Hydrogenated nitrile rubber / natural rubber composite material with high cutting resistance, wear resistance and compatibility and preparation method thereof

Abstract

The invention relates to the technical field of rubber nano composite materials, and discloses a high-cutting-resistant wear-resistant high-compatibility hydrogenated nitrile rubber / natural rubber composite material and a preparation method thereof. In the presence of an initiator and a solvent, itaconic anhydride and epoxidized isoprene rubber are subjected to a grafting reaction, and the itaconic anhydride grafted epoxidized isoprene rubber is obtained. After itaconic anhydride grafted epoxidized isoprene rubber is introduced into a natural rubber (NR) / hydrogenated butadiene-acrylonitrile rubber (HNBR) composite material to serve as a compatilizer, a polar anhydride group in the compatilizer and a nitrile group in hydrogenated butadiene-acrylonitrile rubber are subjected to hydrogen bond or dipole-dipole interaction, and interface chemical bonding is enhanced; meanwhile, a non-polar main chain in the compatilizer is compatible with the natural rubber, bridging is formed on a natural rubber / hydrogenated nitrile rubber interface, the compatibility between the non-polar NR and the polar HNBR is effectively improved, the synergistic effect of the non-polar NR and the polar HNBR on the microstructure is achieved, and the wear resistance and the cutting resistance of the composite material are improved.

Description

Technical Field

[0001] This invention relates to the field of rubber nanocomposite technology, specifically to a high-cut-resistant, wear-resistant, and highly compatible hydrogenated nitrile butadiene rubber / natural rubber composite material and its preparation method. Background Technology

[0002] The tread compound of existing heavy-duty tires is mainly based on natural rubber (NR). However, NR is a non-polar material without a strong polar structure, resulting in weak intermolecular forces and resistance to stress concentration. Consequently, its wear and cut resistance are relatively poor, making it difficult to meet the requirements for use in high-temperature or harsh environments. Hydrogenated nitrile butadiene rubber (HNBR) retains the nitrile groups (-CN) found in NR. The polarity of these nitrile groups enhances intermolecular forces, giving HNBR higher strength and tear resistance. Simultaneously, HNBR possesses good elastic modulus and tensile strength. The saturated structure formed after hydrogenation can effectively resist the propagation of microcracks caused by mechanical friction, improving wear life. Due to the excellent properties of HNBR, adding it to the NR system to form a composite material is a feasible strategy that balances the superior properties of both. However, the significant difference in polarity between the two leads to poor interfacial compatibility during direct blending, resulting in a decrease in the mechanical properties of the composite material. Problems such as phase separation and poor dispersion occur, causing its wear and cut resistance to worsen rather than improve.

[0003] To improve the compatibility of HNBR and NR blends, compatibilizers or modifiers need to be introduced. Currently available compatibilizers have certain drawbacks: maleic anhydride-grafted EPDM-g-MAH has a low maleic anhydride grafting rate, limiting its "compatibility enhancement" effect on polar rubbers (such as HNBR). The grafted groups are mostly concentrated on the main chain surface; if unevenly dispersed or weakly bonded to polarity, they cannot adequately improve the interface. Maleic anhydride-grafted natural rubber (NR-g-MAH) suffers from poor thermal stability, unstable grafting rates, excessive cross-linking side reactions, and uneven molecular weight. Although MAH increases polarity, the overall polarity of the NR skeleton remains low, limiting the interfacial bonding depth with highly polar rubbers such as HNBR with high acrylonitrile content.

[0004] Epoxidized isoprene rubber (EIR) is a product in which epoxy groups are introduced into the isoprene rubber molecular chain. It possesses a certain degree of polarity, which improves its compatibility with polar rubbers while maintaining good compatibility with natural rubber (NR). EIR not only retains the good mechanical properties of natural rubber but also imparts a certain degree of polarity, making it a modified material that combines performance and processability. However, the interfacial bonding between EIR and HNBR still faces certain obstacles, especially in highly polar or highly filled systems, requiring the introduction of more polar groups to enhance the interfacial interaction between EIR and HNBR molecules.

[0005] Based on the above background, there is an urgent need to develop a new type of compatibilizer to enhance the compatibility of HNBR / NR composite materials and improve their wear resistance and cut resistance. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems existing in the prior art and provide a high-cut-resistant, wear-resistant, and highly compatible hydrogenated nitrile butadiene rubber / natural rubber composite material and its preparation method.

