A salt spray resistant epoxy resin material and its preparation method

Abstract

This invention relates to the field of epoxy resin materials technology, specifically to a salt spray corrosion-resistant epoxy resin material and its preparation method. The raw materials for preparing the epoxy resin material include: 1.2-1.5 parts DETA-cainol, 10-15 parts modified montmorillonite, 2-3 parts aminated nano-silica, 150-250 parts epoxy resin E51, and 30-50 parts diaminodiphenylmethane. The epoxy resin material obtained by this invention exhibits excellent salt spray corrosion resistance, hydrophobicity, and mechanical properties, making it suitable for harsh corrosive environments such as marine, coastal, and shipboard environments.

Description

Technical Field

[0001] This invention relates to the field of epoxy resin materials technology, specifically to a salt spray corrosion resistant epoxy resin material and its preparation method. Background Technology

[0002] Epoxy resin, with its unique molecular structure and cross-linking properties, has become a core matrix resin in advanced material systems. When mixed and cured with matching curing agents and appropriate fillers, it possesses excellent properties such as adhesion, mechanical properties, electrical properties, corrosion resistance, and heat resistance. Based on this, epoxy resin is widely used as a matrix for adhesives, coatings, and composite materials in many industrial fields such as electronics, machinery manufacturing, chemical corrosion protection, aerospace, and biomedical materials. It is an indispensable basic material for various industrial fields and is of great significance to industrial development.

[0003] Although epoxy resin has a certain degree of resistance to chemical media after curing, it is still susceptible to damage in environments containing chloride ions (Cl-), such as marine environments, coastal areas, bridges, offshore wind power, ships, and outdoor chemical plants. - In high-humidity and high-salt environments, there are still shortcomings: free volume and microcracks exist after epoxy curing, Cl - Na + Salt solutions can penetrate the coating / bonding interface with moisture. Salt solutions penetrate the epoxy-metal (steel / aluminum) interface, causing anodic dissolution, resulting in blistering, peeling, and filiform corrosion. Salt spray, damp heat, and UV radiation accelerate the plasticizing, hydrolysis, and dissolution of the toughening phase in epoxy, leading to a decline in mechanical properties. Therefore, it is necessary to improve the salt spray resistance of epoxy resin materials and delay the degradation of Cl-. - / H2O penetration and interface corrosion.

[0004] Currently, the main method to improve the salt spray resistance of epoxy resins is to fill them with inert barrier fillers, such as flake fillers like glass flakes, mica iron oxide, flake graphite, and boron nitride, which can extend the diffusion path of water molecules / ions; and layered nanofillers such as montmorillonite and graphene / graphene oxide, whose nanosheets improve density and barrier properties. Filling with inert barrier fillers can significantly improve water resistance and salt spray resistance at a controllable cost. However, they have problems such as difficulty in dispersion and easy aggregation, and excessive amounts can reduce adhesion and impact toughness. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a salt spray corrosion resistant epoxy resin material and its preparation method.

[0006] This invention is achieved through the following technical solution: A salt spray resistant epoxy resin material is prepared by means of the following components in parts by weight: DETA-cainol 1.2-1.5 parts, modified montmorillonite 10-15 parts, aminated nano-silica 2-3 parts, epoxy resin E51 150-250 parts, and diaminodiphenylmethane 30-50 parts.

[0007] Furthermore, the aminated nano-silica is KH550 modified nano-silica, with a preferred particle size of 20-30 nm.

[0008] Furthermore, the method for preparing the DETA-cashewol includes the following steps: L1. Take cashew phenol, stir and heat to 60°C, add diethylenetriamine (DETA) dropwise, and continue stirring at 60°C for 15-20 min after the addition is complete. L2. After stirring in step L1, add 37% formaldehyde solution dropwise, heat to 90-95℃, reflux for 3-4 hours, and distill under reduced pressure to obtain DETA-cashew phenol.

[0009] Furthermore, the molar ratio of cashew phenol, diethylenetriamine, and formaldehyde is 1:1:1.

[0010] Furthermore, the raw materials for preparing the modified montmorillonite include the following components in parts by weight: 20-30 parts of polytetrahydrofuran ether diol (PTMG, Mn=1000), 4-6 parts of 1,4-butanediol (BDO), 3-4 parts of 2,2-dihydroxymethylbutyric acid (DMBA), 20-30 parts of montmorillonite, and 10-15 parts of perfluorohexylethanol.

