methyl ethyl ketone (MEK) from Alfa Aesar and acetone from VWR Chemicals.
  • a hydrophobic organic aerogel may be obtained by reacting an isocyanate compound and an epoxy compound in a presence of a catalyst.
  • Suitable catalyst for the use in the present invention is selected from the group consisting of alkyl amines, aromatic amines, imidazole derivatives, aza compounds, guanidine derivatives and amidines, preferably selected from the group consisting of triethylamine, trimethylamine, N,N- Dimethylbenzylamine, 1 ,4-diazabicyclo[2.2.2]octane, 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), dibutyltin dilaurate and mixtures thereof.
  • Examples of commercially available catalysts for use in the present invention are but not limited to triethylamine, trimethylamine, diazabicyclo[5.4.0]undec-7-ene (DBU), 1 ,5,7-triazabicyclo[4.4.0]dec- 5-ene (TBD), Dabco 33V and dibutyltin dilaurate (DBTDL) from Sigma Aldrich, N,N- dimethylbenzylamine from Merck Millipore, 1 ,4-diazabicyclo[2.2.2]octane from Alfa Aesar.
  • DBU diazabicyclo[5.4.0]undec-7-ene
  • TBD 1,5,7-triazabicyclo[4.4.0]dec- 5-ene
  • Dabco 33V dibutyltin dilaurate
  • DBTDL dibutyltin dilaurate
  • the catalyst is added from 0 to 10% by weight of the total weight of the reaction mixture (including solvent), preferably from 1 to 10% and more preferably from 1 .5 to 10%.
  • a range from 1 .5 to 10% is preferred, because aerogel performances reach a plateau around 10% of a catalyst, and higher catalyst content would not improve any properties above this point.
  • a hydrophobic organic aerogel according to the present invention further comprises at least one reinforcement or filler.
  • Suitable reinforcement or filler for use in the present invention is selected from the group consisting of fibres, particles, fibre fabrics and mats, 3D structures and mixtures thereof.
  • Non-limiting examples of suitable fibres are cellulose, aramid, carbon, glass and lignocellulosic fibres.
  • Non-limiting examples of suitable particles are carbon black, microcrystalline cellulose, silica, cork, lignin, and aerogel particles.
  • Non-limiting examples of suitable fibre fabrics and mats are non-woven and woven glass, aramid, carbon and lignocellulosic fibre fabrics.
  • Non-limiting examples of suitable 3D structures are aramid fibre-phenolic, glass fibre-phenolic, polycarbonate and polypropylene honeycombs and 3D printed structures.
  • At least one reinforcement or filler is selected from the group consisting of cellulose fibres, aramid fibres, carbon fibres, glass fibres, lignocellulosic fibres, glass wool, carbon black, microcrystalline cellulose, silica particles, cork particles, lignin particles, aerogel particles, non- woven and woven glass fibre fabrics, aramid fibre fabrics, carbon fibre fabrics, jute fibre fabrics, flax fibre fabrics, aramid fibre-phenolic honeycomb, glass fibre-phenolic honeycomb, polycarbonate honeycomb, polypropylene honeycomb, and mixtures thereof, more preferably at least one reinforcement or filler is selected from the group consisting of cellulose fibres, aramid fibres, carbon fibres, glass fibres, glass wool, carbon black, microcrystalline cellulose, non-woven glass fibre fabrics, woven aramid fibre fabrics, woven jute fibre fabrics, woven flax fibre fabrics, aramid fibre- phenolic honeycomb, glass fibre-phenolic, cardboard honeycomb, polypropylene honeycomb and mixture
  • Examples of commercially available reinforcements for use in the present invention are but not limited to Acros Organics microcrystalline cellulose, ocellulose Sigma Aldrich powder, MT1 100, IC3120 and P300 silica aerogel particles from Cabot, CSX 691 carbon black from Cabot, Procotex aramid fibre, Procotex CF-MLD100-13010 carbon fibres, E-glass Vetrotex textiles fibres EC9 134 z28 T6M ECG 37 1/0 0.7z, Unfilo ® U809 Advantex ® glass fiber, Composites Evolution Biotex jute plain weave, Composites Evolution Biotex flax 2/2 twill, Easycomposites aramid cloth fabric satin weave, Euro-composites ECG glass fibre-phenolic honeycomb, Euro-composites ECAI aramid fibre- phenolic honeycomb, Easycomposites aramid fibre-phenolic honeycomb, Cel Components Alveolar PP8-80T30 3D structure, Cel Components Alveolar 3.5-90 3
  • the reinforcement or filler percentage in the final material may vary from 0.01 % up to 80% based on the total weight of the initial solvent, preferably from 0.5 to 70%.
  • a hydrophobic organic aerogel according to the present invention has a solid content from 4 to 40%, based on initial solid content of the solution, preferably from 5 to 30%.
  • Solid content in the range from 4 to 40% is ideal, because it provides a good compromise between thermal insulating properties and mechanical properties.
  • High solid content provides high mechanical properties; however, high solid content provides poor thermal insulating properties.
  • low solid content provides lower thermal conductivities, but mechanical properties are not ideal.
  • a hydrophobic organic aerogel according to the present invention has a thermal conductivity less than 60 mW/m-K, preferably less than 55 mW/m-K, more preferably less than 50 mW/rn-K, and even more preferably less than 45 mW/m-K.
  • the thermal conductivity can be measured either by using diffusivity sensor method or steady-state condition system method, method to be used depends on whether the material to be tested is lab scale or larger.
  • the thermal conductivity is measured by using a diffusivity sensor.
  • the heat source and the measuring sensor are on the same side of the device.
  • the sensors measure the heat that diffuses from the sensor throughout the materials. This method is appropriate for lab scale tests.
  • the thermal conductivity is measured by using a steady-state condition system.
  • the sample is sandwiched between a heat source and a heat sink.
  • the temperature is risen on one side, the heat flows through the material and once the temperature on the other side is constant, both heat flux and difference of temperatures are known, and thermal conductivity can be measured.
  • a hydrophobic organic aerogel according to the present invention has a compression Young’s modulus more than 0.1 MPa, preferably more than 15 MPa, and more preferably more than 30 MPa, wherein Compression Young Modulus is measured according to the method ASTM D1621.
  • An organic aerogel according to the present invention has preferably a compressive strength more than 0.01 MPa, more preferably more than 0.45 MPa, and even more preferably more than 1 MPa. Compressive strength is measured according to the standard ASTM D1621.
  • An organic aerogel according to the present invention has preferably a specific surface area ranging from 5 m 2 /g to 400 m 2 /g.
  • Surface area is determined from N2 sorption analysis at -196°C using the Brunauer-Emmett-Teller (BET) method, in a specific surface analyser Quantachrome-6B.
  • BET Brunauer-Emmett-Teller
  • Quantachrome-6B High surface area values are preferred because they are indicative of small pore sizes, and which may be an indication of low thermal conductivity values.
  • BJH Barret-Joyner-Halenda
  • a hydrophobic organic aerogel according to the present invention has low-density structure having a bulk density ranging from 0.01 to 0.8 g/cc. Bulk density is calculated from the weight of the dry aerogel and its volume.
  • a hydrophobic organic aerogel according to the present invention is resistant to low temperatures exposure (-160°C). Additionally, the hydrophobic organic aerogels may resist liquid nitrogen immersion (-196°C) and subsequent evaporation.
  • FIG. 1a illustrates an aerogel described in WO2017016755A1 , wherein bisphenol A-DGE was used as an epoxy compound
  • figures 1 b and 1 c illustrate a hydrophobic aerogel according to the present invention, wherein Erisys GE35 (1 b) and Cardolite NC- 547 (1 c) were used as an epoxy compound.
  • the aerogels according to the present invention repel the water drops, which remains clearly as water droplets on the surface of the aerogel.
  • the aerogel according to the prior art does not repel the water drops as intensely, and some of the water penetrates the surface of the aerogel.
  • a hydrophobic organic aerogel according to the present invention has preferably a water contact angle higher than 90°C. Wettability is quantified by measuring the contact angle (Q) between the tangent to a drop of water, where it meets the surface and the surface itself. The contact angle (Q) measurement is illustrated in figure 2.
  • Figure 2a is a theoretical illustration and figure 2b is illustration of the example according to the present invention.
  • the water contact angle is higher than 90°, the solid surface is considered hydrophobic.
  • Contact angle measurements can be done by using EasyDrop Contact Angle Measuring Instrument (Kmss GmbH) in static mode with a drop of water of 10 pi.
  • hydrophobic organic aerogels For the preparation of hydrophobic organic aerogels according to the present invention, several aspects must be taken into consideration.
  • the equivalent ratio of functionalities, the initial solid content, the amount and type of catalyst (if present), type of solvent, gelation time and temperature are crucial factors that affect the final properties of the material.
  • a hydrophobic organic aerogel according to the present invention may be prepared by using a method comprising the steps of:
  • the reaction mixture is prepared in a closed container.
  • Gelation step (3) is carried out in a closed mould for the pre-set time and temperature.
  • temperature is applied in step 3, more preferably, temperature from room temperature to 160°C is applied while gel is forming, and most preferably, temperature from room temperature to 80°C is applied. Temperatures from room temperature to 160°C are preferred because the best performing aerogels are obtained.
  • Gelation time is preferably from 0.5 to 48 hours, more preferably from 1 to 36 hours and even more preferably from 1 to 24 hours.
  • Washing time in step (4) is preferably from 1 hour to 72 hours, preferably from 18 hours to 72 hours, and more preferably from 24 hours to 48 hours.
  • the solvent of wet gels of step (3) is changed one or more times after the gelation.