[0007] To achieve the above objectives, the first aspect of the present invention provides a composite rubber compatibilizer, wherein the composite rubber compatibilizer is itaconic anhydride-grafted epoxidized isoprene rubber.

[0008] A second aspect of the present invention provides a method for preparing a composite rubber compatibilizer according to the first aspect, wherein the method comprises: in the presence of an initiator and a solvent, subjecting itaconic anhydride to a grafting reaction with epoxidized isoprene rubber to obtain itaconic anhydride-grafted epoxidized isoprene rubber.

[0009] A third aspect of the present invention provides a composite rubber compatibilizer prepared according to the preparation method described in the second aspect.

[0010] The fourth aspect of the present invention provides the use of the composite rubber compatibilizer according to the first or third aspect in the preparation of rubber composite materials.

[0011] The fifth aspect of the present invention provides a natural rubber / hydrogenated nitrile butadiene rubber composite material, wherein the raw materials of the composite material include natural rubber, hydrogenated nitrile butadiene rubber, the composite rubber compatibilizer described in the first or third aspect, and other additives.

[0012] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0013] This invention provides an itaconic anhydride-grafted epoxidized isoprene rubber, which can be used as a compatibilizer in composite rubber. After introducing itaconic anhydride-grafted epoxidized isoprene rubber as a compatibilizer into the NR / HNBR composite material, the polar anhydride groups in the compatibilizer undergo hydrogen bonding or dipole-dipole interactions with the nitrile groups in the hydrogenated nitrile butadiene rubber, enhancing the interfacial chemical bonding. Simultaneously, the non-polar backbone in the compatibilizer is compatible with natural rubber, forming a bridge at the natural rubber / hydrogenated nitrile butadiene rubber interface, effectively improving the compatibility between non-polar NR and polar HNBR, achieving a synergistic effect in their microstructure, and enhancing the wear resistance and cut resistance of the composite material. Detailed Implementation

[0014] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0015] The first aspect of the present invention provides a composite rubber compatibilizer, wherein the composite rubber compatibilizer is itaconic anhydride-grafted epoxidized isoprene rubber.

[0016] This invention grafts itaconic anhydride onto epoxidized isoprene rubber to increase its polarity, resulting in the aforementioned composite rubber compatibilizer. Introducing it into a system composed of two rubbers with different polarities (e.g., a natural rubber / hydrogenated nitrile rubber system) can improve the compatibility between the rubbers, ultimately improving the wear resistance and cut resistance of the composite material.

[0017] In some embodiments of the present invention, the epoxy degree of the epoxidized isoprene rubber is 10-50%.

[0018] In some embodiments of the present invention, the grafting rate of itaconic anhydride in the itaconic anhydride-grafted epoxidized isoprene rubber is 1-7%, preferably 3-5%.

[0019] In this invention, the epoxy degree is obtained by comparing the integral area ratio of the epoxy peak in the 1H NMR spectrum before and after epoxidation; the grafting rate is calculated by titrating the acidic groups (such as -COOH) introduced after itaconic anhydride grafting with a standard NaOH solution to neutralize them.

[0020] A second aspect of the present invention provides a method for preparing a composite rubber compatibilizer according to the first aspect, wherein the method comprises: in the presence of an initiator and a solvent, subjecting itaconic anhydride to a grafting reaction with epoxidized isoprene rubber to obtain itaconic anhydride-grafted epoxidized isoprene rubber.

[0021] This invention grafts itaconic anhydride (IA) onto epoxidized isoprene rubber (EIR) via a free radical grafting reaction. The mechanism essentially involves the thermal decomposition of an initiator to generate free radicals. These free radicals attack the olefins (C=C) on the EIR backbone, initiating the formation of large molecular free radicals. By grafting itaconic anhydride (IA) through addition and polymerization, it introduces nucleophilic polar groups from natural rubber and improves the compatibility and interfacial bonding between hydrogenated nitrile butadiene rubber and natural rubber, acting as a bridge between them. The resulting composite material exhibits high cut and abrasion resistance.

