Elastomeric composition comprising at least one sp2-hybridized carbon allotrope and 2, 5-disubstituted pyrrole derivative

Abstract

The present invention relates generally to elastomeric compositions comprising at least one sp2-hybridized carbon allotrope and a 2, 5-disubstituted pyrrole derivative, preferably provided in the form of a preformed adduct, processes for their preparation and tires comprising such elastomeric compositions. The invention also relates to adducts between said pyrrole derivatives and sp2 hybrid carbon allotropes and to processes for their preparation.

Description

[0001] The present invention generally relates to a composition comprising at least one sp 2 Elastomer compositions of hybrid carbon allotropes and 2,5-disubstituted pyrrole derivatives (preferably provided in the form of preformed adducts), methods for their preparation and tires comprising such elastomeric compositions. The present invention also relates to said pyrrole derivatives and sp 2 Adducts between hybrid carbon allotropes and methods for their preparation. Prior art

[0002] A unique feature of elastomeric composites is entropic elasticity, which occurs above the glass transition temperature of the elastomers and is the basis of their properties. Diene elastomers, i.e. elastomers with unsaturations in the main chain, such as poly(1,4-cis-butadiene) and poly(1,4-cis-isoprene), are characterized by a large mobility of the main chain due to the ease with which the polymer chains rotate around single bonds close to the unsaturations. Upon crosslinking the polymer chains of these unsaturated elastomers, the composites acquire the properties of entropic elasticity. However, despite their outstanding elasticity, elastomeric composites do not have the mechanical properties required for demanding applications, such as those in tire compounds. In order to achieve such properties, the composites must be loaded with reinforcing fillers.

[0003] Carbon black has been used as a reinforcing filler for elastomeric composites since the beginning of the twentieth century. Thanks to the addition of carbon black, both the static and dynamic mechanical properties of elastomeric composites increase. But carbon black also causes a significant increase in the hysteresis of elastomeric composites and therefore a significant increase in the energy dissipation. In fact, it is known that the elastic modulus of a composite filled with carbon black (to which a sinusoidal stress has been applied) decreases, from a minimum strain up to a strain of about 25% (the limit estimated for linear behavior). This phenomenon is known as the "Payne effect" and is an indicator of the energy dissipation of a material.

[0004] In order to have mechanical reinforcement and low energy dissipation, silica is used as a reinforcing filler instead of or together with carbon black. Thanks to the use of coupling agents, usually silanes containing sulfur atoms, chemical bonds are established between silica and elastomer chains, which leads to a reduction in hysteresis and energy dissipation. Therefore, despite the disadvantages associated with its use, the use of silica has increased dramatically in the last decades.

[0005] In fact, silica leads to an increase in the viscosity of the compound, a deterioration in the processability and a reduction in the storage time of the composite. These disadvantages are due to the surface activity of silica: the polar groups promote extensive supramolecular interactions. It is worth noting that the shorter storage time requires specific planning of the production of the compound and of the procedures for storing and moving the compound, with a clear impact on logistics.

[0006] Furthermore, specific and expensive mixing equipment is required to achieve effective mixing of silica-based composites. Due to the use of silanes, silica-based sizing compounds have increased adhesion to the metal parts of the mixer, and this requires special treatment of the metal surfaces. Finally, silica is corrosive and abrasive, which also requires special treatment of the metal surfaces and modified maintenance procedures.

[0007] These disadvantages are all relevant on an industrial scale, for example when silica-based elastomeric composites are used in tire compounds. However, tire compounds, in particular those used in tire treads, are usually almost entirely based on silica as a reinforcing filler, and there are increasing research efforts to use silica as a partial replacement of carbon black in tire compounds other than tire treads as well. Research efforts have also been made to use silica as the sole filler in tire compounds other than tire treads. This is because the main purpose is to reduce the energy dissipation of the rolling tire, and at least in the existing prior art, this purpose has never been achieved with carbon black as the sole reinforcing filler.

[0008] In fact, several attempts have been made to reduce the Payne effect due to carbon black, for example by optimizing its dispersion in the elastomeric matrix, separating the aggregates and / or elemental particles therefrom, covering them with an elastomeric layer.

[0009] The applicant has reported different methods for achieving this (see, for example, WO 2016 / 050887, WO 2020 / 225595A1, WO 2020 / 222103). However, no attempts to partially or completely replace silica have been reported so far. SUMMARY OF THE INVENTION

[0011] The Applicant has addressed the need to obtain an elastomeric composition that at least partially overcomes the above-mentioned drawbacks.

[0012] In particular, the Applicant has solved the problem of providing an elastomeric composition which imparts the dynamic mechanical properties usually obtained by using silica as reinforcing filler, while imparting the processability and the above-mentioned advantages associated with the use of carbon black.

[0013] The Applicant has also solved the problem of obtaining such an elastomeric composition by a simple technique, having a reduced environmental impact and using standard solid-state mixing techniques used in the tire industry.

[0014] Surprisingly, the applicant has found that the use of at least one sp 2 Hybridized carbon allotropes and 2,5-disubstituted pyrrole derivatives, preferably provided as preformed adducts with each other, as reinforcing fillers in elastomeric compositions enable a balance between the advantages offered by both silica and carbon black while overcoming the associated disadvantages.

[0015] The elastomeric composition thus obtained exhibits low hysteresis and reduced Payne effect, with consequent reduced energy dissipation, and is therefore particularly suitable as a rubber compound for tires.

[0016] Thus, according to a first aspect, the present invention relates to an elastomeric composition comprising at least one sp 2 Hybridized carbon allotropes and compounds of formula (I):

[0017]

[0018] wherein X and Y are independently selected from: -NHR' and OR"; and

[0019] wherein R" is selected from hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl and heteroaryl; and

[0020] wherein R and R' are independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl, and carboxyl;

[0021] Either R and / or R' is

[0022] Wherein M, Q and J are independently selected from amine, hydroxyl, hydrogen, straight chain or branched C1-C10 alkyl and straight chain or branched C2-C10 alkenyl or alkynyl, or selected from:

[0023]

[0024] Where R1-R 15 independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl and carboxyl;

[0025] and R 10 -R 12 It can be -OCH2-CH3 or -OCH3;

[0026] and R 14 It can be -CH2-SH or -CH2-CH2-S-CH3;

[0027] and wherein T is -O- or -S-, and when T is -S- then p' is an integer from 1 to 4, and when T is -O- then p' is an integer from 1 to 2;

[0028] and wherein I', p', q', r' are independently integers from 0 to 12;

[0029] Either R and / or R' is

[0030] Where R 16 is selected from the group consisting of hydrogen, alkyl, aryl, benzyl, amine, alkylamine, arylamine, benzylamine, and aminoaryl; and

[0031] R 17 -R 21 Independently selected from the group consisting of: hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, and 1-(4-aminocyclohexyl)methylene.

[0032] In an embodiment of the present invention, the elastomeric composition comprises said compound of formula (I) and said at least one sp 2 preformed adducts between hybridized carbon allotropes, i.e., the compound of formula (I) and the at least one sp 2 The hybridized carbon allotropes are provided as preformed adducts.

[0033] In a second aspect, the present invention relates to a process for preparing an elastomeric composition as defined above, the process comprising:

[0034] a) providing one or more elastomers, at least one sp 2 a hybrid carbon allotrope, a compound of formula (I) as defined above, optionally one or more further reinforcing fillers, optionally one or more additives and optionally one or more vulcanizing agents; and

[0035] b) performing at least one mixing step.

[0036] In a third aspect, the invention relates to a tyre for vehicle wheels comprising at least one structural element comprising a crosslinked elastomeric material obtained by crosslinking an elastomeric composition as defined above.

[0037] Finally, in a fourth and fifth aspect, the present invention also relates to sp 2 The invention relates to an adduct between a hybrid carbon allotrope and a compound of formula (I) as defined above, and respectively to a process for preparing said adduct, which comprises the following steps:

[0038] i) providing a compound of formula (I) and sp 2 mixtures of hybridized carbon allotropes; and

[0039] ii) supplying energy to the mixture obtained in step i) to obtain an adduct; and

[0040] iii) optionally isolating the adduct obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The description is presented herein with reference to the accompanying drawings, which are provided by way of illustration only and are not limiting of the invention.

[0043] Figure 1 : Profile of a transverse half-section of a tyre comprising, in one or more components, the elastomeric composition according to the invention.

[0044] Figure 2a-2b : Exemplary TGA spectra of the adduct according to the present invention before and after the purification procedure, respectively.

[0045] Figure 3 : Graph showing the variation of G' (y-axis) versus deformation amplitude (x-axis) for the elastomeric compositions of Examples 6-10.

