An epoxy resin self-repairing agent, a preparation method and application thereof
By introducing self-healing agents containing imine and diselenyl bonds into epoxy resin, the stability and self-healing problems of epoxy resin molds under high temperature and chemical corrosion environments have been solved, improving their application performance in high-end ceramic production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING INST OF TECH
- Filing Date
- 2024-08-09
- Publication Date
- 2026-07-14
Smart Images
Figure BDA0004986530270000051 
Figure BDA0004986530270000161
Abstract
Description
Technical Field
[0001] This invention belongs to the field of epoxy resin modification technology, and particularly relates to an epoxy resin self-healing agent, its preparation method and application. Background Technology
[0002] In modern ceramic production, slip casting technology is widely used due to its ability to precisely replicate complex shapes. Traditional slip casting uses plaster molds, relying on the capillary water absorption of plaster to form the ceramic body. However, plaster molds have poor physical and chemical stability, especially their performance under high temperature and chemical corrosion environments, which limits their application in high-end ceramic production.
[0003] Epoxy resins are considered for mold making due to their excellent mechanical properties and chemical stability. However, traditional epoxy resins often exhibit brittleness after curing, which limits their use in applications requiring high toughness. Currently, when traditional epoxy resin composites are used to prepare resin molds, they often face the problem of low flexural strength due to high filler content. In addition, epoxy resin composites also tend to crack during demolding and are difficult to repair.
[0004] In summary, it is essential to provide an epoxy resin self-healing agent, its preparation method, and its application. Summary of the Invention
[0005] To address one or more technical problems existing in the prior art, this invention provides an epoxy resin self-healing agent, its preparation method, and its application. The epoxy resin self-healing agent of this invention introduces imine and diselenyl bonds through the reaction of vanillin monoglyceride with selenocysteine, which can significantly enhance the mechanical properties and self-healing ability of epoxy resin composite materials.
[0006] The present invention provides a method for preparing an epoxy resin self-healing agent in a first aspect, the method comprising the following steps:
[0007] (1) Vanillin was reacted with epichlorohydrin to obtain vanillin monoglyceride;
[0008] (2) Vanillin monoglyceride and selenocysteine were mixed evenly with dichloromethane and reacted. After filtration, washing and drying, epoxy resin self-healing agent was obtained.
[0009] Preferably, in step (1): the reaction is carried out in the presence of benzyltriethylammonium chloride and an aqueous solution of sodium hydroxide; the reaction is as follows: vanillin, epichlorohydrin and benzyltriethylammonium chloride are mixed evenly and reacted at 70-90°C for 1-3 hours, then the temperature is lowered to 15-35°C and an aqueous solution of sodium hydroxide is added and reacted at 15-35°C for 0.5-1.5 hours to obtain vanillin monoglyceride; the mass ratio of vanillin, epichlorohydrin, benzyltriethylammonium chloride and aqueous solution of sodium hydroxide is 2:(4-6):(0.05-0.15):(5-8); the aqueous solution of sodium hydroxide contains 25-35% sodium hydroxide by mass.
[0010] Preferably, the molar ratio of vanillin monoglyceride to selenocysteine is 1:(0.4-0.6); and / or the mass ratio of dichloromethane to vanillin monoglyceride is (10-20):1.
[0011] Preferably, in step (2), the temperature of the reaction is 15–35°C; and / or the reaction time is 4–8 h.
[0012] Preferably, in step (2), after filtration, washing and drying, the reaction product obtained by reacting vanillin monoglyceride with cystamine is added and reacted at a temperature of 50-60°C for 4-8 hours, while acetonitrile is added during the reaction.
[0013] Preferably, the mass ratio of the reactant obtained from the reaction of vanillin monoglyceride with cystamine to acetonitrile is 1:(10-20); in the reaction of vanillin monoglyceride with cystamine, the molar ratio of vanillin monoglyceride to cystamine is 1:(0.4-0.6); and / or in the reaction of vanillin monoglyceride with selenocystamine and the reaction of vanillin monoglyceride with cystamine, the molar ratio of selenocystamine to cystamine is 1:(0.8-1.2).
[0014] In a second aspect, the present invention provides an epoxy resin self-healing agent prepared by the preparation method described in the first aspect of the present invention.
[0015] In a third aspect, the present invention provides the application of the epoxy resin self-healing agent prepared by the preparation method described in the first aspect in the preparation of epoxy resin materials for resin molds.
