Nitrile rubber composite material and preparation method thereof

Abstract

The invention discloses a nitrile rubber composite material and a preparation method thereof. The nitrile rubber composite material is mainly prepared from the following raw materials in parts by weight: 100 parts of nitrile rubber; 4 to 10 parts of modified carbon nanotubes; the modified carbon nano tube is a carboxyl carbon nano tube modified by perfluoropolyether alcohol. By adopting the perfluoropolyether alcohol modified carbon nanotubes, the mechanical property and heat resistance of the nitrile rubber composite material are enhanced, the intermolecular internal friction of the nitrile rubber composite material is effectively reduced, and the wear resistance of the nitrile rubber composite material is improved.

Description

Technical Field

[0001] The invention relates to a nitrile rubber composite material and a preparation method thereof. Background Art

[0002] In recent years, the proportion of unconventional resources represented by shale oil and gas and tight oil and gas in oil and gas production has gradually increased. At the same time, as more and more deep wells are developed and put into production, the exploitation of oil and gas in ultra-deep formations, high temperature, high pressure and high sulfur wells has become an important strategic development direction. Among them, the key core tools for speed and efficiency improvement of screw drilling tools are in great demand. As other components of screw drilling tools are relatively mature and stable, the nitrile stator rubber bushing, which is relatively weak in itself, has become one of the most important factors determining the performance of screw drilling tools. Its strength, wear resistance, modulus, thermal stability and other properties directly determine the performance and life of screw drilling tools.

[0003] Carbon nanotubes are a classic one-dimensional nano-reinforcement with a high aspect ratio, a modulus of up to 1TPa, a tensile strength of 100GPa, high thermal stability, and a high chemical activity due to its surface effect and small size effect. Due to its outstanding performance, it has been widely studied and used as a reinforcing material for rubber composites. However, carbon nanotubes have poor compatibility with rubber matrices and are not easy to disperse. There are two main reasons for this: first, carbon nanotubes have fewer surface active groups and weak interaction with the rubber matrix; second, carbon nanotubes have high surface energy, and self-entanglement and agglomeration phenomena are serious, resulting in a decrease in the overall performance of rubber. Summary of the invention

[0004] The present invention is made in order to improve the problem that the nitrile rubber may be partially torn and damaged under high-speed rotation, or may be worn by complex mud sand particles, thereby reducing the sealing performance of drilling tools.

[0005] As a first aspect of the present invention, it relates to a nitrile rubber composite material, which is mainly prepared from the following raw materials in parts by weight:

[0006] 100 parts of nitrile rubber; 4-10 parts of modified carbon nanotubes; 40-65 parts of carbon black; 3-6 parts of zinc oxide; 1-3 parts of stearic acid; 2.5-4.5 parts of vulcanization accelerator; 0.5-2.5 parts of antioxidant; 1-2 parts of sulfur.

[0007] In one or some optional embodiments, the modified carbon nanotubes are carboxyl carbon nanotubes modified by perfluoropolyether alcohol.

[0008] In one or some optional embodiments, the modified carbon nanotubes are prepared by the following method:

[0009] The carboxyl carbon nanotubes are placed in a three-necked flask, and a fluorine-containing solvent is added to the three-necked flask, followed by ultrasonic dispersion treatment while stirring; an esterification activator is then added to the three-necked flask, and the temperature is controlled to be stirred at room temperature; perfluoropolyether alcohol and an esterification catalyst are then added to the three-necked flask, and a suspension is obtained after stirring for reaction; finally, the suspension is filtered, and a precipitate is obtained by washing with ethanol and deionized water respectively, and the precipitate is dried to obtain modified carbon nanotubes.

[0010] In one or some optional embodiments, the mass ratio of the carboxyl carbon nanotubes, the fluorine-containing solvent, the esterification activator, the perfluoropolyether alcohol and the esterification catalyst is (1-4): (1000-1500): (2-10): (1-8): (1-4).

[0011] In one or some optional embodiments, the carboxyl carbon nanotubes have a carboxyl content of 1-2 wt %.

[0012] In one or some optional embodiments, the fluorine-containing solvent is perfluorotriethylamine, perfluorotoluene or monofluorodichloroethane; preferably monofluorodichloroethane.