  • the washing steps are done gradually, and if required, to the preferred solvent for the drying process.
  • the wet gel remains in the proper solvent, it is dried in supercritical (CO2) or ambient conditions obtaining the final aerogel material.
  • the washing steps are done gradually as follows: 1 ) acetone/DMAc 1 :3; 2) acetone/DMAc 1 : 1 ; 3) acetone/DMAc 3: 1 ; and 4) acetone.
  • washing steps are done with acetone.
  • all four washing steps are done gradually with hexane.
  • the supercritical state of a substance is reached once its liquid and gaseous phases become indistinguishable.
  • the pressure and temperature at which the substance enters this phase is called critical point.
  • the fluid presents the low viscosity of a gas, maintaining the higher density of a liquid. It can effuse through solids like a gas and dissolve materials like a liquid.
  • the solvent can be dried, minimizing shrinkage and possible collapse of the gel network.
  • the drying process at supercritical conditions is performed by exchanging the solvent in the gel with CO2 or other suitable solvents in their supercritical state. Due to this, capillary forces exerted by the solvent during evaporation in the nanometric pores are minimized and shrinkage of the gel body can be reduced.
  • the method for preparing a hydrophobic organic aerogel involves the recycling of the CO2 from the supercritical drying step.
  • wet gels can be dried at ambient conditions, in which the solvent is evaporated at room temperature.
  • the liquid evaporates from the pores, it can create a meniscus that recedes back into the gel due to the difference between interfacial energies. This may create a capillary stress on the gel, which responds by shrinking. If these forces are high enough, they can even lead to the collapse or cracking of the whole structure.
  • One practical solution involves the use of solvents with low surface tension to minimize the interfacial energy between the liquid and the pore.
  • Hexane is usually used as a convenient solvent for ambient drying, as its surface tension is one of the lowest among the conventional solvents.
  • the present invention compasses a thermal insulating material or an acoustic material comprising a hydrophobic organic aerogel according to the present invention.
  • a hydrophobic organic aerogel according to the present invention can be used as a thermal insulating material or acoustic material.
  • a hydrophobic organic aerogel according to the present invention can be used as a thermal insulating material for the storage of cryogens.
  • Hydrophobic organic aerogels according to the present invention may be used in a variety of applications such as building construction, electronics or for the aerospace industry.
  • An hydrophobic organic aerogel could be used as thermal insulating material for refrigerators, freezers, automotive engines and electronic devices.
  • Other potential applications for aerogels is as a sound absorption material and a catalyst support.
  • Hydrophobic organic aerogels according to the present invention can be used for thermal insulation in different applications such as aircrafts, space crafts, pipelines, tankers and maritime ships replacing currently used foam panels and other foam products, in car battery housings and under hood liners, lamps, in cold packaging technology including tanks and boxes, jackets and footwear and tents.
  • Hydrophobic organic aerogels according to the present invention can also be used in construction materials due to their lightweight, strength, ability to be formed into desired shapes and superior thermal insulation properties.
  • Hydrophobic organic aerogels according to the present invention can be also used as thermal insulation for storage and transportation of cryogens.
  • Hydrophobic organic aerogels according to the present invention can be also used as an adsorption agent for oil spill clean-up, due to their high oil absorption rate.
  • Hydrophobic organic aerogels according to the present invention can be also used in safety and protective equipment as a shock-absorbing medium.
  • Density was determined as the mass of aerogel divided by the geometrical volume of aerogel.
  • Linear shrinkage was determined as the difference between the gel and aerogel diameters divided by the gel diameter.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5 wt% and 5wt% of a catalyst.
  • a sample of 30 mL 0.58 g of Cardolite NC-547 was dissolved in 23.1 1 g of MIBK and subsequently 0.64 g of Desmodur N3300 was added. The mixture was stirred manually and 0.06 g of DABCO was added. The solution was left overnight at room temperature.
  • Equivalent ratio isocyanate/epoxy was 4: 1 with a total solid content of 5 wt% and 10wt% of a catalyst.
  • a sample of 30 ml_ 0.46 g of Cardolite NC-514 was dissolved in 23.57 g of MIBK and subsequently 0.84 g of Desmodur N3900 was added. The mixture was stirred manually and 0.124 g of DABCO was added. The solution was left overnight at room temperature.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 2 illustrates measured properties of the obtained aerogel.
  • Equivalent ratio isocyanate/epoxy was 4: 1 with a total solid content of 5 wt% and 10wt% of a catalyst.
  • a sample of 30 ml_ 0.43 g of Cardolite NC-514 was dissolved in 23.1 1 g of MIBK and subsequently 0.78 g of Desmodur N3200 was added. The mixture was stirred manually and 0.122 g of DABCO was added. The solution was left overnight at room temperature.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 3 illustrates measured properties of the obtained aerogel.
  • Equivalent ratio isocyanate/epoxy was 6:1 with a total solid content of 6 wt% and 10 wt% of a catalyst.
  • a sample of 30 ml_ 0.50 g of Erisys GE35 was dissolved in 22.93 g of MIBK and subsequently 0.96 g of Desmodur N3300 was added. The mixture was stirred manually and 0.146 g of DABCO was added. The solution was left overnight at room temperature.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 4 illustrates measured properties of the obtained aerogel.
  • Aerogel obtained using tris(2,3-epoxypropyl)isocyanurate and Desmodur 44V
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 10 wt% and 10wt% of a catalyst.
  • a sample of 30 ml_ 0.38 g of tris(2,3-epoxypropyl)isocyanurate was dissolved in 21.90 g of acetone and subsequently 2.05 g of Desmodur 44V was added. The mixture was stirred manually and 0.243 g of DABCO was added. The solution was left for 6h at room temperature.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 5 illustrates measured properties of the obtained aerogel.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 15 wt% and 10% of a catalyst.
  • a sample of 30 ml_ 2.03 g of Erisys GE35 was dissolved in 21.08 g of MIBK and subsequently 1.69 g of Desmodur 44V was added. The mixture was stirred manually and 0.37g of DABCO was added. The solution was left for 1 h and 30 min in the oven at 80°C.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 6 illustrates measured properties of the obtained aerogel.
  • Aerogel obtained using Erisys GE35 and Desmodur RE in DMAC Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 10 wt% and 10% of a catalyst.
  • First solution was prepared by dissolving 1.57 g of Erisys GE35 in 1 1.07 g of DMAc and subsequently 4.72 g of Desmodur RE was added.
  • the second solution was prepared by dissolving 0.284 g of TBD in 1 1.07g of DMAc. First and second solutions were mixed together and after 5 min the gel was formed.
  • the resulting gel was washed stepwise in a mixture of acetone 1 :3 DMAc, acetone 1 :1 DMAc, acetone 3: 1 DMAc and acetone, during 24 h for each washing cycle, and using three times the volume of the gel in solvent for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 7 illustrates measured properties of the obtained aerogel.
  • Aerogel obtained using Vikoflex 7170 and Desmodur RE in MEK Aerogel obtained using Vikoflex 7170 and Desmodur RE in MEK
  • Equivalent ratio isocyanate/epoxy was 4: 1 with a total solid content of 5 wt% and 10wt% of a catalyst.
  • a sample of 30 ml_ 0.31 g of Vikoflex 7170 was dissolved in 20.93 g of MEK and then 3.40 g of Desmodur RE was added. The mixture was stirred manually and then 0.29 g of DABCO was added. The solution was left at room temperature for 1 h.
  • Equivalent ratio aromatic isocyanate / aliphatic Isocyanate/ epoxy was 1 :3: 1 with a total solid content of 6 wt% and 1 .5wt% of a catalyst.
  • a sample of 30 ml_ 0.44 g of Cardolite NC- 514S was dissolved in 22.70 g of acetone, then 0.69 g of Desmodur N3300 was added and finally 0.62g of Desmodur IL was added. The mixture was stirred manually and then 0.02 g of DABCO was added. The solution was left at room temperature for 3h.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 10 illustrates measured properties of the obtained aerogel.
  • Aerogel obtained using Epiclon HP-7200H and mixture of Desmodur RE and Desmodur N3300 reinforced with glass wool and glass fiber chopped strand mats ( ⁇ 30w% based on weight of aerogel).
  • Equivalent ratio aromatic isocyanate / aliphatic Isocyanate/ epoxy was 1 :3: 1 with a total solid content of 6wt% and 10wt% of a catalyst.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5wt% and 10wt% of a catalyst.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 12 illustrates measured properties of the obtained aerogel.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 15wt% and 10wt% of a catalyst.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 13 illustrates measured properties of the obtained aerogel.
  • Aerogel obtained using Erisys GE35 and Desmodur 44V reinforced with glass wool and glass fiber chopped strand mats ( ⁇ 30w% based on weight of aerogel).
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5wt% and 10% of a catalyst.
  • a sample of 30 ml_ 0.64 g of Erisys GE35 was dissolved in 23.09g of MIBK and then 0.57 g of Desmodur 44V was added. The mixture was stirred manually and then 0.12g of DABCO was added. Then, the glass fiber chopped strand mats (0.23g) and the glass wool (0.15g) were incorporated. The solution was left for 1 h and 30 min in the oven at 80°C.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5wt% and 10% of a catalyst.
  • a sample of 30 ml_ 0.64 g of Erisys GE35 was dissolved in 23.09g of MIBK and then 0.57 g of Desmodur 44V was added. The mixture was stirred manually and then 0.12g of DABCO was added. Then, the honeycomb (cell size of 3.2mm and density of 48kg/m 3 ) was incorporated, and the solution was left for 1 h and 30 min in the oven at 80°C.
  • the resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD).
