Modified basalt flake-epdm composite material, preparation method and application thereof

Abstract

The present application relates to a modified basalt flake-EPDM composite material, a preparation method and application thereof, the modified basalt flake-EPDM composite material comprises 100 parts of EPDM and 5-25 parts of modified basalt flake by weight; the modified basalt flake is prepared by coupling agent treatment and polymer coating of basalt flake. The present application modifies the basalt flake, the modified basalt flake is like a roof tile and is parallelly laid in the EPDM, forms a dense physical barrier, the synergistic effect of the physical reinforcing effect of two-dimensional flake and interface modification constructs a stable, strong bonding micro "armor" structure in the EPDM matrix, effectively solves the technical bottleneck that the traditional fiber filler is easy to agglomerate and the interface is weak, simultaneously realizes the significant improvement of the wear resistance and tear strength of the composite material on the premise of maintaining the processing performance and elasticity of the composite material.

Description

Technical Field

[0001] This invention relates to the field of modified materials technology, and in particular to a modified basalt flake-EPDM rubber composite material, its preparation method, and its application. Background Technology

[0002] Offshore wind power technology has matured significantly after more than 20 years of development and is now in a stage of large-scale development with a very broad prospect. Currently, marine organism control devices, as an environmentally friendly and effective means of removing marine organisms, are attracting increasing attention. When these devices are applied to new wind turbine foundations, a rubber buffer layer needs to be added to prevent damage to the foundation coating.

[0003] Ethylene propylene diene monomer (EPDM) rubber is a copolymer of ethylene, propylene, and a small amount of non-conjugated diene. It is a type of ethylene propylene rubber, and its molecular structure is highly compatible with the requirements of the seawater environment, which includes high chloride ion corrosion, salt spray erosion, long-term immersion swelling, temperature fluctuations (-40℃~150℃), microbial adhesion, and mechanical stress aging. EPDM's molecular structure (saturated backbone, low polarity, and controllable crosslinking system) and properties specifically address these problems. However, EPDM rubber has poor abrasion resistance and cannot be used for extended periods in the high-frequency friction environment of ocean waves, necessitating modification. Existing technologies often involve adding modified reinforcing fillers, such as carbon black, to EPDM, or blending it with highly unsaturated rubbers such as natural rubber and styrene-butadiene rubber to improve the overall performance of EPDM. However, none of these materials are suitable for long-term use in the dynamic marine environment.

[0004] Therefore, the development of a wear-resistant rubber material that can be used for a long time in seawater environment, has excellent mechanical properties and wear resistance, and can be used for a long time in the high-frequency friction environment of sea waves has become an urgent problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a modified basalt flake-EPDM rubber composite material, its preparation method, and its application. By adding two-dimensional modified basalt flakes to EPDM rubber, the wear resistance and tear strength of the composite material are significantly improved while maintaining its processing performance and elasticity. This provides a novel solution for high-performance wear-resistant rubber products in high-frequency friction environments such as ocean waves.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a modified basalt flake-EPR rubber composite material, wherein the modified basalt flake-EPR rubber composite material comprises 100 parts of EPR rubber and 5-25 parts of modified basalt flakes by weight. The modified basalt flakes are prepared by treating basalt flakes with a coupling agent and coating them with a polymer.

[0007] The number of portions can be 5 to 25, for example, 5 portions, 10 portions, 15 portions, 20 portions, or 25 portions.

[0008] This invention introduces two-dimensional modified basalt flakes into EPDM rubber. The modified basalt flakes are stacked parallel within the EPDM matrix like roof tiles, forming a dense physical barrier that effectively deflects and hinders the propagation path of wear cracks and prevents external forces from directly tearing the rubber molecular chains. Its efficiency improvement is far higher than that of traditional particulate or short fiber fillers. This invention modifies the basalt flakes through an interface design of "coupling agent modification-polymer coating." Coupling agent modification achieves chemical activation and organication of the basalt flake surface, while polymer coating provides a flexible and compatible coating layer. The two work synergistically to achieve high dispersion, strong interfacial bonding, and mechanical reinforcement of the basalt flakes.

[0009] Preferably, the basalt flakes have a grain size of 70-90 mesh, such as 70 mesh, 75 mesh, 80 mesh, 85 mesh or 90 mesh.

[0010] Preferably, the diameter of the basalt flakes is 170-210 μm, for example, it can be 170μm, 180μm, 190μm, 200μm or 210μm.

[0011] Preferably, the thickness of the basalt flakes is 1-3 μm, for example, it can be 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm.

[0012] Preferably, the diameter-to-thickness ratio of the basalt flakes is 60-200, for example, it can be 60, 80, 100, 120, 140, 150, 160, 180 or 200, etc.

[0013] Preferably, the coupling agent comprises a silane coupling agent.

[0014] Preferably, the silane coupling agent comprises bis-[γ-(triethoxysilane)propyl]tetrasulfide.

[0015] Preferably, the polymer comprises a maleic anhydride-grafted ethylene-vinyl acetate copolymer.

[0016] Preferably, the modified basalt flakes are prepared by the following method, which includes: surface modification of basalt flakes with a coupling agent to obtain coupling agent-modified basalt flakes; and coating the coupling agent-modified basalt flakes with a polymer to obtain the modified basalt flakes.

[0017] Preferably, the preparation method includes the following steps: (1) Mix the coupling agent, solvent A and pH adjuster to obtain a coupling agent solution; The coupling agent solution was mixed with basalt flakes and reacted to obtain coupling agent modified basalt flakes. (2) The basalt flakes modified with coupling agent are mixed with polymer solution, reacted, and then cured to obtain the modified basalt flakes; the polymer solution includes a combination of polymer and solvent B.