[0011] Furthermore, the preparation method of the modified montmorillonite includes the following steps: V1. Take polytetrahydrofuran ether diol that has been heated and stirred under vacuum to remove moisture, add isophorone diisocyanate, dibutyltin dilaurate and tetrahydrofuran (THF) at 80°C, stir at 80°C for 2 h under nitrogen atmosphere, mix and dissolve 1,4-butanediol and 2,2-dimethylolbutyric acid in THF and add to the above reaction system, stir at 80°C under N2 atmosphere for 4 h; V2. After the reaction in step V1 is completed, montmorillonite ground through a 200-mesh sieve and vacuum dried is added. The reaction is carried out at 80°C under N2 atmosphere for 4 h. Then, perfluorohexylethanol is added, and the reaction is continued for 4 h. After cooling, the mixture is filtered. The filter cake is washed with tetrahydrofuran and ethanol, and then vacuum dried to obtain modified montmorillonite.

[0012] Further, in step V1, the mass ratio of the polytetrahydrofuran ether diol to isophorone diisocyanate is 4:5.

[0013] Furthermore, in step V1, the mass ratio of the polytetrahydrofuran ether diol to THF is 2:3.

[0014] Further, in step V1, the amount of dibutyltin dilaurate used is 0.15wt%-0.2wt% of the mass of isophorone diisocyanate.

[0015] Furthermore, the present invention also provides a method for preparing the salt spray resistant epoxy resin material, comprising the following steps: S1. Modified montmorillonite was ultrasonically dispersed in DMF, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) and 1-hydroxybenzotriazole (HOBt) were added. The mixture was stirred in an ice-water bath for 1 h, DETA-cainol was added, and the mixture was stirred at room temperature for 30 min. Aminated nano-silica was then added, and the reaction was continued for 3-4 h. The mixture was filtered, and the filter cake was washed with acetone and ethanol and dried under vacuum. S2. Add the product obtained in step S1 to a xylene / n-butanol (v / v=7:3) mixed solution, stir and disperse, add to epoxy resin E51, stir evenly at 60-80℃, add diaminodiphenylmethane, stir evenly, and degas under vacuum to obtain a salt spray resistant epoxy resin material.

[0016] Further, in step S1, the mass concentration of the modified montmorillonite in DMF is 10-15 mg / mL.

[0017] Further, in step S1, the mass ratio of the modified montmorillonite, EDCI, and HOBt is 10:1:0.7.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a salt spray corrosion resistant epoxy resin material and its preparation method. Through the synergistic effect of DETA-cainol, modified montmorillonite, and aminated nano-silica, the salt spray corrosion resistance, hydrophobicity, and mechanical properties are simultaneously improved, making it suitable for harsh corrosive environments such as marine, coastal, and ship environments. This invention prepares modified montmorillonite by polymerizing polytetrahydrofuran ether glycol, 1,4-butanediol, and 2,2-dimethylolbutyric acid to prepare a polyurethane prepolymer with carboxyl groups in the side chains. The isocyanate groups at both ends of the prepolymer react with the hydroxyl groups on the surface of montmorillonite and perfluorohexyl ethanol, grafting the carboxyl-containing polyurethane chains and fluorinated segments onto the montmorillonite surface. Montmorillonite is a two-dimensional layered nanomaterial. After organic modification with polyurethane-perfluorohexyl ethanol, the interlayers are stretched by long organic chains, making it easy to peel and uniformly disperse in the epoxy matrix. Its layered structure can form a tortuous "maze effect," significantly extending the Cl... -The diffusion path of corrosive media such as H2O is blocked, reducing the penetration rate. Perfluorohexylethanol segments have extremely low surface energy, imparting strong hydrophobic properties to the coating, inhibiting the wetting and spreading of brine on the coating surface, and reducing the entry of corrosive media. Modified montmorillonite, after organic treatment, has improved compatibility with epoxy groups; the lamellar layers can effectively hinder crack propagation under stress, causing crack deflection and bifurcation, consuming more fracture energy. This invention introduces aminated nano-silica, which can effectively fill the micropores and free volumes formed during epoxy resin curing, improving coating density and further blocking corrosion channels. Aminated nano-silica provides a nanoscale rough structure, enhancing the hydrophobic effect. The surface of aminated nano-silica is rich in amino groups, which can interact with carboxyl groups, acting as a uniformly dispersed nano-reinforcing phase, effectively transferring loads and improving tensile strength. This invention prepares DETA-cainol by reacting diethylenetriamine with cashew nut shell powder. DETA-cainol is linked to the carboxyl groups on the surface of modified montmorillonite via amide bonds. The DETA-cainol contains unsaturated long chains of cashew nut shell powder, whose flexible segments can be intercalated within the epoxy resin crosslinking network. Under external force, the chain segment movement absorbs and disperses stress, improving material toughness, preventing stress concentration, eliminating interfacial microcracks and defects, and preventing corrosive media from penetrating along the interface. The long-chain alkyl groups of DETA-cainol further increase the hydrophobic component, and chemical bonding ensures uniform dispersion of the hydrophobic component, preventing local aggregation and resulting in stable overall hydrophobic properties of the coating. Modified montmorillonite is organically modified with polyurethane-fluorocarbon chains, increasing the interlayer spacing and enhancing hydrophobicity, making it easy to peel off and uniformly disperse in epoxy resin. Aminated nano-silica and DETA-cainol are composited with modified montmorillonite via amide bonds to form a multi-scale hybrid filler, preventing nanoparticle aggregation. Attached Figure Description

