ADDUCTS BETWEEN CARBON ALLOTROPES AND SERINOL DERIVATIVES

Abstract

An adduct consists of derivatives of serinol pyrrole and of carbon allotropes in which the carbon is sp.sup.2 hybridized, such as carbon nanotubes, graham or nano-graphites or carbon black, in order to improve the chemical-physical properties of the allotropes increasing above all their dispersibility and stability in liquid media and in polymer matrices, and a process for preparation of the adduct.

Claims

1-10. (canceled)

11. An adduct of a compound of formula (I) ##STR00008## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 are independently selected from the group consisting of: hydrogen, C.sub.1-C.sub.3alkyl, C.sub.2-C.sub.22 linear or branched alkenyl or alkynyl, aryl, C.sub.1-C.sub.22linear or branched alkyl-aryl, C.sub.2-C.sub.22 linear or branched alkenyl-aryl, and C.sub.1-C.sub.22 linear or branched alkynyl-aryl, heteroaryl; and a carbon allotrope or its derivatives.

12. The adduct according to claim 11, wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from the group consisting of: H, CH.sub.3, CH.sub.2CH.sub.3, and phenyl.

13. The adduct according to claim 11, wherein said carbon allotrope or its derivative are selected from the group consisting of carbon black, fullerene, single-wall or multiwall carbon nanotubes, graphene, and graphite with a number of graphene layers from 2 to 10000.

14. The adduct according to claim 11, wherein said carbon allotrope derivative contains functional groups selected from the group consisting of: oxygenated functional groups; functional groups containing carbonyls; functional groups containing nitrogen atoms; and functional groups containing sulfur atoms,

15. The adduct according to claim 14, wherein the oxygenated functional groups are hydroxyls or epoxies.

16. The adduct according to claim 14, wherein the functional groups containing carbonyls are aldehydes, ketones or carboxylic acids.

17. The adduct according to claim 14, wherein the functional groups containing nitrogen atoms are amines, amides, nitriles, diazonium salts, or brines.

18. The adduct according to claim 14, wherein the functional groups containing sulfur atoms are sulfides, disulfides, mercaptans, sulfones, or sulfonic groups.

19. The adduct according to claim 11, wherein said carbon allotrope derivative is graphite oxide.

20. The adduct according to claim 11, wherein carbon allotrope derivative is graphene oxide.

21. A process for the preparation of an adduct according claim 11, comprising; i. providing a solution of a compound of formula (I) in a protic or aprotic polar solvent; ii. providing a suspension of the carbon allotrope in the protic or aprotic polar solvent used for the preparation of the solution in i.; iii. mixing said solution and said suspension; iv. removing said solvent from said mixture obtained in iii.; and v. providing thermal and/or mechanical energy and/or photon irradiation energy to the mixture obtained in iv.

22. The process according to claim 21, wherein said thermal energy is provided at a temperature from 50 to 180° C. for from 15 to 360 minutes.

23. The process according to claim 21, wherein said mechanical energy is provided from 15 to 360 minutes,

24. The process according to claim 21, wherein said photon irradiation energy is provided at a wavelength from 200 to 380nm for 30 to 180 minutes.

Description

[0121] Characteristics and advantages of the invention will be more apparent from the description of preferred embodiments, shown by way of non-limiting example in the accompanying drawings, wherein:

[0122] FIG. 1 shows the IR spectrum of the composition according to Example 1;

[0123] FIG. 2 shows the UV spectrum of the composition according to Example 1;

[0124] FIG. 3 shows the IR spectrum of the composition according to Example 2;

[0125] FIG. 4 shows the UV spectrum of the composition according to Example 2;

[0126] FIG. 5 shows the IR spectrum of the composition according to Example 4;

[0127] FIG. 6 shows the UV spectrum of the composition according to Example 4;

[0128] FIG. 7 shows the UV spectrum of the composition according to Example 4;

[0129] FIG. 8 shows the IR spectrum of the composition according to Example 5;