[0018] Preferably, the mass ratio of the coupling agent to the basalt flakes is (0.01-0.02):1, for example, it can be 0.01:1, 0.012:1, 0.014:1, 0.015:1, 0.016:1, 0.018:1 or 0.02:1, etc.

[0019] Preferably, the pH adjuster comprises an aqueous solution of acetic acid.

[0020] Preferably, the mass concentration of acetic acid in the aqueous acetic acid solution is 0.5-2%, for example, it can be 0.5%, 1%, 1.5% or 2%, etc.

[0021] Preferably, solvent A comprises an aqueous solution of ethanol.

[0022] Preferably, the mass concentration of ethanol in the aqueous ethanol solution is 85-95%, for example, it can be 85%, 86%, 88%, 90%, 92%, 94% or 95%, etc.

[0023] Preferably, the mass ratio of the polymer to the basalt flakes is (0.01-0.1):1, for example, it can be 0.01:1, 0.02:1, 0.04:1, 0.05:1, 0.06:1, 0.08:1 or 0.1:1, etc.

[0024] Preferably, the mass concentration of the coupling agent in the coupling agent solution is 1-3%, for example, it can be 1%, 1.5%, 2%, 2.5% or 3%, etc.

[0025] Preferably, the pH value of the coupling agent solution is 4-5, for example, it can be pH=4, pH=4.2, pH=4.4, pH=4.5, pH=4.6, pH=4.8 or pH=5, etc.

[0026] Preferably, the polymer concentration in the polymer solution is 5-15%, for example, it can be 5%, 6%, 8%, 10%, 12%, 14% or 15%, etc.

[0027] Preferably, the reaction temperature in step (1) is 75-85℃, for example, 75℃, 76℃, 78℃, 80℃, 82℃, 84℃ or 85℃, and the reaction time is 2-4 h, for example, 2 h, 2.5 h, 3 h, 3.5 h or 4 h.

[0028] Preferably, solvent B comprises toluene.

[0029] Preferably, the mixing in step (2) is performed under ultrasound.

[0030] Preferably, the mixing time in step (2) is 20-40 min, for example, it can be 20 min, 25 min, 30 min, 35 min or 40 min.

[0031] Preferably, the reaction temperature in step (2) is 80-90℃, for example, 80℃, 82℃, 84℃, 85℃, 86℃, 88℃ or 90℃, and the reaction time is 1-3 h, for example, 1 h, 1.5 h, 2 h, 2.5 h or 3 h.

[0032] Preferably, the curing temperature in step (2) is 80-90℃, for example, it can be 80℃, 82℃, 84℃, 85℃, 86℃, 88℃ or 90℃, and the curing time is 0.5-2 h, for example, it can be 0.5 h, 1 h, 1.5 h or 2 h.

[0033] Preferably, the modified basalt flake-EPDM rubber composite material further includes additives.

[0034] Preferably, the additives, by weight, include any one or a combination of at least two of the following: 40-80 parts reinforcing filler, 1-3 parts vulcanizing agent, 0.1-0.5 parts sulfur carrier, 1-10 parts compatibilizer, 0.1-2 parts lubricant, 1-2 parts accelerator, 1-5 parts antioxidant, 10-30 parts plasticizer, or 0.1-2 parts processing aid.

[0035] Among them, 40-80 portions can be, for example, 40, 45, 50, 55, 60, 65, 70, 75, or 80 portions; 1-3 portions can be, for example, 1, 1.5, 2, 2.5, or 3 portions; 0.1-0.5 portions can be, for example, 0.1, 0.2, 0.3, 0.4, or 0.5 portions; 1-10 portions can be, for example, 1, 2, 4, 5 portions, etc. 6, 8, or 10 portions, etc.; 0.1-2 portions, for example, 0.1, 0.5, 1, 1.5, or 2 portions, etc.; 1-2 portions, for example, 1, 1.2, 1.4, 1.5, 1.6, 1.8, or 2 portions, etc.; 1-5 portions, for example, 1, 2, 3, 4, or 5 portions, etc.; 10-30 portions, for example, 10, 15, 20, 25, or 30 portions, etc.

[0036] Preferably, the reinforcing filler comprises carbon black and / or fumed silica.

[0037] Preferably, the vulcanizing agent comprises sulfur.

[0038] Preferably, the sulfur support comprises 4,4'-dithiodimorpholine.

[0039] Preferably, the compatibilizer comprises zinc oxide.

[0040] Preferably, the lubricant comprises stearic acid.

[0041] Preferably, the accelerator comprises N-cyclohexyl-2-benzothiazole sulfenamide and / or tetramethylthiuram disulfide.

[0042] Preferably, the antioxidant comprises poly(2,2,4-trimethyl-1,2-dihydroquinoline) and / or N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine.

[0043] Preferably, the plasticizer comprises paraffin oil.

[0044] Preferably, the processing aid includes polyethylene wax.

[0045] In a second aspect, the present invention provides a method for preparing the modified basalt flake-EPDM rubber composite material as described in the first aspect, the method comprising the following steps: The modified basalt flakes-EPD rubber composite material is obtained by mixing EPD rubber, modified basalt flakes, and optionally additives.

[0046] Preferably, the preparation method of the modified basalt flake-EPDM rubber composite material includes: (A) EPDM rubber is coated onto rollers and then plasticized through a thin pass to obtain roller-coated rubber; (B) The modified basalt flakes are mixed with the roller-wrapping rubber, and then subjected to thin-pass plasticizing, sheeting, and curing to obtain modified basalt flake-EPDM rubber masterbatch. (C) The modified basalt flake-EPR rubber masterbatch is rolled and plasticized, then mixed with optional additives, and then sheeted, aged, vulcanized and molded and post-treated to obtain the modified basalt flake-EPR rubber composite material.