[0022] After the grafting reaction, the reaction mixture is poured into a solvent (selected from at least one of methanol, ethanol, acetone, ethyl acetate, dichloromethane, n-hexane, ethyl acetate and tetrahydrofuran), stirred to precipitate the product, then filtered and washed: washed 1-5 times with solvent to remove unreacted itaconic anhydride and unreacted initiator or byproducts, finally obtaining itaconic anhydride-grafted epoxidized isoprene rubber.

[0023] In some embodiments of the present invention, the mass ratio of itaconic anhydride to epoxidized isoprene rubber is 50:5.5-10.5, for example 50:5.5, 50:6.5, 50:7.5, 50:9.5, 50:10.5, and any value within the range of any two of the above values, preferably 50:6.5-9.5.

[0024] In some embodiments of the present invention, the initiator is selected from at least one of dicumyl peroxide, benzoyl peroxide, azobisisobutyronitrile, potassium persulfate, and tert-butyl peroxide.

[0025] In some embodiments of the present invention, the mass ratio of the initiator to itaconic anhydride is 0.1-5:0.1-15, for example 1:5, 1.3:6.5, 1.9:9.5, 2.1:10.5, etc., and any value within the range of any two of the above values.

[0026] In some embodiments of the present invention, the solvent is selected from at least one of toluene, tetrahydrofuran, chloroform and dichloromethane.

[0027] In some embodiments of the present invention, the conditions for the grafting reaction include: a reaction temperature of 50-150°C, such as 50°C, 55°C, 65°C, 70°C, 100°C, 110°C, 130°C, 150°C, etc., and any value within the range of any two of the above values, preferably 55-110°C; and a reaction time of 1-12h, such as 1h, 2h, 4h, 8h, 10h, 12h, etc., and any value within the range of any two of the above values, preferably 2-10h.

[0028] In some embodiments of the present invention, the method further includes adding a terminator to terminate the grafting reaction.

[0029] In some embodiments of the present invention, the terminator is selected from at least one of p-benzoquinone, 2,2,6,6-tetramethylpiperidine-1-oxy radical, 2,6-di-tert-butyl-p-cresol, phenol, and hydroquinone.

[0030] In some embodiments of the present invention, the mass ratio of the terminator to the initiator is 0.1-5:0.1-5, such as 1:1.1, 1.1:1.3, 1.1:1.5, 1.2:1.9, 1.5:2.1, etc., and any value within the range of any two of the above values.

[0031] In some embodiments of the present invention, the grafting reaction is carried out in a protective atmosphere, preferably nitrogen.

[0032] In some embodiments of the present invention, before the grafting reaction, the epoxidized isoprene rubber is dissolved at 20-80°C for 0.1-12 hours.

[0033] In some embodiments of the present invention, the melting temperature is 40-60°C.

[0034] In some embodiments of the present invention, the dissolution time is 6-12 hours.

[0035] In this invention, epoxidized isoprene rubber can be prepared by methods known in the art. For example, it includes the following steps:

[0036] (1) Place the isoprene rubber raw material in a reaction vessel and dissolve it in a solvent (selected from at least one of toluene, tetrahydrofuran, p-xylene, cyclohexane, acetone, dimethyl sulfoxide and chloroform), i.e.: heat to 20-100℃ and stir thoroughly for 0.1-12h; dilute to the required solid content and keep the temperature constant at 0-100℃; adjust the pH of the system to 7-12 with ammonia water to obtain the pretreated isoprene rubber latex.

[0037] (2) Place the pretreated isoprene rubber latex in a reactor, add a catalyst (selected from at least one of peracetic acid, peroxyformic acid, m-CPBA (meta-chloroperoxybenzoic acid), peroxybenzoic acid and hydrogen peroxide / acetic acid), and add the catalyst dropwise over a period of 0.1-3 hours. Heat the mixture to 40-100°C and stir thoroughly for 0.1-12 hours. After the reaction is complete, adjust the pH to 7-12 with ammonia water, wash the latex with deionized water to remove residual catalyst, and dry it to obtain epoxidized isoprene rubber (EIR).

[0038] A third aspect of the present invention provides a composite rubber compatibilizer prepared according to the preparation method described in the second aspect.

[0039] The fourth aspect of the present invention provides the use of the composite rubber compatibilizer according to the first or third aspect in the preparation of rubber composite materials.