[0019] Figure 1 This demonstrates the salt spray corrosion resistance of the epoxy resin materials described in Embodiment 1 and Comparative Examples 1-5 of the present invention. Figure 2 The hydrophobic properties of the epoxy resin materials described in Embodiment 1 and Comparative Examples 1-5 of this invention; Figure 3 The tensile strength of the epoxy resin materials described in Embodiment 1 and Comparative Examples 1-5 of this invention; Figure 4 The images show scanning electron microscope (SEM) morphology of the brittle fracture section (left) and tensile fracture section (right) of the epoxy resin material described in Embodiment 1 of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. However, this invention is not limited to the following embodiments. It should be noted that, unless otherwise specified, all chemical reagents involved in this invention are purchased through commercial channels.

[0021] Example 1: A salt spray resistant epoxy resin material, the raw materials for preparation include the following components in parts by weight: DETA-cainol 1.5 parts, modified montmorillonite 15 parts, aminated nano silica 3 parts, epoxy resin E51 250 parts, and diaminodiphenylmethane 50 parts.

[0022] Aminated nano-silica is KH550 modified nano-silica with a particle size of 30 nm.

[0023] The preparation method of DETA-cashewol includes the following steps: L1. Take 0.1 mol of cashew phenol, stir and heat to 60℃, add 0.1 mol of diethylenetriamine (DETA) dropwise, and continue stirring at 60℃ for 20 min after the addition is complete; L2. After stirring in step L1, a 37% formaldehyde solution (0.1 mol of formaldehyde) was added dropwise, the temperature was raised to 95°C, and the mixture was refluxed for 4 h. The mixture was then distilled under reduced pressure to obtain DETA-cashewol.

[0024] The raw materials for preparing modified montmorillonite include the following components in parts by weight: 30 parts of polytetrahydrofuran ether diol (PTMG, Mn=1000), 6 parts of 1,4-butanediol (BDO), 4 parts of 2,2-dihydroxymethylbutyric acid (DMBA), 30 parts of montmorillonite, and 15 parts of perfluorohexylethanol.

[0025] The preparation method of modified montmorillonite includes the following steps: V1. Take 30 g of polytetrahydrofuran ether diol (PTFE) that has been heated and stirred under vacuum to remove moisture, add 37.5 g of isophorone diisocyanate, 75 mg of dibutyltin dilaurate and 45 g of tetrahydrofuran (THF) at 80°C, stir at 80°C for 2 h under nitrogen atmosphere, then add 6 g of 1,4-butanediol and 4 g of 2,2-dimethylolbutyric acid (DMA) dissolved in THF to the above reaction system, and stir at 80°C under N2 atmosphere for 4 h. V2. After the reaction in step V1 is completed, 30 g of montmorillonite ground through a 200-mesh sieve and vacuum dried is added. The reaction is carried out at 80°C under N2 atmosphere for 4 h. Then, 15 g of perfluorohexylethanol is added, and the reaction is continued for 4 h. After cooling, the mixture is filtered. The filter cake is washed with tetrahydrofuran and ethanol, and then vacuum dried to obtain modified montmorillonite.

