Process for preparation of stable homogeneous dispersions of sp2 carbon allotropes in lipophilic matrices and related composites obtainable thereby

Abstract

A process is described for preparing a lipophilic matrix composite comprising a dispersion of sp2 carbon allotropes, comprising the steps of: (A) mixing sp2 carbon allotropes with a compound comprising a pyrrole ring of formula (i) wherein:-R1 and R3, independently of each other, are hydrogen or an alkyl group containing 1 to 20 carbon atoms; -R3 is a linear or branched aliphatic group, with or without unsaturation, unsubstituted and free of functional groups such as OH, C = O, said R3 containing 1 to 40 carbon atoms; (B) heating the mixture; and (C) mixing the mixture obtained in the step (B) with a lipophilic compound forming the matrix of the composite material to obtain the composite material. (i).

Description

Technical Field

[0001] This invention relates to a method for preparing sp 2 A method for uniform dispersions of carbon allotropes, particularly at least one allotrope with a dimension less than 100 nm (e.g., graphene and nanographite), said allotropes being stable in a lipophilic matrix because the dispersibility of said allotropes in the lipophilic matrix is ​​improved.

[0002] In particular, the present invention relates to a method as defined above for promoting sp 2 The dispersion of carbon allotropes in lipophilic matrices and their compatibility, such as:

[0003] - Elastomer matrices (e.g., unsaturated elastomers such as natural rubber or saturated elastomers such as ethylene / propylene copolymers, which can be used to obtain gaskets, conveyor belts, etc.) and / or polymer matrices (including non-elastomer matrices) result in improved dynamic mechanical properties, such as a reduction in the nonlinearity of the elastic modulus (G' when measured by shear stress), and therefore, a decrease in its variation (ΔG') with elongation due to the reduction in the number of lattices formed by the allotropy itself;

[0004] - Lubricating base oil, which gives the allotropic dispersion good stability in the lubricant;

[0005] - Grease, which has improved lubrication due to the uniform dispersion of allotropes;

[0006] - Waxy compounds, such as paraffin, animal wax, plant wax or other waxy compounds (e.g. saturated fatty acid methyl esters with C atoms greater than or equal to C12 and up to 32, such as lauric acid derivatives, stearic acid derivatives), when the wax matrix is ​​above its melting point, improve the stability of the carbon allotropic dispersion in the wax matrix.

[0007] More particularly, the present invention relates to functionalized sp that can be obtained by the above method. 2 Composite materials of carbon allotropes, which can be used as additives (e.g., masterbatches) in lubricating oils, greases and / or elastomer compositions. Background Technology

[0008] In chemistry, allotropes are forms of chemical elements whose atoms are bonded together in different ways.

[0009] Carbon is one of the many known allotropic forms of a chemical element, and the classification of carbon allotropes is usually based on the hybridization of the carbon atom: carbon in diamond is sp... 3 Hybridized, while carbon is a sp. in carbon black, graphite, nanographite, graphene, fullerene, and carbon nanotubes. 2Hybridized carbons, almost all of these, are commonly used to prepare composite materials.

[0010] Graphite, carbon nanotubes, and carbon black are composed of graphene layers with different structures, and the graphene layer is an aromatic condensation polymer system composed of a single carbon atom, with a thickness of a single carbon atom.

[0011] The aforementioned sp 2 Carbon allotropes (hereinafter also referred to as carbonaceous materials) are essentially polymers. The repeating unit is an aromatic ring, which typically has 5 or 6 carbon atoms.

[0012] sp 2 Carbon allotropes are traditionally classified as "nanoscale" and "nanostructure".

[0013] Chemical substances are defined as “nanoscale” when at least one dimension is less than 100 nm: graphene, nanographite, fullerene, and carbon nanotubes belong to this category.

[0014] On the other hand, carbon black, used to reinforce polymeric materials and many other applications, is “nanostructured” because it consists of nanoscale basic spherical particles that combine to form aggregates, where these basic particles are held together by covalent bonds. These aggregates are larger than 100 nm. The typical thermomechanical stresses of carbon black mixed with a polymer matrix and the thermomechanical stresses experienced by the composite material during its application cannot separate the aggregates into their basic components.

[0015] sp 2 Carbon allotropes possess excellent electrical and thermal conductivity due to their aromatic properties and structure, and can be endowed with important mechanical properties, such as mechanical enhancement: "nanoscale" and "nanostructured" sp. 2 Carbon allotropes therefore have a wide variety of important applications.

[0016] In order to prepare a product containing sp 2 For carbon allotropy composites, a mixing operation must be performed between the allotropy and the matrix of the composite to achieve the distribution and dispersion of the allotropy in the matrix.

[0017] For a uniform distribution, allotropes must be evenly distributed throughout the matrix of the composite material, regardless of the agglomeration and aggregation state of the initial carbonaceous material. During mixing, the basic spherical particles or carbon atom layers of the allotropic aggregates must be dispersed within the matrix to achieve optimal dispersion.

[0018] However, it is well known that distributing and dispersing graphite materials (e.g., graphene, nanographite, fullerene) and having stable and uniform graphite layer dispersions in lipophilic matrices is difficult, also because the graphite layers re-aggregate in some cases (e.g., crosslinking). See, for example, Galimberti, M., Cipolletti, V., Musto, S., Cioppa, S., Peli, G., Mauro, M., & Kumar, V. (2014). Recent advances in rubber nanocomposites. Rubber Chemistry and Technology, 87(3), 417-442, which describes the preparation of elastomeric composites with high surface area nanographite (HSAG) in synthetic isoprene rubber (poly(1,4-cis-isoprene)).

[0019] For other SPs 2 The same mixing and reaggregation problems in lipophilic matrices have also been reported in the literature for carbon allotropes (such as carbon nanotubes (CNTs) and carbon black).

[0020] sp in composite matrix 2 The stability of carbon allotropic dispersions is also a necessary condition for the development of composite materials to an industrial scale.

[0021] One example is the coatings industry, where the uniform dispersion of carbonaceous materials, especially carbon black, is absolutely essential. See, for example, Nsib, F., Ayed, N., & Chevalier, Y. (2006) Selection of dispersants for the dispersion of carbon black in organic medium. Progress in organiccoatings, 55(4), 303-310.

[0022] To achieve sp 2 One approach to achieving better dispersion of carbon allotropes is to functionalize them by introducing specific types of substituents, which are determined for the specific type of matrix under consideration. See the aforementioned literature.

[0023] sp 2Functionalization reactions of carbon allotropes can produce more or fewer unstable bonds, namely covalent or supramolecular bonds. In both cases, compounds that can be defined as "adducts" are formed. Covalent functionalizations typically form compounds that retain their chemical properties in the composite material, and such adducts do not segregate into their starting components after being added to the composite matrix. If the functionalization is supramolecular, the compound usually tends to segregate into its components (substrate and functionalizing agent) in the composite material. This depends on the relative strength of the interactions between the substrate, functionalizing agent, and matrix.

[0024] In addition, sp 2 The functionalization of carbon allotropes (hereinafter also referred to as carbonaceous materials) appears to require specific chemical reactions, carried out using conventional chemical synthesis equipment, typically using ingredients that are critical from the perspective of their health and environmental impact, and also using harsh process conditions.

[0025] Furthermore, it is known from the literature that each functionalization reaction introduces a specific type of substituent / functionalizing agent. That is, a specific type of chemical reaction is required to introduce a specific type of functional group. Therefore, it is difficult to imagine using the same carbon allotropes functionalized by the same type of chemical reaction in matrices with different chemical properties (because they are used in different fields) but sharing the common fact of being lipophilic matrices.

[0026] Therefore, in a matrix with a lipophilic matrix and containing sp 2 In the field of carbon allotropic composite materials, there is a great need for a method to prepare sp 2 A method for producing uniform dispersions of carbon allotropes, wherein the dispersions are stable in any lipophilic matrix (particularly in lubricants (oils and / or greases) and waxy compounds) without requiring dispersants specific to the type of lipophilic matrix, thereby allowing the sp... 2 Carbon allotropic dispersions are widely used in various fields, but what these fields have in common is the use of lipophilic matrices.

[0027] It is also desirable to have a method as defined above that also allows for the preparation of stable composite materials containing a high concentration of dispersed carbonaceous material (e.g., about 1% by weight relative to the weight of the lipophilic matrix, but may also be greater than 1% (so-called masterbatch)), which is also uniformly dispersed in the final lipophilic matrix of the composite material so that it can be used as an additive. Summary of the Invention

[0028] Therefore, the object of the present invention is to provide a method for preparing a composite material, the composite material comprising sp 2 A concentrated or diluted dispersion of carbon allotropes in a lipophilic matrix of a composite material, the method comprising the following steps:

[0029] (A) Optionally, in the presence of one or more solvents, sp 2 Carbon allotropes, especially allotropes with at least one dimension less than 100 nm, are mixed with compounds containing a pyrrole ring of formula (i).

[0030] (i)

[0031] in:

[0032] - R1 and R2 are independently hydrogen or alkyl groups containing 1 to 20, preferably 1 to 10, more preferably 1 to 5, or even more preferably 1 to 2 carbon atoms.

[0033] R1 and R2 are preferably alkyl groups as defined above;

[0034] - R3 is an unsubstituted straight-chain or branched aliphatic group, with or without unsaturation, and without functional groups such as OH, C=O, wherein R3 contains 1 to 40, preferably 1 to 30, more preferably 1 to 20, and even more preferably 6 to 20 carbon atoms.

[0035] or

[0036] -R3 is a polymer chain, preferably derived from polyamines such as triethylenetetramine (TETA), diethylenetriamine (DETA), and derived from polyisobutylene (PIB) and maleimide; or R3 is a polymer chain composed of polyetheramines containing polyoxyethylene chains, such as jeffamine (5,8-dimethyl-4,7,10-trioxatridecane-2,12-diamine).

[0037] The compound (i) is optionally obtained in situ in step (A) by reacting a 1,4-dione with a primary amine R-NH2, where R = R3 of the compound (i);

[0038] (A') Optionally, one or more of the solvents are removed in the presence of the solvents to obtain a solid or semi-solid mixture;

[0039] (B) Preferably, heating is performed while stirring and / or mixing, containing sp 2 A mixture of carbon allotropes and pyrrole compounds of formula (i);

[0040] (C) Preferably, the mixture obtained in step (B) is mixed with a lipophilic compound constituting the lipophilic matrix of the composite material under heating to obtain the sp at a predetermined concentration in the lipophilic matrix. 2 The composite material of carbon allotropes is preferably in the form of a paste;

[0041] and optional

[0042] (D) Preferably, under mixing conditions, the composite material obtained in step (C) is diluted with the same or different lipophilic compound used in step (C) to obtain the sp 2 The total concentration of carbon allotropes is lower than the predetermined concentration of the composite material obtained in step (C).