[0016] Preferably, the epoxy resin material for the resin mold comprises bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyamide curing agent, accelerator, epoxy resin self-healing agent and aqueous phase filler.
[0017] Preferably, the mass ratio of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, the polyamide curing agent, the accelerator, the epoxy resin self-healing agent, and the aqueous filler is 10:(2-8):(3-8):(0.5-1.5):(1-5):(50-80); the aqueous filler comprises hydrophilic fumed silica, precipitated silica, nano titanium dioxide, and water in a mass ratio of (15-25):(5-15):(5-15):(20-30); the polyamide curing agent is polyamide epoxy curing agent 5140 and / or polyamide epoxy curing agent 2636; and / or the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.
[0018] Compared with the prior art, the present invention has at least the following beneficial effects:
[0019] (1) The method of the present invention first reacts vanillin with epichlorohydrin to generate vanillin monoglyceride, and then reacts it with selenocysteine in a subsequent step to form an epoxy resin self-healing agent. In the present invention, vanillin monoglyceride, as a reaction intermediate, plays a connecting and regulating role in the preparation of epoxy resin self-healing agent. It forms a self-healing agent with a specific structure by reacting with selenocysteine. Through the reaction of vanillin monoglyceride with selenocysteine, imine bonds and diseleno bonds can be introduced. Vanillin monoglyceride plays a regulatory role in the imine bonds and diseleno bonds formed in the reaction. The imine bond itself is a self-healing functional group, and its combination with the diselenyl bond enhances the self-healing effect. The formation of the imine and diselenyl bonds gives the self-healing agent a dual dynamic characteristic, enabling it to undergo reversible changes under external force, thereby enhancing the toughness and self-healing ability of epoxy resin composites. Furthermore, vanillin monoglyceride has highly active epoxy groups, which readily participate in the reaction between epoxy resin and curing agent. The epoxy resin self-healing agent of this invention helps to enhance the hardness and strength of epoxy resin composites in the preparation of epoxy resin composites, and is beneficial to improving the mechanical properties of epoxy resin composites.
[0020] (2) The epoxy resin self-healing agent in this invention is obtained by modifying vanillin and introducing imine bonds and diselenide bonds, which can significantly increase the mechanical strength and repairability of epoxy resin composite materials. This invention found that imine bonds and diselenide bonds have high dynamics and reversibility, and can be rebuilt under appropriate conditions after fracture, thereby enhancing the self-healing ability of the material. The epoxy resin material for resin molds using the epoxy resin self-healing agent described in this invention can significantly improve the application performance of resin molds in high-pressure environments, so that the prepared resin molds can be mainly used in ceramic slip casting that requires complex geometric structures and high-precision dimensional stability, such as high-grade daily ceramics, sanitary ceramics and high-tech ceramic slip casting.
[0021] (3) The introduction of diselenide bonds in the epoxy resin self-healing agent of the present invention can accelerate the dynamic exchange of materials, enhance the mechanical properties and self-healing ability of epoxy resin composites, and enable the materials to self-repair at the molecular level when subjected to stress, which can significantly improve the ductility, fracture toughness and flexural strength of epoxy resin composites. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments thereof. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0023] The present invention provides a method for preparing an epoxy resin self-healing agent in a first aspect, the method comprising the following steps:
[0024] (1) Vanillin was reacted with epichlorohydrin to obtain vanillin monoglyceride;
[0025] (2) Vanillin monoglyceride and selenocysteine are mixed evenly with dichloromethane and reacted, and then filtered, washed and dried to obtain an epoxy resin self-healing agent; In this invention, the reaction is carried out, for example, at room temperature of 15-35°C; In this invention, the washing is carried out, for example, with water; The drying is carried out, for example, with sodium sulfate drying and vacuum drying; This invention does not specifically limit the operation of filtration, washing and drying, and those skilled in the art can choose according to their needs.
[0026] In this invention, the reaction between vanillin monoglyceride and selenocysteine is, for example, as shown in Formula I below.