[0026] This embodiment also provides a method for preparing the salt spray corrosion resistant epoxy resin material, including the following steps: S1. Add 15 g of modified montmorillonite to 1000 mL of DMF and disperse by ultrasonication. Add 1.5 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) and 1.05 g of 1-hydroxybenzotriazole (HOBt). Stir in an ice-water bath for 1 h. Add 1.5 g of DETA-cainol and stir at room temperature for 30 min. Then add 3 g of aminated nano-silica and continue the reaction for 4 h. Filter, wash the filter cake with acetone and ethanol, and dry under vacuum. S2. Add the product obtained in step S1 to a xylene / n-butanol (v / v=7:3) mixed solution, stir and disperse, add 250 g of epoxy resin E51, stir evenly at 80℃, add 50 g of diaminodiphenylmethane, stir evenly, and degas under vacuum to obtain a salt spray resistant epoxy resin material.

[0027] Example 2: A salt spray resistant epoxy resin material, the raw materials for preparation include the following components in parts by weight: DETA-cainol 1.2 parts, modified montmorillonite 10 parts, aminated nano silica 2 parts, epoxy resin E51 150 parts, and diaminodiphenylmethane 30 parts.

[0028] Aminated nano-silica is KH550 modified nano-silica with a particle size of 20 nm.

[0029] The preparation method of DETA-cashewol includes the following steps: L1. Take 0.1 mol of cashew phenol, stir and heat to 60℃, add 0.1 mol of diethylenetriamine (DETA) dropwise, and continue stirring at 60℃ for 15 min after the addition is complete; L2. After stirring in step L1, a 37% formaldehyde solution (0.1 mol of formaldehyde) was added dropwise, the temperature was raised to 90°C, and the mixture was refluxed for 3 h. The mixture was then distilled under reduced pressure to obtain DETA-cashewol.

[0030] The raw materials for preparing modified montmorillonite include the following components in parts by weight: 20 parts of polytetrahydrofuran ether diol (PTMG, Mn=1000), 4 parts of 1,4-butanediol (BDO), 3 parts of 2,2-dihydroxymethylbutyric acid (DMBA), 20 parts of montmorillonite, and 10 parts of perfluorohexylethanol.

[0031] The preparation method of modified montmorillonite includes the following steps: V1. Take 20 g of polytetrahydrofuran ether diol (PTFE) that has been heated and stirred under vacuum to remove moisture, add 25 g of isophorone diisocyanate, 37.5 mg of dibutyltin dilaurate and 30 g of tetrahydrofuran (THF) at 80°C, stir at 80°C for 2 h under nitrogen atmosphere, then add 4 g of 1,4-butanediol and 3 g of 2,2-dimethylolbutyric acid (DMA) dissolved in THF to the above reaction system, and stir at 80°C under N2 atmosphere for 4 h. V2. After the reaction in step V1 is completed, 20 g of montmorillonite ground through a 200-mesh sieve and vacuum dried is added. The reaction is carried out at 80°C under N2 atmosphere for 4 h. Then, 10 g of perfluorohexylethanol is added, and the reaction is continued for 4 h. After cooling, the mixture is filtered. The filter cake is washed with tetrahydrofuran and ethanol, and then vacuum dried to obtain modified montmorillonite.

[0032] This embodiment also provides a method for preparing the salt spray corrosion resistant epoxy resin material, including the following steps: S1. 10 g of modified montmorillonite was added to 1000 mL of DMF and ultrasonically dispersed. 1 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) and 0.7 g of 1-hydroxybenzotriazole (HOBt) were added to the mixture. The mixture was stirred in an ice-water bath for 1 h. 1.2 g of DETA-cainol was added, and the mixture was stirred at room temperature for 30 min. Then 2 g of aminated nano-silica was added, and the reaction was continued for 3 h. The mixture was filtered, and the filter cake was washed with acetone and ethanol and dried under vacuum. S2. Add the product obtained in step S1 to a xylene / n-butanol (v / v=7:3) mixed solution, stir and disperse, add 150 g of epoxy resin E51, stir evenly at 60℃, add 30 g of diaminodiphenylmethane, stir evenly, and degas under vacuum to obtain a salt spray resistant epoxy resin material.