[0043] The term "lipophilic compound constituting the matrix of the composite material" is understood herein to refer to the lipophilic matrix constituting the main component of the composite material based on concentration / quantity. The term "lipophilic compound" preferably does not include solvents such as toluene, heptane, xylene, hexane, ethyl acetate, acetone, and isoprene rubber (IR), butadiene rubber (BR), etc.

[0044] In one embodiment of the present invention, the lipophilic compound constituting the lipophilic matrix of the composite material is a compound with a molecular weight greater than 200 g / mol, and is not isoprene rubber (IR), butadiene rubber (BR), etc.

[0045] Steps (A), (B), and (C) above are independent steps performed sequentially.

[0046] - Alternatively, all three steps can be performed simultaneously, with each component (allotropy, pyrrole compound (i), and lipophilic matrix) added separately in any order under stirring. In this case, if the mixing in step (C) causes the mixture to heat up, then the heating in step (B) can be omitted.

[0047] or

[0048] - The first two steps (A) and (B) are performed simultaneously to obtain sp 2 The addition product of carbon allotrope and pyrrole compound (i) is then carried out in step (C), wherein the addition product obtained from step (B), such as an adduct, is mixed with a lipophilic matrix;

[0049] However, this does not depart from the scope of the present invention.

[0050] Steps (A) and (B), performed sequentially or simultaneously prior to step (C), typically produce an adduct in the form of an adduct, which usually has covalent bonds, although this is not mandatory for the purposes of this invention.

[0051] In fact, the term "adduct" is generally used to refer to compounds obtained by addition reactions, whose components are linked by more or fewer unstable bonds (supramolecular or covalent bonds), and which can be prepared in advance for subsequent use or obtained in situ. To aid understanding of the examples in this specification, the term "adduct" will be used primarily to refer to the addition of an allotrope to a pyrrole compound prepared prior to addition to a lipophilic matrix, while the term sp... 2 The terms “combination” or “mixture” of carbon allotropes and pyrrole compounds (i) will be used to indicate the fact that the allotropes and pyrrole compounds (i) are added individually and simultaneously to the lipophilic matrix, regardless of the type of covalent or supramolecular bond formed between the allotropes and pyrrole compounds (i).

[0052] The presence of covalent or supramolecular bonds between the allotrope and the pyrrole compound (i) implies that the aforementioned components of the adduct do not exist as individual elements. This can be indirectly confirmed by stability tests, XRD diffraction patterns, and mechanical tests, which will be detailed in the examples.

[0053] In a preferred embodiment, steps (A), (B), and (C) are performed simultaneously by optionally adding the allotrope and pyrrole compound (i) separately to the lipophilic matrix while heated. This is advantageous primarily from an operational standpoint (one-step, one-pot process); furthermore, this approach can indiscriminately result in the formation of adducts with covalent bonds between the components, or in the formation of products in which the allotrope and pyrrole compound (i) have supramolecular bonds.

[0054] According to the present invention, the singular indefinite article “a” is understood to also include the meaning of “at least one”, unless otherwise stated.

[0055] In this specification of the invention, unless otherwise stated, range values ​​include the extreme values ​​of the range.

[0056] In this specification of the invention, unless otherwise stated, percentages (%) should be understood as weight percentages.

[0057] In this specification of the invention, as a particular limitation, the term "comprising" also includes the meaning of "consisting of".

[0058] In this specification of the invention, the term "consistent essentially of..." means

[0059] - The composition or method must include the listed ingredients or steps;

[0060] and

[0061] - The composition or method is open to unlisted ingredients or steps that do not significantly affect the fundamental and innovative properties of the composition or method.

[0062] In this specification of the invention, unless otherwise stated, “part” and “parts” refer to one part by weight and multiple parts by weight, respectively. Attached Figure Description

[0063] Figure 1-3 Three samples of different paraffin composite materials prepared in the examples are shown, one of which was prepared according to the present invention, and their stability was visually evaluated according to method 3 as described in the characterization of the examples;

[0064] Figure 4 The trends of elastic shear modulus G' as a function of strain % are shown for a pure EPM rubber sample and three different composite material samples based on EPM (lipophilic matrix) (two of which were obtained according to the present invention).

[0065] Figure 5-8 shows Figure 4 X-ray diffraction spectra of four different materials;

[0066] Figures 9-12 show the X-ray diffraction spectra of one SBS sample and three different SBS-based composite material samples (two of which were obtained according to the present invention) prepared in the examples. Detailed Implementation

[0067] The compound of formula (i) used in step (A) of the method according to the invention can be a 1,4-dione of the following formula.

[0068]

[0069] It is obtained by the Paal-Knorr reaction between the primary amine R-NH2 and the primary amine, wherein the R group of the primary amine is the same as or has the same meaning as the R3 group of the compound of formula (i).

[0070] For example, in the case of compound (i) with R1=R2=CH3, the Paal Knorr reaction is carried out by reacting 2,5-hexanedione with a primary amine R-NH2 (where R corresponds to R3 and has the same meaning as R3) according to the following synthetic schematic diagram known in the art:

[0071]

[0072] The primary amine R-NH2 that can be used to obtain the compound (i) defined above can be aliphatic (with or without unsaturation) or polymeric.

[0073] Primary amines can include:

[0074] -Oleamine (e.g., Armeen OL, industrial grade 95%);

[0075] - Dodecylamine (e.g., commercially available dodecylamine, industrial grade 98%)

[0076] - Octadecylamine, stearylamine (such as commercially available industrial grade 99%).

[0077] -PIBSI (polyisobutylene succinimide) is a primary polymeric amine obtained, for example, by reacting polyisobutylene (PIB) with maleic anhydride and subsequently with a polyamine (e.g., triethylenetetramine (TETA)).

[0078] In step (A) of the method of the present invention, sp can be 2 The carbon allotrope is mixed with the compound (i) prepared in step (A0), or with the compound (i) already available on the market, or the compound (i) is obtained in situ during the implementation of the mixing step (A), as will be explained in detail below without departing from the scope of the invention.

[0079] In a preferred embodiment of the invention, compound (i) is prepared prior to step (A) because it has been prepared in step (A0) or is commercially available.

[0080] In one embodiment, the compound of formula (i) has an R3 group selected from alkyl, alkenyl or alkynyl, aryl, alkyl-aryl, alkenyl-aryl, alkynyl-aryl, and has a plurality of carbon atoms as defined above. Preferably, R3 is oleyl (monovalent oleic acid group), octadecyl, dodecyl, or stearyl (monovalent stearic acid group).

[0081] Preferred examples of compounds of formula (i) are:

[0082] -2,5-Dimethyl-1-oleyl-1H-pyrrole (oleylpyrrole, OP) of the following formula

[0083]

[0084] -2,5-Dimethyl-1-octadecyl-1H-pyrrole (octadecylpyrrole, OCDP)

[0085]

[0086] -2,5-Dimethyl-1-dodecyl-1H-pyrrole (dodecylpyrrole, DodcP) of the following formula.

[0087]

[0088] In one specific embodiment, the compound of formula (i) may also be a compound in which R3 is a polymer chain, such as derived from polyisobutylene succinimide, which may further be derived from a reaction between polyisobutylene (PIB), maleic anhydride and a polyamine (e.g., triethylenetetramine (TETA)).

[0089] In particular, when R3 is a polymer chain, the compound of formula (i) can have the following formula:

[0090]

[0091] PIBSI-P (pyrrole-polyisobutylene succinimide), where n = 1-30.

[0092] The compound PIBSI-P is obtained by the reaction between polyisobutylene succinamide and triethylenetetramine or similar TETA-type polyamines.

[0093] In another embodiment, when R3 is a polymer chain, the compound of formula (i) can have the following formula (I).

[0094]

[0095] The latter compound (i) is obtained by the following reaction.

[0096] (hexanedione)

[0097] In another embodiment, when R3 is a polymer chain, the compound of formula (i) can have the same chemical formula as that of formula (i) above, but wherein R3 is a monovalent group derived from the following compound.

[0098]

[0099] The applicant has discovered that, in the method according to the invention, the compound of formula (i) reacts with sp 2 The combined use of carbon allotropes allows for the acquisition of sp 2 Carbon allotropes, particularly in the case of nanographite and graphene, are homogeneous and stable dispersions in a variety of lipophilic matrices, especially in matrices composed of lubricating oils and / or greases and waxy compounds. Without wishing to be bound by any theory, it can be assumed that the compatibility of nanographite and / or graphene in lipophilic matrices is achieved through the interaction of the compounds with nanographite, graphene, and sp... constituting at least one dimension less than or equal to 100 micrometers (nanometers). 2 It is facilitated by the interaction of the edges of the lamellae of carbon allotropic analogs.

[0100] sp that can be used in the method of the present invention 2Carbon allotropes include carbon black (CB), graphene, nanographite composed of several to dozens of graphene layers, high surface area nanographite (HSAG), graphite or graphene having 2 to 10,000 graphene layers, fullerenes, single-walled or multi-walled carbon nanotubes (CNTs), nanorings, nanocones, graphene nanoribbons, or mixtures thereof.

[0101] Preferably, sp 2 The carbon allotropes are selected from allotropes used as "nano" fillers, such as graphene, nanographite composed of several to dozens of graphene layers, and high surface area nanographite (HSAG) (e.g., 100 to 400 μm). 2 / g), graphite, graphene, fullerene and carbon nanotubes or mixtures thereof.

[0102] In a particularly preferred embodiment, sp 2 Carbon allotropes are selected from graphene, nanographite composed of several (to dozens of) graphene layers, graphite, graphene, and high surface area nanographite (HSAG) (e.g., 100 to 400 μm). 2 / g, preferably 250 to 350 m 2 / g).

[0103] sp that can be used in this invention 2 Carbon allotropes may also contain functional groups such as hydroxyl groups, epoxides, aldehydes, ketones, and carboxylic acids, without departing from the scope of this invention.

[0104] In one embodiment, the mixing step (A) may also be carried out in the presence of one or more solvents, which typically have low boiling points, such as nonpolar solvents, protons or aprotic polar solvents (e.g., alcohols, ketones, esters, amides).