[0027]
[0028] The method of this invention first reacts vanillin with epichlorohydrin to generate vanillin monoglyceride, and then reacts it with selenocysteine in a subsequent step to form an epoxy resin self-healing agent. In this invention, vanillin monoglyceride, as a reaction intermediate, plays a connecting and regulating role in the preparation of the epoxy resin self-healing agent. It reacts with selenocysteine to form a self-healing agent with a specific structure. The reaction between vanillin monoglyceride and selenocysteine introduces imine and diseleno bonds. Vanillin monoglyceride plays a regulatory role in the imine and diseleno bonds formed in the reaction. The amine carbon-nitrogen double bond itself is a self-healing functional group. When used in combination with the diselenyl bond, it enhances the self-healing effect. The formation of the imine bond and the diselenyl bond gives the self-healing agent a dual dynamic characteristic, which can undergo reversible changes under external force, thereby enhancing the toughness and self-healing ability of epoxy resin composites. Furthermore, vanillin monoglyceride has highly active epoxy groups, which readily participate in the reaction between epoxy resin and curing agent. The epoxy resin self-healing agent of this invention helps to enhance the hardness and strength of epoxy resin composites in the preparation of epoxy resin composites, and is beneficial to improving the mechanical properties of epoxy resin composites.
[0029] The epoxy resin self-healing agent of this invention is obtained by modifying vanillin and introducing imine and diselenyl bonds, which can significantly increase the mechanical strength and repairability of epoxy resin composites. This invention finds that imine and diselenyl bonds have high dynamism and reversibility, and can be rebuilt under appropriate conditions after fracture, thereby enhancing the self-healing ability of the material. The epoxy resin self-healing agent of this invention shows a significant effect in improving the dynamic exchange rate of the material. The epoxy resin material for resin molds using the epoxy resin self-healing agent of this invention can significantly improve the application performance of resin molds in high-pressure environments, so that the prepared resin molds can be mainly used in ceramic slip casting that requires complex geometry and high-precision dimensional stability, such as high-grade daily ceramics, sanitary ceramics and high-tech ceramic slip casting. The introduction of diselenylene bonds in the epoxy resin self-healing agent of this invention can accelerate the dynamic exchange of materials, enhance the mechanical properties and self-healing ability of epoxy resin composites, and facilitate self-repair at the molecular level when the material is subjected to stress. This significantly improves the ductility, fracture toughness, and flexural strength of epoxy resin composites. This invention also reveals that diselenylene bonds, due to their low bond energy, can break and reform at lower energies, thus exhibiting better self-healing performance and toughness under dynamic loads. Furthermore, the relatively long bond length and low bond energy of diselenylene bonds make epoxy resin composites more prone to deformation under external forces, thereby better dispersing stress and reducing stress concentration. This contributes to improving the fracture toughness and impact resistance of epoxy resin composites.
[0030] According to some preferred embodiments, in step (1): the reaction is carried out in the presence of benzyltriethylammonium chloride and an aqueous solution of sodium hydroxide; the reaction is as follows: vanillin, epichlorohydrin and benzyltriethylammonium chloride are mixed evenly and reacted at 70-90°C for 1-3 hours, then cooled to 15-35°C and an aqueous solution of sodium hydroxide is added and reacted at 15-35°C for 0.5-1.5 hours to obtain vanillin monoglyceride; the mass ratio of vanillin, epichlorohydrin, benzyltriethylammonium chloride and aqueous solution of sodium hydroxide is 2:(4-6):(0.05-0.15):(5-8); the aqueous solution of sodium hydroxide contains 25-35% sodium hydroxide by mass.
[0031] According to some preferred embodiments, the molar ratio of vanillin monoglyceride to selenocysteine is 1:(0.4 to 0.6) (e.g., 1:0.4, 1:0.45, 1:0.5, 1:0.55 or 1:0.6); and / or the mass ratio of dichloromethane to vanillin monoglyceride is (10 to 20):1 (e.g., 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 or 20:1).
[0032] According to some preferred embodiments, in step (2), the temperature of the reaction is 15 to 35°C (e.g., 15°C, 20°C, 25°C, 30°C or 35°C); and / or the reaction time is 4 to 8 hours (e.g., 4, 5, 6, 7 or 8 hours).
[0033] According to some specific implementation methods, step (2) is as follows: Vanillin monoglyceride and selenocysteine are reacted at a molar ratio of 1:0.5. At room temperature, vanillin monoglyceride is dissolved in dichloromethane, and then selenocysteine is added and mixed evenly. The resulting mixture is reacted at room temperature for 6 hours under magnetic stirring. After the reaction, it is filtered through filter paper, washed with water 3 times, and then dried with sodium sulfate and vacuum in sequence to obtain epoxy resin self-healing agent. The present invention does not specify the speed of magnetic stirring, for example, it can be 100 to 800 r / min. In the present invention, room temperature refers to room temperature of 15 to 35°C.