[0047] Preferably, steps (A), (B), and (C) are each performed independently in an open mill.

[0048] Preferably, the temperature of the front roll of the open mill in the thin-wall plasticizing operation in step (A) is 60-65°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C or 65°C, etc.

[0049] Preferably, the temperature of the back roll of the open mill in the thin-wall plasticizing operation in step (A) is 55-60°C, for example, it can be 55°C, 56°C, 57°C, 58°C, 59°C or 60°C, etc.

[0050] Preferably, the roll gap of the open mill in the thin-wall plasticizing operation described in step (A) is 1-3 mm, for example, it can be 1 mm, 1.5 mm, 2 mm, 2.5 mm or 3 mm, etc.

[0051] Preferably, the number of times the thin-wall plasticizing is performed in step (A) is 3-5 times, for example, 3 times, 4 times or 5 times.

[0052] Preferably, in step (B), during the mixing of modified basalt flakes with the roll-wrapping adhesive, the roll gap of the open mill is 1-1.5 mm when the modified basalt flakes are added, for example, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm, etc. After the addition is completed, the roll gap of the open mill is adjusted to 0.8-1 mm, for example, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm or 1 mm, etc.

[0053] Preferably, the number of times the thin-wall plasticizing is performed in step (B) is 6-8 times, for example, 6 times, 7 times or 8 times.

[0054] Preferably, the roll gap of the open mill during sheet extrusion in step (B) is 2-3 mm, for example, it can be 2 mm, 2.2 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.8 mm or 3 mm, etc.

[0055] Preferably, the temperature for aging in step (B) is 20-30°C, such as 20°C, 22°C, 24°C, 25°C, 26°C, 28°C or 30°C, and the time is 3-5 hours, such as 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours.

[0056] Preferably, the mixing in step (C) includes first mixing the lubricant, compatibilizer, antioxidant and modified basalt flake-EPDM rubber masterbatch, then adding reinforcing filler, plasticizer and processing aid and mixing. After the mixed material is sheeted, cooled and re-rolled, accelerator, vulcanizing agent and sulfur carrier are added and mixed.

[0057] Preferably, the roll temperature of the open mill in the thin-wall plasticizing operation in step (C) is 60-70°C, for example, it can be 60°C, 62°C, 64°C, 65°C, 66°C, 68°C or 70°C, etc.

[0058] Preferably, the number of times the thin-wall plasticizing is performed in step (C) is 2-3 times, for example, 2 or 3 times.

[0059] Preferably, the roll gap of the open mill during sheet extrusion in step (C) is 3-4 mm, for example, it can be 3 mm, 3.2 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.8 mm or 4 mm, etc.

[0060] Preferably, the aging temperature in step (C) is 20-30℃, for example, 20℃, 22℃, 24℃, 25℃, 26℃, 28℃ or 30℃, and the time is 8-24 h, for example, 8 h, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h, 22 h or 24 h.

[0061] Preferably, the aging process described in step (C) is carried out under light-protected conditions.

[0062] Preferably, step (C) further includes roll wrapping and thin-pass plasticizing steps before vulcanization molding.

[0063] Preferably, the roller temperature of the thin-walled plasticizing process is less than or equal to 50°C, for example, it can be 20°C, 30°C, 40°C or 50°C.

[0064] Preferably, the number of times the thin-wall plasticizing is performed is 4-5 times, for example, 4 or 5 times.

[0065] Preferably, the vulcanization molding is carried out in a flat vulcanizing machine.

[0066] Preferably, the vulcanization temperature is 160-175℃, for example, 160℃, 165℃, 170℃ or 175℃, and the time is 10-20 min, for example, 10 min, 12 min, 14 min, 15 min, 16 min, 18 min or 20 min.

[0067] Preferably, the vulcanization molding pressure is 10-15 MPa, for example, it can be 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa or 15 MPa, etc.

[0068] Preferably, the post-processing includes heat treatment.

[0069] Preferably, the temperature of the heat treatment is 120-130℃, such as 120℃, 122℃, 124℃, 125℃, 126℃, 128℃ or 130℃, etc., and the time is 2-4 h, such as 2 h, 2.5 h, 3 h, 3.5 h or 4 h.

[0070] The method for preparing the modified basalt flake-EPD rubber composite material provided by this invention adopts a two-step masterbatch preparation process. First, the modified basalt flakes are mixed with EPD rubber to prepare the modified basalt flake / EPD rubber masterbatch. Then, it is mixed with additives. The core purpose is to solve the three major problems of filler (modified basalt flake) dispersion, interfacial bonding, and additive interference through the step-by-step process of "preparing the masterbatch first and then mixing the additives". Ultimately, it achieves a synergistic improvement in the uniformity of composite material dispersion, interfacial bonding strength, and vulcanization reaction stability, while taking into account both processing performance and final performance, making it suitable for the harsh application conditions of offshore wind power.

[0071] Thirdly, the present invention provides an application of the modified basalt flake-EPDM rubber composite material as described in the first aspect in a marine wind power anti-marine organism device.

[0072] Compared with the prior art, the present invention has at least the following beneficial effects: (1) The present invention introduces modified basalt flakes into EPDM rubber. The modified basalt flakes are laid out in parallel like roof tiles in EPDM rubber to form a dense physical barrier, which can effectively deflect and hinder the propagation path of wear cracks and prevent external forces from directly tearing the rubber molecular chain. Its efficiency improvement is much higher than that of traditional particle or short fiber fillers.