[0130] FIG. 9 shows the UV spectrum of the composition according to Example 5;

[0131] FIG. 10 shows the UV spectrum of the composition according to Example 5;

[0132] FIG. 11 shows the IR spectrum of the composition according to Example 6;

[0133] FIG. 12 shows the UV spectrum of the composition according to Example 6;

[0134] FIG. 13 shows an electron microscope photograph of the dispersion according to Example 14;

[0135] FIG. 14 shows an electron microscope photograph of the dispersion according to Example 14;

[0136] FIG. 15 shows the dependence of the dynamic modulus G′ on the strain amplitude of the composition according to Examples 16, 17, 18.

EXAMPLES

[0137] The compositions obtained by means of the examples indicated below were analyzed as follows: [0138] infrared analysis (FT-IR using KBr pellet): adduct/KBr weight ratios of 1:500 and approximately 80 mg of mixture to form the pellet were used. The pellet was analyzed by means of a Fourier Transform IR spectrophotometer (Varian 640-IR FT-IR spectrometer with ATR option). The samples were irradiated in a range from 2.5 to 20 μm (or from 4000 to 500 cm-1) [0139] UV spectroscopy: the adduct suspensions (3 mL) were placed, using a Pasteur pipette, in quartz cuvettes with a 1 cm optical path length (volume 1 or 3 mL) and analyzed using a UV-Vis spectrophotometer. The instrument was reset with pure solvent and a UV spectrum from 200-340 nm recorded. A blank of the solvent used was recorded. The UV-visible spectrum indicated the absorption intensity as a function of the wavelength of the radiation from 200 to 750 nm. [0140] DLS (Dynamic Light Scattering): the adduct powder was dispersed in water by sonication for 10 minutes. A first analysis was performed collecting the suspended portion (3 mL) and placing it in a quartz cuvette with a 1 cm optical path length (volume 1 or 3 mL). In parallel, the sonicated mixture was placed in a Falcon centrifuge tube. The suspensions were progressively centrifuged and analyzed: (i) 9000 rpm for 5 minutes; (ii) 9000 rpm for 30 minutes. Evaluation of the size distribution by intensity (Intensity %-d. nm) was performed for all samples. [0141] stability in water: after treatment the powder was placed in a laboratory vial, water was added (concentration of 1 mg/mL) and it was sonicated for 10 minutes, after which the extent of decantation was visually evaluated.

Example 1

[0142] Adduct of 2-(2,5-dimethyl-1H-pyrrol-1-yl)-1,3-propandiol (called Serinol pyrrole, indicated below as SP) with graphite.

[0143] The graphite used was Synthetic Graphite 8427, purchased from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8% by weight and a surface area of 330 m.sup.2/g. 10 g of graphite (NanoG) and 50 mL of acetone were fed to a 250 mL one-neck round-bottom flask. The suspension was sonicated in a 2 liter ultrasonic bath with a power of 260 Watts for 15 minutes. After this time, a solution of 2.35 g of SP in 50 mL of acetone was added. The resulting suspension was sonicated for a further 15 minutes. The solvent was removed at reduced pressure. A powder consisting of graphite with adsorbed SP (graphite/SP adduct) was obtained.

[0144] 12 g of graphite/SP adduct was placed in a stainless steel jar with a capacity of 200 mL and containing 5 stainless steel balls. The jar was placed in a planetary mill and rotated at 300 rpm for successive times: 1 hour, a further 1 hour, a further 1 hour, a further 3 hours. after the milling times indicated 500 mg of powder was collected and washed with water. Washing was performed as follows: 16 mL of water was added to 500 mg of powder. The suspension thus obtained, formed by SP/graphite and water, was sonicated in a 2 liter ultrasonic bath with a power of 260 Watts for 15 minutes. It was then centrifuged at 4000 rpm for 10 minutes, using 15 mL Falcon centrifuge tubes and a benchtop centrifuge (Centrifugette 4206-ALC). The supernatant was removed simply by pouring off. The procedure was repeated until no SP was observed in the wash water. In this example it was repeated 8 times. Verification of the presence of SP in the wash water was performed through TLC and GC-MS analysis. After wash no. 6, the presence of SP on the plate was no longer noted (TLC analysis). GC-MS analysis did not detect the presence of SP. The powder was dried at reduced pressure (70 mmHg) and at 40° C.