[0034] According to some preferred embodiments, in step (2), after filtration, washing and drying, the reaction product obtained by reacting vanillin monoglyceride with cystamine is added and reacted at a temperature of 50-60°C for 4-8 hours, while acetonitrile is added during the reaction. The present invention found that by adding the reaction product of vanillin monoglyceride and cystamine to the reaction product of vanillin monoglyceride and selenocystamine and reacting at a high temperature of 50-60°C for 4-8 hours, an epoxy resin self-healing agent containing imine bonds and selenium-sulfur bonds can be obtained, which can further optimize the mechanical properties and self-healing properties of epoxy resin composite materials. The possible reason is that when heated at a higher temperature (50-60°C), the diselenobond is more likely to break first due to its lower bond dissociation energy. The free radicals (or ions) generated by the bond breaking of diselenobond have high reactivity and are easy to cross-react with other unbroken sulfur bonds. Since selenium and sulfur atoms can overlap orbitally well, and the free radicals (or ions) of selenium have high reactivity, they can react with sulfur free radicals (or ions) to form selenium-sulfur. The invention discovered that the newly formed selenium-sulfur bond (-S-Se-) is more beneficial than the diselenate bond in enhancing the mechanical properties and self-healing ability of epoxy resin composites. The invention also found that if vanillin monoglyceride, selenocysteine, and cystamine are reacted directly at a lower temperature (room temperature 15-35°C), a mixture of self-healing agents containing imine and diselenate bonds and those containing imine and disulfide bonds is formed, which is not conducive to further improving the mechanical properties and self-healing ability of epoxy resin composites. This may be because... The invention reveals that self-healing agents containing imine and diselenyl bonds are more effective at accelerating the dynamic exchange of materials compared to those containing imine-disulfide bonds. This is because diselenyl bonds have a larger atomic radius and a longer bond length than disulfide bonds, resulting in better self-healing performance. Furthermore, if self-healing agents containing imine and diselenyl bonds are mixed with those containing diselenyl bonds, the latter will not be as effective and will not further improve the mechanical properties and self-healing ability of epoxy resin composites.
[0035] According to some preferred embodiments, the mass ratio of the reactant obtained from the reaction of vanillin monoglyceride with cystamine to acetonitrile is 1:(10-20); in the reaction of vanillin monoglyceride with cystamine, the molar ratio of vanillin monoglyceride to cystamine is 1:(0.4-0.6); and / or in step (2), in the reaction of vanillin monoglyceride with selenocystamine and in the reaction of vanillin monoglyceride with cystamine, the molar ratio of selenocystamine to cystamine is 1:(0.8-1.2). In some preferred embodiments, the reaction of vanillin monoglyceride with cystamine is as follows: vanillin monoglyceride and cystamine are reacted at a molar ratio of 1:0.5. At room temperature, vanillin monoglyceride is dissolved in dichloromethane, then cystamine is added and mixed evenly. The resulting mixture is reacted at room temperature (15-35°C) for 6 hours under magnetic stirring. After the reaction, the mixture is filtered through filter paper, washed three times with water, and then dried with sodium sulfate and vacuum in sequence to obtain the reactant, which is also referred to as a self-healing agent containing imine bonds and disulfide bonds.
[0036] In a second aspect, this invention provides an epoxy resin self-healing agent prepared by the preparation method described in the first aspect. This invention provides an epoxy resin self-healing agent that can effectively improve the dynamic exchange rate of tough materials. The self-healing agent of this invention not only improves the toughness of epoxy resin composites but also maintains the excellent mechanical properties of epoxy resin composites, making them ideal resin mold materials, particularly suitable for applications in the ceramic industry where high mold performance is required.
[0037] In a third aspect, the present invention provides the application of the epoxy resin self-healing agent prepared by the preparation method described in the first aspect in the preparation of epoxy resin materials for resin molds.