[0105] Examples of low-boiling-point alcohols are ethanol and isopropanol; examples of low-boiling-point ketones are acetone and methyl ethyl ketone, preferably acetone; examples of low-boiling-point esters are ethyl acetate; examples of low-boiling-point amides are N-methylpyrrolidone. Examples of nonpolar solvents are hydrocarbon solvents, such as hexane, heptane, cyclohexane, and toluene.

[0106] A preferred example of a solvent in step (A) is acetone.

[0107] The solvent in step (A) can be advantageously used to form sp. 2 Suspensions / dispersions of carbon allotropes and / or solutions / suspensions forming compound (i).

[0108] In one embodiment, the method according to the invention may include preparing sp 2The dispersion of carbon allotropes is used to perform step (A), in which a primary amine and a diketone as defined above are added to the dispersion to form a pyrrole compound (i) in situ in step (A).

[0109] In another embodiment, step (A) of mixing the allotrope with compound (i) can be performed by stirring sp under stirring. 2 Carbon allotropes and compounds (i) are added to a solvent to carry out the process.

[0110] The stirring of the allotropic dispersion and the pyrrole compound in step (A) can be carried out by, for example, ultrasonic, mechanical stirring, magnetic stirring, with or without one or more solvents as defined above, using a suitable mixing device, such as a planetary mixer, a Silverson mixer, an ultrasonic mixer, a high-speed mixer, a ball mill, etc.

[0111] Depending on whether a solvent is used, the mixing device used in step (A) can be operated at a speed of 1500 rpm to 6000 rpm, or 60-80 rpm, or 100 rpm to 1500 rpm.

[0112] In step (A), when one or more solvents and / or stirring are used, the compound of formula (i) and sp are added relative to the solvent and / or stirring. 2 The order of carbon allotropes is not mandatory for the purposes of this invention.

[0113] In one embodiment of the present invention, sp can be prepared first. 2 A carbon allotrope is suspended in a first solvent, and then the allotrope suspension is stirred / sonicated. Subsequently, a compound (i) that may be soluble in a second solvent is added to the suspension again under stirring / sonication. The first solvent and the second solvent may be the same as or different from each other.

[0114] In another embodiment of the method according to the invention, step (A) involves stirring / sonicating the sp... 2 Carbon allotropes and compounds of formula (i) are added to solvents as defined above.

[0115] If one or more solvents are used in step (A), it is preferable to use sp 2 When the carbon allotrope is successfully mixed with the compound of formula (i), a subsequent step (A') is performed to remove one or more solvents, thereby making the mixture substantially solvent-free and containing sp in step (B). 2 A solid mixture (e.g., powder) or a semi-solid (e.g., paste consistency) of a mixture of carbon allotropes and compounds of formula (i) is subjected to heating.

[0116] The removal of one or more solvents in optional step (A') can be carried out by methods known in the art, such as evaporation, vacuum evaporation, etc.

[0117] The heating in step (B) is carried out at a temperature that is typically 80-100°C to 170°C, preferably 130°C to 170°C, more preferably 130°C to 160°C, and even more preferably about 150°C.

[0118] The heating temperature in step (B) can be higher or lower, preferably higher than the temperature used in step (C) of the method, depending on whether the steps are performed sequentially or simultaneously and the type of lipophilic matrix.

[0119] Typically, the mixing step (C) with the lipophilic matrix is ​​carried out under thermal conditions, especially when the compound that can be used as the lipophilic matrix is ​​solid at room temperature, such as wax, semi-crystalline polymer, or rubber.

[0120] If the lipophilic matrix is ​​in a solid physical state at room temperature, step (C) is advantageously carried out under heating, and thus the heating is carried out by operating at a temperature that depends primarily on the lipophilic matrix being in such a liquid or molten state that it promotes mixing with the remaining components of the composite material.

[0121] In one embodiment, the heating step (C) is performed by operating at a temperature of at least 80-100°C.

[0122] If step (C) is performed simultaneously with steps (A) and (B), such that sp 2 When carbon allotropes are mixed with compounds of formula (i) and lipophilic matrices, it is advantageous to mix them at a temperature in the range of 80°C to 150°C while heating.

[0123] The heating shown in steps (B) and (C) can be performed by methods known in the art, such as by using an oil bath, an electric coil, an electric plate, a hot fluid, photon radiation, etc., without departing from the scope of the present invention.

[0124] If steps (A), (B), and (C) are performed individually in sequence, then in step (B) heating includes sp 2 The mixture of carbon allotropes and compound (i) is subjected to a process of 50 to 150 minutes, preferably 100 to 140 minutes, more preferably 115 to 125 minutes.

[0125] When steps (A), (B) and (C) are performed simultaneously, heating is carried out for 130 to 220 minutes, preferably 150 to 200 minutes, and more preferably 170 to 190 minutes, while the three components (allotropes, pyrrole compounds and lipophilic matrix) are mixed simultaneously.

[0126] In step (C), the mixing of the lipophilic matrix, allotropes and pyrrole compounds (i) in individual or adduct form can be carried out using the same mixing method and mixing apparatus as in step (B).

[0127] Specifically, in step (C), depending on the type of lipophilic matrix, mixing can be performed under stirring using a mixer (e.g., Silverson) that operates at rpm in the range of 1500 rpm to 6000 rpm or a mixer (e.g., Brabender) that operates at about 60-80 rpm.

[0128] Depending on the viscosity and properties of the selected lipophilic matrix and the temperature at which step (C) is performed, the mixing apparatus that can be advantageously used in step (C) is, for example, a Silverson mixer or a Brabender mixer. ® Internal mixer.

[0129] The lipophilic compound constituting the lipophilic matrix of the composite material can be, for example, a combination of one or more compounds selected from the following:

[0130] -Lubricating oils or base oils derived from mineral, synthetic, or renewable raw materials used in the lubricating composition;

[0131] -grease;

[0132] - Solid compounds at room temperature (hereinafter also referred to as waxy compounds), such as paraffin, animal wax, plant wax, such as hydrocarbon compounds, saturated fatty acids, esters, such as saturated fatty acid methyl esters with a carbon number greater than or equal to C12 to up to 32, such as myristic acid, palmitic acid, lauric acid, stearic acid, hexacosanoic acid and esters of similar acids, also referred to as "wax" or "paraffin", whose molecules have alkyl chains with a carbon number greater than or equal to 12 to up to 32;

[0133] - Polymer matrices, such as elastomers (e.g., gaskets, rubber materials), especially "EPR / EPM" (ethylene-propylene copolymer-based rubber) and typical block copolymers called SBS (styrene / butadiene / styrene);

[0134] - Its combination.

[0135] The base oil can be selected from mineral oil, synthetic oil, vegetable oil, animal oil, and mixtures thereof.

[0136] Mineral-derived oils are produced through well-known crude oil refining processes, such as distillation, dewaxing, deasphalting, dearomatization, and hydrogenation.

[0137] The synthetic source of oil preferably includes hydrocarbon oils, such as polymerized and hydrogenated terminal or internal olefins; alkylbenzenes; polyphenols; alkylated diphenyl ethers; polyalkylene glycols and their derivatives, wherein the terminal hydroxyl groups have been modified, for example, by esterification or etherification.

[0138] Another type of synthetic lubricant preferably contains esters formed from synthetic or animal- or plant-derived carboxylic acids and various alcohols or polyols.

[0139] Another type of synthetic lubricant preferably contains esters formed from carbonic acid and various alcohols and polyols.

[0140] Preferably, the vegetable oil is selected from soybean oil, palm oil and castor oil, while the animal-derived oil is preferably selected from suede, lard or whale oil.

[0141] Another method for classifying base oils is the one defined by the American Petroleum Institute (API) in its publication "Engine Oil Licensing and Certification System" (API EOLCS, 1507 - Industrial Services Department, 14th edition, December 1996, Appendix 1, appendices to the March 2014 and 2015 editions).

[0142] Base oils are classified into five groups based on their chemical / physical properties and compositional characteristics. According to this classification, base oils that can be used in the lubricant formulations covered by this invention may belong to all of the above-mentioned API groups, preferably API groups II, III, IV, and V, and even more preferably API groups III, IV, and V.

[0143] The grease that can be used as a lipophilic matrix in this invention can be a grease containing a base oil as defined above and at least one major thickener / thickening agent, having different consistency according to the NLGI scale.

[0144] The solid compound that can be used as a lipophilic matrix in the method of the present invention at room temperature (T=15-25°C) is typically a waxy compound, such as a wax, characterized by the following properties:

[0145] a) Extensibility at room temperature

[0146] b) Low viscosity during melting

[0147] c) Insoluble in water and water-repellent.

[0148] The waxes suitable for the purposes of this invention can be of different sources, such as mineral or synthetic sources, animal sources, plant sources, or mixtures thereof.

[0149] Examples of waxes of mineral or synthetic origin include paraffin waxes, which consist primarily of pure alkanes, preferably long-chain, straight-chain, or mixed alkanes; microcrystalline waxes; polyethylene or polyalphaolefin waxes; Fischer-Tropsch waxes; and amide waxes (e.g., stearamide or oleamide), or mixtures thereof.

[0150] Examples of animal-derived waxes include beeswax, lanolin, or "Chinese wax" or mixtures thereof.

[0151] Examples of plant waxes include carnauba wax, myrtle wax, castor wax, esparto wax, jojoba wax, or mixtures thereof.

[0152] Other examples of waxy compounds may be PCMs (phase change materials) with melting temperatures (Tm) in the range of 70°C to 120°C; hexadecane (Tm of about 18°C); stearic acid (Tm of about 69°C); myristic acid (Tm of about 54°C); palmitic acid (Tm of about 63°C); or mixtures thereof.

[0153] Examples of polymer matrices are amorphous or semi-crystalline polymers, such as polyurethanes, polyamides, polyethers, polyesters, polycarbonates, polyvinyl esters, polyvinyl alcohol, copolymers of ethylene with vinyl acetate or vinyl alcohol, polyolefins (e.g., polyethylene and polypropylene), ethylene-propylene copolymers, diene-derived polymers, natural rubber (i.e., poly(1,4-cis-isoprene)), and copolymers of styrene and butadiene.

[0154] In a preferred embodiment, the lipophilic matrix is ​​selected from:

[0155] - Base oil, preferably belonging to Group 3 (e.g., ETRO 4);

[0156] - Ethylene-propylene copolymer EP(D)M, for example Dutral CO 054;

[0157] -Styrene-butadiene-styrene (SBS) linear block copolymers, such as Europrene SOL TH 2312;

[0158] - Paraffin wax, preferably a mixture of paraffin waxes, such as Paramat wax;

[0159] - Its combination, for example, etro 4 base oil + SBS.