[0046] Figure 4 : Graph showing the variation of tan delta (y-axis) versus deformation (x-axis) for the elastomeric compositions of Examples 6-10. DETAILED DESCRIPTION OF THE INVENTION

[0048] definition

[0049] According to the invention, the term "adduct" is understood to mean a compound obtained by combining two or more components; more specifically, the term adduct denotes a compound whose components are more or less loosely bonded (i.e. by covalent bonds or by more labile intermolecular interactions) in a way that retains their individuality. In particular, according to the invention, the term "adduct" means a compound obtained by combining a pyrrole derivative (i.e. a compound of formula (I) as defined above) with a sp 2 Adducts between hybrid carbon allotropes obtained through covalent or non-covalent interactions.

[0050] According to the present specification, the terms "carbon allotrope" and "carbon-based filler" may be used interchangeably and / or both may be represented by the abbreviation CA.

[0051] In the following, the term "elastomeric composition" is used, comprising the totality of all the components added in the preparation of the elastomeric mix, regardless of the fact that these components may actually all be present at the same time, they may be introduced sequentially or they may then be traceable in the elastomeric mix or in the final tire.

[0052] For the purpose of the present specification and the appended claims, the term "phr" (parts per hundreds of rubber) means parts by weight of a defined component of the elastomeric composition per 100 parts by weight of elastomeric polymer.

[0053] For the purposes of this specification and the appended claims, the expression "comprising at least one sp 2 The term "elastomeric composition comprising a hybrid carbon allotrope and a compound of formula (I)" is intended to mean an elastomeric composition according to the invention which may contain said at least one sp 2 The hybridized carbon allotrope and the compound of formula (I) are either as different components or as a preformed adduct between the two.

[0054] For the purposes of this specification and the appended claims, the expression "providing [...] at least one sp 2 hybrid carbon allotrope, compound of formula (I) [...]" is intended to mean that in the process for preparing an elastomeric composition according to the invention, said at least one sp 2 The hybrid carbon allotrope and the compound of formula (I) may be provided as separate components or as a preformed adduct between the two.

[0055] For the purposes of this specification and the appended claims, the compounds of formula (I) and (II) disclosed herein also include derivatives, such as esters, salts, enantiomers, diastereomers, preferably esters and salts.

[0056] Detailed description

[0057] In a first aspect, the present invention relates to an elastomeric composition comprising at least one sp 2 Hybridized carbon allotropes and compounds of formula (I)

[0058]

[0059] wherein X and Y are independently selected from: -NHR' and OR"; and

[0060] wherein R" is selected from hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl and heteroaryl; and

[0061] wherein R and R' are independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl, and carboxyl;

[0062] Either R and / or R' is

[0063] Wherein M, Q and J are independently selected from amine, hydroxyl, hydrogen, straight chain or branched C1-C10 alkyl and straight chain or branched C2-C10 alkenyl or alkynyl, or selected from:

[0064]

[0065] Where R1-R 15 independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl and carboxyl;

[0066] and R 10 -R 12 It can be -OCH2-CH3 or -OCH3;

[0067] and R 14 It can be -CH2-SH or -CH2-CH2-S-CH3;

[0068] and wherein T is -O- or -S-, and when T is -S- then p' is an integer from 1 to 4, and when T is -O- then p' is an integer from 1 to 2;

[0069] and wherein I', p', q', r' are independently integers from 0 to 12;

[0070] Either R and / or R' is

[0071] Where R 16 is selected from the group consisting of hydrogen, alkyl, aryl, benzyl, amine, alkylamine, arylamine, benzylamine, and aminoaryl; and

[0072] R 17 -R 21 Independently selected from the group consisting of: hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, and 1-(4-aminocyclohexyl)methylene.

[0073] In a preferred embodiment, said R and R' are the same.

[0074] Preferably, the R and R' are independently selected from hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl, carboxyl, straight or branched C1-C10 alkyl-NH2, straight or branched C1-C10 alkyl-SH, straight or branched C1-C10 alkyl-COOH and straight or branched C1-C10 alkyl-Si(OCH2CH3)3, wherein the alkyl is optionally substituted with one or more -OH groups. In a preferred embodiment, the R and R' are the same.

[0075] In a preferred embodiment, the compound of formula (I) is represented by the following formula (II):

[0076]

[0077] Wherein R 22 is selected from hydrogen and C1-C10 straight or branched alkyl optionally substituted by one or more -OH groups; and said R 23 -R 24 are the same and are selected from hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, aryl, straight chain or branched C1-C10 alkyl-aryl, straight chain or branched C2-C10 alkenyl-aryl, straight chain or branched C2-C10 alkynyl-aryl, heteroaryl, straight chain or branched C1-C10 alkyl-NH2, straight chain or branched C1-C10 alkyl-SH, straight chain or branched C1-C10 alkyl-COOH and straight chain or branched C1-C10 alkyl-Si(OCH2CH3)3, wherein the alkyl is optionally substituted by one or more -OH groups.

[0078] In a particularly preferred embodiment of the present invention, the compound of formula (I) is selected from:

[0079] 1-(1,3-dihydroxypropan-2-yl)-5-((1,3-dihydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0080] 1-(1,2-dihydroxypropan-3-yl)-5-((1,2-dihydroxypropan-3-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0081] 1-(2-Hydroxyethyl)-5-((2-hydroxyethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0082] 1-Benzyl-5-(benzylcarbamoyl)-1H-pyrrole-2-carboxylic acid;

[0083] 1-Octyl-5-(octylcarbamoyl)-1H-pyrrole-2-carboxylic acid;

[0084] 1-(1-hydroxypropan-2-yl)-5-((1-hydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0085] 1-(2-mercaptoethyl)-5-((2-mercaptoethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0086] 1-(3-(triethoxysilyl)propyl)-5-((3-(triethoxysilyl)propyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0087] 1-(Carboxymethyl)-5-((carboxymethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid; and

[0088] 1-(2-aminoethyl)-5-((2-aminoethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid.

[0089] Typically, the compound of formula (I) is present in an amount of at least 0.1 phr, preferably from 0.5 phr to 6 phr, even more preferably from 0.5 phr to 4 phr.

[0090] It is noteworthy that the compounds of formula (I) are characterized by the presence of a carbonyl group in each ortho position of the pyrrole nitrogen atom. Without being bound by a particular theory, it is hypothesized that this group may allow a greater and stronger interaction of the compound within the elastomeric composition, namely with the elastomer or elastomers or reinforcing fillers present.

[0091] The pyrrole derivative (ie the compound of formula (I)) used in the elastomeric composition according to the present invention can be prepared according to methods known in the art.

[0092] For example, where the groups R and R' or R 23 -R 24 A convenient synthetic route to the same compounds of formula (I) and (II) above is to react a suitable primary amine with 3-hydroxy-2-oxo-2H-pyran-6-carboxylic acid at a temperature of about 50-100° C. until the reaction is complete. The pyrrole derivative of formula (I) is then isolated by column chromatography.

[0093] It is noteworthy that 3-hydroxy-2-oxo-2H-pyran-6-carboxylic acid can be easily and efficiently obtained from known biomolecules (e.g. from sugars) by methods that comply with green chemistry requirements: therefore, the starting materials for the synthesis of compounds of formula (I) can be easily obtained from cheap and biocompatible sources.

[0094] The following compounds of formula (I) can all be obtained through the synthetic routes disclosed above.

[0095]

[0096]

[0097]

[0098] As will be appreciated by one of ordinary skill in the art, compounds of formula (I) may also be synthesized via synthetic routes other than those reported above, which will be selected by the skilled person based on common general knowledge.

[0099] Preferably, the at least one sp 2 The hybrid carbon allotrope is selected from carbon black, graphene, 2-layer graphene, 3-10-layer graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, longitudinally or helically extended carbon nanotubes, nanocones, nanohorns, nanorings, fullerenes and mixtures thereof.

[0100] Even more preferably, the sp 2 The hybrid carbon allotrope is selected from the group consisting of carbon black, graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, and mixtures thereof.

[0101] In a particularly preferred embodiment, sp 2 A hybrid carbon allotrope is carbon black.

[0102] Typically, the at least one sp 2 The hybridized carbon allotrope is present in an amount of at least 1 phr, preferably from 2 phr to 70 phr, even more preferably from 3 phr to 50 phr.

[0103] The elastomeric composition according to the invention typically further comprises an additional reinforcing filler selected from carbon black, silica, phyllosilicates, mixed oxides of aluminium and magnesium having a lamella structure, aluminium oxides and aluminosilicates and mixtures thereof. Preferably, the additional reinforcing filler is silica and / or carbon black.

[0104] In a preferred embodiment of the present invention, carbon black is present in an amount of at least 10 phr, preferably from 15 phr to 70 phr.

[0105] In an embodiment of the present invention, silica is present in an amount of 0 to 100 phr, preferably 0 to 50 phr.

[0106] In an embodiment of the present invention, the elastomeric composition comprises carbon black as reinforcing filler and at least one sp 2Hybridized carbon allotropes. In this embodiment, the total amount of carbon black is at least 15 phr, preferably from 30 phr to 70 phr.