[0040] In some embodiments of the present invention, the rubber composite material is a natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0041] The fifth aspect of the present invention provides a natural rubber / hydrogenated nitrile butadiene rubber composite material, wherein the raw materials of the composite material include natural rubber, hydrogenated nitrile butadiene rubber, the composite rubber compatibilizer described in the first or third aspect, and other additives.

[0042] In some embodiments of the present invention, the other additives are selected from at least one of nanofillers, crosslinking agents, co-crosslinking agents, antioxidants, and plasticizers.

[0043] In some embodiments of the present invention, the nanofiller is selected from at least one of carbon black, silica, silicon dioxide, MXene, clay, calcium carbonate, clay, graphene, and carbon nanotubes.

[0044] In some embodiments of the present invention, the crosslinking agent is selected from at least one of sulfur, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, bis(2,4-dichlorobenzoyl peroxide), dicumyl peroxide, and di-tert-butylperoxyisopropylbenzene.

[0045] In some embodiments of the present invention, the crosslinking agent is selected from at least one of 2-mercaptobenzothiazole, tetramethylthiuram disulfide, and triallyl isocyanurate.

[0046] In some embodiments of the present invention, the plasticizer is selected from at least one of paraffin oil, DOP, TP-95, ATBC and terpene oil.

[0047] In some embodiments of the present invention, the composite material comprises the following raw materials in parts by weight: 10-80 parts of natural rubber, 10-90 parts of hydrogenated nitrile rubber, 1-20 parts of itaconic anhydride modified epoxidized isoprene rubber, 20-120 parts of nanofiller, 0.2-5 parts of crosslinking agent, 0.1-5 parts of co-crosslinking agent, 0.5-4 parts of antioxidant, and 5-30 parts of plasticizer.

[0048] In this invention, itaconic anhydride-grafted epoxidized isoprene rubber is used as a compatibilizer and mixed evenly with rubber matrix, nanofiller, antioxidant, and plasticizer in a mixing device. A crosslinking agent and / or co-crosslinking agent are then added to obtain a uniformly dispersed compound. The compound is then subjected to high-temperature vulcanization at 120-200°C to finally obtain a highly compatible natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0049] The mixing equipment is one or more of the following: open mill, kneader, and internal mixer.

[0050] During the high-temperature vulcanization reaction, the polar anhydride groups in the compatibilizer undergo hydrogen bonding or dipole-dipole interactions with the nitrile groups in the HNBR, enhancing the interfacial chemical bonding. At the same time, the non-polar backbone in the compatibilizer is compatible with natural rubber, forming a bridge at the natural rubber / hydrogenated nitrile rubber interface, effectively improving the compatibility between non-polar NR and polar HNBR, achieving a synergistic effect between the two in the microstructure, and enhancing the wear resistance and cut resistance of the composite material.

[0051] The present invention will be described in detail below through embodiments.

[0052] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0053] Preparation Example 1

[0054] This embodiment illustrates the preparation of itaconic anhydride-grafted epoxidized isoprene rubber.

[0055] (1) Using 100g of isoprene rubber as raw material, dissolve it in 2L of toluene, heat it to 70℃ and stir it thoroughly for 5h; keep the temperature at 50℃ and adjust the pH of the system to 9 with ammonia water to obtain the pretreated isoprene rubber latex.

[0056] (2) The pretreated isoprene rubber latex was placed in a large glass reactor, and the mixture of acetic acid and hydrogen peroxide (molar ratio of 1:2) was used as a catalyst. The temperature was raised to 50°C and stirred for 8 hours. The pH of the system was adjusted to 10 with ammonia water, the latex was washed with deionized water to remove residual catalyst, and spray dried to obtain EIR dry rubber with an epoxy degree of 50%.

[0057] (3) Take 50g of the obtained EIR dry rubber and place it in a reactor. Add toluene and heat to 60℃ and stir thoroughly for 8h. Add 5.5g itaconic anhydride in a nitrogen atmosphere. Use 1.1g dicumyl peroxide as an initiator and heat to 110℃. Continue the reaction for 4h. Finally, add 1.0g 2,6-di-tert-butyl-p-cresol as a terminator. Wash the reaction product with acetone several times and filter. Dry to obtain itaconic anhydride-grafted epoxidized isoprene rubber with a grafting rate of 2% and a yield of 84%.

[0058] Preparation Example 2

[0059] This embodiment illustrates the preparation of itaconic anhydride-grafted epoxidized isoprene rubber.