[0160] In a particularly preferred embodiment, the lipophilic matrix is ​​a lubricant base oil or grease.

[0161] In another preferred embodiment, the lipophilic matrix is ​​paraffin.

[0162] Optionally, the content containing sp can be included. 2A surfactant, preferably a polymeric surfactant, of a compound containing hybrid carbon atoms is added to the mixture in step (C).

[0163] Examples of polymeric surfactants include polar surfactants, nonpolar surfactants, or mixtures thereof.

[0164] Examples of surfactants that can be used in the method of the present invention are:

[0165] - A star-shaped polymer having approximately 16 polymer arms, the star-shaped polymer being composed of hydrogenated styrene isoprene copolymer (e.g., SV261).

[0166] - Polymers with pour point decreasing properties obtained by combining alkyl methacrylate monomers (Mw 200000 Da), such as HV32;

[0167] - Anionic oligomer dispersants suitable for solvent-based and water-based systems (e.g., KD24).

[0168] - Dispersants based on phosphate esters and PEG (e.g., S23B);

[0169] - A polymer dispersant composed of polybutylene succinate and methylene diisocyanate in the presence of PEG (e.g., S624).

[0170] - A nonionic polymeric dispersant for dispersions based on solvents used in advanced ceramics, electronic materials and nanomaterials (e.g., KD 14).

[0171] - Nonionic surfactants derived from polyethoxylated dehydrated sorbitol and oleic acid (e.g., SPAN 80);

[0172] - A hydrogenated styrene-butadiene linear block copolymer with a styrene content of 30% (e.g., XLZ 18 A).

[0173] In one embodiment, the surfactant is a nonpolar surfactant compound.

[0174] In a preferred embodiment, the dispersant is selected from SV261, HV 32, or a combination thereof.

[0175] In another embodiment, compound PIBSI-P of formula (i) defined above is combined with compound of formula (i) for use in the method according to the invention.

[0176] According to a preferred embodiment of the method of the present invention, steps (A), (B), and (C) are performed simultaneously. In this preferred embodiment, optionally at least one component containing sp 2 Surfactants in compounds with hybrid carbon atoms are added to sp2 In a mixture of carbon allotropes and pyrrole compounds of formula (i).

[0177] The lipophilic matrix of the composite material obtained in step (C) (even when composed of a mixture of different lipophilic matrices) contains sp 2 The predetermined concentration of carbon allotropes is not mandatory for the purposes of this invention. This predetermined concentration (e.g., in phm, where phm represents 100 parts of lipophilic matrix) can typically be within the following range:

[0178] -0.5-50 phm,

[0179] - Preferably 1-35 phm,

[0180] The lipophilic matrix can be a base oil, waxy compound, elastomer, grease or another type of matrix or a mixture thereof as defined above, preferably a base oil, wax or grease as defined above.

[0181] In one embodiment, the lipophilic matrix of the composite material obtained from step (C) contains sp 2 The predetermined concentration of the carbon allotrope can be greater than or equal to 10 phm up to 30-35 phm. In this case, we can discuss concentrating the composite material and then diluting or dispersing it in a lipophilic matrix by performing step D) without departing from the scope of the invention.

[0182] In another embodiment, the lipophilic matrix of the composite material obtained from step (C) contains sp 2 The predetermined concentration of carbon allotropes can be varied in the range of 2-22 phm.

[0183] Compared to the sp used to obtain a predetermined concentration 2 The amount of carbon allotropes, the amount of pyrrole compound of formula (i) used, is in the range of 3 phc to 50 phc (per 100 parts of carbon, considering 100 phc as the amount (by weight) of allotropes used to obtain the aforementioned predetermined concentration).

[0184] In one implementation, relative to sp 2 The amount of the pyrrole compound of formula (i) used in the carbon allotrope is in the range of 5 phc to 10 phc.

[0185] In another implementation, relative to sp 2 The amount of the pyrrole compound of formula (i) used in the carbon allotrope ranges from 10 phc to 37 phc.

[0186] In the case where steps (A) and (B) are performed sequentially to form the adduct to be added in step (C), the adduct can be added to the lipophilic matrix in an amount of 10 phm to 50 phm.

[0187] Besides sp 2 In addition to mixtures of carbon allotropes and pyrrole compounds of formula (i), surfactants containing hybrid sp... 2 The amount of carbon atoms in the compound is:

[0188] -5 phc to 50 phc

[0189] - Preferably 10 phc to 30 phc,

[0190] -More preferably 15 to 20 phc,

[0191] Where phc refers to "per hundred parts of carbon", i.e., sp. 2 The amount (by weight) of carbon allotropes is 100 phc.

[0192] When using surfactants, the maximum total amount of pyrrole compound (i) + surfactant (hereinafter also referred to as "organic matter") is equal to 50 phc, preferably the maximum amount of organic matter is 30 phc, and the minimum amount of organic matter is 8 phc.

[0193] In one embodiment, in the absence of a surfactant, the pyrrole compound is present in an amount of at least 15 phc, preferably at least 30 phc.

[0194] In another embodiment, the pyrrole compound is present in an amount of at least 15 phc, and the surfactant is present in an amount of at least 15 phc.

[0195] If step (C) is performed alone and after steps (A) and (B) are performed sequentially, then sp 2 The mixture of the carbon allotrope and the compound of formula (i) is heated in step (B) of the method of the present invention at a temperature range of 100°C to 170°C, preferably 130°C to 170°C, and even more preferably 140°C to 160°C.

[0196] If steps (A), (B), and (C) are performed individually, in order to form the adduct, sp 2 The mixture of the carbon allotrope and the compound of formula (i) is heated in step (B) of the method for 50 to 150 minutes, preferably 100 to 140 minutes, and even more preferably 115 to 125 minutes (120 minutes is the commonly used time).

[0197] If steps (A), (B) and (C) are performed simultaneously, the system is heated to a temperature range of 100°C to 170°C, preferably 130°C to 170°C, and even more preferably 140°C to 160°C.

[0198] When steps (A), (B), and (C) are performed simultaneously, in order to form an adduct, sp 2 The mixture of the carbon allotrope and the compound of formula (i) is heated in step (B) of the method for 130 to 220 minutes, preferably 150 to 200 minutes, and even more preferably 170 to 190 minutes.

[0199] The composite material obtained from step (C) using this method can be considered a concentrated composite material in terms of allotrope content, and can be used as an additive or as the composite material itself in a variety of fields due to its high stability.

[0200] For example, the concentrated composite material containing a base oil and including the aforementioned allotropes and pyrrole compounds (i) that can be obtained from step (C) of the method of the present invention can be used as a soluble "metal-free" additive to be added to the base oil (lipophilic matrix) in the preparation of a lubricating composition in the form of a lubricating oil or grease to impart anti-friction and anti-wear properties to the lubricating composition.

[0201] According to the present invention, a waxy compound (lipophilic matrix) containing the above-mentioned sp can be obtained. 2 Composites of carbon allotropes and pyrrole compounds (i) can be used as cooling devices for passive cooling of photovoltaic panels due to the thermal conductivity of such composites.

[0202] The composite material obtainable from step (C) of the method according to the invention is based on an elastomer (e.g., SBS, EPM) and also contains sp as described above. 2 Carbon allotropes and pyrrole compounds (i) can be used as masterbatch additives to impart mechanical strength to gaskets, rubber materials, coatings, and generally all elastomer materials.

[0203] The additives themselves are stable over time (e.g., 120 hours), and this stability indicates that, according to the preparation method of the present invention, in the presence of pyrrole compounds, the nanographite is exfoliated and does not tend to aggregate, while in the absence of pyrrole compounds, the nanographite exhibits aggregation due to the instability of the composite material.

[0204] This non-aggregating tendency has been observed in different types of lipophilic matrices. See examples.

[0205] This method and the composite materials that can be obtained from it or obtained by it have many advantages.

[0206] The first advantage is the use of allotropic functionalized compounds, which are not critical from a health and environmental perspective.

[0207] The second advantage is that it uses less demanding process conditions, rather than allotrope-specific dispersants that depend on the different chemical properties of the lipophilic matrix.

[0208] Another advantage is that a single type of allotrope functionalizing agent can be used in any type of lipophilic matrix, thereby enabling the sp... 2 Carbon allotropic dispersions can be widely used in a variety of fields with a common lipophilic matrix.

[0209] Another advantage is the ability to prepare stable and uniform composite materials containing a high concentration of dispersed carbonaceous material, the so-called masterbatch, which can also be uniformly dispersed in the final lipophilic matrix of the composite material (e.g., base oil, elastomer) and remains stable after dilution / dispersion in the final lipophilic matrix.

[0210] The following are some illustrative but non-limiting embodiments of the present invention.

[0211] Example

[0212] Characterization methods

[0213] -Stability tests were performed on the dispersion (concentrated composite, or also defined as "paste") of nanographite, pyrrole compounds, and optional surfactants in oil by visual inspection, with the nanographite concentration at 10 phm relative to oil considered to be 100 phm (Method 1).

[0214] These samples were stored under static conditions in 50 ml of Falcon. TM The stability of concentrated composite material samples (masterbatch) was investigated in conical centrifuge tubes (Corning). Stability was evaluated by measuring the height of the region exhibiting the darkest uniform color and the total height of the composite material using a ruler with millimeter graduations after 24, 48, 120, and 216 hours. The percentage height of the composite material exhibiting the darkest uniform color was calculated using the following equation:

[0215] 100 × (height of the composite material with the darkest uniform color) / (total height of the composite material)

[0216] Stability was assessed by reporting "yes" and "no" in Table 5.

[0217] When the dark area height is ≥ 98% of the initial height, it is reported as "Yes" (see Table 5).

[0218] - By visual inspection, a dispersion (concentrated composite material, or also defined as a "paste") of nano-graphite, pyrrole compounds, and optional surfactants in oil is determined at a concentration of less than or equal to 0.1 v. 糊状物 / v 最终产物 Stability testing was performed using a concentration dilution of % (total volume of the diluted composition) (Method 2):

[0219] By holding the composite sample under static conditions in 50 ml of Falcon TM (Corning) conical centrifuge tubes were used, and the bottom of the tubes was periodically visually inspected to study stability. Physically, the tubes were placed "upside down" to evaluate the presence of black composite material deposits at the bottom.