  • SCD CO2 supercritical drying
  • Aerogel obtained using KR-516 and Desmodur N3300.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 6wt% and 10wt% of a catalyst.
  • a sample of 30 ml_ 0.16 g of KR-516 was dissolved in 5.9 g of DMAc mixed with 17.71 g of Acetone of solvent, and then 1.34 g of Desmodur N3300 was added. The mixture was stirred manually and then 0.15g of DABCO was added. The solution was left for gelation at room temperature.
  • the resulting gel was washed three times with acetone every 24h and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 16 illustrates measured properties of the obtained aerogel.
  • Aerogel obtained using X-12-981 S and Desmodur N3300.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 6wt% and 10wt% of a catalyst.
  • X-12-981 S was dissolved in 5.9 g of DMAc mixed with 17.71 g of Acetone of solvent, and then 1.38 g of Desmodur N3300 was added. The mixture was stirred manually and then 0.15g of DABCO was added. The solution was left for gelation at room temperature.
  • Aerogel obtained using KR-470 and Desmodur N3300.
  • Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 8wt% and 20wt% of a catalyst.
  • KR-470 was dissolved in 1 1.98 g of DMAc mixed with 1 1.98 g of Acetone of solvent, and then 2.0 g of Desmodur N3300 was added. The mixture was stirred manually and then 0.42 g of DMBA was added. The solution was left for gelation at room temperature.
  • the resulting gel was washed three times with acetone every 24h and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 18 illustrates measured properties of the obtained aerogel.
  • the samples were prepared under the same conditions but using different resins.
  • the epoxies used were Erisys GE35 (hydrophobic), Epiclon 7200 (hydrophobic), 1 ,6 hexanediol diglycidyl ether (hydrophilic), Polyethylene glycol diglycidyl ether (hydrophilic).
  • the isocyanate used was Desmodur RE, equivalent ratio isocyanate/epoxy was 4:1 , solid content 10wt% and 10phr of DABCO as catalyst.
  • the amount of the different components is summarized in Table 19. The monomers were dissolved in MIBK and then the catalyst was added. The resulting solution was left in the oven at 80°C for 1 h.
  • the obtained gel was washed three times with acetone every 24h, using an amount of solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD).
  • SCD CO2 supercritical drying

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Abstract

The present invention relates to hydrophobic organic aerogels obtained by reacting an isocyanate compound and an epoxy compound in the presence of a solvent. The aerogels according to the present invention are hydrophobic high-performance materials (lightweight, with low thermal conductivity, low shrinkage, and high mechanical properties).

Description

“Hydrophobic organic aerogels based on epoxy-isocyanate polymer network"
Technical filed of the invention
The present invention relates to hydrophobic organic aerogel obtained by reacting an isocyanate compound and an epoxy compound in a presence of a solvent. The aerogels according to the present invention are hydrophobic high-performance materials (lightweight, with low thermal conductivity, low shrinkage, and high mechanical properties).
Technical background of the invention
Aerogels are three-dimensional, low-density assemblies of nanoparticles derived from drying wet- gels by exchanging the pore-filling solvent to a gas, usually with a supercritical fluid. By these means, the capillary forces exerted by the solvent due to evaporation are minimized, and structures with large internal void space are achieved. The high porosity and small pore size of these materials is reason for their very low thermal conductivity, which makes aerogels extremely attractive materials for thermal insulating applications.
Compared to common thermal insulators in the market, aerogels are lightweight materials with a very low thermal conductivity. Therefore, aerogels are known for being good insulating materials due to their nanostructure. Thus, thickness of the insulating layer can be reduced while obtaining similar insulating properties. Aerogels are environmentally friendly because they are air filled, and furthermore, they are not subject to ageing.
Thermal insulation is important in many different applications in order to save energy and reduce costs. Examples of such applications are construction, transport and industry. For some applications, it is possible to use a thick insulating panel to reduce the heat transfer. However, other applications may require thinner insulating panels/layers because of size limitations. For the thin insulating panels/layers the thermal conductivity of the material has to be extremely low in order to get the same insulating properties than with thicker insulating panels/layers. Additionally, in some cases and depending on the application, high mechanical properties may also be required.
Most known aerogels are inorganic aerogels, mainly based on silica, although different organic aerogels have also been described in the literature.
Inorganic silica aerogels provide high thermal insulating properties; however, they are fragile and have poor mechanical properties. These low mechanical properties are generally attributed to the well-defined narrow interparticle necks. The fragility of silica could be solved by different methods, by crosslinking aerogels with organic polymers or by post-gelation casting of a thin conformal polymer coating over the entire internal porous surface of the preformed wet-gel nanostructure.
Inorganic silica aerogels, represent the most traditional type and offer the best thermal insulating performance. However, these materials are brittle, dusty and easy air-borne, and therefore, cannot withstand mechanical stress. Because of that, sometimes they are classified as hazardous materials. In addition, due to their brittleness, they are not suitable for some applications where mechanical properties are required.
First organic aerogels described in the literature were based on phenol-formaldehyde resins. Generally, organic aerogels are not fragile materials. They are based on polymeric networks of different nature, formed by the cross-linking of monomers in solution to yield a gel that is subsequently dried to obtain a porous material. Considerable number of organic aerogels are based on materials prepared using multifunctional isocyanates. Various isocyanate monomers can be used to prepare polyimide aerogels (by reaction with anhydrides), polyamide aerogels (by reaction with carboxylic acids), polyurethane aerogels (by reaction with hydroxylated compounds), polycarbodiimide aerogels or polyurea aerogels (by reaction with aminated compounds or with water as catalyst).
Polyurethane aerogels can be obtained by reacting of cyclic ether based resins with polyisocyanates and subsequently dried by supercritical drying. These aerogels show low thermal conductivity and good mechanical properties. However, these materials are not usually hydrophobic. Both inorganic and organic aerogels are generally hydrophilic. To improve hydrophobicity of an aerogel, the surface of the aerogel can be hydrophobized by using a modification solution wherein surface groups can be replaced by hydrophobic groups, typically, trimethylsilyl (TMS). The TMS groups are most often introduced through trimethylchlorosilane (TMCS), hexamethyldisilazane (HMDZ), or hexamethyldisiloxane (HMDSO) hydrophobization agents. An alternative, and more direct route to obtain open-porous, hydrophobic materials is to use precursors that contain chemically bound hydrophobic groups, for example, methyltri(m)ethoxysilane (MTMS/MTES) or dimethyldimethoxysilane (DMDMS). Furthermore, crosslinking is another method used to improve water resistance of an aerogel by the substitution of hydrophilic groups and the formation of three- dimensional network. However, the addition of cross-linker increases the production cost. Surface coating by formation of rigid and hydrophobic layers on the surfaces of aerogels can also be used to improve both the compressive strength and water resistance of aerogels. However, all these approaches are disadvantageous because of an additional step in the material preparation process after the gel formation.
Therefore, there is still a need for organic aerogels that are hydrophobic and have a good stability to moisture, while maintaining good mechanical properties and thermal conductivity.
Short description of the figures
Figure 1 illustrates the improved hydrophobicity of the aerogels according to the present invention. Figure 2 illustrates the contact angle (Q) measurement.
Summary of the invention
The present invention relates to a hydrophobic organic aerogel obtained by reacting an isocyanate compound having a functionality from 2 to 6 and an epoxy compound having a functionality from 2 to 6 in a presence of a solvent, wherein said isocyanate compound is selected from the group consisting of
Figure imgf000003_0001
wherein a is an integer from 1 to 30;
Figure imgf000003_0002
wherein b is an integer from 1 to 30;
Figure imgf000003_0003
wherein c is an integer from 1 to 30;
Figure imgf000004_0001
wherein X represents a substituent, or different substituents and are selected independently from the group consisting of hydrogen, halogen and linear or branched C1 -C6 alkyl groups, attached on their respective phenyl ring at the 2-position, 3-position or 4-position, and their respective isomers, and R1 is selected from the group consisting of a single bonded -0-, -S-, -C(O)-, -S(O)2-, -S(P03)-, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted C7-C30 alkylaryl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group and a substituted or unsubstituted C1-C30 heteroalkyl group from and a combination of thereof;
Figure imgf000004_0002
wherein R2 is selected independently from the group consisting of alkyl, hydrogen and alkenyl, and
Y is selected from the group consisting of
Figure imgf000004_0003
and d is an integer from 0 to 3; and mixtures thereof;
and wherein said epoxy compound is selected from the group consisting of
Figure imgf000005_0001
wherein e1 , e2, e3 are same or different and independently selected from 1 to 12; f , f2, f3 are same or different and independently selected from 1 to 12; g1 , g2, g3 are same or different and independently selected from 1 to 26; h1 , h2, h3 are same or different and independently selected from 0 to 6, provided that h1+h2+h3 is at least 2; i1 , i2, i3 are same or different and independently selected from 0 to 25; j1 , j2, j3 are same or different and independently selected from 1 to 26; k1 , k2, k3 are same or different and independently selected from 0 to 6, provided that k1+k2+k3 is at least 2; and I1 , I2, I3 are same or different and independently selected from 0 to 25;
Figure imgf000005_0002
wherein R3 represents a substituent or different substituent and is selected independently from the group consisting of hydrogen, halogen and linear or branched C1-C15 alkyl or alkenyl groups, attached to their respective phenyl ring at the 3-, 4- or 5-position and their respective isomers and m is an integer from 1 to 5; wherein n and o are same or different and independently selected from 1 to 10;
Figure imgf000006_0001
wherein p is an integer from 1 to 5;
Figure imgf000006_0002
and mixtures thereof.