[0145] The samples of adduct collected after the grinding times indicated and washed as illustrated were characterized by FT-IR analysis performed preparing a pellet of the adduct sample in KBr.

[0146] The adduct sample ground for 6 hours was washed according to the procedure indicated and the wash waters were analyzed by UV spectroscopy. The UV spectrum shows no absorption. The washed nanoG sample whose wash waters showed no absorption were analyzed by infrared (IR) spectroscopy. FIG. 1 shows the SP spectrum (FIG. 1 letter a) of the starting nanoG (FIG. 1 letter b), of nanoG after reaction and washing (FIG. 1 letter c). The IR spectrum in FIG. 1-c shows the characteristics SP peaks, confirming the formation of the stable nanoG-SP adduct.

[0147] A suspension was also prepared with the sample of nanoG treated with SP after 6 hours of grinding and after washing. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by ultraviolet (UV) spectroscopy. UV spectra were recorded immediately after sonication and after 24 hours and showed the same absorbance.

[0148] FIG. 2 shows the spectrum recorded after 24 hours.

[0149] The suspension was centrifuged at 2000 rpm, for 5 and for 30 minutes. After centrifugation for 30 minutes, UV analysis showed reduced absorbance with respect to that measured at t=0, without centrifugation.

Example 2

[0150] Adduct of SP with graphite.

[0151] The example was conducted in the same way as Example 1 but with a nanoG/SP ratio of 1 to 2 in moles. Moles of nanoG are intended as the moles of benzene ring, calculated assuming the nanoG is 100% carbon.

[0152] The adduct samples collected after the indicated grinding and washing times as illustrated, were characterized by FT-IR analysis performed preparing a pellet of the adduct sample in KBr.

[0153] The adduct sample ground for 6 hours was washed according to the procedure indicated and the wash waters were analyzed by UV spectroscopy. The UV spectrum showed no absorption. The washed nanoG sample whose wash waters showed no absorption were analyzed by infrared (IR) spectroscopy. FIG. 3 shows the SP spectrum (FIG. 3 letter a) of the starting nanoG (FIG. 3 letter b), of nanoG after reaction and washing (FIG. 3 letter c). The IR spectrum in FIG. 3-c shows the characteristic peaks of SP, confirming the formation of the stable nanoG-SP adduct.

[0154] A suspension was also prepared with the sample of nanoG treated with SP after 6 hours of grinding and after washing. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by ultraviolet (UV) spectroscopy). UV spectra were recorded immediately after sonication and after 24 hours and showed the same absorbance. FIG. 4 shows the spectrum recorded after 24 hours.

Example 3

[0155] Adduct of SP with MWCNT.

[0156] The multiwall carbon nanotubes (MWCNT) used were NC7000 series by NANOCYL Inc. A suspension of 0.100 g of CNT in 30 mL of acetone was sonicated in a 2 liter ultrasonic bath with a power of 260 Watts for 30 minutes. 15 mL of a solution of acetone containing 0.100 g of SP was added to this suspension. The resulting suspension was sonicated again for 30 minutes. The solvent was removed with a rotary evaporator, obtaining a solid residue. The powder without solvent thus obtained consisted of SP adsorbed on CNT. 0.200 g of this powder was placed in a stainless steel jar with a capacity of 200 mL and containing 5 stainless steel balls. The jar was rotated at 300 rpm for 15 minutes at ambient temperature. 2 mg of the powder thus obtained was placed in H.sub.2O (2 mL) and sonicated for 30 minutes.