[0060] (1) Using 100g of isoprene rubber as raw material, dissolve it in 2L of chloroform, heat it to 60℃ and stir it thoroughly for 10h; keep the temperature at 40℃ and adjust the pH of the system to 9 with ammonia water to obtain the pretreated isoprene rubber latex.

[0061] (2) The pretreated isoprene rubber latex was placed in a large glass reactor, and peracetic acid was used as a catalyst. The temperature was raised to 50°C and stirred for 7 hours. The pH of the system was adjusted to 10 with ammonia water, the latex was washed with deionized water to remove residual catalyst, and spray-dried to obtain EIR dry rubber with an epoxy degree of 40%.

[0062] (3) Take 50g of the obtained EIR dry rubber and place it in a reactor. Add tetrahydrofuran and heat to 60℃ and stir thoroughly for 8h. Add 6.5g itaconic anhydride in a nitrogen atmosphere. Use 1.3g dicumyl peroxide as an initiator and heat to 100℃. Continue the reaction for 2h. Finally, add 1.1g 2,2,6,6-tetramethylpiperidine-1-oxy radical as a terminator. Wash the reaction product with ethanol several times and filter it. Dry it to obtain itaconic anhydride-grafted epoxidized isoprene rubber with a grafting rate of 3% and a yield of 85%.

[0063] Preparation Example 3

[0064] This embodiment illustrates the preparation of itaconic anhydride-grafted epoxidized isoprene rubber.

[0065] (1) Using 100g of isoprene rubber as raw material, dissolve it in 2L of cyclohexane, heat it to 70℃ and stir it thoroughly for 10h; keep the temperature at 40℃ and adjust the pH of the system to 10 with ammonia water to obtain the pretreated isoprene rubber latex.

[0066] (2) The pretreated isoprene rubber latex was placed in a large glass reactor, and peroxyformic acid was used as a catalyst. The temperature was raised to 60°C and stirred for 7 hours. The pH was adjusted to 9 with ammonia water, and the latex was washed with deionized water to remove residual catalyst. The latex was spray-dried to obtain EIR dry rubber with an epoxy degree of 30%.

[0067] (3) Take 50g of the obtained EIR dry rubber and place it in a reactor. Add chloroform and heat to 40℃ and stir thoroughly for 10h. Add 7.5g itaconic anhydride in a nitrogen atmosphere and use 1.5g azobisisobutyronitrile as an initiator. Heat to 55℃ and react for 10h. Finally, add 1.1g p-benzoquinone as a terminator. Wash the reaction product with methanol several times and filter. Dry to obtain itaconic anhydride-grafted epoxidized isoprene rubber with a grafting rate of 4% and a yield of 79%.

[0068] Preparation Example 4

[0069] This embodiment illustrates the preparation of itaconic anhydride-grafted epoxidized isoprene rubber.

[0070] (1) Using 100g of isoprene rubber as raw material, dissolve it in 2L of p-xylene, heat it to 70℃ and stir it thoroughly for 8h; keep the temperature at 60℃ and adjust the pH of the system to 9 with ammonia water to obtain the pretreated isoprene rubber latex.

[0071] (2) The pretreated isoprene rubber latex was placed in a large glass reactor and the reaction was carried out at 50°C with m-CPBA (meta-chloroperoxybenzoic acid) as a catalyst for 8 hours. The pH was adjusted to 10 with ammonia water, the latex was washed with deionized water to remove residual catalyst, and spray-dried to obtain EIR dry rubber with an epoxy degree of 20%.

[0072] (3) Take 50g of the obtained EIR dry rubber and place it in a reactor. Add dichloromethane and heat to 50℃. Stir the mixture thoroughly for 12h. Add 9.5g of itaconic anhydride and 1.9g of azobisisobutyronitrile as an initiator in a nitrogen atmosphere. Heat to 65℃ and react for 10h. Finally, add 1.2g of phenol as a terminator. Wash the reaction product with ethyl acetate multiple times and filter. Dry the product to obtain itaconic anhydride-grafted epoxidized isoprene rubber with a grafting rate of 5% and a yield of 81%.

[0073] Preparation Example 5

[0074] This embodiment illustrates the preparation of itaconic anhydride-grafted epoxidized isoprene rubber.