[0073] (2) This invention successfully constructs a stable and strongly bonded microscopic "armor" structure within EPDM rubber by designing an interface of "coupling agent modification-polymer coating" on basalt flakes and combining it with a "two-step" masterbatch preparation process. Through the synergistic effect of the physical reinforcement effect of the two-dimensional flakes and the interface modification, the mechanical strength and wear resistance of the composite material are improved simultaneously. This effectively solves the technical bottleneck of easy agglomeration and weak interface of traditional fiber fillers. Furthermore, while maintaining processing performance and elasticity, it achieves a significant improvement in the wear resistance and tear strength of the composite material, providing a new material solution with excellent cost performance for high-performance wear-resistant rubber products under harsh working conditions. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the preparation process of the modified basalt flake-EPDM rubber masterbatch provided by the present invention; Figure 2 This is a scanning electron microscope image of the modified basalt flake-EPDM rubber composite material prepared in Example 6 of the present invention, with a scale bar of 10 μm; Figure 3 This is a scanning electron microscope image of the basalt flake-EPDM rubber composite material prepared in Comparative Example 6 of this invention. The scale bar is 10 μm. Detailed Implementation

[0075] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0076] The specific information of the materials used in the following specific embodiments of the present invention is as follows: EPDM rubber, 4045M, purchased from Mitsui Chemicals Co., Ltd. Basalt phosphorus flakes, 80 mesh, purchased from Haining Anjie Composite Materials Co., Ltd. Coupling agent, Si-69, was purchased from Hubei Jianghan New Materials Co., Ltd. The polymer, maleic anhydride-grafted ethylene-vinyl acetate copolymer (EVA-g-MAH), was purchased from Shanghai Rizhisheng Technology Co., Ltd. Reinforcing filler, carbon black N220, purchased from Cabot; Reinforcing filler, fumed silica, a conventional commercially available product; Vulcanizing agent, sulfur, commonly available commercial products; Sulfur carrier, 4,4'-dithiodimorpholine (DTDM), a commercially available product; Compatibilizer, zinc oxide, a common commercially available product; Lubricant, stearic acid, a common commercially available product; Accelerator, N-cyclohexyl-2-benzothiazole sulfenamide (CBS), a conventional commercially available product; Accelerator, tetramethylthiuram disulfide (TMTD), a conventional commercially available product; Antioxidant, poly(2,2,4-trimethyl-1,2-dihydroquinoline) (RD), a conventional commercially available product; Antioxidant, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (4020), a conventional commercially available product; Plasticizers, paraffin oil, and other common commercially available products; Processing aid, polyethylene wax, a common commercially available product.

[0077] Example 1 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The modified basalt flake-EPDM rubber composite material comprises, by weight, 100 parts of EPDM rubber (4045M), 5 parts of modified basalt flakes, 50 parts of carbon black (N220), 15 parts of fumed silica, 2 parts of sulfur, 1 part of accelerator (CBS), 0.2 parts of accelerator (TMTD), 0.3 parts of 4,4'-dithiodimorpholine, 5 parts of zinc oxide, 1 part of stearic acid, 1 part of antioxidant (RD), 2 parts of antioxidant (4020), 20 parts of paraffin oil, and 1 part of polyethylene wax.

[0078] The method for preparing the modified basalt flakes includes: (1) Mix silane coupling agent Si-69 with 90% ethanol aqueous solution (the mass concentration of Si-69 in ethanol aqueous solution is 2%, and the mass ratio of Si-69 to basalt flakes is 0.015:1), then add acetic acid aqueous solution (the mass concentration of acetic acid is 1%) to adjust the pH of the system to 4-5, let it stand for 20 min, and obtain coupling agent solution. Maleic anhydride-grafted ethylene-vinyl acetate copolymer was mixed with toluene to prepare a polymer solution with a mass concentration of 10% (mass ratio of maleic anhydride-grafted ethylene-vinyl acetate copolymer to basalt flakes was 0.05:1). Basalt flakes were placed in a high-speed mixer and preheated and dried at 70°C for 30 min. (2) The preheated basalt flakes were mixed with the coupling agent solution and reacted at 80°C for 3 h. After the reaction was completed, the material was vacuum dried at 100°C to constant weight to obtain coupling agent modified basalt flakes. (3) The basalt flakes modified by coupling agent are dispersed in a polymer solution, ultrasonically treated for 30 min, heated to 85°C, and reacted for 2 h. After the reaction, the material is placed in a 90°C oven for further curing for 1 h to obtain the modified basalt flakes.

[0079] The preparation method of the modified basalt flake-EPDM rubber composite material includes: (A) Set the roller temperature of the open mill to 60°C for the front roller and 55°C for the rear roller, adjust the roller gap to 2 mm, put in EPDM rubber (4045M), wrap the rollers, and then plasticize through thin passes 4 times to obtain the roller-wrapped rubber. (B) Adjust the gap between the rollers of the open mill to 1.0 mm, and slowly add the modified basalt flakes to the rubber accumulation area above the roller gap in multiple batches using a special filling spoon. After the modified basalt flakes are added, adjust the gap between the rollers to 0.8 mm, and then perform 7 thin pass plasticizing processes on the material. Then adjust the gap between the rollers of the open mill to 2 mm and sheet out the material. After sheeting, hang the material at room temperature (25℃) for 4 hours to obtain modified basalt flakes / EPDM rubber masterbatch. (C) The modified basalt flake / EPDM rubber masterbatch, after being left to mature, is re-rolled and plasticized three times on an open mill (roll temperature 65℃). Then, stearic acid, zinc oxide, antioxidant (RD), and antioxidant (4020) are added sequentially, with each component being mixed at least three times with left and right cuts to ensure uniform mixing. Next, carbon black N220, fumed silica, paraffin oil, and polyethylene wax are added and mixed. The mixed material is sheeted, cooled to room temperature (25℃), and re-rolled on an open mill with a roll temperature below 50℃. Then, accelerator (CBS), accelerator (TMTD), sulfur, and 4,4'-dithiodimorpholine are added, and the mixture is mixed 10 times with left and right cuts. The roll gap is then adjusted to 4 mm for sheeting. The sheeted material is left to stand at room temperature (25℃) in the dark for 24 hours. After the material has matured, it is re-rolled and plasticized five times on a low-temperature open mill (roll temperature <50℃). Then, the material is filled into a mold preheated to 170℃ and vulcanized for 15 minutes under a pressure of 12 MPa on a flat vulcanizing machine. The vulcanized material is then placed in a forced-air drying oven at 120-130℃ and heat-treated for 3 hours to obtain the modified basalt flake-EPDM rubber composite material.