The present invention also relates to a method for preparing a hydrophobic organic aerogel according to the present invention comprising the steps of: 1 ) dissolving an epoxy compound into a solvent and adding an isocyanate compound and mixing; 2) adding a catalyst if present, and mixing; 3) letting the mixture to stand in order to form a gel; 4) washing said gel with a solvent; and 5) drying said gel by supercritical or ambient drying.
The present invention encompasses a thermal insulating material or an acoustic material comprising a hydrophobic organic aerogel according to the present invention.
The present invention also encompasses use of a hydrophobic organic aerogel according to the present invention as a thermal insulating material or acoustic material.
Detailed description of the invention
In the following passages the present invention is described in more detail. Each aspect so described may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.
In the context of the present invention, the terms used are to be construed in accordance with the following definitions, unless a context dictates otherwise.
As used herein, the singular forms“a”,“an” and“the” include both singular and plural referents unless the context clearly dictates otherwise. The terms “comprising”, “comprises” and “comprised of” as used herein are synonymous with “including”,“includes” or“containing”,“contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps.
The recitation of numerical end points includes all numbers and fractions subsumed within the respective ranges, as well as the recited end points.
All percentages, parts, proportions and then like mentioned herein are based on weight unless otherwise indicated.
When an amount, a concentration or other values or parameters is/are expressed in form of a range, a preferable range, or a preferable upper limit value and a preferable lower limit value, it should be understood as that any ranges obtained by combining any upper limit or preferable value with any lower limit or preferable value are specifically disclosed, without considering whether the obtained ranges are clearly mentioned in the context.
All references cited in the present specification are hereby incorporated by reference in their entirety.
Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of the ordinary skill in the art to which this invention belongs to. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.
By the term‘aerogel’ is meant herein a synthetic porous, low-density material derived from a gel, in which a gas has replaced the liquid component of the gel. Due to their porosity and density, these materials generally present low thermal conductivity.
By the term‘gel’ is meant herein is a solid, jelly-like soft material, having a substantially dilute cross- linked system, which exhibits no flow when in the steady state.
The present invention relates to a hydrophobic organic aerogel obtained by reacting an isocyanate compound and an epoxy compound. The reaction of isocyanate with epoxy groups, allows preparing a polymeric network with a high cross-linking degree because of the polymerization mechanism of epoxy resins. The high cross-linking degree results in lower pore size and better mechanical properties compared to the material having a lower cross-linking degree. Given the reactivity of these functional groups, the resulting aerogels may have different connectivity.
Main reactions, which could occur between isocyanate and epoxides are illustrated in scheme 1 , as representative examples. Urea (a) is formed in reaction between isocyanate and water. Urethane (b) is obtained in reaction between isocyanate and alkoxide after epoxide ring opening. Trimerization of isocyanate leads to formation of isocyanurate (c). Oxazolidone (d) is obtained from the reaction between isocyanate and epoxy at high temperatures.
Figure imgf000007_0001
Figure imgf000008_0003
Therefore, the resulting nanoporous network may include polyurethane (b), polyisocyanurate (c) and polyoxazolidone (d), as well as polyurea (a) in a lesser extent. Hydrophobic organic aerogels according to the present invention have high cross-linking degree, lower pore size and better mechanical properties than less cross-linked aerogels.
The present invention relates to a hydrophobic organic aerogel obtained by reacting an isocyanate compound having a functionality from 2 to 6 and an epoxy compound having a functionality from 2 to 6 in a presence of a solvent.
A hydrophobic organic aerogel according to the present invention has improved hydrophobicity and good water resistance properties. Furthermore, the hydrophobic organic aerogels according to the present invention are lightweight with low thermal conductivity, they have low shrinkage, and good mechanical properties.
A hydrophobic organic aerogel is obtained by reacting an isocyanate compound and an epoxy compound.
Suitable isocyanate compound for use in the present invention is an aliphatic or aromatic isocyanate, selected from the group consisting of
Figure imgf000008_0002
wherein a is an integer from 1 to 30;
Figure imgf000008_0001
wherein b is an integer from 1 to 30;
Figure imgf000009_0004
wherein c is an integer from 1 to 30;
Figure imgf000009_0003
wherein X represents a substituent, or different substituents and are selected independently from the group consisting of hydrogen, halogen and linear or branched C1 -C6 alkyl groups, attached on their respective phenyl ring at the 2-position, 3-position or 4-position, and their respective isomers, and R1 is selected from the group consisting of a single bonded -0-, -S-, -C(O)-, -S(O)2-, -S(P03)-, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted C7-C30 alkylaryl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group and a substituted or unsubstituted C1-C30 heteroalkyl group from and a combination of thereof;
Figure imgf000009_0001
wherein R2 is selected independently from the group consisting of alkyl, hydrogen and alkenyl, and
Y is selected from the group consisting of and d is an integer from 0 to 3; and
Figure imgf000009_0002
mixtures thereof.
Preferably, said isocyanate compound is selected from the group consisting of 3,5-bis(6- isocyanatohexyl)-6-(6-isocyanatohexylimino)-1 ,3,5-oxadiazinane-2,4-dione, 1 ,3-bis[p-({p-[3,5-bis(3- isocyanatotolyl)-2,4,6-trioxo-1 ,3,5-triazinan-1-yl]phenyl}methyl)phenyl]-5-(3-isocyanatotolyl)-1 ,3,5- triazinane-2,4,6-trione, 4,4’-diphenylmethane diisocyanate, 1 ,3,5-tris(6-isocyanatohexyl)-1 ,3,5- triazinane-2,4,6-trione, 1 ,3-bis(6-isocyanatohexyl)-1-(6-isocyanatohexylcarbamoyl)urea, 6-[3-(6- isocyanatohexyl)-2,4-dioxo-1 ,3-diazetidin-1-yl]hexyl N-(6-isocyanatohexyl) carbamate, 1 -[bis(4- isoyanatophenyl)methyl]-4-isocyanatobenzene and mixtures thereof.
Above listed preferred isocyanate compounds are preferred because they provide aerogels with best performance.
Examples of commercially available isocyanate compound for use in the present invention are but not limited to Desmodur N3300, Desmodur N3400, Desmodur N3600, Desmodur N3900, Desmodur N3200, Desmodur 44V, Desmodur RE, Desmodur IL from Covestro; Wannate HT 100 from Wanhua; Diphenylmethane 4,4'-diisocyanate (MDI) from Merck; and VORASTAR HB 6042 from the Dow Chemical Company.
A hydrophobic organic aerogel according to the present invention has an isocyanate compound content from 0.2 to 56 % by weight of the total weight of the reaction mixture (including solvent) preferably from 0.3 to 45% and more preferably from 0.5 to 35%.
If the content of the isocyanate compound is more than 56%, aerogels with high density and high thermal conductivity will be obtained. These are not desired properties for the aerogels according to the present invention.
Suitable epoxy compound for use in the present invention is a long chain aliphatic epoxy compound or an aromatic epoxy compound.
Suitable epoxy compound for use in the present invention is selected from the group consisting of
Figure imgf000010_0001
wherein e1 , e2, e3 are same or different and independently selected from 1 to 12; f , f2, f3 are same or different and independently selected from 1 to 12; g1 , g2, g3 are same or different and independently selected from 1 to 26; h1 , h2, h3 are same or different and independently selected from 0 to 6, provided that h1+h2+h3 is at least 2; i1 , i2, i3 are same or different and independently selected from 0 to 25; j1 , j2, j3 are same or different and independently selected from 1 to 26; k1 , k2, k3 are same or different and independently selected from 0 to 6, provided that k1+k2+k3 is at least 2; and I1 , I2, I3 are same or different and independently selected from 0 to 25;
Figure imgf000010_0002
wherein R3 represents a substituent or different substituent and is selected independently from the group consisting of hydrogen, halogen and linear or branched C1-C15 alkyl or alkenyl groups, attached to their respective phenyl ring at the 3-, 4- or 5-position and their respective isomers and m is an integer from 1 to 5; wherein n and o are same or different and independently selected from 1 to 10;
Figure imgf000011_0001
wherein p is an integer from 1 to 5;
Figure imgf000011_0002
and mixtures thereof.
Preferably, said epoxy compound is selected from the group consisting of 2-[(3-{[2-hydroxy-3-({2-[(2- oxiranyl)methoxy]-4-pentadecylphenyl}methyl)-4-pentadecylphenyl]methyl}-2-[(2-oxiranyl)methoxy]- 4-pentadecylphenyl)methyl]-6-({2-[(2-oxiranyl)methoxy]-6-pentadecylphenyl}methyl)-3- pentadecylphenol, 2,3-bis{(E)-1 1-[(2-oxiranyl)methoxy]-8-heptadecenylcarbonyloxy}propyl (E)-12- [(2-oxiranyl)methoxy]-9-octadecenoate, 2-{[m-(8-{p-[(2- oxiranyl)methoxy]phenyl}pentadecyl)phenoxy]methyl}oxirane, tris(2,3-epoxypropyl)isocyanurate, 2,3-bis(2-{3-[2-(3-propyl-2-oxiranyl)ethyl]-2-oxiranyl}propionoxy)propyl 3-{3-[2-(3-propyl-2- oxiranyl)ethyl]-2-oxiranyl}propionate, polymer with 2-({3-[(3-methoxy-1- naphthyl)methyl]tolyloxy}methyl)oxirane, 7-oxabicyclo[4.1.0]hept-3-ylmethyl 7- oxabicyclo[4.1.0]heptane-3-carboxylate, phenol polymer with 3a,4,7,7a-tetrahydro-4,7-methano-1 H- indene glycidyl ether and mixtures thereof.
Above listed preferred epoxy compounds are preferred because they provide hydrophobic aerogels.