[0075] (1) Using 100g of isoprene rubber as raw material, dissolve it in 2L of chloroform, heat it to 80℃ and stir it thoroughly for 6h; keep the temperature at 40℃ and adjust the pH of the system to 10 with ammonia water to obtain the pretreated isoprene rubber latex.

[0076] (2) The pretreated isoprene rubber latex was placed in a large glass reactor, and peroxybenzoic acid was used as a catalyst. The temperature was raised to 60°C and stirred for 10 hours. The latex was coagulated with 10wt% acetic acid, formic acid / calcium chloride solution. The precipitated EIR gel was collected, rinsed with deionized water, and dried in a vacuum drying oven at 60°C to obtain EIR dry rubber with an epoxy degree of 10%.

[0077] (3) Take 50g of the obtained EIR dry rubber and place it in a reactor. Add toluene and heat to 45℃ and stir thoroughly for 6h. Add 10.5g of itaconic anhydride and 2.1g of tert-butyl peroxide as an initiator in a nitrogen atmosphere. Heat to 70℃ and react for 8h. Finally, add 1.5g of 2,6-di-tert-butyl-p-cresol as a terminator. Wash the reaction product with acetone multiple times and filter. Dry to obtain itaconic anhydride-grafted epoxidized isoprene rubber with a grafting rate of 7% and a yield of 74%.

[0078] Example 1

[0079] This example illustrates the preparation of a natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0080] (1) 80 parts of natural rubber, 20 parts of hydrogenated nitrile rubber, 5 parts of itaconic anhydride-grafted epoxidized isoprene rubber (from preparation example 1), 40 parts of carbon black, 1 part of antioxidant 4010NA, 1 part of antioxidant RD, and 5 parts of paraffin oil were mixed evenly in a mixer, and then 2 parts of sulfur and 1 part of tetramethylthiuram disulfide (TMTD) were added to obtain a uniformly dispersed compound.

[0081] (2) The compound rubber is vulcanized at 165°C to obtain a natural rubber / hydrogenated nitrile rubber composite material.

[0082] Example 2

[0083] This example illustrates the preparation of a natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0084] (1) 70 parts of natural rubber, 30 parts of hydrogenated nitrile rubber, 30 parts of carbon black, 10 parts of graphene, 5 parts of itaconic anhydride-grafted epoxidized isoprene rubber (from preparation example 2), 1 part of antioxidant 4020, 2 parts of antioxidant MB, and 6 parts of paraffin oil were mixed evenly in a mixer, and then 2 parts of bis(2,4-dichlorobenzoyl) peroxide and 1 part of triallyl isocyanurate were added to obtain a uniformly dispersed compound.

[0085] (2) The compound rubber is vulcanized at 170°C to obtain a natural rubber / hydrogenated nitrile rubber composite material.

[0086] Example 3

[0087] This example illustrates the preparation of a natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0088] (1) 60 parts of natural rubber, 40 parts of hydrogenated nitrile rubber, 35 parts of carbon black, 5 parts of silica, 10 parts of itaconic anhydride-grafted epoxidized isoprene rubber (from preparation example 3), 1 part of antioxidant 4020, 1 part of antioxidant 4010NA, and 5 parts of paraffin oil were mixed evenly in a mixer, and then 2 parts of dicumyl peroxide and 1.5 parts of tetramethylthiuram disulfide (TMTD) were added to obtain a uniformly dispersed compound.

[0089] (2) The compound rubber was vulcanized at 160°C to obtain a natural rubber / hydrogenated nitrile rubber composite material.

[0090] Example 4

[0091] This example illustrates the preparation of a natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0092] (1) Mix 50 parts of natural rubber, 50 parts of hydrogenated nitrile rubber, 40 parts of carbon black, 5 parts of carbon nanotubes, 15 parts of itaconic anhydride-grafted epoxidized isoprene rubber (from preparation example 4), 1 part of antioxidant 4010NA, 1 part of antioxidant MB, and 5 parts of paraffin oil in a mixer until uniformly mixed. Then add 2 parts of dicumyl peroxide and 2 parts of tetramethylthiuram disulfide (TMTD) to obtain a uniformly dispersed compound.

[0093] (2) The compound rubber is vulcanized at 170°C to obtain a natural rubber / hydrogenated nitrile rubber composite material.