[0080] Example 2 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The modified basalt flake-EPDM rubber composite material comprises, by weight, 100 parts of EPDM rubber (4045M), 15 parts of modified basalt flakes, 40 parts of carbon black (N220), 10 parts of fumed silica, 1 part of sulfur, 0.5 parts of accelerator (CBS), 1 part of accelerator (TMTD), 0.1 parts of 4,4'-dithiodimorpholine, 1 part of zinc oxide, 0.6 parts of stearic acid, 0.5 parts of antioxidant (RD), 0.5 parts of antioxidant (4020), 10 parts of paraffin oil, and 0.5 parts of polyethylene wax.

[0081] (1) Mix silane coupling agent Si-69 with 90% ethanol aqueous solution (the mass concentration of Si-69 in ethanol aqueous solution is 2%, and the mass ratio of Si-69 to basalt flakes is 0.01:1), then add acetic acid aqueous solution (the mass concentration of acetic acid is 1%) to adjust the pH of the system to 4-5, let it stand for 20 min, and obtain coupling agent solution. Maleic anhydride-grafted ethylene-vinyl acetate copolymer was mixed with toluene to prepare a polymer solution with a concentration of 10% (mass ratio of maleic anhydride-grafted ethylene-vinyl acetate copolymer to basalt flakes was 0.02:1). Basalt flakes were placed in a high-speed mixer and preheated and dried at 70°C for 30 min. (2) The preheated basalt flakes were mixed with the coupling agent solution and reacted at 80°C for 3 h. After the reaction was completed, the material was vacuum dried at 100°C to constant weight to obtain coupling agent modified basalt flakes. (3) The basalt flakes modified by coupling agent are dispersed in a polymer solution, ultrasonically treated for 30 min, heated to 85°C, and reacted for 2 h. After the reaction, the material is placed in a 90°C oven for further curing for 1 h to obtain the modified basalt flakes.

[0082] The preparation method of the modified basalt flake-EPDM rubber composite material is the same as that in Example 1.

[0083] Example 3 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The modified basalt flake-EPDM rubber composite material comprises, by weight, 100 parts of EPDM rubber (4045M), 25 parts of modified basalt flakes, 60 parts of carbon black (N220), 20 parts of fumed silica, 3 parts of sulfur, 0.1 parts of accelerator (CBS), 0.5 parts of accelerator (TMTD), 0.5 parts of 4,4'-dithiodimorpholine, 2 parts of zinc oxide, 2 parts of stearic acid, 2 parts of antioxidant (RD), 2 parts of antioxidant (4020), 30 parts of paraffin oil, and 2 parts of polyethylene wax.

[0084] (1) Mix silane coupling agent Si-69 with 90% ethanol aqueous solution (the mass concentration of Si-69 in ethanol aqueous solution is 2%, and the mass ratio of Si-69 to basalt flakes is 0.02:1), then add acetic acid aqueous solution (the mass concentration of acetic acid is 1%) to adjust the pH of the system to 4-5, let it stand for 20 min, and obtain the coupling agent solution. Maleic anhydride-grafted ethylene-vinyl acetate copolymer was mixed with toluene to prepare a polymer solution with a concentration of 10% (mass ratio of maleic anhydride-grafted ethylene-vinyl acetate copolymer to basalt flakes was 0.08:1). Basalt flakes were placed in a high-speed mixer and preheated and dried at 70°C for 30 min. (2) The preheated basalt flakes were mixed with the coupling agent solution and reacted at 80°C for 3 h. After the reaction was completed, the material was vacuum dried at 100°C to constant weight to obtain coupling agent modified basalt flakes. (3) The basalt flakes modified by coupling agent are dispersed in a polymer solution, ultrasonically treated for 30 min, heated to 85°C, and reacted for 2 h. After the reaction, the material is placed in a 90°C oven for further curing for 1 h to obtain the modified basalt flakes.

[0085] The preparation method of the modified basalt flake-EPDM rubber composite material is the same as that in Example 1.

[0086] Example 4 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference from Embodiment 1 is that the amount of modified basalt flakes is adjusted to 10 parts by weight.

[0087] Example 5 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference from Embodiment 1 is that the amount of modified basalt flakes is adjusted to 15 parts by weight.

[0088] Example 6 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference from Embodiment 1 is that the amount of modified basalt flakes is adjusted to 20 parts by weight.

[0089] Example 7 This embodiment provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference from Embodiment 1 is that the amount of modified basalt flakes is adjusted to 25 parts by weight.

[0090] Comparative Example 1 This comparative example provides a EPDM rubber composite material and its preparation method. The difference from Example 1 is that the EPDM rubber composite material does not contain modified basalt flakes.

[0091] Comparative Example 2 This comparative example provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference from Example 1 is that the amount of modified basalt flakes is adjusted to 3 parts by weight.