[0220] -Stability testing of composite materials based on adducts / combinations of paraffin and nanographite with pyrrole compounds (Method 3):

[0221] A wax-based composite material containing nano-graphite and pyrrole compounds was held in a graduated cylinder at 150°C (in an oil bath) for 6 hours. The oil bath was removed, and the material was then cooled to room temperature. Once room temperature was reached, the total height of the composite material and the height of the composite material showing the darkest, most uniform color were measured using a ruler with millimeter graduations.

[0222] The height % of the composite material displaying the darkest uniform color is calculated using the following equation:

[0223] 100 × (height of the composite material with the darkest uniform color) / (total height of the composite material).

[0224] If the calculated height is greater than or equal to 90% of the initial height, the dispersion is considered stable.

[0225] - Rheological characterization of EPR-based composites and adducts / combinations of nanographite and pyrrole compounds by dynamic-mechanical shear testing (Method 4):

[0226] Rheological characterization of elastomer composites based on EPR and combinations / adducts of nanographite and pyrrole compounds (i) was performed using an RPA (Rubber Processing Analyzer) rheometer.

[0227] The following protocol was followed for rheological characterization using annealing and strain scanning tests: a first strain scan was performed at 60°C to eliminate previous thermomechanical history, with a strain amplitude of 0.2% to 100% and a frequency of 1 Hz. Then, an annealing test was performed again at 60°C for 15 minutes, maintaining a strain of 0.2%. Finally, a second strain scan was performed, with a strain amplitude of 0.2% to 100% and a frequency of 1 Hz.

[0228] Then the elastic shear modulus G' is measured as a function of the strain amplitude.

[0229] The curve describing the dependence of the elastic modulus G' on the strain amplitude is as follows: Figure 4 As shown.

[0230] The decrease in shear modulus G' at minimum strain and the difference ΔG' between the minimum and maximum shear modulus values ​​G' in the elastomer are related to the reduction in the amount of lattice formed by allotropes, as reported in the literature (e.g., Warasitthinon, N., Genix, AC, Sztucki, M., Obrdisse, J., & Robertson, CG (2019). The Payne effect: Primarilypolymer-related or filler-related phenomenon?. Rubber Chemistry and Technology, 92(4), 599-611.).

[0231] X-ray diffraction of EPR and SBS themselves, as well as EPR and SBS-based composites containing adducts / combinations of nano-graphite and pyrrole compounds (Method 5):

[0232] Wide-angle X-ray diffraction (WAXD) patterns were obtained using a Bruker D8 Advance automated diffractometer with nickel-filtered Cu-Kα radiation in reflection mode.

[0233] Because the diffraction angle of the peak is 2θ, these graphs are recorded using 2θ, which ranges from 4.7° to 90°. The obtained spectra are processed using MATLAB.

[0234] X-ray analysis was performed by irradiating two orthogonal portions of each sample.

[0235] Therefore, each diffraction pattern (Figures 5, 6, 7, 8) refers to the same sample that was irradiated at different intensities at two different orthogonal positions, producing two different diffraction patterns (red lines and blue lines), and their trends are basically similar.

[0236] -NMR analysis:

[0237] NMR analysis was performed using a Bruker AV 400 spectrometer (Bruker, Rheinstetten, Germany) operated at 400 MHz with deuterated chloroform (CDCl3) as solvent.

[0238] Material

[0239] - Nanographite: Sold by Asbury Carbon with a surface area of ​​approximately 350 m² 2 / g of HSAG nano24 graphite;

[0240] -EPR = ethylene-propylene copolymer elastomer, sold by Versalis under the trade name Dutral CO 054 (EP(D)M);

[0241] -SBS = styrene-butadiene-styrene linear block copolymer, marketed by Versalis under the trade name EuropreneSOL TH 2312;

[0242] -Etro 4+oil = Group 3 base oil, sold by Petronas, density = 0.8348 kg / L;

[0243] - Paraffin = Paraffin mixture, sold by VWR Chemicals under the trade name Paramat;

[0244] - Hexanedione = Produced by Sigma-Aldrich and sold by Merck (CAS 110-13-4)

[0245] - Surfactants

[0246]

[0247] Examples 1-3: Preparation of different pyrrole compounds of formula (i)

[0248] Example 1: Synthesis of oleylpyrrole (OP, 2,5-dimethyl-1-oleyl-1Hpyrrole)

[0249]

[0250] 2 g of oleylamine (1 equivalent, 5.23 mmol) and 597 mg of 2,5-hexanedione (1 equivalent, 5.23 mmol) were added to a 50 mL flask. All substances were magnetically stirred at 130 °C for 1 h. The reaction mixture was then cooled to room temperature. The pure product was obtained in 95% yield.

[0251] Below is the successful synthesis of oil-based pyrrole. 1 H-NMR and 13 C-NMR data.

[0252] 1H NMR (CDCl3, 400 MHz); δ (ppm)=5.81 (s, 2H, CH), 5.55 (m, 2H, CH=CH), 3,89-3,87 (t, 2H, N-CH2-CH2-), 2,40 (s, 6H, CH3), 2,20 (m, 4H, CH2-CH=CH-CH2), 1,79 (m, 2H, N-CH2-CH2-R), 1.49 (m, 22H, R-CH2-R), 0.95 (m, 3H,CH3).

[0253] 13 C NMR (CDCl3, 100 MHz); δ (ppm)= 130.6, 127.6, 105.6, 43.72, 33.7, 32.01, 31.10, 29.78, 29.3, 27.5, 22.76, 14.16, 12.51.

[0254] Example 2: Dodecylpyrrole ( DodcP, Synthesis of 2,5-dimethyl-1-dodecyl-1H-pyrrole

[0255]

[0256] 16.24 g of dodecylamine (1 equivalent, 87.61 mmol) and 10 g of 2,5-hexanedione (1 equivalent, 87.61 mmol) were added to a 250 mL flask. All substances were magnetically stirred at 130 °C for 2 h. The reaction mixture was then cooled to room temperature. The pure product was obtained in 92% yield.

[0257] The following provides a successful example of the synthesis of oil-based pyrrole. 1 H-NMR and 13 C-NMR data.

[0258] 1 H NMR (CDCl3, 400 MHz); δ (ppm)=5.81 (s, 2H, CH), 3.87- 3,89 (t, 2H,N-CH2-CH2-), 2.41 (s, 6H, CH3), 1.80 (m, 2H, N-CH2-CH2-CH2-R), 1.49 (m, 18H,CH2), 0.95 (m, 3H, CH3).

[0259] 13C NMR (CDCl3, 100 MHz); δ (ppm) = 127.27, 105.03, 43.72, 32.01, 31.10, 29.78, 27.05, 22.76, 14.16, 12.51.

[0260] Example 3: Synthesis of octadecylpyrrole (ODcP; 2,5-dimethyl-1-octadecyl-1H-pyrrole)

[0261]

[0262] 0.5 g of octadecylamine (1.85 mmol) and 0.2 g of 2,5-hexanedione (1.85 mmol) were added to a 10 mL glass vial equipped with a magnetic stirrer. The mixture was stirred at 130 °C for 3 h. The reaction time was selected according to literature on the synthesis of pyrrole compounds at similar temperatures. The reaction mixture was then cooled to room temperature. The pure product was obtained in a yield of 0.518 g (73%).

[0263] Below is the successful synthesis of octadecylpyrrole. 1 H-NMR and 13 C-NMR data.

[0264] 1 H NMR (CDCl3, 400 MHz); δ (ppm) = 5.81 (s, 2H, CH), 3.78–3.74 (t, 2H,N–CH2–CH2–), 2.27 (s, 6H, CH3), 1.66 (m, 2H, N-CH2 –CH2–CH2–R), 1.37 (m, 2H,CH2–CH3) 1.33 (m, 12H, CH2), 0.95 (m, 3H, CH3).

[0265] 13 C NMR (CDCl3, 100 MHz); δ (ppm) = 127.27, 105.03, 43.72, 32.01, 31.10, 29.78, 27.05, 22.76, 14.16, 12.51.

[0266] Example 3a: Synthesis of the following pyrrole compound (i) with an R3 polymer chain (PIBSI-P)

[0267]

[0268] In an Erlenmeyer flask containing 850 mL of xylene, 200.535 g of PIBSI 1300-HEPA of the following formula was dissolved under gentle heating and magnetic stirring.

[0269]

[0270] And its molecular weight is 1665 g / mol (1300 (PIB) + 98 (maleic anhydride) + 285 (HEPA) - 18 (H2O)).

[0271] The contents of the flask were then transferred to a 2L round-bottom flask equipped with a magnetic stirrer and a Dean-Stark water separator, and the flask was washed with 50 mL of solvent (xylene).

[0272] The temperature of the reaction mixture was raised to 110°C, and then 16 mL of hexanedione (~15.58 g, 0.136 mol) was added dropwise using a syringe.

[0273] Raise the temperature to 140°C for reflux and maintain for 7 hours, then heat it again for 8 hours to 145°C the next day until the theoretical amount (~4 ml) of water is collected in the Dean-Stark distributor.

[0274] Examples 4-6: Preparation of adducts / combinations of pyrrole compounds and nanographite

[0275] Example 4: Synthesis of Nanographite / Oil-based Pyrrole (OP) Adduct

[0276] Place 85 mL of acetone in a 250 mL round-bottom flask. With magnetic stirring, add 1 g of HSAG nano24 graphite (14 mmol; molecular weight 72) to the acetone, followed by 0.3 g (0.87 mmol; molecular weight 345) of the oil-based pyrrole (OP) prepared in Example 1.

[0277] The mixture was heated from room temperature to 90°C. After the acetone had completely evaporated, the temperature was raised to 180°C again with magnetic stirring and held at that temperature for 2 hours.

[0278] The mixture was then placed in a sintered glass Buchner funnel (Buchner filter), thoroughly washed with acetone, and then the mixture was recovered and weighed, recovering 90-95% of the adduct. In such a mixture, the OP is 30 phc relative to nanographite.

[0279] Example 5: Synthesis of Nanographite / Dodecylpyrrole DodcP Adduct

[0280] In a 50 mL round-bottom flask, add HSAG nano24 (200 mg, 2.8 mmol, molecular weight 71.42) and acetone (15 mL) sequentially. Sonicate the suspension for 15 minutes using a 2 L ultrasonic bath.

[0281] Add 0.28 mmol of dodecylpyrrole (5 mL) to 5 mL of acetone. Sonicate the resulting suspension for 15 minutes. Remove the solvent under reduced pressure.

[0282] The HSAG / DodP black powder was poured into a 25 mL round-bottom flask equipped with a magnetic stirrer and heated to 180°C for 2 hours.