[0038] According to some preferred embodiments, the epoxy resin material for the resin mold comprises bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyamide curing agent, accelerator, epoxy resin self-healing agent and aqueous filler; in this invention, the bisphenol A type epoxy resin may be, for example, E51 liquid epoxy resin, and the bisphenol F type epoxy resin may be, for example, Epikote 862 liquid bisphenol F type epoxy resin.
[0039] According to some preferred embodiments, the mass ratio of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, the polyamide curing agent, the accelerator, the epoxy resin self-healing agent, and the aqueous filler is 10:(2-8):(3-8):(0.5-1.5):(1-5):(50-80). Preferably, the mass ratio of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, the polyamide curing agent, the accelerator, the epoxy resin self-healing agent, and the aqueous filler is 10:(2-8):(3-8):(0.5-1.5):(1-5):(50-80). The aqueous filler comprises hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water in a mass ratio of (15-25):(5-15):(5-15):(20-30); This invention does not specifically limit the particle size of the hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide, which can be conventionally selected by those skilled in the art; In this invention, the hydrophilic fumed silica is, for example, HDKT30, and the precipitated silica is, for example, ZEODENT. 103, the nano-titanium dioxide is, for example, R-FC5; the polyamide curing agent is polyamide epoxy curing agent 5140 and / or polyamide epoxy curing agent 2636, preferably, the polyamide curing agent is a mixture of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 in a mass ratio of 4:(2-4); and / or the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol (accelerator DMP-30).
[0040] According to some specific embodiments, the preparation of the epoxy resin material for the resin mold includes:
[0041] (a) Preparation of aqueous filler: Hydrophilic fumed silica, precipitated silica and nano titanium dioxide are gradually added to water and stirred at 600 r / min until all inorganic particles are uniformly dispersed to form a uniform suspension, thus obtaining aqueous filler.
[0042] (b) Bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyamide curing agent, accelerator and epoxy resin self-healing agent are stirred and mixed evenly at a speed of 600 r / min to obtain a resin phase. Then, aqueous phase filler is added to the resin phase at a speed of 600 r / min and stirred and mixed evenly to obtain epoxy resin material for resin molds. In this invention, steps (a) and (b) are carried out at room temperature of 25°C.
[0043] When preparing a resin mold using the epoxy resin material for resin molds, the epoxy resin material for resin molds can be placed in a molding mold pre-designed according to the structure of the resin mold (the inner surface of the molding mold is pre-coated with a layer of release agent), and then cured at 30-40°C for 10-18 hours. After demolding, the resin mold can be obtained.
[0044] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments.
[0045] In the following examples and comparative examples, the hydrophilic fumed silica used is HDK T30, the precipitated silica used is ZEODENT 103, and the nano titanium dioxide used is R-FC5.
[0046] Example 1
[0047] ① First, vanillin, epichlorohydrin, and benzyltriethylammonium chloride are mixed evenly and reacted at 80°C for 2 hours. Then, excess epichlorohydrin is removed by vacuum filtration. After cooling to 25°C, an aqueous sodium hydroxide solution is added and reacted at 25°C for 1 hour to obtain vanillin monoglyceride. The mass ratio of vanillin, epichlorohydrin, benzyltriethylammonium chloride, and aqueous sodium hydroxide solution is 2:5:0.1:7. The aqueous sodium hydroxide solution contains 28% sodium hydroxide by mass.
[0048] ② The vanillin monoglyceride obtained in step ① was reacted with selenocysteine at a molar ratio of 1:0.5: Vanillin monoglyceride was dissolved in dichloromethane at room temperature (25°C), then selenocysteine was added and mixed evenly. The resulting mixture was reacted at room temperature (25°C) for 6 hours under magnetic stirring at 600 r / min. After the reaction, the mixture was filtered and washed three times with water. Then, it was dried with sodium sulfate and vacuum dried in sequence to obtain the epoxy resin self-healing agent. The mass ratio of dichloromethane to vanillin monoglyceride was 15:1.