Examples of commercially available epoxy compound for use in the present invention are but not limited to Cardolite NC-547, Cardolite NC-514S and Cardolite NC-514 from Cardolite, Erisys GE35 from CVC thermosets, CER 4221 from DKSH, Vikoflex 7170 and Vikoflex 7190 from Arkema, Epiclon HP-5000, Epiclon HP-7200H and Epiclon HP-9500 from DIC Corporation, Jagroxy-505 from Jayant Agro-Organics Ltd., and KR-470, X-12-981 S, KR-517, KR-516, X-41-1059A and X-24-9590 from Shin Etsu.
A hydrophobic organic aerogel according to the present invention has an epoxy compound content from 0.7 to 60% by weight of the total weight of the reaction mixture (including solvent), preferably from 1 to 40% and more preferably from 1.5 to 20%.
If the epoxy compound quantity is higher than 60%, gelation is very slow whereas quantity less than 0.7% would lead to precipitation and heterogenous gel. In a hydrophobic organic aerogel according to the present invention a ratio of epoxy groups to isocyanate groups is 1 : 15 - 5: 1 , preferably 1 :8 - 3:1 and more preferably 1 :6 - 2:1.
When the ratio of epoxy groups to isocyanate groups is higher than 1 : 15, there will be a high quantity of unreacted isocyanate monomers in the reaction mixture. On the other hand, when the ratio of epoxy groups to isocyanate groups is higher that 5: 1 gelation does not happen. The preferred ratio range 1 :6 - 2:1 provides the best performing aerogels.
A hydrophobic organic aerogel is obtained by reacting an isocyanate compound and an epoxy compound in a presence of a solvent.
Suitable solvent to be used in the present invention is a polar solvent, preferably polar aprotic solvent. Preferably, the solvent is selected from the group consisting of N,N-dimethylacetamide (DMAc), 1- methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), acetonitrile, acetone, methyl ethyl ketone (MEK), 4-methyl-2-pentanone (MIBK) and mixtures thereof.
Above listed preferred solvents are preferred because they provide the best performing aerogels.
Examples of commercially available solvents for use in the present invention are but not limited to N,N-dimethylacetamide, 1-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO) and acetonitrile from Merck Millipore, 4-methyl-2-pentanone (MIBK), methyl ethyl ketone (MEK) from Alfa Aesar and acetone from VWR Chemicals.
In one embodiment according to the present invention, a hydrophobic organic aerogel may be obtained by reacting an isocyanate compound and an epoxy compound in a presence of a catalyst.
Suitable catalyst for the use in the present invention is selected from the group consisting of alkyl amines, aromatic amines, imidazole derivatives, aza compounds, guanidine derivatives and amidines, preferably selected from the group consisting of triethylamine, trimethylamine, N,N- Dimethylbenzylamine, 1 ,4-diazabicyclo[2.2.2]octane, 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), dibutyltin dilaurate and mixtures thereof.
Above-mentioned preferred catalysts are preferred because they provide faster gelation, and require lower temperature for it.
Examples of commercially available catalysts for use in the present invention are but not limited to triethylamine, trimethylamine, diazabicyclo[5.4.0]undec-7-ene (DBU), 1 ,5,7-triazabicyclo[4.4.0]dec- 5-ene (TBD), Dabco 33V and dibutyltin dilaurate (DBTDL) from Sigma Aldrich, N,N- dimethylbenzylamine from Merck Millipore, 1 ,4-diazabicyclo[2.2.2]octane from Alfa Aesar.
The catalyst is added from 0 to 10% by weight of the total weight of the reaction mixture (including solvent), preferably from 1 to 10% and more preferably from 1 .5 to 10%.
A range from 1 .5 to 10% is preferred, because aerogel performances reach a plateau around 10% of a catalyst, and higher catalyst content would not improve any properties above this point.
In one embodiment a hydrophobic organic aerogel according to the present invention further comprises at least one reinforcement or filler.
Suitable reinforcement or filler for use in the present invention is selected from the group consisting of fibres, particles, fibre fabrics and mats, 3D structures and mixtures thereof.
Non-limiting examples of suitable fibres are cellulose, aramid, carbon, glass and lignocellulosic fibres.
Non-limiting examples of suitable particles are carbon black, microcrystalline cellulose, silica, cork, lignin, and aerogel particles.
Non-limiting examples of suitable fibre fabrics and mats are non-woven and woven glass, aramid, carbon and lignocellulosic fibre fabrics.
Non-limiting examples of suitable 3D structures are aramid fibre-phenolic, glass fibre-phenolic, polycarbonate and polypropylene honeycombs and 3D printed structures.
In a preferred embodiment at least one reinforcement or filler is selected from the group consisting of cellulose fibres, aramid fibres, carbon fibres, glass fibres, lignocellulosic fibres, glass wool, carbon black, microcrystalline cellulose, silica particles, cork particles, lignin particles, aerogel particles, non- woven and woven glass fibre fabrics, aramid fibre fabrics, carbon fibre fabrics, jute fibre fabrics, flax fibre fabrics, aramid fibre-phenolic honeycomb, glass fibre-phenolic honeycomb, polycarbonate honeycomb, polypropylene honeycomb, and mixtures thereof, more preferably at least one reinforcement or filler is selected from the group consisting of cellulose fibres, aramid fibres, carbon fibres, glass fibres, glass wool, carbon black, microcrystalline cellulose, non-woven glass fibre fabrics, woven aramid fibre fabrics, woven jute fibre fabrics, woven flax fibre fabrics, aramid fibre- phenolic honeycomb, glass fibre-phenolic, cardboard honeycomb, polypropylene honeycomb and mixtures thereof.
Examples of commercially available reinforcements for use in the present invention are but not limited to Acros Organics microcrystalline cellulose, ocellulose Sigma Aldrich powder, MT1 100, IC3120 and P300 silica aerogel particles from Cabot, CSX 691 carbon black from Cabot, Procotex aramid fibre, Procotex CF-MLD100-13010 carbon fibres, E-glass Vetrotex textiles fibres EC9 134 z28 T6M ECG 37 1/0 0.7z, Unfilo® U809 Advantex® glass fiber, Composites Evolution Biotex jute plain weave, Composites Evolution Biotex flax 2/2 twill, Easycomposites aramid cloth fabric satin weave, Euro-composites ECG glass fibre-phenolic honeycomb, Euro-composites ECAI aramid fibre- phenolic honeycomb, Easycomposites aramid fibre-phenolic honeycomb, Cel Components Alveolar PP8-80T30 3D structure, Cel Components Alveolar 3.5-90 3D structure, polypropylene honeycomb from Tubus Bahuer, glass fibre chopped strand mats from Easycomposites, Thermex PEI honeycomb from Econcore, Thermex PP honeycomb from Econcore, PU 3D printed structure from Thingiverse, cardboard honeycombs and glass microfibres from Unifrax.
Depending on the reinforcement incorporated into a hydrophobic organic aerogel according to the present invention, the reinforcement or filler percentage in the final material may vary from 0.01 % up to 80% based on the total weight of the initial solvent, preferably from 0.5 to 70%.
A hydrophobic organic aerogel according to the present invention has a solid content from 4 to 40%, based on initial solid content of the solution, preferably from 5 to 30%.
Solid content in the range from 4 to 40% is ideal, because it provides a good compromise between thermal insulating properties and mechanical properties. High solid content provides high mechanical properties; however, high solid content provides poor thermal insulating properties. On the other hand, low solid content provides lower thermal conductivities, but mechanical properties are not ideal.
A hydrophobic organic aerogel according to the present invention has a thermal conductivity less than 60 mW/m-K, preferably less than 55 mW/m-K, more preferably less than 50 mW/rn-K, and even more preferably less than 45 mW/m-K. The thermal conductivity can be measured either by using diffusivity sensor method or steady-state condition system method, method to be used depends on whether the material to be tested is lab scale or larger.
Diffusivity sensor method
In this method, the thermal conductivity is measured by using a diffusivity sensor. In this method, the heat source and the measuring sensor are on the same side of the device. The sensors measure the heat that diffuses from the sensor throughout the materials. This method is appropriate for lab scale tests.
Steady-state condition system method
In this method the thermal conductivity is measured by using a steady-state condition system. In this method, the sample is sandwiched between a heat source and a heat sink. The temperature is risen on one side, the heat flows through the material and once the temperature on the other side is constant, both heat flux and difference of temperatures are known, and thermal conductivity can be measured.
A hydrophobic organic aerogel according to the present invention has a compression Young’s modulus more than 0.1 MPa, preferably more than 15 MPa, and more preferably more than 30 MPa, wherein Compression Young Modulus is measured according to the method ASTM D1621.
An organic aerogel according to the present invention has preferably a compressive strength more than 0.01 MPa, more preferably more than 0.45 MPa, and even more preferably more than 1 MPa. Compressive strength is measured according to the standard ASTM D1621.
An organic aerogel according to the present invention has preferably a specific surface area ranging from 5 m2/g to 400 m2/g. Surface area is determined from N2 sorption analysis at -196°C using the Brunauer-Emmett-Teller (BET) method, in a specific surface analyser Quantachrome-6B. High surface area values are preferred because they are indicative of small pore sizes, and which may be an indication of low thermal conductivity values.
An organic aerogel according to the present invention has preferably an average pore size ranging from 5 to 80 nm. Pore size distribution is calculated from Barret-Joyner-Halenda (BJH) model applied to the desorption branch from the isotherms measured by N2 sorption analysis. Average pore size was determined by applying the following equation: Average pore size = (4*V/ SA) wherein V is total pore volume and SA is surface area calculated from BJH. Porosity of the samples can also be evaluated by He pycnometry.