[0283] The mixture was then placed in a sintered glass Buchner funnel (Buchner filter), thoroughly washed with acetone, and then the mixture was recovered and weighed, recovering 90-95% of the adduct.

[0284] Example 6: Synthesis of adduct nanographite / octadecylpyrrole (ODcP)

[0285] Example 5 was repeated, except that octadecylpyrrole was added instead of dodecylpyrrole as compound (i).

[0286] Examples 7-17: Preparation of concentrated lubricating oil-based composite materials containing nano-graphite and pyrrole compounds, and stability testing of the composite materials (Method 1).

[0287] Example 7 (Comparative): Preparation of composite material of Etro 4 oil and nanographite

[0288] Add 10 g of HSAG nanographite and 100 ml of Etro 4 oil (83.48 g) to a 150 ml beaker.

[0289] The mixture was heated to 150°C and mixed at 5700 rpm for 3 hours using a Silverson mixer. Table 4 shows the composition.

[0290] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0291] Example 8: Preparation of a composite material containing Etro 4 oil and nanographite / oil-based pyrrole combined with a lipophilic matrix added separately.

[0292] 10 g of HSAG nanographite, 3 g of oil-based pyrrole obtained in Example 1, and 100 ml of Etro 4 oil (83.48 g) were added to a 150 ml beaker.

[0293] All substances were heated to 150°C and mixed using a Silverson mixer. The mixture was first kept at 1800 rpm for 2 h, and then at 5700 rpm for 1 h. Table 4 shows the composition.

[0294] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0295] Example 9: Preparation of a composite material containing Etro 4 oil, a nano-graphite / oil-based pyrrole combination added separately to a lipophilic matrix, and a surfactant (SV261).

[0296] 10 g of HSAG nanographite, 1.5 g of oil-based pyrrole obtained in Example 1, 1.5 g of surfactant SV261 and 100 ml of Etro 4 oil (83.48 g) were added to a 150 ml beaker.

[0297] The mixture was heated to 150°C and mixed using a Silverson mixer. The mixture was first kept at 1800 rpm for 2 h, then at 5700 rpm for 1 h. Table 4 shows the composition.

[0298] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0299] Example 10: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole composites added to a lipophilic matrix, and surfactant (HV32).

[0300] Example 9 was repeated using the same amounts of components, except that surfactant HV32 was used instead of surfactant SV261. The composition is shown in Table 4.

[0301] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0302] Example 11: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination added to a lipophilic matrix, and surfactant (KD24).

[0303] Example 9 was repeated using the same amounts of components, except that surfactant KD24 was used instead of surfactant SV261. The composition is shown in Table 4.

[0304] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0305] Example 12: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination added to a lipophilic matrix, and surfactant (S23B).

[0306] Example 9 was repeated using the same amounts of components, except that surfactant S23B was used instead of surfactant SV261. The composition is shown in Table 4.

[0307] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0308] Example 13: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combinations added to a lipophilic matrix, and surfactant (S624).

[0309] Example 9 was repeated using the same amounts of components, except that surfactant S624 was used instead of surfactant SV261. The composition is shown in Table 4.

[0310] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0311] Example 14: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination added to a lipophilic matrix, and surfactant (KD14).

[0312] Example 9 was repeated using the same amounts of components, except that surfactant KD14 was used instead of surfactant SV261. The composition is shown in Table 4.

[0313] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0314] Example 15: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination added to a lipophilic matrix, and surfactant (SPAN80).

[0315] Example 9 was repeated using the same amounts of components, except that surfactant SPAN80 was used instead of surfactant SV261. The composition is shown in Table 4.

[0316] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0317] Example 16: Preparation of a composite material containing Etro 4 oil, nanographite / oil-based pyrrole combination and a second pyrrole compound (PIBSI-P) respectively added to a lipophilic matrix

[0318] Example 9 was repeated using the same amounts of components, except that the second pyrrole compound (PIBSI-P) prepared in Example 3a was added instead of surfactant SV261. Table 4 shows the composition.

[0319] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0320] Example 17: Preparation of a composite material containing Etro 4 oil, nanographite / oil-based pyrrole composites added to a lipophilic matrix, and surfactant (XLZ 18A).

[0321] Example 9 was repeated using the same amount of components, except that surfactant XLZ 18A was used instead of surfactant SV261.

[0322] Table 4 shows the composition.

[0323] The stability of the composite material was then tested using method 1, and the results are shown in Table 5.

[0324] Table 4

[0325]

[0326] Table 5: Stability of the concentrated composite materials from Examples 7-17 (Method 1)

[0327]

[0328] By comparing the stability data of Comparative Example 7 and Example 8 according to the present invention, it can be observed that the presence of the pyrrole compound of formula (i) determines the stability of the nano-graphite dispersion in the lubricating oil as a lipophilic matrix, and thus determines the stability of the concentrated composite material in the oil.

[0329] The stability of the composite material of this invention indicates that, in the presence of pyrrole compounds, the nanographite exfoliated during preparation does not exhibit aggregation in the lipophilic matrix, while in the absence of pyrrole compounds, the nanographite exhibits aggregation because the darker regions in the sample are much lower in height, leaving a brighter upper region relative to the lipophilic matrix, which indicates a two-phase system.

[0330] Furthermore, it is noted that the presence of pyrrole compounds provides the composite material of the present invention with stability in oil for up to 120 hours (5 days), regardless of the type of surfactant used.

[0331] Examples 18-23: Composite materials and stability tests in lubricating oil after dilution of previously prepared oils.

[0332] Example 18: A composite material containing nano-graphite / oil-based pyrrole was diluted with Etro 4 oil at a concentration of 0.1 vol / vol%.

[0333] 0.5 mL of the composite material obtained in Example 8 (equivalent to 0.4824 g and containing 0.065 g of adduct, of which 0.05 g is graphite and 0.015 g is oil-based pyrrole, with the remainder being Etro 4 oil) was added to 49.5 mL of Etro 4 oil. All materials were mixed with a magnetic stirrer for 2 minutes.

[0334] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0335] Example 19: Preparation of a composite material of nano-graphite / oil-based pyrrole adduct and Etro 4 oil, diluted to 0.05 vol / vol% oil.

[0336] Following the method described in Example 18, 0.25 mL of the composite material obtained in Example 8 was added to 49.75 mL of Etro 4 oil. All substances were mixed for 2 minutes.

[0337] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0338] Example 20: Preparation of a composite material containing Etro 4 oil and nano-graphite / oil-based pyrrole, diluted to 0.01 vol / vol%.

[0339] Following the method described in Example 18, 0.05 mL of the composite material prepared in Example 8 was added to 49.75 mL of Etro 4 oil. All substances were mixed for 2 minutes.

[0340] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0341] Example 21: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination, and surfactant SV261, diluted to 0.1 vol / vol%.

[0342] Following the method described in Example 18, 0.5 mL of the composite material obtained in Example 9 (equivalent to 0.4824 g, and containing 0.05 g of graphite and 0.008 g of oil-based pyrrole) was added to 49.5 mL of Etro 4 oil. The mixture was mixed for 2 minutes.

[0343] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0344] Example 22: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination, and SV261 surfactant, diluted to 0.05 vol / vol%.

[0345] Following the method described in Example 18, 0.25 mL of the composite material obtained in Example 9 (equivalent to 0.2412 g, and containing 0.025 g of graphite and 0.004 g of oil-based pyrrole) was added to 49.75 mL of Etro 4 oil. The mixture was mixed for 2 minutes.

[0346] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0347] Example 23: Preparation of a composite material containing Etro 4 oil, nano-graphite / oil-based pyrrole combination, and surfactant SV261, diluted to 0.01 vol / vol%.

[0348] Following the method described in Example 18, 0.05 mL of the composite material obtained in Example 9 was added to 49.75 mL of Etro 4 oil. The mixture was mixed for 2 minutes.

[0349] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0350] Example 23a (Comparative): Preparation of a composite material containing Etro 4 oil and nanographite, diluted to 0.1 vol / vol%.

[0351] Following the method described in Example 18, 0.5 mL of the composite material obtained in Comparative Example 7 (equivalent to 0.4674 g and containing 0.05 g of graphite) was added to 49.5 mL of Etro 4 oil. The mixture was mixed for 2 minutes.

[0352] The stability of the diluted composite material was then tested using method 2, and the results are shown in Table 6.

[0353] Table 6: Stability of the lubricants in Examples 18-23a (Method 2)

[0354]

[0355] Examples 24-26: Preparation and stability testing of paraffin composites containing adducts / combinations of nanographite and pyrrole compounds (Method 3)

[0356] Example 24 (Comparative): Preparation of Paraffin and Nanographite Composite Material

[0357] Place 50 g of paraffin wax in a 100 mL graduated cylinder and heat to 150°C. After it is completely melted, add 5 g of HSAGnano24 nano-graphite.

[0358] Mix the mixture at 150°C for 10 minutes with magnetic stirring, then let it stand at 150°C for 6 hours and allow it to return to room temperature (Method 3). Observe the mixture. Figure 1 The results reported in China.

[0359] Table 7 provides the composition, while based on Figure 1 The results observed are presented in Table 8, which provides the results of the stability test (Method 3).

[0360] Example 25: Preparation of composite materials of paraffin and nanographite and oil-based pyrrole added separately to a lipophilic matrix

[0361] Comparative Example 24 was repeated, except that after mixing for 10 minutes, 1.4 g of the oil-based pyrrole (OP) prepared in Example 1 was added to the wax + nanographite mixture under mixed conditions at T=150°C.

[0362] Table 7 shows the composition, while based on Figure 2 The results observed and the stability results evaluated by applying method 3 are shown in Table 8.

[0363] Example 26: Preparation and stability testing of composite materials of paraffin wax and nano-graphite / oil-based pyrrole adducts

[0364] The method of Example 24 was repeated, except that 6.4 g of the nano-graphite / oil-based pyrrole adduct (4.9 g nano-graphite + 1.5 g oil-based pyrrole) prepared in Example 4 was added to the wax instead of nano-graphite.

[0365] Table 7 shows the composition, while based on Figure 3 The results observed and the stability results evaluated by applying method 3 are shown in Table 8.

[0366] Table 7

[0367]

[0368] Table 8

[0369]

[0370] As can be seen from the data in Table 8, the use of pyrrole compounds results in higher stability of the composite material compared to composite materials containing only nano-graphite.