[0013] In one or some optional embodiments, the esterification active agent is N,N'-dicyclohexylcarbodiimide (ie DCC), carbodiimide hydrochloride (ie DCPIP) or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (ie EDC); preferably EDC.

[0014] In one or some optional embodiments, the perfluoropolyether alcohol is a K-type trihydroxy perfluoropolyether.

[0015] In one or some optional embodiments, the esterification catalyst is p-toluenesulfonic acid (ie PTSA), triethylbenzylammonium chloride (ie TEBAC) or 4-dimethylaminopyridine (ie DMAP); preferably DMAP.

[0016] In one or some optional embodiments, the nitrile rubber composite material further comprises the following raw materials in parts by weight:

[0017] Carbon black 40-65 parts;

[0018] 3-6 parts of zinc oxide;

[0019] 1-3 parts of stearic acid;

[0020] Vulcanization accelerator 2.5-4.5 parts;

[0021] Anti-aging agent 0.5-2.5 parts;

[0022] 1-2 parts of sulfur.

[0023] In one or some preferred embodiments, the weight proportion of the carbon black is 50-60 parts.

[0024] In one or some preferred embodiments, the weight proportion of the vulcanization accelerator is 3-4.5 parts.

[0025] In one or some preferred embodiments, the weight proportion of the antioxidant is 1-2 parts.

[0026] As a second aspect of the present invention, it relates to a method for preparing the above-mentioned nitrile rubber composite material, the method comprising:

[0027] The raw nitrile rubber, modified carbon nanotubes, carbon black, vulcanization accelerator, antioxidant and sulfur are fully mixed in an open mill according to weight proportions, the open mill temperature is controlled at 40±5° C., the mixture is mixed until uniform, and finally a flat vulcanizer is used to vulcanize the mixed rubber to obtain a nitrile rubber composite material.

[0028] The present invention adopts perfluoropolyether alcohol with relatively low surface tension, and utilizes its hydroxyl group to react chemically with the carboxyl group of carboxyl carbon nanotubes to modify the carboxyl carbon nanotubes, thereby reducing the surface energy of the carbon nanotubes, reducing the agglomeration and entanglement of the carbon nanotubes themselves, and improving the dispersibility and compatibility of the carbon nanotubes. Meanwhile, the perfluoropolyether has internal lubricity, and can effectively reduce the internal friction between nitrile rubber molecules, and significantly improve the wear resistance of the nitrile rubber composite material. The carbon nanotubes modified by the perfluoropolyether alcohol are more conducive to the transmission of stress on the carbon nanotubes, avoiding stress concentration, and synergistically improving the strength, aging resistance and wear resistance of the nitrile rubber composite material. DETAILED DESCRIPTION

[0029] The following is a detailed description of the embodiments of the present invention: The embodiments of the present invention are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and processes are given, but the protection scope of the present invention is not limited to the following embodiments. The process parameters for which specific conditions are not specified in the following embodiments are generally based on conventional conditions.

[0030] The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in the present invention.

[0031] The inventors referred to the patent CN115197487A, a composition of hydrogenated nitrile rubber resistant to high temperature and pressure, and implemented the relevant technical solutions. It was found that the technology directly blended carbon nanotubes with rubber as fillers without modifying them, and did not mention the improvement of rubber wear resistance. The inventors referred to the patent CN103333311A, a fluorinated carbon nanotube / thermoplastic fluorinated polyurethane composite elastomer and its preparation method, and implemented the relevant technical solutions. It was found that the carbon nanotube modifier in the technology is polymethacrylate perfluoroalkyl ester, and the self-lubricating property of polymethacrylate perfluoroalkyl ester is lower than that of perfluoropolyether. As a modifier, the dispersion degree of carbon nanotubes is not as good as that of perfluoropolyether. At the same time, its heat resistance is lower than that of perfluoropolyether, and the improvement of the heat resistance of nitrile rubber is limited. The inventors referred to the patent CN202110062446.7, a high-strength wear-resistant rubber material and its application in sand suction hoses, and implemented the relevant technical solutions. It was found that the hydroxyl-functionalized carbon nanotubes in this technology are obtained by acidifying carbon nanotubes, and then sequentially performing chlorination and polyol esterification reactions, and the steps are cumbersome. The inventors referred to the patent CN202011467793.X, a method for preparing modified carbon nanotube aging-resistant nitrile rubber, and implemented the relevant technical solutions. It was found that the modified carbon nanotube filler in this technology is prepared by treating carbon nanotubes with mixed acid, modifying carbon nanotubes with zinc nitrate hexahydrate and sodium borohydride, and grafting nano zinc oxide on carbon nanotubes, and there is no mention of improvement in rubber wear resistance. The inventors referred to the patent CN201610767358.6, a high-performance stator rubber suitable for water-based drilling fluid environment, and implemented the relevant technical solutions. It was found that the carbon nanotube reinforcement used in the technology was not modified and was directly blended with the rubber. At the same time, there was no mention of the improvement of the wear resistance and abrasion resistance of the stator rubber. The inventors referred to the patent CN201910528402.1, a self-lubricating wear-resistant rubber material, and implemented the relevant technical solutions. It was found that the carbon nanotubes used in the technology were only used as co-crosslinking agents, and the improvement of wear resistance was mainly achieved by the addition of additional molybdenum disulfide. The inventors referred to the patent CN201610417006.8, a method for preparing a nitrile rubber filled with heat-oxidative aging-resistant carbon nanotubes, and implemented the relevant technical solutions. It was found that the technology was used to prepare modified carbon nanotubes with oxidation-resistant aging functions through hindered phenol modification, which was insufficient to improve the wear resistance of nitrile.