An aerogel pore size below the mean free path of an air molecule (which is 70 nm) is desired, because that allows obtaining high performance thermal insulation aerogels having very low thermal conductivity values.
A hydrophobic organic aerogel according to the present invention has low-density structure having a bulk density ranging from 0.01 to 0.8 g/cc. Bulk density is calculated from the weight of the dry aerogel and its volume.
A hydrophobic organic aerogel according to the present invention is resistant to low temperatures exposure (-160°C). Additionally, the hydrophobic organic aerogels may resist liquid nitrogen immersion (-196°C) and subsequent evaporation.
Water penetrates the surface of a hydrophilic aerogel and aerogel can break. Whereas, a hydrophobic aerogel resists water without breaking. The aerogels according to the present invention have improved hydrophobicity and water-resistance. This is illustrated in figure 1. Drops of water are on top of aerogels - figure 1a illustrates an aerogel described in WO2017016755A1 , wherein bisphenol A-DGE was used as an epoxy compound, whereas figures 1 b and 1 c illustrate a hydrophobic aerogel according to the present invention, wherein Erisys GE35 (1 b) and Cardolite NC- 547 (1 c) were used as an epoxy compound. It can be clearly seen from the figures 1 a and 1 b/1 c that the aerogels according to the present invention repel the water drops, which remains clearly as water droplets on the surface of the aerogel. Whereas, the aerogel according to the prior art does not repel the water drops as intensely, and some of the water penetrates the surface of the aerogel.
A hydrophobic organic aerogel according to the present invention has preferably a water contact angle higher than 90°C. Wettability is quantified by measuring the contact angle (Q) between the tangent to a drop of water, where it meets the surface and the surface itself. The contact angle (Q) measurement is illustrated in figure 2. Figure 2a is a theoretical illustration and figure 2b is illustration of the example according to the present invention. Generally, if the water contact angle is higher than 90°, the solid surface is considered hydrophobic. Contact angle measurements can be done by using EasyDrop Contact Angle Measuring Instrument (Kmss GmbH) in static mode with a drop of water of 10 pi.
For the preparation of hydrophobic organic aerogels according to the present invention, several aspects must be taken into consideration. The equivalent ratio of functionalities, the initial solid content, the amount and type of catalyst (if present), type of solvent, gelation time and temperature are crucial factors that affect the final properties of the material.
In one embodiment, a hydrophobic organic aerogel according to the present invention may be prepared by using a method comprising the steps of:
1 ) dissolving an epoxy compound into a solvent and adding an isocyanate compound and mixing;
2) adding a catalyst if present, and mixing;
3) letting the mixture to stand in order to form a gel;
4) washing said gel with a solvent; and
5) drying said gel by supercritical or ambient drying.
The reaction mixture is prepared in a closed container.
Gelation step (3) is carried out in a closed mould for the pre-set time and temperature. Preferably, temperature is applied in step 3, more preferably, temperature from room temperature to 160°C is applied while gel is forming, and most preferably, temperature from room temperature to 80°C is applied. Temperatures from room temperature to 160°C are preferred because the best performing aerogels are obtained.
Gelation time is preferably from 0.5 to 48 hours, more preferably from 1 to 36 hours and even more preferably from 1 to 24 hours.
Washing time in step (4) is preferably from 1 hour to 72 hours, preferably from 18 hours to 72 hours, and more preferably from 24 hours to 48 hours.
The solvent of wet gels of step (3) is changed one or more times after the gelation. In some embodiments, the washing steps are done gradually, and if required, to the preferred solvent for the drying process. Once the wet gel remains in the proper solvent, it is dried in supercritical (CO2) or ambient conditions obtaining the final aerogel material.
In one embodiment, the washing steps are done gradually as follows: 1 ) acetone/DMAc 1 :3; 2) acetone/DMAc 1 : 1 ; 3) acetone/DMAc 3: 1 ; and 4) acetone. In another embodiment, washing steps are done with acetone. In another embodiment all four washing steps are done gradually with hexane. Once the solvent has been completely replaced by acetone, gel is dried in supercritical (CO2) or ambient conditions obtaining the final aerogel material.
The supercritical state of a substance is reached once its liquid and gaseous phases become indistinguishable. The pressure and temperature at which the substance enters this phase is called critical point. In this phase, the fluid presents the low viscosity of a gas, maintaining the higher density of a liquid. It can effuse through solids like a gas and dissolve materials like a liquid. Considering an aerogel, once the liquid inside the wet gel pores reaches the supercritical phase, its molecules do not possess enough intermolecular forces to create the necessary surface tension that creates capillarity stress. Hence, the solvent can be dried, minimizing shrinkage and possible collapse of the gel network.
The drying process at supercritical conditions is performed by exchanging the solvent in the gel with CO2 or other suitable solvents in their supercritical state. Due to this, capillary forces exerted by the solvent during evaporation in the nanometric pores are minimized and shrinkage of the gel body can be reduced.
In one embodiment, the method for preparing a hydrophobic organic aerogel involves the recycling of the CO2 from the supercritical drying step.
Alternatively, wet gels can be dried at ambient conditions, in which the solvent is evaporated at room temperature. However, as the liquid evaporates from the pores, it can create a meniscus that recedes back into the gel due to the difference between interfacial energies. This may create a capillary stress on the gel, which responds by shrinking. If these forces are high enough, they can even lead to the collapse or cracking of the whole structure. However, there are different possibilities to minimize this phenomenon. One practical solution involves the use of solvents with low surface tension to minimize the interfacial energy between the liquid and the pore. Unfortunately, not all the solvents lead to gelation, which means that some cases would require the exchange of solvent between an initial one required for the gel formation and a second one most appropriate for the drying process. Hexane is usually used as a convenient solvent for ambient drying, as its surface tension is one of the lowest among the conventional solvents.
The present invention compasses a thermal insulating material or an acoustic material comprising a hydrophobic organic aerogel according to the present invention.
A hydrophobic organic aerogel according to the present invention can be used as a thermal insulating material or acoustic material.
In highly preferred embodiment a hydrophobic organic aerogel according to the present invention can be used as a thermal insulating material for the storage of cryogens.
Hydrophobic organic aerogels according to the present invention may be used in a variety of applications such as building construction, electronics or for the aerospace industry. An hydrophobic organic aerogel could be used as thermal insulating material for refrigerators, freezers, automotive engines and electronic devices. Other potential applications for aerogels is as a sound absorption material and a catalyst support.
Hydrophobic organic aerogels according to the present invention can be used for thermal insulation in different applications such as aircrafts, space crafts, pipelines, tankers and maritime ships replacing currently used foam panels and other foam products, in car battery housings and under hood liners, lamps, in cold packaging technology including tanks and boxes, jackets and footwear and tents.
Hydrophobic organic aerogels according to the present invention can also be used in construction materials due to their lightweight, strength, ability to be formed into desired shapes and superior thermal insulation properties.
Hydrophobic organic aerogels according to the present invention can be also used as thermal insulation for storage and transportation of cryogens.
Hydrophobic organic aerogels according to the present invention can be also used as an adsorption agent for oil spill clean-up, due to their high oil absorption rate.
Hydrophobic organic aerogels according to the present invention can be also used in safety and protective equipment as a shock-absorbing medium.
Examples
For all the examples following test methods were used:
Thermal conductivity measured with the C-Therm TCi.
Mechanical properties (compression modulus) determined in accordance with ASTM D1621.
Density was determined as the mass of aerogel divided by the geometrical volume of aerogel.
Figure imgf000016_0001
Linear shrinkage was determined as the difference between the gel and aerogel diameters divided by the gel diameter.
Figure imgf000016_0002
Water absorbed by the aerogel samples was determined using the following equation:
Figure imgf000016_0003
Example 1
Aerogel obtained by using Cardolite NC-547 and Desmodur N3300
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5 wt% and 5wt% of a catalyst. For the preparation of a sample of 30 mL 0.58 g of Cardolite NC-547 was dissolved in 23.1 1 g of MIBK and subsequently 0.64 g of Desmodur N3300 was added. The mixture was stirred manually and 0.06 g of DABCO was added. The solution was left overnight at room temperature.
The resulting gel was washed three times with acetone every 24h, using solvent three times the volume of the gel in each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 1 illustrates measured properties of the obtained aerogel.
Table 1
Figure imgf000016_0004
Example 2
Aerogel obtained using Cardolite NC-514 and Desmodur N3900
Equivalent ratio isocyanate/epoxy was 4: 1 with a total solid content of 5 wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.46 g of Cardolite NC-514 was dissolved in 23.57 g of MIBK and subsequently 0.84 g of Desmodur N3900 was added. The mixture was stirred manually and 0.124 g of DABCO was added. The solution was left overnight at room temperature.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 2 illustrates measured properties of the obtained aerogel.
Table 2
Figure imgf000017_0001
Example 3
Aerogel obtained using Cardolite NC-514 and Desmodur N3200
Equivalent ratio isocyanate/epoxy was 4: 1 with a total solid content of 5 wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.43 g of Cardolite NC-514 was dissolved in 23.1 1 g of MIBK and subsequently 0.78 g of Desmodur N3200 was added. The mixture was stirred manually and 0.122 g of DABCO was added. The solution was left overnight at room temperature.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 3 illustrates measured properties of the obtained aerogel.
Table 3
Figure imgf000017_0002
Example 4
Aerogel obtained using Erisys GE35 and Desmodur N3300
Equivalent ratio isocyanate/epoxy was 6:1 with a total solid content of 6 wt% and 10 wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.50 g of Erisys GE35 was dissolved in 22.93 g of MIBK and subsequently 0.96 g of Desmodur N3300 was added. The mixture was stirred manually and 0.146 g of DABCO was added. The solution was left overnight at room temperature.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 4 illustrates measured properties of the obtained aerogel.