[0371] Examples 27-29: Preparation of EPR elastomer-based composite materials containing nanographite and pyrrole compounds, followed by rheological characterization (Method 4) and diffraction measurements (Method 5).

[0372] Use Brabender with a 50 mL mixing chamber ® Composite materials are prepared using a type of internal mixer.

[0373] Nanographite was added to different samples at 35 phr (per hundred parts of rubber): the unit “phr” used here is considered equivalent to the unit “phm” (per hundred parts of matrix) used in other examples for lipophilic matrices other than rubber.

[0374] Example 27 (Comparative): Preparation of EPR composite material containing nanographite

[0375] 32.74 g of EPR granules were introduced into the mixer at 80°C and plasticized at a rotor speed of 60 rpm for 2 minutes.

[0376] Then 11.46 g of HSAG nano 24 nm graphite was added and mixed at 80 °C for 3 minutes. The composition is shown in Table 9.

[0377] The product, consisting of an EPR-based composite containing nanographite, was then rheologically characterized using method 4 to measure the elastic shear modulus G' as a function of a specific strain amplitude.

[0378] The curve describing the dependence of the elastic modulus G' on the strain amplitude is as follows: Figure 4 As shown in Table 10, the G' and ΔG' values ​​(G'0.2-G'40) at strain amplitudes of 0.2%, 20%, and 40% are shown in Table 10.

[0379] The product consisting of an EPR-based composite material containing nanographite was also subjected to X-ray diffraction using method 5, and the results are shown in Figure 6.

[0380] The EPR sample was also subjected to X-ray diffraction according to Method 5, and the results are shown in Figure 5.

[0381] Example 28: Preparation of an EPR composite containing a combination of nanographite and oil-based pyrrole (OP) separately added to a lipophilic matrix

[0382] 30.85 g of EPR was introduced into the mixer at 80°C and plasticized at a rotor speed of 60 rpm for 2 minutes.

[0383] Then 10.80 g of nano-graphite and 2.47 g of oil-based pyrrole from Example 1 were added and mixed (80°C, 60 rpm) for 3 minutes. The composition is shown in Table 9.

[0384] The product, consisting of an EPR-based composite containing individually dispersed nanographite and oil-based pyrrole, was then rheologically characterized by applying method 4 to measure the elastic shear modulus G' as a function of specific strain amplitudes (0.2%, 20%, and 40%).

[0385] The curve describing the dependence of the elastic modulus G' on the strain amplitude is as follows: Figure 4 As shown in Table 10, the G' and ΔG' values ​​(G'0.2-G'40) at strain amplitudes of 0.2%, 20%, and 40% are shown in Table 10.

[0386] The product, consisting of an EPR-based composite material containing nano-graphite and oil-based pyrrole, was also subjected to X-ray diffraction using method 5, and the results are shown in Figure 7.

[0387] The EPM sample was also subjected to X-ray diffraction according to Method 5, and the results are shown in Figure 5.

[0388] Example 29: Preparation of EPR composite material containing nano-graphite / oil-based pyrrole adduct

[0389] 31.70 g of EPR was introduced into the mixer at 80°C and plasticized at a rotor speed of 60 rpm for 2 minutes.

[0390] Then, 13.63 g of the nanographite / oil-based pyrrole adduct prepared in Example 4 (containing 10 g of HSAG nanographite 24 and 3.63 g of oil-based pyrrole) was added, and the mixture was further mixed at 60 rpm and 80 °C for 3 minutes. The composition is shown in Table 9.

[0391] The product, consisting of an EPR-based composite containing nano-graphite / oil-based pyrrole adduct, was then rheologically characterized using method 4 to measure the elastic shear modulus G' as a function of specific strain amplitudes (0.2%, 20%, and 40%).

[0392] The curve describing the dependence of the elastic modulus G' on the strain amplitude is as follows: Figure 4 As shown in Table 10, the G' and ΔG' values ​​(G'0.2-G'40) at strain amplitudes of 0.2%, 20%, and 40% are shown in Table 10.

[0393] Method 5 was also applied to X-ray diffraction of the product composed of EPR-based composite material containing nano-graphite / oil-based pyrrole adduct, and the results are shown in Figure 8.

[0394] The individual EPM samples were also subjected to X-ray diffraction according to Method 5, and the results are shown in Figure 5.

[0395] Table 9

[0396]

[0397] Table 10: G' values ​​of composite materials

[0398]

[0399] Figure 4 The curves in the figure and the data in Table 10 can be interpreted as follows.

[0400] Polyolefin materials without nanographite exhibit a linear viscoelastic region for strains up to 40%, where the elastic shear modulus G' is independent of the strain amplitude, as expected. The decrease in modulus G' corresponding to high strains above 40% is simply because the modulus G' was measured in the nonlinear viscoelastic state of the material.

[0401] For the composite material containing only nano-graphite and no pyrrole compounds (EPM+HSAG 35phr), the highest values ​​of modulus G' and ΔG' (which represents the decrease of modulus G' as strain amplitude increases) were observed in the test material.

[0402] These higher values ​​indicate that a nanofiller-based lattice (nanographite) is formed in the EPM+HSAG 35phr composite material compared to EPM itself, and that this lattice formed by HSAG allotropes exists in a greater quantity in the EPM+HSAG 35phr composite material than in other elastomer materials.

[0403] Compared to the values ​​of modulus G' and ΔG' of EPM+HSAG 35phr composite containing only nanographite, the addition of pyrrole compounds as a single component during the mixing process (Example 28) or as a component of the nanographite / OP adduct prepared before being added to the mixer (Example 29) resulted in a decrease in elastic shear modulus G' and ΔG'.

[0404] These results indicate that the amount of filler network (i.e., nanographite) formed in composites containing nanographite + pyrrole compounds is less than that in composites containing nanographite but without pyrrole compounds.

[0405] Therefore, pyrrole compounds promote the distribution and dispersion of nanographite in composite materials because they lead to a reduction in the nanographite lattice.

[0406] The diffraction patterns shown in Figures 5 to 8 can be explained as follows.

[0407] The RX curve of EPM in Figure 5 shows no reflection at 2θ=26.7, which is a typical characteristic of nano-graphite crystals.

[0408] The RX curves of EPM+ nanographite in Figure 6 show the typical reflection (002) of nanographite along two orthogonal directions at 2θ=26.7.

[0409] The RX curves of EPM+nanographite+OP in Figure 7 show typical reflections (002) of nanographite at 2θ=26.7 along two orthogonal directions. However, the reflection at 2θ=26.7 appears less intense when compared to the EPM+nanographite bands in Figure 6.

[0410] The RX curve of the EPM+ nanographite / OP adduct in Figure 8 shows the typical reflection (002) of the nanographite at 2θ = 26.7. The reflection appears even less intense when compared with the EPM+ nanographite band in Figure 6.

[0411] It should also be noted that in Figure 8, the two spectra along the two directions are different from each other, which indicates that the nanographite is exfoliated during the mixing with the pyrrole compound (i) and incorporated into the EPM in this form.

[0412] The results showed that pyrrole compounds promoted the dispersion of nanographite in the composite material: since the nanographite is composed of stacked layers, and this stacking is detected at 2θ=26.7 in the X-ray diffraction pattern, the lower the reflection at 2θ=26.7, the lower the stacking.

[0413] A reasonable explanation for the aforementioned reflection attenuation is that the combination / adduct of nanographite and pyrrole promotes the reduction of stacking, thereby facilitating the separation of nanographite into its individual layers, which are then dispersed in the matrix.

[0414] Furthermore, the aforementioned attenuation also indicates that pyrrole-modified nanographite aggregates less in the lipophilic matrix than unmodified nanographite.

[0415] Examples 30-32: Preparation of SBS elastomer-based composite materials (and Etro4 oil) containing nanographite and pyrrole compounds

[0416] Example 30 (Comparative): Preparation of SBS (+Etro 4 oil) composite material containing nano-graphite

[0417] Place 6.48 g SBS, 15.54 g Etro 4 oil and 5.44 g nanographite (24.7 phm nanographite compared to SBS+oil) in a 200 mL rapid mixer container.

[0418] Etro 4 oil was used to enable the preparation of SBS-based composites using a rapid mixer, thereby reducing their viscosity for easier mixing. The mixture was placed in a Hauschild DAC 150.1 FVZ rapid mixer at 3000 rpm for 3 minutes. The composition is shown in Table 11.

[0419] The product composed of SBS-based composite material containing nanographite was also subjected to X-ray diffraction using method 5, and the results are shown in Figure 10.

[0420] An SBS+Etro 4 oil sample, prepared by mixing 6.48 g of SBS and 15.54 g of Etro 4 oil in a 200 mL rapid mixer container, was subjected to X-ray diffraction according to Method 5. The results of Method 5 are shown in Figure 9.

[0421] Example 31: Preparation of SBS+Etro 4 oil composite material containing nanographite and oil-based pyrrole separately added to a lipophilic matrix.

[0422] Following the method in Example 30, 6.20 g of SBS, 14.85 g of Etro 4 oil, 4 g of nanographite, and 1.20 g of the oil-based pyrrole prepared in Example 1 were placed in a rapid mixer container. The mixture was placed in the rapid mixer used in Example 30 at 3000 rpm for 3 minutes, and a temperature rise was observed, indicating that the mixture had been heated. Table 11 shows the composition.

[0423] The product consisting of an SBS-based composite material containing nano-graphite and oil-based pyrrole was also subjected to X-ray diffraction using method 5, and the results are shown in Figure 11.

[0424] Example 32: Preparation of SBS+Etro 4 oil composite material containing nano-graphite / oil-based pyrrole adduct

[0425] Following the method in Example 30, 6.32 g of SBS, 15.17 g of Etro 4 oil, and 6.52 g of the nanographite / oil-based pyrrole adduct prepared in Example 4 (containing 5 g of nanographite and 1.52 g of oil-based pyrrole) were placed in a rapid mixer container. The mixture was placed in the rapid mixer at 3000 rpm used in Example 30 for 3 minutes. Table 11 shows the composition.

[0426] Method 5 was also applied to perform X-ray diffraction on the product composed of SBS-based composite material containing nano-graphite and oil-based pyrrole adduct, and the results are shown in Figure 12.

[0427] Table 11

[0428]

[0429] The diffraction patterns shown in Figures 9 to 12 can be explained as follows.

[0430] The RX curve of SBS in Figure 9 shows no reflection at 2θ=26.7, which is a typical characteristic of nano-graphite crystals.

[0431] The RX curves of SBS+ nanographite in Figure 10 show the typical reflection (002) of nanographite along two orthogonal directions at 2θ=26.7.