[0092] Comparative Example 3 This comparative example provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference from Example 1 is that the amount of modified basalt flakes is adjusted to 30 parts by weight.

[0093] Comparative Example 4 This comparative example provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference between this and Example 1 is that the preparation method of the modified basalt flakes includes: (1) Mix maleic anhydride-grafted ethylene-vinyl acetate copolymer with toluene to prepare a polymer solution with a concentration of 10% (mass ratio of maleic anhydride-grafted ethylene-vinyl acetate copolymer to basalt flakes is 0.05:1). Basalt flakes were placed in a high-speed mixer and preheated and dried at 70°C for 30 min. (2) The preheated basalt flakes were dispersed in a polymer solution, ultrasonically treated for 30 min, heated to 85°C, and reacted for 2 h. After the reaction, the material was placed in a 90°C oven for further curing for 1 h to obtain the modified basalt flakes.

[0094] Comparative Example 5 This comparative example provides a modified basalt flake-EPDM rubber composite material and its preparation method. The difference between this and Example 1 is that the preparation method of the modified basalt flakes includes: (1) Mix silane coupling agent Si-69 with 90% ethanol aqueous solution (the mass concentration of Si-69 in ethanol aqueous solution is 2%, and the mass ratio of Si-69 to basalt flakes is 0.015:1), then add acetic acid aqueous solution (the mass concentration of acetic acid is 1%) to adjust the pH of the system to 4-5, let it stand for 20 min, and obtain coupling agent solution. Basalt flakes were placed in a high-speed mixer and preheated and dried at 70°C for 30 min. (2) The preheated basalt flakes were mixed with the coupling agent solution and reacted at 80°C for 3 h. After the reaction was completed, the material was vacuum dried at 100°C to constant weight to obtain the modified basalt flakes.

[0095] Comparative Example 6 This comparative example provides a basalt flake-EPDM rubber composite material and its preparation method. The difference from Example 6 is that the modified basalt flakes are replaced with unmodified basalt flakes in equal amounts.

[0096] This invention uses field emission scanning electron microscopy (Zeiss / Bruker, Gemini 500) to characterize the microstructure of the modified basalt flake-EPDM rubber composite material prepared in Example 6. The SEM results are as follows: Figure 2 As shown, the scale bar is 10 μm; the microstructure of the basalt flake-EPDM rubber composite material prepared in Comparative Example 6 was characterized by SEM results as follows. Figure 3 As shown, the scale bar is 10 μm.

[0097] from Figures 2-3 As can be seen from the above, the modified basalt flake-EPD rubber composite material prepared in Example 6 of this invention has a tight bond between the basalt flakes and the EPD rubber interface after the basalt flakes are modified by coupling agent and coated with polymer. The modified basalt flakes are uniformly dispersed in the matrix without agglomeration, forming a continuous physical barrier without obvious interface defects. In contrast, the basalt flake-EPD rubber composite material prepared in Comparative Example 6 has basalt flakes distributed as large agglomerates in the EPD rubber. The agglomerate size is much larger than that of a single flake. There are clear gaps and debonding phenomena at the interface between the basalt flakes and the EPD rubber. The physical barrier effect is weak. A small number of interfacial gaps between the flakes and the rubber can be seen in the composite material, and the stress transfer efficiency is low.

[0098] Test methods The modified basalt flake-EPDM rubber composites provided in Examples 1-7 and Comparative Examples 1-6 were subjected to the following performance tests: Tensile strength (MPa): Tested in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber"; Right-angle tear strength (N / mm): Tested according to GB / T 529-2008 "Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser type, right-angle type and crescent type specimens)"; DIN wear (mm) 3 The test was conducted in accordance with GB / T 9867-2008 "Determination of abrasion resistance of vulcanized rubber or thermoplastic rubber (rotary roller abrasion tester method)".

[0099] The test results are shown in Table 1 below: Table 1 The test results show that: (1) As can be seen from Examples 1 to 7, the present invention significantly improves the wear resistance and tear strength of the composite material by adding two-dimensional modified basalt flakes to EPDM rubber. The prepared modified basalt flake-EPDM rubber composite material has a tensile strength of 17.0-21.3 MPa, a right-angle tear strength of 68.1-88.5 N / mm, and a DIN abrasion of 83.0-182.3 mm. 3 .

[0100] (2) As can be seen from Examples 1 and 4-7, under the raw material formulation and preparation process conditions specified in this invention, as the amount of modified basalt flakes gradually increases from 5 parts by weight to 25 parts by weight, the mechanical properties and wear resistance of the modified basalt flake-EPDM rubber composite material show a trend of "steady increase - tending to level off".

[0101] The modified basalt flakes, after undergoing an interface design involving "silane coupling agent modification and maleic anhydride grafted ethylene-vinyl acetate copolymer coating," form stable chemical bonds and physical entanglements with EPDM rubber, constructing a microscopic "armor" structure. The two-dimensional lamellar basalt flakes, stacked parallel within the EPDM rubber, efficiently transfer tensile loads. As the amount of modified basalt flakes increases, the continuity of the stress transfer network strengthens, and the overall load-bearing capacity of the composite material gradually improves. However, when the amount of modified basalt flakes exceeds 20 parts by weight, the dispersion of the modified basalt flakes in the matrix reaches saturation; further increases in amount cannot significantly improve stress transfer efficiency, thus the increase in tensile strength tends to plateau.