[0107] In an embodiment of the present invention, the elastomeric composition comprises a compound of formula (I) as defined above and said at least one sp 2 adducts between hybridized carbon allotropes. This means that the compound of formula (I) and sp 2 The hybrid carbon allotrope is provided in the form of a preformed adduct. Typically, the adduct is present in an amount of at least 1 phr, preferably from 2 phr to 70 phr, even more preferably from 9 phr to 50 phr.

[0108] Thus, in the elastomeric composition according to the invention, the total amount of reinforcing filler, meaning at least one sp 2 The sum of the amounts of hybridized carbon allotrope, preferably provided in the form of a preformed adduct with the compound of formula (I) as defined above, and of further reinforcing fillers may reach 11 to 150 phr, preferably 20 to 150 phr, even more preferably 30 to 80 phr.

[0109] The elastomeric composition according to the invention comprises at least one unsaturated elastomer, which is preferably selected from the group consisting of poly(1,4-cis-isoprene), natural rubber or synthetic polymers, poly(3,4-isoprene), poly(butadiene), in particular poly(butadiene) with a high content of 1,4-cis units, i.e. poly(1,4-cis-butadiene), isoprene / isobutylene copolymers, halogenated isoprene / isobutylene copolymers such as halogenated butyl rubbers, in particular chlorinated butyl rubber and brominated butyl rubber, 1,3-butadiene / acrylonitrile copolymers, styrene / 1,3-butadiene copolymers, styrene / isoprene / 1,3-butadiene copolymers, styrene / 1,3-butadiene / acrylonitrile copolymers and mixtures thereof.

[0110] The elastomeric composition according to the invention may further contain at least one elastomer of one or more monoolefins. The monoolefins may be chosen from: ethylene and 1-olefins having 3 to 12 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene or mixtures of these monoolefins.

[0111] The monoolefin elastomer(s) may comprise a diene, which generally has from 4 to 20 carbon atoms and is preferably selected from: 1,3-butadiene, isoprene, 1,4-hexadiene, 1,4-cyclohexadiene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, vinyl norbornene or mixtures of these dienes. The diene may optionally be halogenated.

[0112] Among these elastomers of monoolefin(s), the following are preferred: ethylene / propylene copolymers (EPR) or ethylene / propylene / diene copolymers (EPDM) and poly(isobutylene).

[0113] The elastomeric composition may further contain an unsaturated elastomer based on diene or non-diene monomers, functionalized by reaction with suitable terminators or coupling agents. In particular, the diene elastomeric polymer may be obtained by anionic polymerization promoted by organometallic initiators, in particular alkyl lithiums, and terminated by reaction with suitable terminators or coupling agents, such as epoxides, carbonyl compounds (such as cyclohexanone and benzophenone), substituted or unsubstituted imines, carbodiimides, alkyl tin halides, alkoxysilanes or aryloxysilanes.

[0114] Advantageously, the elastomeric composition contains a vulcanizing agent and the vulcanization is carried out according to known techniques, in particular using a sulfur-based vulcanization system conventionally used for diene elastomeric polymers. For this purpose, in the material, after one or more thermomechanical treatment steps, a sulfur-based vulcanizing agent is incorporated together with a vulcanization accelerator. In the last treatment step, the temperature is generally kept below 120° C., preferably below 100° C., in order to avoid any undesirable pre-crosslinking phenomena.

[0115] Preferably, the vulcanizing agent comprises a sulfur-based vulcanization system comprising sulfur or molecules comprising sulfur (sulfur donors), and vulcanization accelerators and / or activators known in the art.

[0116] Particularly effective activators are zinc compounds, in particular ZnO, ZnCO3 and zinc salts of saturated or unsaturated fatty acids containing 8 to 18 carbon atoms, for example zinc stearate, which are preferably formed in situ in the elastomeric composition from ZnO and fatty acids, or mixtures thereof.

[0117] Commonly used accelerators may be selected from: dithiocarbamates, guanidines, thioureas, thiazoles, sulfenamides, thiurams, amines and xanthates and mixtures thereof.

[0118] Preferred vulcanizing agents are, for example, stearic acid, ZnO, TBBS (N-tert-butyl-2-benzothiazolylsulfenamide) and sulfur or mixtures thereof.

[0119] According to a preferred embodiment, the elastomeric composition contains a vulcanizing agent in an amount greater than or equal to about 1 phr, preferably greater than or equal to about 2 phr.

[0120] Preferably, the vulcanizing agent is used in an amount less than or equal to about 20 phr, preferably less than or equal to about 10 phr.

[0121] Advantageously, sulfur is used in an amount of about 0.5 phr to about 8 phr.

[0122] The elastomeric composition may contain other conventional additives selected based on the specific application intended for the composition, such as antioxidants, anti-aging agents, plasticizers, adhesives, antiozonants, modifying resins or mixtures thereof.

[0123] In particular, for the purpose of improving processability, a plasticizer, typically selected from mineral oils, vegetable oils, synthetic oils or mixtures thereof (such as, for example, aromatic oils, naphthenic oils, phthalates, soybean oils or mixtures thereof), can be added to the elastomer composition. The amount of plasticizer is typically 0 phr to about 70 phr, preferably about 5 phr to about 30 phr.

[0124] Another aspect of the present invention is a process for preparing an elastomeric composition according to the present invention, the process comprising the following steps:

[0125] a) providing one or more elastomers, at least one sp 2 a hybrid carbon allotrope, a compound of formula (I) as defined above, optionally one or more further reinforcing fillers, optionally one or more additives and optionally one or more vulcanizing agents; and

[0126] b) performing at least one mixing step.

[0127] In an embodiment of the present invention, the compound of formula (I) and the at least one sp 2 The hybridized carbon allotropes are provided as preformed adducts.

[0128] The polymer component may be mixed with at least one sp according to techniques known in the art. 2 The hybrid carbon allotrope and the compound of formula (I) according to the invention, preferably provided in the form of a preformed adduct, together with other reinforcing fillers and other additives that may be present, are mixed to prepare the elastomeric composition. The elastomeric composition can be prepared, for example, using an open mixer of the "roll mill" type and / or with tangential rotors. and / or with intermeshing rotors (Intermix TM ) type internal mixer, and / or in a Ko-Kneader TM The mixing is carried out in a continuous mixer of the extruder type and / or a twin-screw or multi-screw type and / or a planetary type.

[0129] The components of the elastomeric composition are usually not all introduced into the mixer at the same time, but are usually added sequentially. In particular, vulcanizing additives, such as vulcanizing agents which may include accelerators and retarders, are usually added in a downstream step relative to the incorporation and processing of all other components.

[0130] In a vulcanizable or finally vulcanized elastomeric composition, the individual components of the elastomeric composition do not always remain unchanged or individually traceable, since they can be completely or partially transformed by the influence of interactions with other components, heat and / or mechanical processing.

[0131] Another aspect of the invention is represented by a tyre for vehicle wheels, said tyre comprising at least one structural element comprising a crosslinked elastomeric material obtained by crosslinking the elastomeric composition according to the invention.

[0132] In particular, the tire comprises: at least one carcass structure having opposite lateral edges associated with corresponding annular reinforcing structures; a belt structure applied in a radially external position relative to the carcass structure; a crown applied in a radially external position relative to the carcass structure; and a pair of sidewalls applied transversely on opposite sides relative to the carcass structure.

[0133] Advantageously, the structural element is chosen from a crown, sidewalls, sidewall inserts, layers of elastomeric material radially internal to the crown, such as liners and microsidewalls, filler beads and rubber coatings of fabric and metal. In a particularly preferred embodiment, the structural element is a crown.

[0134] The elastomeric composition according to the invention can advantageously be used to prepare structural elements characterized by low hysteresis and limited Payne effect, thereby obtaining significant advantages in road holding and, in general, in the performance of the tire, such as resistance to deformations due to, for example, temperature increases. In particular, as indicated above, the elastomeric composition according to the invention is able to impart the desired mechanical-dynamic properties to the tire with limited or no use of silica, thus overcoming the drawbacks known in the art and discussed in the preceding paragraphs.

[0135] The tyre according to the invention may be used on vehicles having two, three, four or even more wheels.

[0136] The tire according to the invention can be used for summer or winter use, or for all seasons.

[0137] The tire according to the invention can be manufactured according to a method comprising the following steps:

[0138] - assembling the components of the green tyre on at least one building drum;

[0139] - Moulding and vulcanizing of green tyres;

[0140] At least one component of the green tire contains the vulcanizable elastomeric composition as described above.

[0141] The term "green" is generally used to refer to a material, composition, component or tire that has not yet been cured.

[0142] Figure 1 An exemplary tire for a vehicle wheel according to the invention is shown in a radial half-section view.