[0032] As the above cannot satisfy the inventor's expectations, the inventor has made the present invention after further research and development.

[0033] It should be noted that the carbon black used in the embodiments of the present invention is a commercially available product, such as N330. The vulcanization accelerator used in the embodiments of the present invention is a commercially available product, such as TMTD or CZ. The antioxidant used in the embodiments of the present invention is a commercially available product, such as MB, DNP or 4010NA.

[0034] It should be noted that the raw material information used in the embodiments of the present invention is shown in Table 1 below, the equipment information used is shown in Table 2 below, and the analysis method used is shown in Table 3 below.

[0035] Table 1 Raw material information

[0036]

[0037] Table 2 Equipment information table

[0038]

[0039] Table 3 Analysis items and methods

[0040] project Test Standards unit Tear strength GB / T 529-2008 KN / m Tensile Strength GB / T 528-2009 MPa Thermal Oxidative Aging GB / T 3512-2001 - Akron Wear GB / T1689-2014 <![CDATA[cm 3 / 1.61km]]>

[0041] Example 1

[0042] Preparation of modified carbon nanotubes:

[0043] 3g of carboxyl carbon nanotubes were placed in a three-necked flask, added into 1100g of monofluorodichloroethane for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 4g of EDC was added into the three-necked flask, and the temperature was controlled to stir at room temperature; then 4g of k-type trihydroxy perfluoropolyether and 2g of DMAP were added into the three-necked flask respectively, and the reaction was stirred for 3h to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0044] Preparation of nitrile rubber composites:

[0045] 100 parts of nitrile rubber, 6 parts of modified carbon nanotubes, 55 parts of N330, 3 parts of zinc oxide, 1 part of stearic acid, 3 parts of TMTD, 1.5 parts of 4010NA and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0046] Example 2

[0047] Preparation of modified carbon nanotubes:

[0048] 3g of carboxyl carbon nanotubes were placed in a three-necked flask, added into 1100g of monofluorodichloroethane for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 3g of EDC was added into the three-necked flask, and the temperature was controlled to stir at room temperature; then 2g of k-type trihydroxy perfluoropolyether and 2g of DMAP were added into the three-necked flask respectively, and the reaction was stirred for 3h to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0049] Preparation of nitrile rubber composites:

[0050] 100 parts of nitrile rubber, 5 parts of modified carbon nanotubes, 45 parts of N330, 3 parts of zinc oxide, 1 part of stearic acid, 2.5 parts of TMTD, 1 part of 4010NA and 1 part of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0051] Example 3

[0052] Preparation of modified carbon nanotubes:

[0053] 2g of carboxyl carbon nanotubes were placed in a three-necked flask, added into 1400g of monofluorodichloroethane for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 3g of EDC was added into the three-necked flask, and the temperature was controlled to stir at room temperature; then 2g of k-type trihydroxy perfluoropolyether and 1g of DMAP were added into the three-necked flask respectively, and the reaction was stirred for 3h to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0054] Preparation of nitrile rubber composites:

[0055] 100 parts of nitrile rubber, 4 parts of modified carbon nanotubes, 50 parts of N330, 3.5 parts of zinc oxide, 1.5 parts of stearic acid, 2.5 parts of CZ, 2 parts of 4010NA and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0056] Example 4

[0057] Preparation of modified carbon nanotubes:

[0058] 4 g of carboxyl carbon nanotubes were placed in a three-necked flask, added to 1500 g of monofluorodichloroethane for ultrasonic dispersion treatment, and strongly mechanically stirred; then 10 g of EDC was added to the three-necked flask, and the temperature was controlled to stir at room temperature; then 6 g of k-type trihydroxy perfluoropolyether and 4 g of DMAP were added to the three-necked flask respectively, and the reaction was stirred for 3 hours to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0059] Preparation of nitrile rubber composites:

[0060] 100 parts of nitrile rubber, 10 parts of modified carbon nanotubes, 40 parts of N330, 4.5 parts of zinc oxide, 2.5 parts of stearic acid, 4.5 parts of TMTD, 2 parts of 4010NA and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0061] Example 5

[0062] Preparation of modified carbon nanotubes:

[0063] 3 g of carboxyl carbon nanotubes were placed in a three-necked flask, added into 1500 g of monofluorodichloroethane for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 8 g of EDC was added into the three-necked flask, and the temperature was controlled to stir at room temperature; 5 g of k-type trihydroxy perfluoropolyether and 3 g of DMAP were added into the three-necked flask respectively, and the reaction was stirred for 3 hours to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0064] Preparation of nitrile rubber composites:

[0065] 100 parts of nitrile rubber, 8 parts of modified carbon nanotubes, 60 parts of N330, 4 parts of zinc oxide, 1.5 parts of stearic acid, 3 parts of CZ, 2 parts of 4010NA and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0066] Example 6

[0067] Preparation of modified carbon nanotubes:

[0068] 1g of carboxyl carbon nanotubes was placed in a three-necked flask, added into 1200g of monofluorodichloroethane for ultrasonic dispersion treatment, and strongly mechanically stirred at the same time; then 2g of EDC was added into the three-necked flask, and the temperature was controlled to stir at room temperature; then 3g of k-type trihydroxy perfluoropolyether and 1g of DMAP were added into the three-necked flask respectively, and the reaction was stirred for 3h to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0069] Preparation of nitrile rubber composites:

[0070] 100 parts of nitrile rubber, 4 parts of modified carbon nanotubes, 55 parts of N330, 6 parts of zinc oxide, 3 parts of stearic acid, 4 parts of CZ, 0.5 parts of 4010NA and 2 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0071] Example 7

[0072] Preparation of modified carbon nanotubes:

[0073] 2 g of carboxyl carbon nanotubes were placed in a three-necked flask, added to 1300 g of perfluorotriethylamine for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 7 g of DCC was added to the three-necked flask, and the temperature was controlled to stir at room temperature; 6 g of k-type trihydroxy perfluoropolyether and 2.5 g of PTSA were added to the three-necked flask respectively, and the reaction was stirred for 3 hours to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0074] Preparation of nitrile rubber composites:

[0075] 100 parts of nitrile rubber, 8 parts of modified carbon nanotubes, 50 parts of N330, 4.5 parts of zinc oxide, 1.5 parts of stearic acid, 3 parts of TMTD, 1.5 parts of MB and 2 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0076] Example 8

[0077] Preparation of modified carbon nanotubes:

[0078] 3 g of carboxyl carbon nanotubes were placed in a three-necked flask, added to 1300 g of perfluorotriethylamine for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 8 g of DCC was added to the three-necked flask, and the temperature was controlled to stir at room temperature; 5 g of k-type trihydroxy perfluoropolyether and 3 g of PTSA were added to the three-necked flask respectively, and the reaction was stirred for 3 hours to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0079] Preparation of nitrile rubber composites:

[0080] 100 parts of nitrile rubber, 8 parts of modified carbon nanotubes, 60 parts of N330, 4 parts of zinc oxide, 1.5 parts of stearic acid, 3 parts of CZ, 2 parts of MB and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0081] Example 9

[0082] Preparation of modified carbon nanotubes:

[0083] 3 g of carboxyl carbon nanotubes were placed in a three-necked flask, added into 1300 g of perfluorotoluene for ultrasonic dispersion treatment, and strongly mechanically stirred; then 7 g of DCPIP was added into the three-necked flask, and the temperature was controlled to stir at room temperature; 6 g of k-type trihydroxy perfluoropolyether and 2.5 g of TEBAC were added into the three-necked flask respectively, and the reaction was stirred for 3 hours to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0084] Preparation of nitrile rubber composites:

[0085] 100 parts of nitrile rubber, 8 parts of modified carbon nanotubes, 50 parts of N330, 5 parts of zinc oxide, 2 parts of stearic acid, 2.5 parts of TMTD, 2 parts of DNP and 1 part of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0086] Example 10

[0087] Preparation of modified carbon nanotubes:

[0088] 3 g of carboxyl carbon nanotubes were placed in a three-necked flask, added into 1300 g of perfluorotoluene for ultrasonic dispersion treatment, and strong mechanical stirring was performed at the same time; then 8 g of DCPIP was added into the three-necked flask, and the temperature was controlled to stir at room temperature; 5 g of k-type trihydroxy perfluoropolyether and 3 g of TEBAC were added into the three-necked flask respectively, and the reaction was stirred for 3 hours to obtain a suspension; finally, the suspension was filtered, and the precipitate was washed with ethanol and deionized water respectively to obtain a precipitate, and the precipitate was placed in a vacuum drying oven for drying to obtain modified carbon nanotubes.

[0089] Preparation of nitrile rubber composites:

[0090] 100 parts of nitrile rubber, 8 parts of modified carbon nanotubes, 60 parts of N330, 4 parts of zinc oxide, 1.5 parts of stearic acid, 3 parts of CZ, 2 parts of DNP and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and mixed until uniform. Finally, the mixed rubber was vulcanized using a flat vulcanizer to obtain a nitrile rubber composite material. Its properties are shown in Table 4.

[0091] Comparative Example 1

[0092] Preparation of aminopolysiloxane-based carbon nanotubes:

[0093] Referring to the method for preparing modified carbon nanotubes from polysiloxane disclosed in patent CN202211003264.3, 100 parts by weight of acidified carbon nanotubes are dispersed in N,N-dimethylformamide, 1500-4000 parts by weight of diphenylmethane diisocyanate are added, heated to 70-90°C for reaction for 6-18h, centrifuged, washed with distilled water and acetone to obtain isocyanate-based carbon nanotubes. Disperse isocyanate-based carbon nanotubes in N,N-dimethylformamide, add polyaminopolysiloxane and dibutyltin dilaurate, react at 50-75°C for 6-12h, centrifuged, washed with distilled water and ethanol to obtain aminopolysiloxane-based carbon nanotubes.

[0094] Preparation of nitrile rubber composites:

[0095] 100 parts of nitrile rubber, 8 parts of aminopolysiloxane-based carbon nanotubes, 60 parts of N330, 4 parts of zinc oxide, 1.5 parts of stearic acid, 3 parts of CZ, 2 parts of 4010NA and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C and the mixture was mixed until uniform. Finally, a flat vulcanizer was used to vulcanize the mixed rubber to obtain a nitrile rubber composite material. The properties of the composite material are shown in Table 4.

[0096] Comparative Example 2

[0097] Preparation of nitrile rubber composites:

[0098] 100 parts of nitrile rubber, 3 parts of carboxyl carbon nanotubes, 5 parts of K-type trihydroxy perfluoropolyether, 60 parts of N330, 4 parts of zinc oxide, 1.5 parts of stearic acid, 3 parts of CZ, 2 parts of 4010NA, and 1.5 parts of sulfur were fully mixed in an open mill. The mixing temperature was controlled at 40±5°C. The mixture was mixed until uniform. Finally, a flat vulcanizer was used to vulcanize the mixed rubber to obtain a nitrile rubber composite material. The properties of the composite material are shown in Table 4.

[0099] The properties of the nitrile rubber composite materials obtained in Examples 1-10 and Comparative Examples 1 and 2 were evaluated, and the results are shown in Table 4 below.