[0102] The right-angle tear strength exhibits a similar trend to the tensile strength with increasing modified basalt flake content. The two-dimensional lamellar structure of the modified basalt flakes effectively deflects and hinders the propagation path of tear cracks. When the composite material is subjected to tearing force, the modified basalt flakes force the crack to propagate meanderingly along the flake surface or the interface between the flakes and EPDM rubber, rather than directly penetrating the rubber molecular chain, thus significantly improving the material's tear resistance. As the modified basalt flake content increases, the layup density of the modified basalt flakes in EPDM rubber increases, and the hindering effect on crack propagation gradually strengthens. When the modified basalt flake content reaches 20 parts by weight, the physical barrier formed is sufficiently dense, and further increasing the content has little effect on inhibiting crack propagation; therefore, the tear strength tends to stabilize.

[0103] The DIN wear rate showed a trend of "significant decrease - tending to stabilize" with the increase of modified basalt flake content. Modified basalt flakes themselves possess excellent hardness and wear resistance. After being uniformly dispersed and stacked in parallel within EPDM rubber, they form a dense, wear-resistant surface layer that can directly withstand the wear caused by friction, reducing the direct wear of EPDM rubber. As the amount of modified basalt flakes increases, the continuity and density of the wear-resistant surface layer gradually improve, and the wear rate continues to decrease. When the amount of modified basalt flakes reaches 20 parts, the wear-resistant surface layer can completely resist the damage caused by wave friction. Further increasing the amount has a negligible effect on reducing wear rate; therefore, the wear rate tends to stabilize.

[0104] (3) As can be seen from Examples 1-5 and Comparative Example 1, Comparative Example 1 lacks the physical support and wear-resistant barrier effect of the two-dimensional reinforcing phase due to the absence of modified basalt flakes. It fails to solve the core technical problem of poor wear resistance of EPDM rubber, and its comprehensive performance is not essentially different from that of ordinary EPDM rubber.

[0105] (4) As can be seen from Examples 1-5 and Comparative Examples 2-3, when the amount of modified basalt flakes is too small, the insufficient amount of modified basalt flakes leads to the inability to effectively exert the reinforcing and wear-resistant effects, the flake dispersion density does not reach the critical value, and an effective functional network cannot be formed, thus failing to achieve the invention goal of "synergistic optimization of mechanical properties and wear resistance". When the amount of modified basalt flakes is too large, it leads to deterioration of dispersibility and redundant performance decay. Even if the basalt flakes are modified, their dispersion difficulty in EPDM rubber increases significantly, and agglomerates are easily formed. Agglomerates are equivalent to "defect points" inside the material, which will lead to stress concentration, and the performance will not only not improve but will also decrease, resulting in waste of raw materials.

[0106] (5) As can be seen from Examples 1-5 and Comparative Example 4, the modified basalt flakes used in Comparative Example 4 were not modified by silane coupling, and their interfacial compatibility with EPDM rubber deteriorated. The maleic anhydride-grafted ethylene-vinyl acetate copolymer coating layer and EPDM rubber only had physical adsorption, and the interfacial bonding force was extremely weak.

[0107] (6) As can be seen from Examples 1-5 and Comparative Example 5, the modified basalt flakes used in Comparative Example 5 were not coated with maleic anhydride-grafted ethylene-vinyl acetate copolymer, and the lack of polymer coating layer resulted in insufficient dispersibility and interfacial stability.

[0108] (7) As can be seen from Examples 1-5 and Comparative Example 6, the unmodified basalt flakes used in Comparative Example 6 have extremely poor compatibility with EPDM rubber, and are severely agglomerated. Moreover, there is no bonding force at the interface. The agglomerates not only cannot enhance the material, but also become a "stress concentration source", resulting in a significant decrease in the mechanical properties of the material.

[0109] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A modified basalt flake-EPDM rubber composite material, characterized in that, The modified basalt flake-EPR rubber composite material comprises, by weight, 100 parts of EPR rubber and 5-25 parts of modified basalt flakes; The modified basalt flakes are prepared by treating basalt flakes with a coupling agent and coating them with a polymer.

2. The modified basalt flake-EPDM rubber composite material according to claim 1, characterized in that, The basalt flakes have a grain size of 70-90 mesh; Preferably, the diameter of the basalt flakes is 170-210 μm; Preferably, the thickness of the basalt flakes is 1-3 μm; Preferably, the diameter-to-thickness ratio of the basalt flakes is 60-200.

3. The modified basalt flake-EPDM rubber composite material according to claim 1 or 2, characterized in that, The coupling agent includes a silane coupling agent; Preferably, the silane coupling agent comprises bis-[γ-(triethoxysilane)propyl]tetrasulfide; Preferably, the polymer comprises a maleic anhydride-grafted ethylene-vinyl acetate copolymer.

4. The modified basalt flake-EPDM rubber composite material according to any one of claims 1-3, characterized in that, The modified basalt flakes are prepared by the following method, which includes: surface modification of basalt flakes with a coupling agent to obtain coupling agent-modified basalt flakes; and coating the coupling agent-modified basalt flakes with a polymer to obtain the modified basalt flakes. Preferably, the preparation method includes the following steps: (1) Mix the coupling agent, solvent A and pH adjuster to obtain a coupling agent solution; The coupling agent solution was mixed with basalt flakes and reacted to obtain coupling agent modified basalt flakes. (2) The basalt flakes modified with coupling agent are mixed with a polymer solution, reacted, and then cured to obtain the modified basalt flakes; the polymer solution includes a combination of polymer and solvent B; Preferably, the mass ratio of the coupling agent to the basalt flakes is (0.01-0.02):1; Preferably, the pH adjuster comprises an aqueous solution of acetic acid; Preferably, the mass concentration of acetic acid in the aqueous acetic acid solution is 0.5-2%; Preferably, solvent A comprises an aqueous solution of ethanol; Preferably, the ethanol concentration in the aqueous ethanol solution is 85-95% by mass. Preferably, the mass ratio of the polymer to basalt flakes is (0.01-0.1):1; Preferably, the mass concentration of the coupling agent in the coupling agent solution is 1-3%; Preferably, the pH value of the coupling agent solution is 4-5; Preferably, the polymer concentration in the polymer solution is 5-15% by mass; Preferably, the reaction temperature in step (1) is 75-85℃ and the reaction time is 2-4 h; Preferably, solvent B comprises toluene; Preferably, the mixing in step (2) is performed under ultrasound; Preferably, the mixing time in step (2) is 20-40 min; Preferably, the reaction temperature in step (2) is 80-90℃ and the reaction time is 1-3 h; Preferably, the curing temperature in step (2) is 80-90℃ and the curing time is 0.5-2 h.