[0143] exist Figure 1 In the equation, "a" represents the axial direction, "X" represents the radial direction, and in particular, XX represents the trajectory of the equatorial plane. Figure 1 Only a portion of the tire is shown, the remaining portions not shown are identical and are positioned symmetrically relative to the equatorial plane "XX".

[0144] The tyre 100 for a four-wheeled vehicle comprises at least one carcass structure including at least one carcass layer 101 having mutually opposite end edges joined to respective annular anchoring structures 102, called bead cores, possibly in combination with filler strips 104.

[0145] The tyre region comprising the bead core 102 and the filler bead 104 forms a bead structure 103 intended for anchoring the tyre on a corresponding mounting rim (not shown).

[0146] The carcass structure is usually of radial type, i.e. the reinforcing elements of at least one carcass layer 101 are substantially located in a plane comprising the axis of rotation of the tyre and substantially perpendicular to the equatorial plane of the tyre. The reinforcing elements are usually represented by textile cords, such as rayon, nylon or polyester (e.g. polyethylene naphthalate PEN). Each bead structure is connected to the carcass structure by folding behind the opposite lateral edges of at least one carcass layer 101 around an annular anchoring structure 102 so as to form a so-called carcass turn-up 101a.

[0147] In one embodiment, the connection between the carcass structure and the bead structure can be achieved by means of a second carcass layer ( Figure 1 ), which second carcass layer is applied in an axially outer position relative to the first carcass layer.

[0148] A wear strip 105 , possibly implemented with an elastomeric composition according to the invention, is arranged in a position external to each bead structure 103 .

[0149] Associated with the carcass structure is a belt structure 106 comprising one or more belt layers 106a, 106b placed radially superimposed relative to each other and the carcass layers, typically having textile or metal reinforcement cords incorporated in a layer of vulcanized elastomeric material.

[0150] Such reinforcement cords may have a crossed orientation with respect to the circumferential development direction of the tire 100. A "circumferential" direction is understood to mean a direction generally oriented in the direction of rotation of the tire.

[0151] In a radially more outer position of the belt layers 106a, 106b, at least one zero-degree reinforcement layer 106c, commonly referred to as a "0° belt", can be applied, which typically incorporates a plurality of elongated reinforcing elements, typically metal or textile cords, oriented substantially in a circumferential direction so as to form an angle of several degrees (e.g., between about 0° and 6°) relative to a direction parallel to the equatorial plane of the tire and is coated with a vulcanized elastomeric material.

[0152] In a position radially external to the belt structure 106, a crown 109 of vulcanized elastomeric material is applied.

[0153] Furthermore, on the lateral surfaces of the carcass structure, each extending from one of the lateral edges of the tread 109 until a position where it coincides with the respective bead structure 103, a respective sidewall 108 in vulcanized elastomeric material is applied at an axially outer position.

[0154] In a radially outer position, the crown 109 has a rolling surface 109a intended to come into contact with the ground. Figure 1 Circumferential grooves connected to define a plurality of small blocks of various forms and sizes distributed on the rolling surface 109a are usually realized in this surface 109a, which, for simplicity, is Figure 1 Shown as smooth.

[0155] A bottom layer 111 of vulcanized elastomeric material may be positioned between the belt structure 106 and the tread crown 109 .

[0156] Strips of elastomeric composition 110 in vulcanized elastomeric material, generally called “micro-sidewalls”, may optionally be present in the connection zone between the sidewall 108 and the crown 109, generally obtained by coextrusion with the crown 109 and allowing to improve the mechanical interaction between the crown 109 and the sidewall 108. Preferably, the ends of the sidewall 108 directly cover the lateral edges of the crown 109.

[0157] In the case of a tubeless tyre, there may also be provided, in a radially internal position relative to the carcass structure 101 , a rubber layer 112 , generally called “liner”, which provides the necessary impermeability to the air that inflates the tyre.

[0158] The rigidity of the tyre 108 in the radial direction can be improved by giving the bead structure 103 a reinforcement layer 120 , generally called “outer flanging” or a strip-addition insert.

[0159] The outer bead filler 120 is a reinforcement layer that is wound around the corresponding bead core 102 and the filler bead 104 so as to at least partially surround them.

[0160] The outer retainer 120 generally comprises a plurality of textile cords incorporated within a layer of vulcanized elastomeric material.

[0161] The tyre bead structure 103 may comprise an additional protective layer, which is generally referred to by the term “chafer” 121 or a protective strip and which has the function of further increasing the rigidity and / or integrity of the bead structure 103 .

[0162] The chafer 121 generally comprises a plurality of cords incorporated in a rubber coating of a vulcanized elastomeric material. Such cords are generally implemented in a textile material (such as aramid or rayon) or a metallic material (such as steel cords).

[0163] A layer or sheet of elastomeric material may be positioned between the belt structure and the carcass structure ( Figure 1 ). The layer may have a uniform thickness. Alternatively, the layer may have a variable thickness in the axial direction. For example, the layer may have a maximum thickness near its axial outer edge relative to the central (crown) zone.

[0164] Advantageously, the layer or sheet may extend over an area substantially corresponding to the developed surface of said belt structure.

[0165] In a preferred embodiment, a layer or sheet of elastomeric material as described above may be placed between the belt structure and the crown, wherein said complementary layer or sheet preferably extends over a zone substantially corresponding to the developed surface of the belt structure.

[0166] In another aspect, the present invention relates to sp 2 Adducts between hybrid carbon allotropes and compounds of formula (I):

[0167]

[0168] wherein X and Y are independently selected from: -NHR' and OR"; and

[0169] wherein R" is selected from hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl and heteroaryl; and

[0170] wherein R and R' are independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl, and carboxyl;

[0171] Either R and / or R' is

[0172] Wherein M, Q and J are independently selected from amine, hydroxyl, hydrogen, straight chain or branched C1-C10 alkyl and straight chain or branched C2-C10 alkenyl or alkynyl, or selected from:

[0173]

[0174] Where R1-R 15 independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl and carboxyl;

[0175] and R 10 -R 12 It can be -OCH2-CH3 or -OCH3;

[0176] and R 14 It can be -CH2-SH or -CH2-CH2-S-CH3;

[0177] and wherein T is -O- or -S-, and when T is -S- then p' is an integer from 1 to 4, and when T is -O- then p' is an integer from 1 to 2;

[0178] and wherein I', p', q', r' are independently integers from 0 to 12;

[0179] Either R and / or R' is

[0180] Where R 16 is selected from the group consisting of hydrogen, alkyl, aryl, benzyl, amine, alkylamine, arylamine, benzylamine, and aminoaryl; and

[0181] R 17 -R 21 Independently selected from the group consisting of: hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, and 1-(4-aminocyclohexyl)methylene.

[0182] In a preferred embodiment, said R and R' are the same.

[0183] Preferably, the R and R' are independently selected from: hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl and carboxyl, straight or branched C1-C10 alkyl-NH2, straight or branched C1-C10 alkyl-SH, straight or branched C1-C10 alkyl-COOH, and straight or branched C1-C10 alkyl-Si(OCH2CH3)3, wherein the alkyl is optionally substituted with one or more -OH groups. In a preferred embodiment, the R and R' are the same.

[0184] In a preferred embodiment, the compound of formula (I) is represented by the following formula (II):

[0185]

[0186] Wherein R 22 is selected from hydrogen and C1-C10 straight or branched alkyl optionally substituted by one or more -OH groups; and said R 23 -R 24 are the same and are selected from hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, aryl, straight chain or branched C1-C10 alkyl-aryl, straight chain or branched C2-C10 alkenyl-aryl, straight chain or branched C2-C10 alkynyl-aryl, heteroaryl, straight chain or branched C1-C10 alkyl-NH2, straight chain or branched C1-C10 alkyl-SH, straight chain or branched C1-C10 alkyl-COOH and straight chain or branched C1-C10 alkyl-Si(OCH2CH3)3, wherein the alkyl is optionally substituted by one or more -OH groups.

[0187] In a particularly preferred embodiment of the present invention, the compound of formula (I) is selected from:

[0188] 1-(1,3-dihydroxypropan-2-yl)-5-((1,3-dihydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0189] 1-(1,2-dihydroxypropane-3-yl)-5-((1,2-dihydroxypropane-3-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0190] 1-(2-Hydroxyethyl)-5-((2-hydroxyethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0191] 1-Benzyl-5-(benzylcarbamoyl)-1H-pyrrole-2-carboxylic acid;

[0192] 1-Octyl-5-(octylcarbamoyl)-1H-pyrrole-2-carboxylic acid;

[0193] 1-(1-hydroxypropan-2-yl)-5-((1-hydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0194] 1-(2-mercaptoethyl)-5-((2-mercaptoethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0195] 1-(3-(triethoxysilyl)propyl)-5-((3-(triethoxysilyl)propyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0196] 1-(Carboxymethyl)-5-((carboxymethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid; and

[0197] 1-(2-aminoethyl)-5-((2-aminoethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid.