Table 4
Figure imgf000018_0002
Example 5
Aerogel obtained using tris(2,3-epoxypropyl)isocyanurate and Desmodur 44V
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 10 wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.38 g of tris(2,3-epoxypropyl)isocyanurate was dissolved in 21.90 g of acetone and subsequently 2.05 g of Desmodur 44V was added. The mixture was stirred manually and 0.243 g of DABCO was added. The solution was left for 6h at room temperature.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 5 illustrates measured properties of the obtained aerogel.
Table 5
Figure imgf000018_0003
Example 6
Aerogel obtained using Erisys GE35 and Desmodur 44V
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 15 wt% and 10% of a catalyst. For the preparation of a sample of 30 ml_ 2.03 g of Erisys GE35 was dissolved in 21.08 g of MIBK and subsequently 1.69 g of Desmodur 44V was added. The mixture was stirred manually and 0.37g of DABCO was added. The solution was left for 1 h and 30 min in the oven at 80°C.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each washing cycle. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 6 illustrates measured properties of the obtained aerogel.
Table 6
Figure imgf000018_0001
Example 7
Aerogel obtained using Erisys GE35 and Desmodur RE in DMAC Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 10 wt% and 10% of a catalyst. For the preparation of a sample of 30 ml_ two solutions were used. First solution was prepared by dissolving 1.57 g of Erisys GE35 in 1 1.07 g of DMAc and subsequently 4.72 g of Desmodur RE was added. The second solution was prepared by dissolving 0.284 g of TBD in 1 1.07g of DMAc. First and second solutions were mixed together and after 5 min the gel was formed.
The resulting gel was washed stepwise in a mixture of acetone 1 :3 DMAc, acetone 1 :1 DMAc, acetone 3: 1 DMAc and acetone, during 24 h for each washing cycle, and using three times the volume of the gel in solvent for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 7 illustrates measured properties of the obtained aerogel.
Table 7
Figure imgf000019_0001
Example 8
Aerogel obtained using CER 4221 and Desmodur 44V
Equivalent ratio isocyanate/epoxy was 1 :2 with a total solid content of 12 wt% and 10% of a catalyst. For the preparation of a sample of 30 ml_ 1.99 g of CER 4221 was dissolved in 21.55 g of acetone and then 0.96 g of Desmodur 44V was added. The mixture was stirred manually and then 0.239 g of DABCO was added. The solution was left overnight at room temperature.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 8 illustrates measured properties of the obtained aerogel.
Table 8
Figure imgf000019_0002
Example 9
Aerogel obtained using Vikoflex 7170 and Desmodur RE in MEK
Equivalent ratio isocyanate/epoxy was 4: 1 with a total solid content of 5 wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.31 g of Vikoflex 7170 was dissolved in 20.93 g of MEK and then 3.40 g of Desmodur RE was added. The mixture was stirred manually and then 0.29 g of DABCO was added. The solution was left at room temperature for 1 h.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 9 illustrates measured properties of the obtained aerogel. Table 9
Figure imgf000020_0002
Example 10
Aerogel obtained using Cardolite NC-514S and mixture of isocyanates Desmodur IL and Desmodur N3300
Equivalent ratio aromatic isocyanate / aliphatic Isocyanate/ epoxy was 1 :3: 1 with a total solid content of 6 wt% and 1 .5wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.44 g of Cardolite NC- 514S was dissolved in 22.70 g of acetone, then 0.69 g of Desmodur N3300 was added and finally 0.62g of Desmodur IL was added. The mixture was stirred manually and then 0.02 g of DABCO was added. The solution was left at room temperature for 3h.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 10 illustrates measured properties of the obtained aerogel.
Table 10
Figure imgf000020_0003
Example 11
Aerogel obtained using Epiclon HP-7200H and mixture of Desmodur RE and Desmodur N3300 reinforced with glass wool and glass fiber chopped strand mats (~30w% based on weight of aerogel).
Equivalent ratio aromatic isocyanate / aliphatic Isocyanate/ epoxy was 1 :3: 1 with a total solid content of 6wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.42 g of Epiclon HP- 7200H was dissolved in 23.03g of acetone and then 0.68 g of Desmodur N3300 and finally 0.88 g of Desmodur RE was added. The mixture was stirred manually and then 0.15g of DABCO was added. Then, the glass fiber chopped strand mats (0.22g) and the glass wool (0.14g) were incorporated. The solution was left for 1 h at ambient temperature.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 1 1 illustrates measured properties of the obtained aerogel.
Table 11
Figure imgf000020_0001
Example 12
Aerogel obtained using Epiclon HP-5000 and Desmodur RE
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.42 g of Epiclon HP-5000 was dissolved in 21.21 g of MIBK and then 3.01 g of Desmodur RE was added. The mixture was stirred manually and then 0.12g of DABCO was added. The solution was left for 30 min in the oven at 80°C.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 12 illustrates measured properties of the obtained aerogel.
Table 12
Figure imgf000021_0001
Example 13
Aerogel obtained using Epiclon HP-9500 and Desmodur RE
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 15wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 1 .25 g of Epiclon HP-9500 was dissolved in 14.90 g of MIBK and then 9.79 g of Desmodur RE was added. The mixture was stirred manually and then 0.39 g of DABCO was added. The solution was left for 30 min in the oven at 80°C.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 13 illustrates measured properties of the obtained aerogel.
Table 13
Figure imgf000021_0002
Example 14
Aerogel obtained using Erisys GE35 and Desmodur 44V reinforced with glass wool and glass fiber chopped strand mats (~30w% based on weight of aerogel).
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5wt% and 10% of a catalyst. For the preparation of a sample of 30 ml_ 0.64 g of Erisys GE35 was dissolved in 23.09g of MIBK and then 0.57 g of Desmodur 44V was added. The mixture was stirred manually and then 0.12g of DABCO was added. Then, the glass fiber chopped strand mats (0.23g) and the glass wool (0.15g) were incorporated. The solution was left for 1 h and 30 min in the oven at 80°C.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 14 illustrates measured properties of the obtained aerogel. Table 14
Figure imgf000022_0001
Example 15
Aerogel obtained using Erisys GE35 and Desmodur 44V reinforced with a honeycomb based on aramid fiber and phenolic resin.
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 5wt% and 10% of a catalyst. For the preparation of a sample of 30 ml_ 0.64 g of Erisys GE35 was dissolved in 23.09g of MIBK and then 0.57 g of Desmodur 44V was added. The mixture was stirred manually and then 0.12g of DABCO was added. Then, the honeycomb (cell size of 3.2mm and density of 48kg/m3) was incorporated, and the solution was left for 1 h and 30 min in the oven at 80°C.
The resulting gel was washed three times with acetone every 24h, and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD).
Table 15
Figure imgf000022_0002
Example 16
Aerogel obtained using KR-516 and Desmodur N3300.
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 6wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.16 g of KR-516 was dissolved in 5.9 g of DMAc mixed with 17.71 g of Acetone of solvent, and then 1.34 g of Desmodur N3300 was added. The mixture was stirred manually and then 0.15g of DABCO was added. The solution was left for gelation at room temperature.
The resulting gel was washed three times with acetone every 24h and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 16 illustrates measured properties of the obtained aerogel.
Table 16
Figure imgf000022_0003
Example 17
Aerogel obtained using X-12-981 S and Desmodur N3300.
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 6wt% and 10wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.13 g of X-12-981 S was dissolved in 5.9 g of DMAc mixed with 17.71 g of Acetone of solvent, and then 1.38 g of Desmodur N3300 was added. The mixture was stirred manually and then 0.15g of DABCO was added. The solution was left for gelation at room temperature.
The resulting gel was washed three times with acetone every 24h and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 17 illustrates measured properties of the obtained aerogel.
Table 17
Figure imgf000023_0001
Example 18
Aerogel obtained using KR-470 and Desmodur N3300.
Equivalent ratio isocyanate/epoxy was 4:1 with a total solid content of 8wt% and 20wt% of a catalyst. For the preparation of a sample of 30 ml_ 0.08 g of KR-470 was dissolved in 1 1.98 g of DMAc mixed with 1 1.98 g of Acetone of solvent, and then 2.0 g of Desmodur N3300 was added. The mixture was stirred manually and then 0.42 g of DMBA was added. The solution was left for gelation at room temperature.
The resulting gel was washed three times with acetone every 24h and using solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). Table 18 illustrates measured properties of the obtained aerogel.
Table 18
Figure imgf000023_0002
Example 19
Comparison between aerogels obtained using hydrophilic and hydrophobic resins.
All the samples were prepared under the same conditions but using different resins. The epoxies used were Erisys GE35 (hydrophobic), Epiclon 7200 (hydrophobic), 1 ,6 hexanediol diglycidyl ether (hydrophilic), Polyethylene glycol diglycidyl ether (hydrophilic). The isocyanate used was Desmodur RE, equivalent ratio isocyanate/epoxy was 4:1 , solid content 10wt% and 10phr of DABCO as catalyst. The amount of the different components is summarized in Table 19. The monomers were dissolved in MIBK and then the catalyst was added. The resulting solution was left in the oven at 80°C for 1 h. The obtained gel was washed three times with acetone every 24h, using an amount of solvent three times the volume of the gel for each step. Subsequently the gel was dried via CO2 supercritical drying (SCD). The properties of the aerogel obtained are summarized in Tables 20 and 21. Table 19 Formulation of the samples prepared with the different epoxy resins and same conditions.