[0094] Example 5

[0095] This example illustrates the preparation of a natural rubber / hydrogenated nitrile butadiene rubber composite material.

[0096] (1) 90 parts of natural rubber, 10 parts of hydrogenated nitrile rubber, 35 parts of carbon black, 5 parts of MXene, 15 parts of itaconic anhydride-grafted epoxidized isoprene rubber (from preparation example 5), 1.5 parts of antioxidant MBT, 1 part of antioxidant RD, and 6 parts of paraffin oil were mixed evenly in a mixer, and then 2 parts of sulfur and 1 part of 2-mercaptobenzothiazole (MBT) were added to obtain a uniformly dispersed compound.

[0097] (2) The compound rubber is vulcanized at 170°C to obtain a natural rubber / hydrogenated nitrile rubber composite material.

[0098] Example 6

[0099] Natural rubber / hydrogenated nitrile rubber composite material was prepared according to the method of Example 5, except that itaconic anhydride-grafted epoxidized isoprene rubber was replaced with an equal amount of itaconic anhydride-grafted epoxidized isoprene rubber from Preparation Example 4.

[0100] Comparative Example 1

[0101] A natural rubber / hydrogenated nitrile rubber composite material was prepared according to the method of Example 1, except that the itaconic anhydride-grafted epoxidized isoprene rubber in Example 1 was replaced with an equal amount of maleic anhydride-grafted epoxidized natural rubber.

[0102] Comparative Example 2

[0103] Natural rubber / hydrogenated nitrile rubber composite material was prepared according to the method of Example 2, except that the itaconic anhydride-grafted epoxidized isoprene rubber in Example 2 was replaced with an equal amount of maleic anhydride-grafted EPDM rubber.

[0104] Comparative Example 3

[0105] (1) 70 parts of natural rubber matrix, 30 parts of hydrogenated nitrile rubber, 10 parts of maleic anhydride grafted natural rubber, 30 parts of carbon black, 5 parts of silica, 1 part of antioxidant 4020, 1 part of antioxidant 4010NA and 5 parts of paraffin oil are mixed evenly in an internal mixer, and then 2 parts of dicumyl peroxide and 1.5 parts of crosslinking tetramethylthiuram disulfide (TMTD) are added to obtain a uniformly dispersed compound.

[0106] (2) The compound rubber was vulcanized at 170°C to obtain a natural rubber / maleic anhydride grafted natural rubber / hydrogenated nitrile rubber composite material.

[0107] Comparative Example 4

[0108] A natural rubber / hydrogenated nitrile rubber composite material was prepared according to the method of Example 3, except that the itaconic anhydride-grafted epoxidized isoprene rubber in Example 3 was replaced with an equal amount of itaconic anhydride-grafted epoxidized natural rubber.

[0109] Comparative Example 5

[0110] Natural rubber / hydrogenated nitrile rubber composite material was prepared according to the method of Example 4, except that the itaconic anhydride-grafted epoxidized isoprene rubber in Example 4 was replaced with an equal amount of maleic anhydride-grafted isoprene rubber.

[0111] Test Example 1

[0112] The abrasion resistance and cut resistance of the natural rubber / hydrogenated nitrile rubber composites prepared in Examples 1-6 and Comparative Examples 1-5 were tested.

[0113] Among them, the abrasion resistance was tested using GB / T 1689-2014 "Determination of abrasion resistance of vulcanized rubber (using Akron abrasion tester)", with test conditions of 800 rpm for pre-grinding and 3418 rpm for routine testing (equivalent mileage 1.61 km); the cut resistance was tested using project number 20231138-T-606 "Determination of dynamic cut resistance of vulcanized rubber or thermoplastic rubber", with test conditions of 20 min for test time, 720 rpm for sample rotation speed, and 120 cuts / min.

[0114] The test results are shown in Table 1.

[0115] Table 1

[0116]

[0117]

[0118] As can be seen from the data in Table 1, compared with the comparative example, the present invention effectively improves the compatibility of two rubber materials with different polarities by using itaconic anhydride-grafted epoxy isoprene rubber as a compatibilizer for NR / HNBR composite materials, enhances the intermolecular interface interaction, and ultimately improves the wear resistance and cut resistance of NR / HNBR composite materials. Moreover, compared with the addition of other compatibilizers, the effect is more prominent, and it can meet the requirements for introducing HNBR as a base material for tread rubber.