[0198] Preferably, the sp used to prepare the adduct according to the invention 2 The hybrid carbon allotrope is as defined above, i.e. is selected from: carbon black, graphene (which may be graphene with 2 layers (bilayer graphene) or graphene with a few layers (from 3 to 10 layers, few-layer graphene)), graphite, in particular high surface area graphite, single-walled or multi-walled carbon nanotubes, carbon nanotubes with longitudinal or helical extension, nanocones, nanohorns, nanorings, fullerenes, and mixtures thereof.

[0199] Even more preferably, the sp 2 The hybrid carbon allotrope is selected from the group consisting of carbon black, graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, and mixtures thereof.

[0200] In a particularly preferred embodiment, sp 2 A hybrid carbon allotrope is carbon black.

[0201] In one embodiment, sp 2 Hybridized carbon allotropes contain functional groups selected from:

[0202] - oxygen-containing groups, preferably hydroxyl groups or epoxide groups;

[0203] - a carbonyl-containing group, preferably an aldehyde, a ketone or a carboxylic acid;

[0204] - a nitrogen atom-containing group, preferably an amine, an amide, a nitrile, a diazonium salt or an imine;

[0205] - groups containing sulfur atoms, preferably sulfide, disulfide, thiol, sulfone or sulfinic acid and sulfonic acid groups.

[0206] In a particularly preferred embodiment of the invention, the adduct comprises a carbon allotrope selected from carbon black, graphene, graphite, high surface area graphite or single-walled or multi-walled carbon nanotubes, and a compound of formula (I) selected from the following:

[0207] 1-(1,3-dihydroxypropan-2-yl)-5-((1,3-dihydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0208] 1-(1,2-dihydroxypropane-3-yl)-5-((1,2-dihydroxypropane-3-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0209] 1-(2-Hydroxyethyl)-5-((2-hydroxyethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0210] 1-Benzyl-5-(benzylcarbamoyl)-1H-pyrrole-2-carboxylic acid;

[0211] 1-Octyl-5-(octylcarbamoyl)-1H-pyrrole-2-carboxylic acid;

[0212] 1-(1-hydroxypropan-2-yl)-5-((1-hydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0213] 1-(2-mercaptoethyl)-5-((2-mercaptoethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0214] 1-(3-(triethoxysilyl)propyl)-5-((3-(triethoxysilyl)propyl)carbamoyl)-1H-pyrrole-2-carboxylic acid;

[0215] 1-(Carboxymethyl)-5-((carboxymethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid; and

[0216] 1-(2-aminoethyl)-5-((2-aminoethyl)carbamoyl)-1H-pyrrole-2-carboxylic acid.

[0217] Preferably, the adduct of the invention is characterized in that the weight ratio between the allotrope and the pyrrole derivative is from 100:1 to 1:10, even more preferably from 100:1 to 1:1.

[0218] Due to the fact that they are more or less reactive aromatic systems, carbon allotropes can form various types of intermolecular interactions both of the covalent type and via more labile intermolecular interactions.

[0219] Without being bound by any theory, the following two types of interactions can be hypothesized in the adduct formation reaction:

[0220] (i) π-π interaction: An interaction that can exist between systems with π electrons and therefore has sp 2 Or sp hybridization. The interaction is between a pair of π electrons and a σ orbital, or between an electron from a σ orbital and a π orbital, or again between electrons from two π orbitals. This type of adduct is also called a "π complex" and is characterized by the so-called stacking, i.e. a stacked arrangement of the aromatic molecules.

[0221] (ii) Covalent bonding between the compound of formula (I) and the carbon allotrope, which is carried out by reactions typical of polycyclic aromatic systems, such as 1,3-dipolar cycloaddition, Diels-Alder reaction.

[0222] It is believed that the presence of electron-withdrawing groups such as carboxyl groups enhances the reaction of pyrroles with sp 2 Reactivity of carbon allotropes.

[0223] Adduct formation may also occur through interactions between functional groups of the pyrrole derivatives of formula (I) and functional groups that may be present on the carbon allotrope. These interactions may be of an intermolecular nature, such as hydrogen bonding and dipole interactions, or of a covalent nature, such as esterification by reaction with an acidic group.

[0224] According to a more "green" embodiment, such interactions (whether of an intermolecular or covalent nature) can therefore also be achieved simply by inputting energy (eg mechanical or thermal energy, or by irradiation with photons) without the use of solvents.

[0225] Therefore, another aspect of the present invention is to prepare sp 2 A method for hybridizing an adduct between a carbon allotrope and a compound of formula (I) as defined above, the method comprising the steps of:

[0226] i) providing a compound of formula (I) as defined above and sp 2 mixtures of hybridized carbon allotropes; and

[0227] ii) supplying energy to the mixture obtained in step i) to obtain an adduct; and

[0228] iii) optionally isolating the adduct obtained.

[0229] The process, in particular steps i) to iii), involves forming the adduct in the form of a preformed adduct prior to preparing the elastomeric composition.

[0230] In one embodiment, the mixture provided in step i) is a powder mixture.

[0231] In another embodiment, the process according to the invention comprises, between steps i) and ii), a further step i'), wherein the mixture is suspended in a solvent, preferably a non-polar solvent.

[0232] Preferably, the solvent used in step i') is selected from: non-polar hydrocarbon solvents, such as decalin, hexane, cyclohexane, toluene.

[0233] In yet another embodiment, the method according to the present invention comprises the following steps, which are performed before steps i) to iii) to provide the mixture of step i):

[0234] A. Providing a compound of formula (I) and sp in a polar protic or aprotic solvent selected from: water, alcohols, carbonyl solvents such as acetone, esters such as ethyl acetate, dimethyl sulfoxide, acetonitrile, ethers, and mixtures thereof 2 Hybridized carbon allotropes;

[0235] B. forming a mixture, preferably by ultrasonic treatment or stirring;

[0236] C. Removing the solvent from the mixture obtained in step B).

[0237] The process of removing the solvent from the obtained mixture (step C) can be performed by any suitable solvent removal method, such as vacuum evaporation, spray drying, and the like.

[0238] The energy transfer of step ii) of the process according to the invention is carried out to improve the interaction between the compound of formula (I) and the carbon allotrope. In the absence of energy transfer, this interaction would be weaker and could lead to a partial release of the compound of formula (I) from the carbon allotrope, in particular if the adduct is in an environment of a polar nature. Preferably, the energy is supplied in step ii) for a period of at least 1 minute, preferably at least 5 minutes.

[0239] The forms of energy that can be transferred to the composition to facilitate the formation of the adduct are: mechanical energy, thermal energy and energy by irradiation with photons, or a combination of two or more of these forms of energy.

[0240] Mechanical Energy

[0241] The mechanical treatment may, for example, consist of placing the powder obtained (allotrope / compound of formula (I)) in a ball mill, for example comprising a tank equipped with stainless steel balls. Once closed, the tank is placed in a planetary mixer and rotated at a rate of 200 to 500 rpm for a period of 1 to 360 minutes. The powder is then immediately transferred.

[0242] Mechanical treatment is used to promote the separation of carbon allotropes into their elementary components (e.g. exfoliation in the case of graphite) and to favor the relative dispersion of the allotropes and the compound of formula (I) so as to obtain a better distribution of the compound of formula (I) on the allotropes and induce the formation of more stable interactions.

[0243] Thermal Energy

[0244] The heat treatment may, for example, consist of placing the obtained powder (carbon allotrope / compound of formula (I)) in a reaction flask equipped with a condenser, or in a closed container. Once the reactor is placed on a heating plate, the reaction is carried out at a temperature of 25 to 180° C. The heating is maintained for a period of 15-360 minutes.

[0245] Alternatively the thermal treatment can be carried out by means of a fluidized bed reactor or by spray drying.

[0246] Photon

[0247] The photon treatment may, for example, consist in placing the obtained powder (carbon allotrope / compound of formula (I)) in a laboratory crystallizer to form a thin layer, or placing the powder in a closed quartz vial. Once the reactor is set in a closed chamber equipped with a 254 nm low-pressure mercury lamp (or using a reactor equipped with the same type of Reactor), the mixture was irradiated for a period varying from 30 to 180 minutes. At the end of this time, the mixture was transferred and analyzed.

[0248] Preferably, thermal energy is supplied at a temperature of 50°C to 180°C, for example for a period of 5 to 360 minutes.

[0249] Preferably, the mechanical energy is supplied for a period of 1 to 360 minutes.

[0250] Preferably, the energy for irradiating with photons is supplied at a wavelength of 200-380 nm, for example for a period of 30-180 minutes.

[0251] The process according to this embodiment makes it possible to obtain a homogeneous dispersion of carbon allotropes and of at least one compound of formula (1), and therefore of the compound of formula (1) in the carbon-based filler.

[0252] The adducts obtained according to the invention can be used as reinforcing fillers for the preparation of different mixtures of elastomers or composites.