[0033] Example 3: A salt spray resistant epoxy resin material, the raw materials for which are prepared include the following components in parts by weight: DETA-cainol 1.4 parts, modified montmorillonite 12 parts, aminated nano silica 2.5 parts, epoxy resin E51 200 parts, and diaminodiphenylmethane 40 parts.

[0034] Aminated nano-silica is KH550 modified nano-silica with a particle size of 25 nm.

[0035] The preparation method of DETA-cashewol includes the following steps: L1. Take 0.1 mol of cashew phenol, stir and heat to 60℃, add 0.1 mol of diethylenetriamine (DETA) dropwise, and continue stirring at 60℃ for 18 min after the addition is complete; L2. After stirring in step L1, add 37% formaldehyde solution (0.1 mol formaldehyde) dropwise, heat to 92℃, reflux for 3.5 h, and distill under reduced pressure to obtain DETA-cashewol.

[0036] The raw materials for preparing modified montmorillonite include the following components in parts by weight: 25 parts of polytetrahydrofuran ether diol (PTMG, Mn=1000), 5 parts of 1,4-butanediol (BDO), 3.5 parts of 2,2-dihydroxymethylbutyric acid (DMBA), 25 parts of montmorillonite, and 12 parts of perfluorohexylethanol.

[0037] The preparation method of modified montmorillonite includes the following steps: V1. Take 25 g of polytetrahydrofuran ether diol (PTFE) that has been heated and stirred under vacuum to remove moisture. Add 31.25 g of isophorone diisocyanate, 56 mg of dibutyltin dilaurate, and 37.5 g of tetrahydrofuran (THF) at 80°C. Stir at 80°C for 2 h under nitrogen atmosphere. Dissolve 1,4-butanediol and 2,2-dimethylolbutyric acid in THF and add the mixture to the above reaction system. Stir at 80°C under N2 atmosphere for 4 h. V2. After the reaction in step V1 is completed, 25 g of montmorillonite ground through a 200-mesh sieve and vacuum dried is added. The reaction is carried out at 80°C under N2 atmosphere for 4 h. Then, 12 g of perfluorohexylethanol is added, and the reaction is continued for 4 h. After cooling, the mixture is filtered. The filter cake is washed with tetrahydrofuran and ethanol, and then vacuum dried to obtain modified montmorillonite.

[0038] This embodiment also provides a method for preparing the salt spray corrosion resistant epoxy resin material, including the following steps: S1. 12 g of modified montmorillonite was added to 1000 mL of DMF and ultrasonically dispersed. 1.2 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) and 0.84 g of 1-hydroxybenzotriazole (HOBt) were added to the mixture. The mixture was stirred in an ice-water bath for 1 h. 1.4 g of DETA-cainol was added, and the mixture was stirred at room temperature for 30 min. Then 2.5 g of aminated nano-silica was added, and the reaction was continued for 3.5 h. The mixture was filtered, and the filter cake was washed with acetone and ethanol and dried under vacuum. S2. Add the product obtained in step S1 to a xylene / n-butanol (v / v=7:3) mixed solution, stir and disperse, add 200 g of epoxy resin E51, stir evenly at 70℃, add 40 g of diaminodiphenylmethane, stir evenly, and degas under vacuum to obtain a salt spray resistant epoxy resin material.

[0039] The only difference between Comparative Example 1 and Example 1 is that DETA-cashewol is not added.

[0040] The only difference between Comparative Example 2 and Example 1 is that cashew phenol is used instead of DETA-cashew phenol.

[0041] The only difference between Comparative Example 3 and Example 1 is that montmorillonite is used instead of modified montmorillonite. Montmorillonite, DETA-cainol and aminated nano-silica are added to a xylene / n-butanol (v / v=7:3) mixed solution, stirred and dispersed, and then carried out in subsequent operations to prepare epoxy resin material.

[0042] The only difference between Comparative Example 4 and Example 1 is that no modified montmorillonite was added.

[0043] The only difference between Comparative Example 5 and Example 1 is that aminated nano-silica is not added.