Figure imgf000024_0001
Table 20 Result obtained for the samples prepared with the different epoxy resins.
Figure imgf000024_0002
Table 21 Water absorption test results for the samples prepared with the different epoxy resins.
Figure imgf000025_0001

Claims

Claims
1. A hydrophobic organic aerogel obtained by reacting an isocyanate compound having a functionality from 2 to 6 and an epoxy compound having a functionality from 2 to 6 in a presence of a solvent, wherein said isocyanate compound is selected from the group consisting of
Figure imgf000026_0002
wherein a is an integer from 1 to 30;
Figure imgf000026_0003
wherein b is an integer from 1 to 30;
Figure imgf000026_0004
wherein c is an integer from 1 to 30;
Figure imgf000026_0001
wherein X represents a substituent, or different substituents and are selected independently from the group consisting of hydrogen, halogen and linear or branched C1-C6 alkyl groups, attached on their respective phenyl ring at the 2-position, 3-position or 4-position, and their respective isomers, and R1 is selected from the group consisting of a single bonded -O-, -S-, - C(O)-, -S(O)2-, -S(P03)-, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted C7-C30 alkylaryl group, a substituted or unsubstituted C3-C30 heterocycloalkyl group and a substituted or unsubstituted C1-C30 heteroalkyl group from and a combination of thereof;
Figure imgf000027_0002
wherein R2 is selected independently from the group consisting of alkyl, hydrogen and alkenyl, and Y is selected from the group consisting of and d is an integer from 0
Figure imgf000027_0001
to 3; and mixtures thereof;
and wherein said epoxy compound is selected from the group consisting of
Figure imgf000028_0001
wherein e1, e2, ea are same or different and independently selected from 1 to 12; f1, f2, f3 are same or different and independently selected from 1 to 12; g1, g2, g3 are same or different and independently selected from 1 to 26; h1, h2, h3 are same or different and independently selected from 0 to 6, provided that h1+h2+ha is at least 2; i1, i2, i3 are same or different and independently selected from 0 to 25; j1, j2, j3 are same or different and independently selected from 1 to 26; k1, k2, k3 are same or different and independently selected from 0 to 6, provided that k1+kz+k3 is at least 2; and I1, 12, P are same or different and independently selected from 0 to 25;
Figure imgf000028_0002
wherein Ra represents a substituent or different substituent and is selected independently from the group consisting of hydrogen, halogen and linear or branched C1-C15 alkyl or alkenyl groups, attached to their respective phenyl ring at the 3-, 4 or 5-position and their respective isomers arid m is an integer from 1 to 5; wherein n and o are same or different and independently selected from 1 to 10;
Figure imgf000029_0001
wherein p is an integer from 1 to 5;
Figure imgf000029_0002
and mixtures thereof.
2. A hydrophobic organic aerogel according to claim 1 , wherein said isocyanate compound and said epoxy compound are reacted in the presence of a catalyst.
3. A hydrophobic organic aerogel according to claim 1 or 2. wherein said isocyanate compound is selected from the group consisting of 3,5-bis(6-isocyanatohexyl)-6-(6-isocyanatohexylimino)- 1 ,3,5-oxadiazinane-2,4-dione, 1 ,3-bis[p-({p-[3,5-bis(3-isacyanatotolyl)-2,4,6-trioxo-1,3,5- triazinan-l-yllphenyl)methyl)phenyll-5-(3-isocyanatotolyl)-1 ,3,5-triazinane-2,4,6-trione. 4,4’- diphenylmethane diisocyanate, 1 ,3,5-tris(6-isocyanatohexyl)-1 ,3,5-triazinane-2,4,6-trione, 1 ,3- bis(6-isocyanatohexyl)-1-(6-isocyanatohexylcarbamoyl)urea, 6-f3-(6-isocyanatohexyl)-2,4- dioxo-1 ,3-diazet!din-1-yl]hexyl N-(6-isocyanatohexyl) carbamate, 1-[bis(4- isoyanatophenyl)methyl)4-4-isocyanatobenzene and mixtures thereof.
4. A hydrophobic organic aerogel according to any of claims 1 to 3, wherein said epoxy compound is selected from the group consisting of 2-[(3-{[2-hydroxy-3-({2-[(2-oxiranyl)methoxy]-4- pentadecylphenyl}methyl)-4-pentadecylphenyl]methyl}-2-[(2-oxirany|)methoxy]-4- pentadecylphenyl)methyl]-6-({2-[(2-oxiranyl)methoxy]-6-pentadecylpheny|}methy|)-3- pentadecylphenol, 2,3-bis{(E)-11-I(2-oxiranyl)methoxy]-8-heptadeceny|carbony|oxy}propyl (£)- 12-[(2-oxiranyl)methoxy]-9-octadecenoate, 2-{[m-(8-{p-[(2- oxiranyl)methoxy]phenyl}pentadecyl)phenoxy]methyl}oxirane, tris(2,3- epoxypropyljisocyanu rate, 2,3-bis(2-{3-[2-(3-propyl-2-oxiranyl)ethyl]-2- oxiranyl}propionoxy)propyl 3-{3-[2-(3-propyl-2-oxiranyl)ethyl]-2-oxiranyl}propionate, polymer with 2-({3-[(3-methoxy-1-naphthyl)methyl]tolyloxy}methyl)oxirane, 7-oxabicydo[4.1.0]hept-3- ylmethyl 7-oxabicyclo[4.1.0]heptane-3-carboxylate, phenol polymer with 3a,4,7,7a-tetrahydro- 4,7-methano-1 H-lndene glycidyl ether and mixtures thereof.
5. A hydrophobic organic aerogel according to any of claims 1 to 4, wherein ratio of epoxy groups to isocyanate groups is 1 :15 - 5:1 , preferably 1 :8 - 3:1 and more preferably 1 :6 - 2:1.
6. A hydrophobic organic aerogel according to the any of claims 1 to 5, wherein said solvent is a polar solvent, preferably polar aprotic solvent selected from the group consisting of dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone (NMP), dimethyl sulfoxide (DMSO), acetonitrile, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK) and mixtures thereof.
7. A hydrophobic organic aerogel according to the any of claims 2 to 6, wherein said catalyst is selected from the group consisting of alkyl amines, aromatic amines, imidazole derivatives, aza compounds, guanidine derivatives and amidines, preferably selected from the group consisting of triethylamine, trirnethylamine, N,N-dimethylbenzylamine, 1 ,4-diazabicyclo[2.2.2]octane, 1 ,8- diazabicydo[5.4.0]undec-7-ene (DBU), 1 ,5,7-triazabicydo[4.4.0]dec-5-ene (TBD), dibutyltin dilaurate and mixtures thereof.
8. A hydrophobic organic aerogel according to any of claims 1 to 7, wherein said aerogel further comprises at least on© reinforcement, wherein said reinforcement is selected from the group consisting of fibres, particles, fibre fabrics and mats, 3D structures and mixtures thereof.
9,. A hydrophobic organic aerogel according to the any of claims 1 to 8, wherein said hydrophobic organic aerogel has a solid content from 4 to 40%, based on initial solid content of the solution, preferably from 5 to 30%.
10. A hydrophobic organic aerogel according to the any of claims 1 to 9. wherein said hydrophobic organic aerogel has a thermal conductivity less than 60 mW/m K, preferably less than 55 mW/m K, more preferably less than 50 mW/m-K, and even more preferably less than 45. mW/m-K.
11. A method for preparing a hydrophobic organic aerogel according any of claims 1 to 10 comprising the steps of: 1) dissolving an epoxy compound into a solvent and adding an isocyanate compound and mixing;
2) adding a catalyst if present, and mixing;
3) letting the mixture to stand in order to form a gel;
4) washing said gel with a solvent; and
5) drying said gel by supercritical or ambient drying.
12. A method according to claim 11 , wherein temperature from room temperature to 160°C is applied at step 3 to form a gel, preferably temperature from room temperature to 80°C is applied.
13. A thermal insulating material or an acoustic material comprising a hydrophobic organic aerogel according any of claims 1 to 10.
14. Use of a hydrophobic organic aerogel according to the any of claims 1 to 10 as a thermal insulating material or acoustic material.
15. Use of a hydrophobic organic aerogel according to the claim 14 as a thermal insulating material for the storage of cryogens.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114045004A (en) * 2021-11-25 2022-02-15 航天特种材料及工艺技术研究所 Phase-change composite thermal protection material and preparation method thereof
CN114481680A (en) * 2022-03-10 2022-05-13 咸宁优维科技有限公司 Preparation method of aramid fiber material and superfine meta-position and para-position aramid fiber film, sponge and aerogel material prepared by same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017016755A1 (en) 2015-07-28 2017-02-02 Henkel Ag & Co. Kgaa Organic aerogels based on isocyanate and cyclic ether polymer networks

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* Cited by examiner, † Cited by third party
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WO2017016755A1 (en) 2015-07-28 2017-02-02 Henkel Ag & Co. Kgaa Organic aerogels based on isocyanate and cyclic ether polymer networks

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* Cited by examiner, † Cited by third party
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CN114045004A (en) * 2021-11-25 2022-02-15 航天特种材料及工艺技术研究所 Phase-change composite thermal protection material and preparation method thereof
CN114481680A (en) * 2022-03-10 2022-05-13 咸宁优维科技有限公司 Preparation method of aramid fiber material and superfine meta-position and para-position aramid fiber film, sponge and aerogel material prepared by same
CN114481680B (en) * 2022-03-10 2023-08-22 咸宁优维科技有限公司 Preparation method of aramid fiber material, aerogel and pumping filter membrane material

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