[0253] The present invention will be further described below by means of experimental examples, which are provided for illustrative purposes only and are not intended to limit the present invention in any way.

[0254] Experimental Section

[0255] Material

[0256] All reagents and solvents used for the preparation of pyrrole derivatives were obtained from Sigma-Aldrich and used without further purification.

[0257] Recorded on samples dissolved in deuterated chloroform (CDCl3) and dimethyl sulfoxide (DMSO-d6) 1 H-NMR spectrum.

[0258] The elastomers used are:

[0259] - Poly(1,4-cis-isoprene) (NR), solid natural rubber SIR20, from Eatern GR Thailand-Chonburi, Mooney viscosity (ML(1+4)@100°C): 73MU;

[0260] -Poly (1,4-cis-butadiene) (butadiene rubber, BR) Europrene From PolimeriEuropa;

[0261] The carbon allotropes used are:

[0262] -Carbon black N326 from Cabot Corporation

[0263] Other ingredients used in the preparation of the elastomeric composition:

[0264] -X50S (bis(triethoxysilylpropyl)polysulfide) from Evonik

[0265] -Silica Grade 1165MP from Solvay

[0266] -Stearic acid from Undesa

[0267] -ZnO, from Zincol Ossidi;

[0268] -6PPD ((1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) from Eastman;

[0269] -TBBS (N-tert-butyl-2-benzothiazolylsulfenamide) from Solutia Eastman

[0270] -Sulfur from International Sulfur Inc.

[0271] - PVI (prevulcanization inhibitor, N-(cyclohexylthio)phthalimide) from Brenntag Spa,

[0272] Characterization

[0273] The obtained pyrrole compounds were analyzed by NMR spectroscopy. The pyrrole compounds were analyzed by NMR spectroscopy using a Bruker 400 MHz (100 MHz 13 C) Instrument Records 1 H-NMR and 13 C-NMR spectrum. Chemical shifts are expressed in parts per million (ppm), with the peak of the solvent residue as the internal standard (DMSO-d6; δH=2.50 ppm, CDCl3; δH=7.26 ppm).

[0274] The adducts between carbon allotropes and pyrrole compounds were characterized as follows.

[0275] Thermogravimetric analysis (TGA) is a quantitative analysis technique that provides the weight loss of the analyzed material as a function of time and temperature. In other words, the material is heated in a given heating manner and can undergo a transformation, which results in the loss of part or all of the material itself, which enters the gas phase. According to standard method ISO9924-1, TGA is performed using a Mettler TGA SDTA / 851 instrument under a N2 stream (60 mL / min). The sample (10 mg) is heated from 30°C to 300°C at 10°C / min, held at 300°C for 10 minutes, and then immediately heated to 550°C (20°C / min). After they are kept at 550°C for 15 minutes, they are further heated to 650°C at a rate of 30°C / min and held at 650°C for 20 minutes under an air stream (60 mL / min).

[0276] The functionalization yield of the obtained adduct was calculated using the following equation, i.e., with sp 2 Weight percentage of molecules with hybridized carbon allotropes combined:

[0277]

[0278] The values ​​stated for calculation purposes refer to the amount of pyrrole compound contained in the adduct determined by TGA before and after the purification process and to the % weight loss determined from the TGA graph in the temperature range of 0 to 900°C. Figure 2a-2b Exemplary TGA spectra are shown, respectively, before and after the purification procedure of the adduct according to the invention.

[0279] The elastomeric compositions were vulcanized and characterized by the following procedures and techniques.

[0280] The tensile tests are carried out on dumbbell ISO 3 type test pieces with linear axes. Dumbbell specimens are cut from 100×100×2 mm rubber sheets obtained by curing the green rubber in a mold at 170° C. for 10 minutes in a hydraulic press. The static mechanical properties are measured at 23° C. according to standard ISO 37:2005. In particular, the loads are measured at different levels of elongation 50%, 100% and 300%, named in the order σ100, σ200, σ300, and the stress at break and the elongation at break are named in the order σB and εB.

[0281] Dynamic mechanical properties are measured by applying dynamic stress via shear stress at a constant frequency and at a constant temperature, increasing the deformation amplitude. The test was carried out with a Monsanto RPA 2000 rheometer. A sample of the elastomeric material composition was kept in the rheometer at 50°C for 90 seconds, and then a stress was applied at 50°C with a deformation amplitude range of 0.1% to 25% and a frequency of 1Hz, thereby increasing the deformation amplitude within the above range. This treatment was carried out to eliminate the "previous thermomechanical history". Vulcanization was then carried out at 170°C at a frequency of 1.667Hz and an angle of 6.98% (0.5 radians) for 20 minutes. The vulcanized sample was placed in the instrument at 50°C for 10 minutes. A sinusoidal stress was then applied at 50°C under the same conditions already stated. Then, always under the same experimental conditions, a sinusoidal stress was applied again. A curve is then obtained, which represents the value of the modulus as a function of the deformation amplitude. Such a modulus is shown below. G' modulus is the elastic modulus. The G" modulus is the viscous modulus. The ratio G" / G' is expressed as Tanδ. According to the strain sweep test, the values ​​of the following parameters are obtained: G'γ=0.28%, which is the G' value at the minimum deformation, ΔG' is the difference between the G' value at the minimum deformation and the G' value measured when the maximum deformation is reached, G"max is the maximum value of G" observed in the G" curve, and (tanδ)max is the maximum value of tanδ observed in the curve.

[0282] The dynamic mechanical properties are further measured by applying axial stress in compression-traction mode using an Instron dynamic device according to the following method. The raw elastomeric composition sample, vulcanized at 170°C for 10 minutes, having a cylindrical shape (length = 25 mm; diameter = 14 mm), compression-preloaded to 25% longitudinal deformation relative to the initial length and maintained at a predetermined temperature (equal to 10°C, +23°C and +70°C) for the entire length of the test, is then subjected to a sinusoidal dynamic tension with an amplitude of ±3.5% relative to the length under preload and a frequency of 10 Hz. The dynamic mechanical properties are expressed as the dynamic modulus of elasticity (E') and tan δ (loss factor) values. The Tan δ value is calculated as the ratio of the viscous modulus (E") and the elastic modulus (E').

[0283] The measured static and dynamic mechanical properties are summarized in Table 1 below.

[0284] Table 1

[0285]

[0286]

[0287] Example 1: 1-(1,3-dihydroxypropan-2-yl)-5-((1,3-dihydroxypropan-2-yl)carbamoyl)-1H-pyrrolidone Synthesis of 2-pyrrole-2-carboxylic acid

[0288]

[0289] 3-Hydroxy-2-oxo-2H-pyran-6-carboxylic acid (135 mg, 0.87 mmol) and serinol (2-amino-1,3-propanediol, 455 mg, 4.87 mmol) were charged into a 25 mL round bottom flask. The heterogeneous system was heated at 60 °C, then closed and kept at this temperature with stirring until the reaction was complete, which was determined by the reaction mixture sample. 1 H-NMR and 13 C-NMR analysis was performed. Then, 1-(1,3-dihydroxypropan-2-yl)-5-((1,3-dihydroxypropan-2-yl)carbamoyl)-1H-pyrrole-2-carboxylic acid (Compound 1) was isolated by column chromatography (75% yield).

[0290] Example 2-5: Preparation of adducts between pyrrole derivatives and carbon black (CB)

[0291] Example 2 - Preparation of a physical mixture of CB and compound (1)

[0292] In a 25 mL round bottom flask were added CB N326 (1 g), compound 1 (0.1 g) obtained as disclosed in Example 1 above and acetone (10 mL) in sequence.

[0293] The unstable suspension thus obtained was sonicated for 15 min using a 2 L ultrasonic bath (260 W).

[0294] Thereafter, the solvent was removed by a rotary evaporator to obtain a compound (1) / CB powder mixture (1 g).

[0295] Example 3 - Pure preparation of the adduct between compound (1) and CB

[0296] The compound (1) / CB physical mixture prepared as described in Example 2 was stirred at 170°C in the presence of air for 10 minutes. It was then cooled to room temperature and washed repeatedly with acetone. The final powder was obtained by filtration.

[0297] The functionalization yield determined by TGA as disclosed above was 89%.

[0298] Example 4 - Preparation of the adduct between compound (1) and CB in a solvent

[0299] The compound (1) / CB physical mixture prepared as described in Example 2 was poured into a 25 mL two-necked flask in the presence of decalin (5 mL) as a solvent under a nitrogen stream.

[0300] The mixture was first stirred at 150°C for 5 minutes and then at 170°C for 10 minutes. The mixture was then cooled to room temperature and washed repeatedly with acetone. The final powder was obtained by filtration.

[0301] The functionalization yield determined by TGA as disclosed above was 93%.