[0049] ③ Hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide are mixed evenly with water at a speed of 600 r / min to obtain an aqueous filler. The mass ratio of hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water is 20:10:10:25. Bisphenol A epoxy resin (E51 liquid epoxy resin), bisphenol F epoxy resin (Epikote 862 liquid bisphenol F epoxy resin), polyamide curing agent, accelerator DMP-30, and the epoxy resin self-healing agent obtained in step ② are mixed at a mass ratio of 10:5:7:1:1 at a speed of [missing information - likely a speed measurement]. The mixture is stirred at 600 r / min until homogeneous to obtain a resin phase. Aqueous filler is then added to the resin phase at 600 r / min, and the mixture is stirred and stirred at 600 r / min until homogeneous to obtain an epoxy resin material for resin molds. The polyamide curing agent is composed of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 mixed at a mass ratio of 4:3. The mass ratio of bisphenol A epoxy resin, bisphenol F epoxy resin, polyamide curing agent, accelerator DMP-30, epoxy resin self-healing agent, and aqueous filler is 10:5:7:1:1:65.
[0050] Example 2
[0051] Example 2 is basically the same as Example 1, except that:
[0052] ③ Hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide are mixed evenly with water at a speed of 600 r / min to obtain an aqueous filler. The mass ratio of hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water is 20:10:10:25. Bisphenol A epoxy resin (E51 liquid epoxy resin), bisphenol F epoxy resin (Epikote 862 liquid bisphenol F epoxy resin), polyamide curing agent, accelerator DMP-30, and the epoxy resin self-healing agent obtained in step ② are mixed at a mass ratio of 10:5:7:1:3 at a speed of [missing information - likely a speed measurement]. The mixture is stirred at 600 r / min until homogeneous to obtain a resin phase. Aqueous filler is then added to the resin phase at 600 r / min, and the mixture is stirred and mixed until homogeneous to obtain an epoxy resin material for resin molds. The polyamide curing agent is composed of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 mixed at a mass ratio of 4:3. The mass ratio of bisphenol A epoxy resin, bisphenol F epoxy resin, polyamide curing agent, accelerator DMP-30, epoxy resin self-healing agent, and aqueous filler is 10:5:7:1:3:65.
[0053] Example 3
[0054] Example 3 is basically the same as Example 1, except that:
[0055] ③ Hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide are mixed evenly with water at a speed of 600 r / min to obtain an aqueous filler. The mass ratio of hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water is 20:10:10:25. Bisphenol A epoxy resin (E51 liquid epoxy resin), bisphenol F epoxy resin (Epikote 862 liquid bisphenol F epoxy resin), polyamide curing agent, accelerator DMP-30, and the epoxy resin self-healing agent obtained in step ② are mixed at a mass ratio of 10:5:7:1:5 at a speed of [missing information - likely a speed measurement]. The mixture is stirred at 600 r / min until homogeneous to obtain a resin phase. Aqueous filler is then added to the resin phase at 600 r / min, and the mixture is stirred and mixed until homogeneous to obtain an epoxy resin material for resin molds. The polyamide curing agent is composed of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 mixed at a mass ratio of 4:3. The mass ratio of bisphenol A epoxy resin, bisphenol F epoxy resin, polyamide curing agent, accelerator DMP-30, epoxy resin self-healing agent, and aqueous filler is 10:5:7:1:5:65.
[0056] Example 4
[0057] ① First, vanillin, epichlorohydrin, and benzyltriethylammonium chloride are mixed evenly and reacted at 80°C for 2 hours. Then, excess epichlorohydrin is removed by vacuum filtration. After cooling to 25°C, an aqueous sodium hydroxide solution is added and reacted at 25°C for 1 hour to obtain vanillin monoglyceride. The mass ratio of vanillin, epichlorohydrin, benzyltriethylammonium chloride, and aqueous sodium hydroxide solution is 2:5:0.1:7. The aqueous sodium hydroxide solution contains 28% sodium hydroxide by mass.
[0058] ② The vanillin monoglyceride obtained in step ① is reacted with selenocysteine at a molar ratio of 1:0.5: Vanillin monoglyceride is dissolved in dichloromethane (mass ratio of dichloromethane to vanillin monoglyceride is 15:1) at room temperature (25°C), then selenocysteine is added and mixed thoroughly. The resulting mixture is reacted at room temperature (25°C) for 6 hours under magnetic stirring at 600 r / min. After the reaction, the mixture is filtered, washed three times with water, and then dried successively with sodium sulfate and vacuum. The reactants obtained from the reaction of vanillin monoglyceride and cysteine, along with acetonitrile, are added and mixed thoroughly. The mixture is then reacted at 60°C for 6 hours under magnetic stirring at 600 r / min to obtain the epoxy resin self-healing agent. The mass ratio of the reactants to acetonitrile should be 1:15; wherein, the reaction of vanillin monoglyceride with cystamine is as follows: vanillin monoglyceride (the preparation of vanillin monoglyceride is the same as step ① of this embodiment) is reacted with cystamine at a molar ratio of 1:0.5. At room temperature (25°C), vanillin monoglyceride is dissolved in dichloromethane (the mass ratio of dichloromethane to vanillin monoglyceride is 15:1), then cystamine is added and mixed evenly. The resulting mixture is reacted at room temperature (25°C) for 6 hours under magnetic stirring at 600 r / min; in step ②, the molar ratio of selenocystamine to cystamine in the reaction of vanillin monoglyceride with selenocystamine and the reaction of vanillin monoglyceride with cystamine is 1:1.