[0100] Table 4 Properties of the nitrile rubber composite materials obtained in Examples 1-10 and Comparative Examples 1 and 2

[0101]

[0102]

[0103] From the analysis of Table 4, it can be seen that when the raw materials and their weight proportions for preparing the nitrile rubber composite material are the same, the nitrile rubber composite material provided by the embodiment of the present invention uses perfluoropolyether alcohol modified carbon nanotubes, and its comprehensive performance is significantly better than that of the comparative example of the nitrile rubber composite material prepared by using polysiloxane modified carbon nanotubes; at the same time, under the same conditions, the nitrile rubber composite material prepared by the embodiment of the present invention using perfluoropolyether modified carbon nanotubes has better aging resistance and wear resistance than the nitrile rubber composite material prepared by using carboxyl carbon nanotubes / perfluoropolyether alcohol blend in the comparative example, indicating that perfluoropolyether alcohol modified carbon nanotubes are more conducive to enhancing the mechanical properties and heat resistance of nitrile rubber.

[0104] Although the specific embodiments of the present invention have been described in detail, it will be understood by those skilled in the art. According to all the teachings disclosed, various modifications and replacements can be made to those details, and these changes are all within the protection scope of the present invention. The full scope of the present invention is given by the attached claims and any equivalents thereof.

Claims

1. A nitrile rubber composite material, characterized in that: The nitrile rubber composite material is mainly prepared from the following raw materials in parts by weight: 100 parts of nitrile rubber; 4-10 parts of modified carbon nanotubes; The modified carbon nanotubes are carboxyl carbon nanotubes modified by perfluoropolyether alcohol.

2. The nitrile rubber composite material according to claim 1, wherein The modified carbon nanotubes are prepared by the following method: The carboxyl carbon nanotubes are placed in a three-necked flask, and a fluorine-containing solvent is added to the three-necked flask, followed by ultrasonic dispersion treatment while stirring; an esterification activator is then added to the three-necked flask, and the temperature is controlled to be stirred at room temperature; perfluoropolyether alcohol and an esterification catalyst are then added to the three-necked flask, and a suspension is obtained after stirring for reaction; finally, the suspension is filtered, and a precipitate is obtained by washing with ethanol and deionized water respectively, and the precipitate is dried to obtain modified carbon nanotubes.

3. The method according to claim 2, characterized in that The mass ratio of the carboxyl carbon nanotubes, the fluorine-containing solvent, the esterification activator, the perfluoropolyether alcohol and the esterification catalyst is (1-4): (1000-1500): (2-10): (1-8): (1-4).

4. The method according to claim 2, characterized in that The carboxyl carbon nanotubes have a carboxyl content of 1-2 wt %.

5. The method according to claim 2, characterized in that The fluorine-containing solvent is perfluorotriethylamine, perfluorotoluene or monofluorodichloroethane; preferably monofluorodichloroethane.

6. The method according to claim 2, characterized in that The esterification active agent is N,N'-dicyclohexylcarbodiimide, carbodiimide hydrochloride or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; preferably 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.

7. The method according to claim 2, characterized in that The perfluoropolyether alcohol is a K-type trihydroxy perfluoropolyether.

8. The method according to claim 2, characterized in that The esterification catalyst is p-toluenesulfonic acid, triethylbenzylammonium chloride or 4-dimethylaminopyridine, preferably 4-dimethylaminopyridine.

9. The vulcanized stator rubber material according to claim 1, characterized in that: The nitrile rubber composite material also includes the following raw materials in parts by weight: Carbon black 40-65 parts; 3-6 parts of zinc oxide; 1-3 parts of stearic acid; Vulcanization accelerator 2.5-4.5 parts; Anti-aging agent 0.5-2.5 parts; 1-2 parts of sulfur.

10. The nitrile rubber composite material according to claim 9, characterized in that The weight proportion of the carbon black is 50-60 parts.

11. The nitrile rubber composite material according to claim 9, characterized in that The weight proportion of the vulcanization accelerator is 3-4.5 parts.

12. The nitrile rubber composite material according to claim 9, characterized in that The weight proportion of the antioxidant is 1-2 parts.

13. A method for preparing the nitrile rubber composite material according to any one of claims 1 to 12, characterized in that: The method comprises: The raw nitrile rubber, modified carbon nanotubes, carbon black, vulcanization accelerator, antioxidant and sulfur are fully mixed in an open mill according to weight proportions, the open mill temperature is controlled at 40±5° C., the mixture is mixed until uniform, and finally a flat vulcanizer is used to vulcanize the mixed rubber to obtain a nitrile rubber composite material.

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