[0157] A suspension was also prepared with the sample of CNT treated with SP after 15 minutes of grinding and after washing. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by UV spectroscopy. UV spectra were recorded immediately after sonication and after 12 hours and showed the same absorbance.

Example 4

[0158] Adduct of SP with Carbon black.

[0159] The Carbon black used was Carbon Black N326 (CB) (Cabot), having the following properties: 30 nm average diameter of the spherical particles, surface area of 77 m.sup.2/g (determined by nitrogen absorption), DBP absorption of 85 mL/100 g.

[0160] 1 g of carbon black and 15 mL of acetone were added to a 100 mL one-neck round-bottom flask. The suspension was sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 0.235 g of SP in 15 mL of acetone was added. The resulting suspension was sonicated for a further 15 minutes. The solvent was removed at reduced pressure. A powder consisting of carbon black with absorbed SP (CB/SP adduct) was obtained.

[0161] 0.700 g of CB/SP adduct was placed in a 30 mL vial equipped with magnetic stirrer. The reaction mixture was heated to the temperature of 180° C. for 2 hours. After this time, the powder was cooled to 25° C.

[0162] The powder was then placed in a Buchner funnel with filter and washed repeatedly with distilled water. The wash water was colorless. The presence of SP in the wash water was verified by TLC and GC-MS analysis. After wash no. 6, the presence of SP on the plate was no longer noted (TLC analysis). GC-MS analysis did not detect the presence of SP.

[0163] The samples of adduct collected after the heating times indicated and washed as illustrated were characterized by FT-IR analysis preparing a pellet of the adduct sample in KBr.

[0164] The adduct sample treated for 2 hours at 180° C. was washed according to the procedure indicated and the wash waters were analyzed by UV spectroscopy. The UV spectrum shows no absorption.

[0165] The washed carbon black sample whose wash waters showed no absorption were analyzed by infrared (IR) spectroscopy. FIG. 5 shows the SP spectrum (FIG. 5 letter a) of the starting carbon black (FIG. 5 letter b), of the carbon black after reaction and washing (FIG. 5 letter c). The IR spectrum in FIG. 5-cshows the characteristic peaks of SP, confirming the formation of the stable Carbon black-SP adduct.

[0166] A suspension was also prepared with the sample of carbon black treated with SP after heating to 180° C. for 2 hours and after washing. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by ultraviolet (UV) spectroscopy. UV spectra were recorded immediately after sonication and after 24 hours and showed the same absorbance. FIG. 6 shows the spectrum recorded after 24 hours.

[0167] The suspension was then centrifuged at 2000 rpm, for 5 and for 30 minutes, without observing any reduction of absorbance in the UV absorption spectrum as shown in FIG. 7.

Example 5

[0168] Adduct of SP with Carbon black.

[0169] The example was conducted in the same was as Example 4 but with Carbon black/SP ratios of 1 to 2 in moles. Moles of carbon black are intended as the moles of benzene ring, calculated assuming the carbon black is 100% carbon.

[0170] The adduct sample treated for 2 hours at 180° C. was washed according to the procedure indicated and the wash waters were analyzed by UV spectroscopy. The UV spectrum shows no absorption.

[0171] The sample of washed carbon black sample whose wash waters showed no absorption was analyzed by infrared (IR) spectroscopy. FIG. 8 shows the SP spectrum (FIG. 8 letter a) of the starting carbon black (FIG. 8 letter b), of the carbon after reaction and washing (FIG. 8 letter c). The IR spectrum in FIG. 8-c shows the characteristic peaks of SP, confirming the formation of the stable Carbon black-SP adduct.

[0172] A suspension was also prepared with the sample of carbon black treated with SP after heating to 180° C. for 2 hours and after washing. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by ultraviolet (UV) spectroscopy. UV spectra were recorded immediately after sonication and after 24 hours and showed the same absorbance. FIG. 9 shows the spectrum recorded after 24 hours.