[0044] Example 1: Following the methods of Example 1 and Comparative Examples 1-5, a salt spray resistant epoxy resin material was prepared. Q235 low-carbon steel was selected as the substrate, with dimensions of 70 mm × 40 mm × 1.5 mm. The substrate was ultrasonically cleaned with acetone or ethanol, and then surface-polished using 240-grit, 400-grit, 800-grit, and 1200-grit sandpaper, respectively. The salt spray resistant epoxy resin material was coated onto the substrate to a thickness of 80 μm and cured at room temperature. The salt spray corrosion resistance of the coating was tested. A salt spray test chamber was used to simulate typical corrosive conditions such as salt spray in a marine environment, and accelerated corrosion tests were conducted under simulated marine conditions. The experiment used a neutral salt spray (NSS) test chamber. Following the standard GB / T 2423.17-2024, "Environmental Testing Part 2: Test Methods Test Ka: Salt Spray," the test surface of the flat sample was placed at a 30° angle to the vertical direction. The corrosion rate of the experimental samples was evaluated using the weighing method. Samples were taken after 24 hours, rinsed with distilled water, dried, and weighed. The corrosion rate was calculated (g·m). 2 ·h -1 ) = |m0 - m1| / St. Where m0 and m1 are the masses before and after corrosion (g), and S is the sample area (m²). 2 ), where t is the corrosion time (h). The results are as follows: Figure 1 As shown.

[0045] Figure 1 The results showed that the corrosion rate of Example 1 was significantly lower than that of Comparative Examples 1-5, indicating that the present invention effectively delayed the corrosion of Cl through the synergistic modification of DETA-cainol, modified montmorillonite, and aminated nano-silica. -This relates to the penetration of moisture into the coating / metal interface. Comparative Examples 1 and 2 lack DETA-cainol or are replaced with ordinary cashew phenol, resulting in weakened interfacial bonding. Comparative Example 3 uses unmodified montmorillonite, which has poor dispersibility, is prone to agglomeration, and lacks fluorocarbon chain modification. Comparative Example 4 does not contain modified montmorillonite and lacks lamellar barrier filler and fluorocarbon hydrophobic segments. Comparative Example 5 does not add aminated nano-silica, resulting in a lack of nanoparticle filling effect. The salt spray corrosion resistance of Comparative Examples 1-5 is reduced.

[0046] Experimental Example 2: The salt spray resistant epoxy resin materials prepared in Example 1 and Comparative Examples 1-5 were injected into a mold, left at room temperature for 2 hours, cured at 80°C for 2 hours, and cured at 120°C for 2 hours. Samples were cut into 10 mm × 10 mm × 2 mm pieces. The water contact angle was tested according to GB / T30693-2014, and the results are as follows. Figure 2 As shown.

[0047] Figure 2 The results showed that the epoxy resin materials of Example 1 and Comparative Examples 1-5 all exhibited good hydrophobicity. The perfluorohexylethanol segments introduced into the modified montmorillonite reduced the surface energy, while the aminated nano-silica provided a nanoscale rough structure, synergistically forming a hydrophobic surface. Comparative Examples 1 and 2 lacked DETA-cainol or were replaced with ordinary cashew phenol. Comparative Example 3 used unmodified montmorillonite, resulting in uneven dispersion. Comparative Example 4 did not add modified montmorillonite, lacked fluorocarbon hydrophobic segments, and showed a decreased contact angle. Comparative Example 5 did not add aminated nano-silica. The hydrophobic properties of Comparative Examples 1-5 all decreased.

[0048] Experimental Example 3: Following the methods of Example 1 and Comparative Examples 1-5, a salt spray resistant epoxy resin material was prepared, injected into a mold, and left at room temperature for 2 hours, cured at 80°C for 2 hours, and then cured at 120°C for 2 hours to obtain a 75 mm × 4 mm × 2 mm specimen. Tensile properties were tested according to the standard "Determination of Tensile Properties of Plastics" (GB / T 1040.2-2022), and the results are as follows. Figure 3 As shown. The specimens of Example 1 were subjected to liquid nitrogen brittle fracture and tensile fracture treatments, and the morphology of the brittle fracture section and tensile fracture surface was observed by scanning electron microscopy.