[0302] Example 5 - Preparation of the adduct between compound (1) and CB with long reaction time

[0303] In a 100 mL round bottom flask, a solution of CB (15.0 g), acetone (25 mL) and compound (1) (1.5 g) in acetone / water (5 mL) was sonicated for 15 minutes using a 2 L ultrasonic bath (260 W). Thereafter, the solvent was removed by a rotary evaporator to obtain a black powder, which was maintained at 150° C. under vigorous stirring for 2 hours.

[0304] The mixture was then cooled to room temperature and washed repeatedly with a mixture of acetone / water (5 / 1 wt / wt) (3 x 20 mL). The final powder was obtained by filtration.

[0305] The functionalization yield determined by TGA as disclosed above was 84%.

[0306] Preparation of Elastomer Compositions - General Instructions

[0307] Elastomeric compositions were prepared by melt blending according to the compositions summarized in Table 3. The compound (1) / CB adduct used was the one obtained as described in Example 5 above.

[0308] Table 3

[0309] . Ex.6^ Ex.7 Ex.8 Ex.9 Ex.10 [phr] [phr] [phr] [phr] [phr] NR(SIR-20) 70 70 70 70 70 BR 30 30 30 30 30 X50S 5,6 5,6 5,6 5,6 5,6 N326 30 30 30 30 30 SILICA 35 23,45 12 0 12 ZnO 4 4 4 4 4 Stearic acid 2 2 2 2 2 6PPD 2 2 2 2 2 sulfur 2 2 2 2 2 PVI 0.5 0.5 0.5 0.5 0.5 TBBS 1.8 1.8 1.8 1.8 1.8 N326 / Compound (1) 0 9,9 19,72 30 0 N326 0 0 0 0 18,73 Compound (1) 0 0 0 0 0,99

[0310] ^ Compare

[0311] Example 6 - Elastomer composition comprising silica and CB (Comparative Example)

[0312] 70 phr of natural rubber (SIR-20) and 30 phr of poly (1,4-butadiene) (BR) were fed into The mixture was placed in an internal mixer and masticated at 130°C for 1 minute. CB, silica Zeosil 1156MP and X50S were added to the mixer and mixed at the same temperature for 3 minutes. ZnO, stearic acid and 6PPD were then added and mixed for 2 minutes.

[0313] The compound thus obtained was unloaded at 130°C.

[0314] These composites were fed again into the internal mixer at 45° C. Sulfur, PVI and TBBS (N-tert-butyl-2-benzothiazolylsulfenamide) were then added and mixed for another 2 minutes.

[0315] The final rubber composite was discharged and cooled at room temperature and mixed several times on a 2-roll mill before characterization.

[0316] Example 7 - Elastomer composition comprising silica, CB and compound (1) / CB adduct

[0317] The procedure disclosed in Example 6 was repeated, but replacing 33% of the silica with the compound (1) / CB adduct obtained in Example 5. The same volume % of filler was maintained.

[0318] Example 8 - Elastomer composition comprising silica, CB and compound (1) / CB adduct

[0319] The procedure disclosed in Example 6 was repeated, but replacing 66% of the silica with the compound (1) / CB adduct obtained in Example 5. The same volume % of filler was maintained.

[0320] Example 9 - Elastomer composition comprising CB and compound (1) / CB adduct

[0321] The procedure disclosed in Example 6 was repeated, but completely replacing the silica with the compound (1) / CB adduct obtained in Example 5. The same volume % of filler was maintained.

[0322] Example 10 - Elastomer composition comprising silica, CB and compound (1) as ingredients

[0323] The procedure disclosed in Example 6 was repeated, however replacing 66% of the silica with pristine CB and adding 0.99 phr of compound (1) obtained as disclosed in Example 1. The same % by volume of filler was maintained.

[0324] Dynamic mechanical characterization of elastomeric compositions by shear stress

[0325] According to the previously described mode of operation, dynamic mechanical characterization was performed by applying sinusoidal stresses with the aid of shear stresses.

[0326] In Table 4, data are shown regarding the dynamic modulus G' at the minimum deformation (0.1), the variation of the G' modulus with the deformation amplitude between 0.28% and 25% (ΔG'), the maximum value of the dissipation modulus G", and the maximum value of tan δ.

[0327] The variation curves of G' and tanδ with respect to deformation amplitude are shown in Figure 3 and Figure 4 middle.

[0328] Table 4

[0329]

[0330] ^ Compare

[0331] The use of pyrrole derivatives (compound (1)) as modifiers of CB or as ingredients of elastomeric compositions allows partial or total replacement of silica with CB, reproducing substantially the same dynamic mechanical properties measured on compositions based on pristine CB. In fact, the values ​​of ΔG' and Tanδmax of Examples 7-10 in Table 4 are completely consistent with those of the comparative composition (Ex. 6^).

[0332] ΔG' indicates that the elastic G' modulus decreases with increasing strain amplitude, thus it indicates nonlinearity of the modulus. This phenomenon is known as the Payne effect and indicates the presence of a filler network due to supramolecular interactions of the filler particles either directly or mediated by rubber chains. Disruption of the filler network is a source of energy dissipation.

[0333] Tanδmax is a selected parameter indicating the energy dissipation. Therefore, the higher the ΔG' and Tanδmax values, the higher the energy dissipation.

[0334] Substituting CB for silica with substantially the same AG' and Tan δmax values ​​indicates that the pyrrole derivative (compound (1)) together with CB (in the form of an adduct or by adding each substance separately to the elastomeric composition) can indeed replace silica.

[0335] In particular, it is noteworthy that the use of the pyrrole derivative (compound (1)) as a constituent of the elastomeric composition leads to the same Tan δ values ​​and significantly lower AG' values ​​(Table 4).

[0336] Dynamic Mechanical Characterization of Elastomer Compositions by Axial Stress

[0337] In Table 5, data obtained from dynamic mechanical tests carried out by applying a sinusoidal axial stress are shown. The experimental conditions used to carry out the tests have been stated above.

[0338] Table 5

[0339]

[0340]

[0341] ^ Compare

[0342] The same comments reported above for the dynamic-mechanical characterization in shear mode can also be reported for the results from the axial tests. The use of pyrrole derivatives (compound (1)), either as modifiers of CB or as constituents of elastomeric compositions, allows partial or total replacement of silica by CB, reproducing essentially the same dynamic mechanical properties measured for compositions based on pristine CB (Ex. 6^).

[0343] Furthermore, it is important to observe that:

[0344] (i) For the composition according to the invention, the value of the storage modulus E' is lower at low temperatures. This means that the composition has lower rigidity at low temperatures, which is certainly an advantage;

[0345] (ii) For the composition according to the present invention, the value of ΔE'(E'10°C-E'70°C) is lower or consistent with that of Example 10. This means that the composition has higher dynamic rigidity stability when the temperature increases;

[0346] (iii) The values ​​of tan δ are consistent at all temperatures and are lower for the compositions with compound (1) / CB adduct (Examples 7-9), especially when 66% of the silica is replaced by the adduct (Example 8). This is a clear advantage for elastomeric compositions intended, for example, for inner compounds in tires.

[0347] Characterization of Elastomer Compositions by Tensile Testing

[0348] The tensile properties were determined by quasi-static measurements as disclosed above. In Table 6, the data obtained from the tensile tests are shown.

[0349] Table 6

[0350]

[0351]

[0352] ^ Compare

[0353] The tensile properties confirm the reviewed data of the dynamic-mechanical characterization already reported. The elastomeric composition of the invention has tensile properties that are completely consistent with the comparative composition based on the original CB (Ex. 6^).

[0354] In particular, it is worth noting that:

[0355] (i) The composition comprising the pyrrole derivative (compound (1), Example 10) as an ingredient has better overall final properties;

[0356] (ii) The composition in which 33% of the silica was replaced by compound (1) / CB adduct (Example 7) had higher tensile strength, and similar elongation at break.

Claims

1. An elastomeric composition comprising at least one sp 2 Hybridized carbon allotropes and compounds of formula (I): wherein X and Y are independently selected from: -NHR' and OR"; and wherein R" is selected from hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl and heteroaryl; and wherein R and R' are independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl, and carboxyl; Either R and / or R' is Wherein M, Q and J are independently selected from amine, hydroxyl, hydrogen, straight chain or branched C1-C10 alkyl and straight chain or branched C2-C10 alkenyl or alkynyl, or selected from: Where R1-R 15 independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl and carboxyl; and R 10 -R 12 It can be -OCH2-CH3 or -OCH3; and R 14 It can be -CH2-SH or -CH2-CH2-S-CH3; and wherein T is -O- or -S-, and when T is -S- then p' is an integer from 1 to 4, and when T is -O- then p' is an integer from 1 to 2; and wherein I', p', q', r' are independently integers from 0 to 12; Either R and / or R' is Where R 16 is selected from the group consisting of hydrogen, alkyl, aryl, benzyl, amine, alkylamine, arylamine, benzylamine, and aminoaryl; and R 17 -R 21 Independently selected from the group consisting of: hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, and 1-(4-aminocyclohexyl)methylene.