[0173] The suspension was then centrifuged at 2000 rpm, for 5 and for 30 minutes, without observing any reduction of absorbance in the UV absorption spectrum as shown in FIG. 10.

Example 6

[0174] Adduct of SP with nano-graphite.

[0175] The graphite used was Synthetic Graphite 8427, purchased from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8% by weight and surface area of 330m.sup.2/g.

[0176] 10 g of graphite and 100 mL of acetone were placed in a 250 mL one-neck round-bottom flask. The suspension was sonicated by ultrasonic bath for 15 minutes. After this time, a solution of 2.33 g of SP in 20 mL of acetone was added. The resulting suspension was sonicated for a further 15 minutes. The solvent was removed at reduced pressure. A powder consisting of graphite with adsorbed SP (graphite/SP adduct) was obtained.

[0177] 0.300 g of graphite/SP adduct was placed in a 30 mL vial equipped with magnetic stirrer. The reaction mixture was heated to the temperature of 180° C. for 2 hours. After this time the powder was cooled to 25° C. The powder was then placed in a Buchner funnel with filter and washed repeatedly with distilled water. The filtrate was colorless. The wash water was analyzed by UV spectroscopy.

[0178] The samples of adduct collected after the thermal treatment times indicated and washed as illustrated were characterized by FT-IR analysis performed preparing a pellet of the adduct sample in KBr.

[0179] The sample of adduct heated to 180° C. for 2 hours was washed according to the procedure indicated and the wash waters were analyzed by UV spectroscopy. The UV spectrum showed no absorption.

[0180] The washed nanoG sample whose wash waters showed no absorption were analyzed by infrared (IR) spectroscopy. FIG. 11 shows the SP spectrum (FIG. 11 letter a) of the starting nanoG (FIG. 11 letter b), of nanoG after reaction and washing (FIG. 11 letter c). The IR spectrum in FIG. 11-c shows the characteristic peaks of SP, confirming formation of the stable nanoG-SP adduct.

[0181] A suspension was also prepared with the sample of nanoG treated with SP after heating to 180° C. for 2 hours and after washing. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by ultraviolet (UV) spectroscopy. UV spectra were recorded immediately after sonication and after 24 hours and showed the same absorbance. FIG. 12 shows the spectrum recorded after 24 hours

[0182] The suspension was centrifuged at 2000 rpm, for 5 and for 30 minutes. After centrifugation for 30 minutes, UV analysis showed no reduced absorbance with respect to the absorbance measured at t =0, without centrifugation.

Example 7

[0183] Adduct of SP with MWCNT.

[0184] The multiwall carbon nanotubes (MWCNT) used in this example were prepared according to the procedure indicated in EP2213369A1.

[0185] 1 g of CNT was dispersed in 150 mL of ethyl acetate. The resulting suspension was sonicated for 30 minutes. 15 mL of a solution of ethyl acetate containing 117.5 mg of SP was added to the suspension. The resulting suspension was sonicated again for 30 minutes, and then the solvent was evaporated with a rotary evaporator, obtaining a grainy solid residue that was mechanically broken up and sieved to obtain a flowing powder consisting of SP adsorbed on CNT. The powder was spread on a flat glass plate, so as to form a thin layer of material, and was irradiated at 254 nm for 3 hours. Every 30 minutes, the material was remixed and spread on the glass plate again. 2 mg of the powder thus obtained was placed in H.sub.2O (2 mL) and sonicated for 30 minutes.

[0186] An aqueous suspension was prepared with the sample of CNT/SP treated for 3 hours with UV exposure. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by UV spectroscopy. UV spectra were recorded immediately after sonication and after 7 days and showed the same absorbance.

Example 8

[0187] Adduct of SP with MWCNT.

[0188] The multiwall carbon nanotubes (MWCNT) used in this example were prepared according to the procedure indicated in EP2213369A1.