5. The modified basalt flake-EPDM rubber composite material according to any one of claims 1-4, characterized in that, The modified basalt flake-EPDM rubber composite material also includes additives; Preferably, the additives, by weight, include any one or a combination of at least two of the following: 40-80 parts reinforcing filler, 1-3 parts vulcanizing agent, 0.1-0.5 parts sulfur carrier, 1-10 parts compatibilizer, 0.1-2 parts lubricant, 1-2 parts accelerator, 1-5 parts antioxidant, 10-30 parts plasticizer, or 0.1-2 parts processing aid.

6. The modified basalt flake-EPDM rubber composite material according to claim 5, characterized in that, The reinforcing filler includes carbon black and / or fumed silica; Preferably, the vulcanizing agent includes sulfur; Preferably, the sulfur support comprises 4,4'-dithiodimorpholine; Preferably, the compatibilizer includes zinc oxide; Preferably, the lubricant comprises stearic acid; Preferably, the accelerator comprises N-cyclohexyl-2-benzothiazole sulfenamide and / or tetramethylthiuram disulfide; Preferably, the antioxidant comprises poly(2,2,4-trimethyl-1,2-dihydroquinoline) and / or N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine; Preferably, the plasticizer comprises paraffin oil; Preferably, the processing aid includes polyethylene wax.

7. A method for preparing the modified basalt flake-EPDM rubber composite material as described in any one of claims 1-6, characterized in that, The preparation method includes the following steps: The modified basalt flakes-EPD rubber composite material is obtained by mixing EPD rubber, modified basalt flakes, and optionally additives.

8. The method for preparing the modified basalt flake-EPDM rubber composite material according to claim 7, characterized in that, The preparation method of the modified basalt flake-EPDM rubber composite material includes: (A) EPDM rubber is coated onto rollers and then plasticized through a thin pass to obtain roller-coated rubber; (B) The modified basalt flakes are mixed with the roller-wrapping rubber, and then subjected to thin-pass plasticizing, sheeting, and curing to obtain modified basalt flake-EPDM rubber masterbatch. (C) The modified basalt flake-EPR rubber masterbatch is rolled and plasticized, then mixed with optional additives, and then sheeted, aged, vulcanized and molded and post-treated to obtain the modified basalt flake-EPR rubber composite material.

9. The method for preparing the modified basalt flake-EPDM rubber composite material according to claim 7 or 8, characterized in that, Steps (A), (B), and (C) are each carried out independently in the open mill. Preferably, the temperature of the front roll of the open mill in the thin-wall plasticizing operation described in step (A) is 60-65°C; Preferably, the temperature of the back roll of the open mill in the thin-wall plasticizing operation described in step (A) is 55-60°C; Preferably, the roll gap of the open mill in the thin-wall plasticizing operation described in step (A) is 1-3 mm; Preferably, the number of times the thin-wall plasticizing is performed in step (A) is 3-5 times; Preferably, in step (B), during the operation of mixing modified basalt flakes with roll wrapping rubber, the roll gap of the open mill is 1-1.5 mm when the modified basalt flakes are added, and the roll gap of the open mill is adjusted to 0.8-1 mm after the addition is completed. Preferably, the number of times the thin-wall plasticizing is performed in step (B) is 6-8 times; Preferably, the roll gap of the open mill during sheet extrusion in step (B) is 2-3 mm; Preferably, the temperature for aging in step (B) is 20-30°C and the time is 3-5 hours; Preferably, the mixing in step (C) includes first mixing the lubricant, compatibilizer, antioxidant and modified basalt flake-EPDM rubber masterbatch, then adding reinforcing filler, plasticizer and processing aid and mixing. After the mixed material is sheeted, cooled and re-rolled, accelerator, vulcanizing agent and sulfur carrier are added and mixed. Preferably, the roll temperature of the open mill in the thin-wall plasticizing operation described in step (C) is 60-70°C; Preferably, the number of times the thin-wall plasticizing is performed in step (C) is 2-3 times; Preferably, the roll gap of the open mill during sheet extrusion in step (C) is 3-4 mm; Preferably, the temperature for aging in step (C) is 20-30°C and the time is 8-24 h; Preferably, the aging process described in step (C) is carried out under light-protected conditions; Preferably, step (C) further includes roll wrapping and thin-pass plasticizing steps before vulcanization molding; Preferably, the roller temperature of the thin-walled plasticizing process is less than or equal to 50°C; Preferably, the thin-wall plasticizing process is performed 4-5 times; Preferably, the vulcanization molding is carried out in a flat vulcanizing machine; Preferably, the vulcanization molding temperature is 160-175℃ and the time is 10-20 min; Preferably, the pressure of the vulcanization molding is 10-15 MPa; Preferably, the post-processing includes heat treatment; Preferably, the heat treatment is performed at a temperature of 120-130°C for 2-4 hours.

10. The application of a modified basalt flake-EPDM rubber composite material as described in any one of claims 1-6 in an offshore wind power anti-marine organism device.

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