[0119] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A composite rubber compatibilizer, characterized in that, The composite rubber compatibilizer is itaconic anhydride-grafted epoxidized isoprene rubber.

2. The composite rubber compatibilizer according to claim 1, wherein, The epoxy degree of the epoxidized isoprene rubber is 10-50%; Preferably, in the itaconic anhydride-grafted epoxidized isoprene rubber, the grafting rate of itaconic anhydride is 1-7%, more preferably 3-5%.

3. A method for preparing a composite rubber compatibilizer according to claim 1 or 2, characterized in that, The method includes: in the presence of an initiator and a solvent, subjecting itaconic anhydride to a grafting reaction with epoxidized isoprene rubber to obtain itaconic anhydride-grafted epoxidized isoprene rubber.

4. The preparation method according to claim 3, wherein, The mass ratio of itaconic anhydride to epoxidized isoprene rubber is 50:5.5-10.5, preferably 50:6.5-9.5; Preferably, the initiator is selected from at least one of dicumyl peroxide, benzoyl peroxide, azobisisobutyronitrile, potassium persulfate, and tert-butyl peroxide; Preferably, the mass ratio of the initiator to itaconic anhydride is 0.1-5:0.1-15; Preferably, the solvent is selected from at least one of toluene, tetrahydrofuran, chloroform, and dichloromethane; Preferably, the grafting reaction conditions include: a reaction temperature of 50-150℃, more preferably 55-110℃; and a reaction time of 1-12h, more preferably 2-10h.

5. The preparation method according to claim 3 or 4, wherein, The method further includes: adding a terminator to terminate the grafting reaction; Preferably, the terminator is selected from at least one of p-benzoquinone, 2,2,6,6-tetramethylpiperidine-1-oxy radical, 2,6-di-tert-butyl-p-cresol, phenol, and hydroquinone; Preferably, the mass ratio of the terminator to the initiator is 0.1-5:0.1-5.

6. The preparation method according to any one of claims 3-5, wherein, The grafting reaction is carried out in a protective atmosphere, preferably nitrogen. Preferably, before the grafting reaction, the epoxidized isoprene rubber is dissolved in a solvent; Preferably, the dissolution temperature is 20-80℃, more preferably 40-60℃; Preferably, the dissolution time is 0.1-12 hours, and more preferably 6-12 hours.

7. The composite rubber compatibilizer prepared by the preparation method according to any one of claims 3-6.

8. The application of the composite rubber compatibilizer according to claims 1-3 and 7 in the preparation of rubber composite materials; Preferably, the rubber composite material is a natural rubber / hydrogenated nitrile butadiene rubber composite material.

9. A natural rubber / hydrogenated nitrile butadiene rubber composite material, characterized in that, The raw materials for the composite material include natural rubber, hydrogenated nitrile rubber, the composite rubber compatibilizer as described in any one of claims 1-3 or 7, and other additives.

10. The natural rubber / hydrogenated nitrile butadiene rubber composite material according to claim 9, wherein, The other additives are selected from at least one of nanofillers, crosslinking agents, co-crosslinking agents, antioxidants, and plasticizers; Preferably, the nanofiller is selected from at least one of carbon black, silica, silicon dioxide, MXene, clay, calcium carbonate, clay, graphene, and carbon nanotubes; Preferably, the crosslinking agent is selected from at least one of sulfur, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, bis(2,4-dichlorobenzoyl peroxide), dicumyl peroxide, and di-tert-butylperoxyisopropylbenzene. Preferably, the crosslinking agent is selected from at least one of 2-mercaptobenzothiazole, tetramethylthiuram disulfide, and triallyl isocyanurate; Preferably, the plasticizer is selected from at least one of paraffin oil, DOP, TP-95, ATBC, and terpene oil; Preferably, the composite material comprises the following raw materials in parts by weight: 10-80 parts of natural rubber, 10-90 parts of hydrogenated nitrile rubber, 1-20 parts of itaconic anhydride modified epoxidized isoprene rubber, 20-120 parts of nanofiller, 0.2-5 parts of crosslinking agent, 0.1-5 parts of co-crosslinking agent, 0.5-4 parts of antioxidant, and 5-30 parts of plasticizer.

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