[0189] 2 g of CNT were dispersed in 150 mL of ethyle acetate. The resulting suspension was sonicated for 30 minutes. 5 mL of a solution of ethyl acetate containing 43 mg of SP was added to the suspension. The resulting suspension was sonicated again for 30 minutes, and then the solvent was evaporated with a rotary evaporator, obtaining a grainy solid residue that was mechanically broken up and sieved to obtain a flowing powder consisting of SP adsorbed on CNT. The powder was transferred to a quartz tube and maintained in suspension by a controlled air flow introduced from the top of the tube. The tube was irradiated at 254 nm for 1 hour.

[0190] An aqueous suspension was prepared with the sample of CNT/SP treated for 1 hour with UV exposure. The suspension, having a concentration of 1 mg/mL, was sonicated for 10 minutes and analyzed by UV spectroscopy. UV spectra were recorded immediately after sonication and after 7 days and showed the same absorbance.

Example 9

[0191] Adduct of SP with graphite.

[0192] The graphite used is Synthetic Graphite 8427, purchased from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8% by weight and a surface area of 330 m.sup.2/g. A suspension of 0.100 g of NanoG in 5 mL of dimethylformamide was sonicated for 30 minutes. 2 mL of a solution of 0.100 g of SP in dimethylformamide was added to this suspension. The resulting suspension was sonicated again for 30 minutes and the solvent was then removed with the rotary evaporator obtaining a flowing powder consisting of SP adsorbed on NanoG (graphite/SP adduct). The powder was placed in a quartz vial, so as to form a thin layer on one of the walls of the vial. The horizontally placed vial was irradiated at 254 nm for 3 hours, during which the vial was rotated every 30 minutes.

[0193] An aqueous suspension was prepared with the sample of NanoG treated with SP treated for 3 hours with UV exposure. The suspension, having a concentration of 1 mg/mL, was sonicated for 30 minutes and analyzed by UV spectroscopy. UV spectra were recorded immediately after sonication and after 1 hour and showed the same absorbance.

[0194] Some examples regarding the electrical conductivity properties of the adducts according to the present invention are illustrated below.

Example 10

[0195] Nano-graphite/SP adduct based coating on glass.

[0196] Deionized water in a ratio of 100 mg/mL was added to the nano-graphite/SP adduct prepared according to Example 2. The mixture obtained was mixed with a spatula. A coating layer on glass was then prepared by spreading a 2 mL front of the mixture with a bar (Printcoat Instruments) suitable to deposit a layer with a thickness of 40 microns. The coating layer was black, shiny and homogeneous in appearance. The water was removed from the coating layer in an oven for 1 hour. After this treatment, the coating layer was homogeneous and dark grey in appearance. The direct current (DC) electrical conductivity was measured using the four point probe method [L. J. Swartzendruber, Solid State Electron. 1964, 7, 413], using an FPP manual device (Jandel Engineering Ltd., UK) with a probe containing tungsten carbide needles (tip radius of 300 millimeters, needle spacing of 635 millimeters, load 60 g) coupled with a Keithley 2601 electrometer. Data were acquired and analyzed by CSM/Win Semiconductor Analysis Program software (MDC, US), and a resistivity of 2630 Ohm was detected.

Example 11

[0197] Nano-graphite/SP adduct based coating on paper.

[0198] Deionized water in a ratio of 100 mg/mL was added to the nano-graphite/SP adduct prepared according to Example 2. The mixture obtained was mixed with a spatula. A coating layer on paper was then prepared by spreading a 2 mL front of the mixture with a bar (Printcoat Instruments) suitable to deposit a layer with a thickness of 40 microns. The coating layer was black and homogeneous in appearance. The paper with the deposited layer was left at atmospheric temperature and pressure for 24 hours. After evaporation of the aqueous phase, the coating layer was homogeneous and black/dark grey in appearance. The direct current (DC) electrical conductivity was measured using the four point probe method [L. J. Swartzendruber, Solid. State Electron. 1964, 7, 413], using an FPP manual device (Jandel Engineering Ltd., UK) with a probe containing tungsten carbide needles (tip radius of 300 millimeters, needle spacing of 635 millimeters, load 60 g) coupled with a Keithley 2601 electrometer. Data were acquired and analyzed by CSM/Win Semiconductor Analysis Program software (MDC, US). A resistivity of 3550 Ohm was detected.