[0049] Figure 3The results showed that the tensile strength of the epoxy resin material in Example 1 was significantly better than that in Comparative Examples 1-5. The C15 long-chain structure contained in cashew nut shell powder can be interwoven into the three-dimensional network of the epoxy resin backbone. When the material is subjected to external impact, the long-chain structure can bear and disperse stress, thereby improving the toughness of the cured product. In Example 1, DETA-cainuophenol improved the organic-inorganic interface bonding, and aminated nano-silica effectively filled the micropores of the matrix and played a reinforcing role. Comparative Example 3 used unmodified montmorillonite, which has poor dispersibility and is prone to agglomeration, forming stress concentration points. Comparative Example 2 used ordinary cashew nut shell powder instead of DETA-cainuophenol. Cashew nut shell powder is difficult to form a stable covalent bridge with modified montmorillonite and epoxy matrix, resulting in weak interfacial bonding. Comparative Example 1 did not contain DETA-cainuophenol, and the interfacial modification was insufficient. Comparative Examples 4 and 5 lacked modified montmorillonite or aminated nano-silica, respectively, resulting in a decrease in tensile strength. Figure 4 The images show SEM images of the brittle fracture section (left) and the tensile fracture section (right). The brittle fracture surface is rough, while the tensile fracture surface has complex textures. The rough fracture surface and the presence of numerous deflection cracks indicate that the material underwent significant crack deflection and energy dissipation during the stress process. The interfacial bonding is strong, and the toughness is good.

[0050] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A salt-fog corrosion resistant epoxy material, characterized by, The raw materials for preparation include the following components in parts by weight: DETA-cainol 1.2-1.5 parts, modified montmorillonite 10-15 parts, aminated nano silica 2-3 parts, epoxy resin E511 50-250 parts, and diaminodiphenylmethane 30-50 parts. The method for preparing the DETA-cashewol includes the following steps: L1. Take cashew phenol, stir and heat, add diethylenetriamine dropwise, and stir; L2. After stirring in step L1, formaldehyde solution was added dropwise, the mixture was heated, refluxed, and distilled under reduced pressure to obtain DETA-cashew phenol; The raw materials for preparing the modified montmorillonite include the following components in parts by weight: 20-30 parts of polytetrahydrofuran ether diol, 4-6 parts of 1,4-butanediol, 3-4 parts of 2,2-dimethylolbutyric acid, 20-30 parts of montmorillonite, and 10-15 parts of perfluorohexylethanol. The preparation method of the modified montmorillonite includes the following steps: V1. Take polytetrahydrofuran ether diol that has been heated and stirred under vacuum to remove moisture, add isophorone diisocyanate, dibutyltin dilaurate and THF at 80°C, stir at 80°C under nitrogen atmosphere, mix and dissolve 1,4-butanediol and 2,2-dimethylolbutyric acid in THF and add it to the above reaction system, react under N2 atmosphere and at 80°C. V2. After the reaction in step V1 is completed, montmorillonite is added, and the reaction is carried out under N2 atmosphere at 80°C. Then, perfluorohexylethanol is added, the reaction is continued, cooled, filtered, the filter cake is washed, and dried under vacuum to obtain modified montmorillonite.

2. The salt-fog corrosion resistant epoxy material of claim 1, wherein, The molar ratio of cashew phenol, diethylenetriamine, and formaldehyde is 1:1:

1.

3. The salt-fog corrosion resistant epoxy resin material according to claim 2, characterized in that, In step V1, the mass ratio of polytetrahydrofuran ether diol to isophorone diisocyanate is 4:

5.

4. The salt-fog corrosion resistant epoxy resin material according to claim 3, characterized in that, In step V1, the mass ratio of polytetrahydrofuran ether diol to THF is 2:

3.

5. The salt-fog corrosion resistant epoxy resin material according to claim 4, wherein In step V1, the amount of dibutyltin dilaurate used is 0.15wt%-0.2wt% of the mass of isophorone diisocyanate.

6. A process for the production of a salt-fog corrosion resistant epoxy resin material as claimed in claims 1-5, characterized in that, Includes the following steps: S1. Modified montmorillonite was added to DMF and ultrasonically dispersed. EDCI and HOBt were added to the mixture, and the mixture was stirred in an ice-water bath. DETA-cainol was added, and the mixture was stirred at room temperature. Aminated nano-silica was then added, and the reaction was continued. The mixture was filtered, the filter cake was washed, and then vacuum dried. S2. Add the product obtained in step S1 to a xylene / n-butanol mixed solution, stir and disperse, add to epoxy resin E51, stir at 60-80℃, add diaminodiphenylmethane, stir, and degas under vacuum to obtain a salt spray resistant epoxy resin material.

7. The method for preparing the salt spray resistant epoxy resin material according to claim 6, characterized in that, In step S1, the mass ratio of the modified montmorillonite, EDCI, and HOBt is 10:1:0.7.

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