[0432] The RX curves of SBS+nanographite+OP in Figure 11 show the typical reflection (002) of nanographite at 2θ=26.7 along two orthogonal directions. However, when compared with the SBS+nanographite bands in Figure 10, the reflection at 2θ=26.7 appears less intense and less sharp.

[0433] The RX curve of the SBS+ nanographite / OP adduct in Figure 12 shows the typical reflection (002) of the nanographite at 2θ = 26.7. Compared with the SBS+ nanographite band in Figure 10, the reflection appears even less intense and even less sharp.

[0434] These results indicate that pyrrole compounds promote the dispersion of nanographite in the composite material. Since the nanographite consists of stacked layers, and this stacking is detected at 2θ=26.7 in the X-ray diffraction pattern, the lower the reflectance at 2θ=26.7, the lower the stacking.

[0435] A reasonable explanation for the above-mentioned reflection attenuation at 2θ=26.7 is that the combination of nanographite and pyrrole, especially in the form of adducts, promotes the reduction of stacking, thereby facilitating the separation of nanographite into its individual layers, which are then dispersed in the matrix.

[0436] Furthermore, the aforementioned attenuation also indicates that carbonaceous materials in the lipophilic matrix did not re-aggregate.

Claims

1. A method for preparing a composite material, wherein the composite material has a lipophilic matrix and contains sp 2 A dispersion of carbon allotropes in the lipophilic matrix of the composite material, the method comprising the following steps: (A) Optionally, in the presence of one or more solvents, sp 2 Carbon allotropes, especially sp(s) with at least one dimension less than 100 nm 2 A mixture of carbon allotropes and compounds containing a pyrrole ring of formula (i). in: - R1 and R2 are independently hydrogen or alkyl groups containing 1 to 20, preferably 1 to 10, more preferably 1 to 5, or even more preferably 1 to 2 carbon atoms. R1 and R2 are preferably alkyl groups as defined above; - R3 is an unsubstituted straight-chain or branched aliphatic group, with or without unsaturation, and without functional groups such as OH, C=O, wherein R3 contains 1 to 40, preferably 1 to 30, more preferably 1 to 20, and even more preferably 6 to 20 carbon atoms. or - R3 is a polymer chain, preferably derived from polyamines such as triethylenetetramine (TETA), diethylenetriamine (DETA), and derived from polyisobutylene (PIB) and maleimide; or R3 is a polymer chain composed of polyetheramines containing polyoxyethylene chains, such as jeffamine (5,8-dimethyl-4,7,10-trioxatridecane-2,12-diamine). The compound (i) is optionally obtained in situ in step (A) by reacting a 1,4-dione with a primary amine R-NH2, wherein R = R3 of the compound of formula (i); (A') Optionally, one or more of the solvents are removed in the presence of the solvents to obtain a solid or semi-solid mixture; (B) Preferably, heating is performed under stirring and / or mixing, containing the sp 2 A mixture of carbon allotropes and the pyrrole compound of formula (i); (C) Preferably, under heating, the mixture obtained in step (B) is mixed with a lipophilic compound constituting the lipophilic matrix of the composite material to obtain a predetermined concentration of the sp in the lipophilic matrix of the composite material. 2 The composite material of carbon allotropes is preferably in the form of a paste; and optional (D) Preferably, under mixing conditions, the composite material obtained in step (C) is diluted with the same or different lipophilic compound used in step (C) to obtain the sp 2 The total concentration of carbon allotropes is lower than the predetermined concentration of the composite material obtained in step (C).

2. The method according to claim 1, wherein the lipophilic compound constituting the lipophilic matrix of the composite material has a molecular weight greater than 200 g / mol, and does not include isoprene rubber, butadiene rubber, etc.

3. The method according to claim 1 or 2, wherein the sp 2 The carbon allotropes are selected from graphene, nanographite composed of several graphene layers (from several to dozens of layers), and preferably have a thickness of 100 to 400 μm. 2 / g of high surface area nano-graphite (HSAG), graphite, graphene, fullerene, carbon nanotubes or combinations thereof; preferably high surface area nano-graphite (HSAG).

4. The method according to claim 1, 2, or 3, wherein steps (A), (B), and (C) can be performed sequentially and individually; or all three steps can be performed simultaneously, with the components (allotropes, pyrrole compound (i), and lipophilic matrix) added in any order; or the first two steps (A) and (B) can be performed simultaneously to obtain the sp 2 The carbon allotrope is added to the pyrrole compound (i), and then step (C) is performed, wherein the product obtained in step (B) is mixed with the lipophilic matrix.

5. The method according to any one of claims 1-4, wherein step (A) is carried out by dispersing the allotrope and the compound (i) in a low-boiling solvent selected from the group consisting of: nonpolar solvents, polar protic solvents, or polar aprotic solvents, under stirring or sonication.

6. The method according to any one of claims 1-4, wherein steps (A), (B) and (C) are performed simultaneously, optionally adding the allotrope and the pyrrole compound (i) to the lipophilic matrix under heating (one-step one-pot method).

7. The method according to any one of the preceding claims, wherein, prior to step (A), a step (A0) is provided for using a 1,4-dione of the following formula. The compound (i) is prepared by the Paal Knorr reaction between the primary amine R-NH2 and the compound, wherein the R group is equal to the R3 group of the compound of formula (i).

8. The method according to any one of the preceding claims, wherein step (B) is performed by heating at a temperature typically from 80-100°C to 170°C, preferably from 130°C to 170°C, more preferably from 130°C to 160°C, and even more preferably about 150°C.

9. The method according to any one of the preceding claims, wherein step (C) is performed by heating the lipophilic matrix at a temperature in which the lipophilic matrix is ​​in a liquid or molten state, preferably at a temperature of at least 80-100°C.

10. The method according to any one of the preceding claims, wherein the sp in the lipophilic matrix of the composite material obtained from step (C) 2 The predetermined concentration range of carbon allotropes is as follows: - 0.5 to 50 phm, - Preferably 1 to 35 phm, Wherein phm refers to per hundred parts of lipophilic matrix (per hundred parts matrix), the lipophilic matrix may be base oil, wax, elastomer, grease or other types of lipophilic matrix or combinations thereof, preferably base oil, wax, grease or combinations thereof.

11. The method according to any one of the preceding claims, wherein, relative to sp 2 The amount of carbon allotropes, the amount of pyrrole compounds of formula (i) is between 3 phc and 50 phc (per hundred parts of carbon, considering 100 phc is the said sp). 2 Within the range of the amount (by weight) of carbon allotropes.

12. The method according to any one of the preceding claims, wherein the lipophilic compound (lipophilic matrix) is selected from the following: - The lubricating oil or base oil used in the lubricating composition, said oil having a mineral or synthetic source, or derived from renewable raw materials; - Fat lubricant; - A waxy solid compound at room temperature, such as paraffin, animal wax, or plant wax, preferably a hydrocarbon compound, saturated fatty acid, or a saturated fatty acid ester with 12 to 32 carbon atoms, such as myristate, palmitate, laurate, stearate, hexadecanoate, etc., whose molecules have an alkyl chain with 12 to 32 carbon atoms. - Polymer matrices, such as elastomers (e.g., gaskets, rubber materials), especially "EPR / EPM" (rubber based on ethylene-propylene copolymer) and typical block copolymers called SBS (styrene / butadiene / styrene); - Its combination.

13. The method according to any one of the preceding claims, wherein, relative to the sp 2 The carbon allotrope used is in the range of 3 phc (per hundred parts of carbon) to 50 phc, where phc means "per hundred parts of carbon", and 100 phc is considered to be the amount (by weight) of the allotrope.

14. A metal-free additive for imparting anti-friction and anti-wear properties to lubricating compositions in the form of oils or greases, said additive being in the form of a composite material comprising: sp 2 Carbon allotropes, especially sp(s) with at least one dimension less than 100 nm 2 Carbon allotropes Pyrrole compounds of formula (i) as defined in any of the preceding claims, Lipophilic matrix in the form of base oil or lubricant as defined in claims 2 and / or 12 The concentration of the allotrope in the base oil or lubricating oil is in the range of 0.5 to 50 phm (per 100 parts matrix, considering 100 phm as the base oil or lubricant). The additive is preferably obtained from step (C) of the method according to any one of the preceding claims.

15. A wax-based composite material, comprising: sp 2 Carbon allotropes, especially sp(s) with at least one dimension less than 100 nm 2 Carbon allotropes Pyrrole compounds of formula (i) as defined in any of the preceding claims, Lipophilic materials in the form of waxy compounds as defined in claims 2 and / or 12, The sp in the waxy compound 2 The concentration range of the carbon allotrope is 0.5 to 50 phm (per 100 parts matrix, considering 100 phm as the waxy compound). The composite material is preferably obtained from step (C) of the method according to any one of the preceding claims.

16. A masterbatch additive for elastomers to impart mechanical strength to elastomer materials such as gaskets, rubber materials, and coatings, said additive being in the form of a composite material comprising: sp 2 Carbon allotropes, especially sp(s) with at least one dimension less than 100 nm 2 Carbon allotropes Pyrrole compounds of formula (i) as defined in any of the preceding claims The lipophilic matrix in the form of an elastomer is preferably selected from SBS and EPM. The sp in the lipophilic matrix 2 The concentration of carbon allotropes ranges from 0.5 to 50 phm (per 100 parts matrix, considering 100 phm as the elastomer). The composite material is preferably obtained from step (C) of the method according to any one of the preceding claims.

17. The additive according to any one of claims 14 and 16 and / or the composite material according to claim 15, wherein the additive... 2 The carbon allotrope is selected from graphene, nanographite composed of several graphene layers (from several to dozens of layers), preferably 100 to 400 μm. 2 / g of high surface area nano-graphite (HSAG), graphite, graphene, fullerene, carbon nanotubes or combinations thereof; preferably high surface area nano-graphite (HSAG).

18. The additive and / or composite material according to any one of claims 14 to 17, wherein, relative to the sp 2 Carbon allotropes, the amount of pyrrole compound of formula (i) used is in the range of 3 phc (per hundred parts of carbon) to 50 phc, where phc means "per hundred parts of carbon", considering 100 phc is the said sp 2 The amount (weight) of carbon allotropes.

19. A lubricating composition in the form of a lubricating oil and / or a lubricating grease, comprising a base oil and at least one metal-free additive that imparts anti-friction and anti-wear properties, wherein the at least one additive is a composite material according to any one of claims 14, 17, and 18.

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