2. The elastomeric composition according to claim 1, wherein R and R' are identical.

3. The elastomer composition according to claim 1, wherein the compound of formula (I) is represented by the following formula (II): Wherein R 22 is selected from hydrogen and C1-C10 straight or branched alkyl optionally substituted by one or more -OH groups; and said R 23 -R 24 are the same and are selected from hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, aryl, straight chain or branched C1-C10 alkyl-aryl, straight chain or branched C2-C10 alkenyl-aryl, straight chain or branched C2-C10 alkynyl-aryl, heteroaryl, straight chain or branched C1-C10 alkyl-NH2, straight chain or branched C1-C10 alkyl-SH, straight chain or branched C1-C10 alkyl-COOH and straight chain or branched C1-C10 alkyl-Si(OCH2CH3)3, wherein the alkyl is optionally substituted by one or more -OH groups.

4. The elastomeric composition according to any one of claims 1 to 3, wherein the compound of formula (I) is present in an amount of at least 0.1 phr.

5. The elastomeric composition according to any one of claims 1 to 4, wherein the sp 2 The hybrid carbon allotrope is selected from the group consisting of carbon black, graphene, 2-layer graphene, 3-10-layer graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, longitudinally or helically extended carbon nanotubes, nanocones, nanohorns, nanorings, fullerenes, and mixtures thereof.

6. The elastomer composition according to claim 5, wherein the sp 2 The hybrid carbon allotrope is selected from the group consisting of carbon black, graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, and mixtures thereof.

7. The elastomeric composition according to any one of claims 1 to 6, comprising at least one unsaturated elastomer selected from the group consisting of poly(1,4-cis-isoprene), natural rubber or synthetic polymers, poly(3,4-isoprene), poly(butadiene), poly(butadiene) with a high content of 1,4-cis units, isoprene / isobutylene copolymers, halogenated isoprene / isobutylene copolymers, halogenated butyl rubbers, chlorinated butyl rubbers, brominated butyl rubbers, 1,3-butadiene / acrylonitrile copolymers, styrene / 1,3-butadiene copolymers, styrene / isoprene / 1,3-butadiene copolymers and styrene / 1,3-butadiene / acrylonitrile copolymers and mixtures thereof.

8. The elastomeric composition according to claim 7, further comprising at least one elastomer of one or more monoolefins, optionally containing a diene.

9. The elastomeric composition according to any one of claims 1 to 8, further comprising an additional reinforcing filler selected from carbon black, silica, phyllosilicates, mixed oxides of aluminum and magnesium having a layered structure, aluminum oxides and aluminosilicates, and mixtures thereof.

10. The elastomeric composition according to claim 9, wherein the additional reinforcing filler is selected from the group consisting of: silica, carbon black and mixtures thereof.

11. The elastomeric composition according to claim 10, wherein carbon black is present in an amount of at least 10 phr.

12. The elastomeric composition according to claim 10, wherein silica is present in an amount ranging from 0 to 100 phr.

13. The elastomeric composition according to any one of claims 1 to 12, further comprising one or more vulcanizing agents, optionally comprising activators and / or accelerators, and one or more additives selected from antioxidants, anti-aging agents, plasticizers, adhesives, antiozonants, modifying resins, and mixtures thereof.

14. The elastomeric composition according to any one of claims 1 to 13, wherein the compound of formula (I) and the at least one sp 2 The hybridized carbon allotropes are provided as preformed adducts.

15. The elastomeric composition according to claim 14, wherein the adduct is present in an amount of at least 1 phr.

16. A method for preparing an elastomer composition according to any one of claims 1 to 15, comprising the following steps: a) providing one or more elastomers, at least one sp 2 hybrid carbon allotrope, a compound of formula (I) as defined in any one of claims 1 to 3, optionally one or more further reinforcing fillers, optionally one or more additives and optionally one or more vulcanizing agents; and b) performing at least one mixing step.

17. The method according to claim 16, wherein the compound of formula (I) and the at least one sp 2 The hybridized carbon allotropes are provided as preformed adducts.

18. Tyre for vehicle wheels comprising at least one structural element comprising a crosslinked elastomeric material obtained by crosslinking the elastomeric composition according to any one of claims 1 to 15.

19. Tire according to claim 18, wherein said structural elements are chosen from: a crown, sidewalls, sidewall inserts, a layer of elastomeric material radially internal with respect to said crown, wherein said radially internal layer is preferably chosen from: liners and micro sidewalls, bead structures and rubber coatings of fabric and metal.

20. A sp 2 Adducts between hybrid carbon allotropes and compounds of formula (I): wherein X and Y are independently selected from: -NHR' and OR"; and wherein R" is selected from hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl and heteroaryl; and wherein R and R' are independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl, and carboxyl; Either R and / or R' is Wherein M, Q and J are independently selected from amine, hydroxyl, hydrogen, straight chain or branched C1-C10 alkyl and straight chain or branched C2-C10 alkenyl or alkynyl, or selected from: Where R1-R 15 independently selected from the group consisting of hydrogen, straight or branched C1-C10 alkyl, straight or branched C2-C10 alkenyl or alkynyl, aryl, straight or branched C1-C10 alkyl-aryl, straight or branched C2-C10 alkenyl-aryl, straight or branched C2-C10 alkynyl-aryl, heteroaryl and carboxyl; and R 10 -R 12 It can be -OCH2-CH3 or -OCH3; and R 14 It can be -CH2-SH or -CH2-CH2-S-CH3; and wherein T is -O- or -S-, and when T is -S- then p' is an integer from 1 to 4, and when T is -O- then p' is an integer from 1 to 2; and wherein I', p', q', r' are independently integers from 0 to 12; Either R and / or R' is Where R 16 is selected from the group consisting of hydrogen, alkyl, aryl, benzyl, amine, alkylamine, arylamine, benzylamine, and aminoaryl; and R 17 -R 21 Independently selected from the group consisting of: hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, and 1-(4-aminocyclohexyl)methylene.

21. The adduct according to claim 20, wherein the compound of formula (I) is represented by the following formula (II): Wherein R 22 is selected from hydrogen and C1-C10 straight or branched alkyl optionally substituted by one or more -OH groups; and said R 23 -R 24 are the same and are selected from hydrogen, straight chain or branched C1-C10 alkyl, straight chain or branched C2-C10 alkenyl or alkynyl, aryl, straight chain or branched C1-C10 alkyl-aryl, straight chain or branched C2-C10 alkenyl-aryl, straight chain or branched C2-C10 alkynyl-aryl, heteroaryl, straight chain or branched C1-C10 alkyl-NH2, straight chain or branched C1-C10 alkyl-SH, straight chain or branched C1-C10 alkyl-COOH and straight chain or branched C1-C10 alkyl-Si(OCH2CH3)3, wherein the alkyl is optionally substituted by one or more -OH groups.

22. The adduct according to any one of claims 20-21, wherein the sp 2 The hybrid carbon allotrope is selected from the group consisting of carbon black, graphene, 2-layer graphene, 3-10-layer graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, longitudinally or helically extended carbon nanotubes, nanocones, nanohorns, nanorings, fullerenes, and mixtures thereof.

23. The adduct according to claim 22, wherein the sp 2 The hybrid carbon allotrope is selected from the group consisting of carbon black, graphene, graphite, high surface area graphite, single-walled or multi-walled carbon nanotubes, and mixtures thereof.

24. A method for preparing the adduct according to any one of claims 20 to 23, comprising the following steps: i) providing a compound of formula (I) as defined in any one of claims 20 to 21 and sp 2 mixtures of hybridized carbon allotropes; and ii) supplying energy to the mixture obtained in step i) to obtain an adduct, and iii) optionally isolating the adduct obtained.

25. The method according to claim 24, wherein the mixture provided in step i) is a powder mixture.

26. The method according to any one of claims 24-25, comprising a further step i') between steps i) and ii), wherein the mixture is suspended in a solvent, preferably a non-polar solvent.

27. The method according to any one of claims 24 to 26, wherein the energy supplied in step ii) is selected from mechanical energy, thermal energy and energy by irradiation with photons, or a combination thereof.

28. The method of claim 27, wherein the energy is thermal energy and is supplied for a period of 5 to 360 minutes.

29. The method according to any one of claims 24 to 28, further comprising the following steps to provide the mixture of step i): A. Providing a compound of formula (I) and sp in a polar protic or aprotic solvent 2 A mixture of hybrid carbon allotropes, wherein the polar protic or aprotic solvent is selected from the group consisting of water, alcohols, carbonyl solvents such as acetone, esters such as ethyl acetate, dimethyl sulfoxide, acetonitrile, ethers, and mixtures thereof; B. subjecting the mixture to ultrasonic treatment; C. Removing the solvent from the mixture obtained in step B).

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