Example 12

Comparison

[0199] Nano-graphite based coating on paper.

[0200] The graphite used was Synthetic Graphite 8427, purchased from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8% by weight and a surface areas of 330 m.sup.2/g. Deionized water in a ratio of 100 mg/mL was added to the nanoG. The mixture obtained was mixed with a spatula. An attempt was made to spread a coating layer on paper, with a 2 mL front of the mixture with a bar (Printcoat Instruments) suitable to deposit a layer with a thickness of 40 microns. However, it was not possible to deposit a continuous layer, as most of the nanoG remained attached to the bar. Nonetheless, the direct current (DC) electrical conductivity was measured using the four point probe method [L. J. Swartzendruber, Solid State Electron. 1964, 7, 413], using an FPP manual device (Jandel Engineering Ltd., UK) with a probe containing tungsten carbide needles (tip radius of 300 millimeters, needle spacing of 635 millimeters, load 60 g) coupled with a Keithley 2601 electrometer. Data were acquired and analyzed by CSM/Win Semiconductor Analysis Program software (MDC, US). A resistivity of 4,320,000 Ohm was detected.

Example 13

Comparison

[0201] Nano-graphite/sodium dodecyl sulfate (SDS) adduct based coating on paper.

[0202] The graphite used was Synthetic Graphite 8427, purchased from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8% by weight and a surface areas of 330 m.sup.2/g. 200 mg of NanoG and 200 mg of SDS were mixed. Deionized water in a ratio of 100 mg/mL was added to the NanoG/SDS mixture. The mixture obtained was mixed with a spatula. A coating layer on paper was then prepared by spreading a 2 mL front of the mixture with a bar (Printcoat Instruments) suitable to deposit a layer with a thickness of 40 microns. The coating layer was black and homogeneous in appearance. The paper with the deposited layer was left at atmospheric temperature and pressure for 24 hours. The direct current (DC) electrical conductivity was measured using the four point probe method [L. J. Swartzendruber, Solid State Electron. 1964, 7, 413], using an FPP manual device (Jandel Engineering Ltd., UK) with a probe containing tungsten carbide needles (tip radius of 300 millimeters, needle spacing of 635 millimeters, load 60 g) coupled with a Keithley 2601 electrometer. Data were acquired and analyzed by CSM/Win Semiconductor Analysis Program software (MDC, US). A resistivity of 20000 Ohm, indicating poor conductivity, was detected. As can be deduced from the aforesaid example, it is possible to obtain a continuous and homogeneous coating layer of black fillers also by mixing them with normal surfactants; however this coating layer has poor electrical conductivity, which greatly limits its use.

[0203] Some examples regarding the dispersibility properties of the adducts according to the present invention and the related energy dissipation properties of the black fillers in the materials in which they are dispersed are illustrated below.

Example 14

[0204] Dispersion of nanographite reacted with SP in natural rubber latex.

[0205] The natural rubber used was poly(1,4-cis-isoprene) from hevea brasiliensis, STR 20 produced by Thai Eastern Group. 0.05 grams of nanographite/SP adduct prepared according to Example 2 was added to 10 mL of water. The dispersion was then sonicated in a 2 liter ultrasonic bath with a power of 260 Watts for 15 minutes. A solution was obtained, in which no presence of powders was noted. This solution was added to 0.84 grams of latex. The dispersion obtained was stirred with magnetic stirrer for 60 minutes and then sonicated for 1 minute. Precipitation was then performed by adding a 0.1 M sulfuric acid solution. A composite material based on natural rubber containing nanographite was obtained. Transmission electron microscope analysis showed an extremely homogeneous dispersion of the carbon nanofiller as shown in FIGS. 13 and 14.

Example 15

[0206] Dispersion of Carbon Black reacted with SP in natural rubber latex.

[0207] The natural rubber used was poly(1,4-cis-isoprene) from hevea brasiliensis, STR 20 produced by Thai Eastern Group. 0.05 grams of Carbon black/SP adduct prepared according to Example 4 was added to 10 mL of water. The dispersion was then sonicated in a 2 liter ultrasonic bath with a power of 260 Watts for 15 minutes. A solution was obtained, in which no presence of powders was noted. This solution was added to 0.84 grams of latex. The dispersion obtained was stirred with magnetic stirrer for 60 minutes and then sonicated for 1 minute. Precipitation was then performed by adding a 0.1 M sulfuric acid solution. A homogeneous and continuous composite material based on natural rubber containing Carbon black was obtained.

Example 16

Comparison

[0208] Elastomeric compound with carbon black as reinforcing filler.

[0209] 29.39 g of poly(1,4-cis-isoprene), commercial grade SKI 3 (by Nizhnekamskneftechim Export), was fed into a Brabender® internal mixer with a mixing chamber with a volume of 50 cc and masticated at 80° C. for 1 minute. 10.29 g of carbon black CB N326 (by Cabot) was then added, mixed for a further 5 minutes and the compound obtained was unloaded at 145° C. The composite thus prepared was then fed into the internal mixer at 80° C., adding 1.47 g of ZnO (by Zincol Ossidi) and 0.59 g of stearic acid (by Aldrich), and mixed for 2 minutes. 0.66 g of sulfur (by Solfotecnica) and 0.21 g of N-tert-butyl-2-benzothiazole sulfenamide (TBBS) (by Flexsys) were then added, mixing for a further 2 minutes. The composite was unloaded at 90° C.

Example 17

Comparison

[0210] Elastomeric compound with carbon black as reinforcing filler, in the presence of silane.

[0211] The compound was prepared according to the preparation of Example 16. 1.10 g of Bis[3-(triethoxysilyl)propyl]tetrasulfide silane (TESPT) was also added to the compound together with the carbon black.

Example 18

[0212] Elastomeric compound with carbon black treated with SP as reinforcing filler, in the presence of silane.

[0213] The compound was prepared according to the preparation of Example 16, the carbon black used for the preparation was pretreated with SP (10.89 g) according to the procedure of Example 4.

Dynamic Mechanical Characterization of the Compounds of Example 16, Example 17 and Example 18.

[0214] The compounds of Examples 16, 17 and 18 were vulcanized at 151° C. for 30 minutes. The value of the dynamic shear modulus was then measured, administering a sinusoidal strain at 50° C. and 1 Hz of frequency, in a strain amplitude ranging from 0.1% to 25%, using a Monsanto RPA 2000 rheometer.

[0215] Operating conditions: The samples were kept in the instrument at 50° C. for 90 seconds, the strain was then administered at 50° C. in the strain amplitude ranging from 0.1% to 25%, with frequency of 1 Hz, increasing the strain amplitude in the range indicated above. This treatment was implemented to cancel the prior thermomechanical history. Administration of strain was then repeated with the same experimental conditions. Vulcanization was then carried out at 150° C. for 30 minutes, with a frequency of 1.667 Hz and an angle of 6.98% (0.5 rad). The vulcanized sample was left in the instrument for 10 minutes at 50° C. The sinusoidal strain was then applied with the same conditions indicated above, leaving the sample in the instrument for 10 minutes at 50° C. The sinusoidal strain was then applied once again, with the same experimental conditions. FIG. 15 shows the strain amplitude dependence of the dynamic modulus G′. It can be observed how the composite prepared in Example 18 shows a lower modulus value at minimum strain and shows a smaller decrease of the modulus with the increase in strain amplitude. Reduction of dynamic modulus with the strain amplitude is a phenomenon known as the Payne effect and is correlated with energy dissipation of the composite material or of the black fillers.