[0059] ③ Hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide are mixed evenly with water at a speed of 600 r / min to obtain an aqueous filler. The mass ratio of hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water is 20:10:10:25. Bisphenol A epoxy resin (E51 liquid epoxy resin), bisphenol F epoxy resin (Epikote 862 liquid bisphenol F epoxy resin), polyamide curing agent, accelerator DMP-30, and the epoxy resin self-healing agent obtained in step ② are mixed at a mass ratio of 10:5:7:1:5 at a speed of [missing information - likely a speed measurement]. The mixture is stirred at 600 r / min until homogeneous to obtain a resin phase. Aqueous filler is then added to the resin phase at 600 r / min, and the mixture is stirred and mixed until homogeneous to obtain an epoxy resin material for resin molds. The polyamide curing agent is composed of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 mixed at a mass ratio of 4:3. The mass ratio of bisphenol A epoxy resin, bisphenol F epoxy resin, polyamide curing agent, accelerator DMP-30, epoxy resin self-healing agent, and aqueous filler is 10:5:7:1:5:65.
[0060] Comparative Example 1
[0061] Comparative Example 1 is basically the same as Example 1, except that:
[0062] ② The vanillin monoglyceride obtained in step ① was reacted with cystamine at a molar ratio of 1:0.5. At room temperature (25°C), the vanillin monoglyceride was dissolved in dichloromethane, and then cystamine was added and mixed evenly. The resulting mixture was reacted at room temperature (25°C) for 6 hours under magnetic stirring at 600 r / min. After the reaction, the mixture was filtered and washed three times with water. Then, it was dried with sodium sulfate and vacuum dried in sequence to obtain the self-healing agent. The mass ratio of dichloromethane to vanillin monoglyceride was 15:1. This self-healing agent was used instead of the epoxy resin self-healing agent in Example 1 for subsequent steps ③.
[0063] Comparative Example 2
[0064] Comparative Example 2 is basically the same as Example 2, except that:
[0065] ② The vanillin monoglyceride obtained in step ① was reacted with cystamine at a molar ratio of 1:0.5. At room temperature (25°C), the vanillin monoglyceride was dissolved in dichloromethane, and then cystamine was added and mixed evenly. The resulting mixture was reacted at room temperature (25°C) for 6 hours under magnetic stirring at 600 r / min. After the reaction, the mixture was filtered and washed three times with water. Then, it was dried with sodium sulfate and vacuum dried in sequence to obtain the self-healing agent. The mass ratio of dichloromethane to vanillin monoglyceride was 15:1. This self-healing agent was used instead of the epoxy resin self-healing agent in Example 2 for subsequent steps ③.
[0066] Comparative Example 3
[0067] Comparative Example 3 is basically the same as Example 3, except that:
[0068] ② The vanillin monoglyceride obtained in step ① was reacted with cystamine at a molar ratio of 1:0.5. At room temperature (25°C), the vanillin monoglyceride was dissolved in dichloromethane, and then cystamine was added and mixed evenly. The resulting mixture was reacted at room temperature (25°C) for 6 hours under magnetic stirring at 600 r / min. After the reaction, the mixture was filtered and washed three times with water. Then, it was dried with sodium sulfate and vacuum dried in sequence to obtain the self-healing agent. The mass ratio of dichloromethane to vanillin monoglyceride was 15:1. This self-healing agent was used instead of the epoxy resin self-healing agent in Example 3 for subsequent steps ③.
[0069] Comparative Example 4
[0070] Hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide were mixed evenly with water at a speed of 600 r / min to obtain an aqueous filler. The mass ratio of hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water was 20:10:10:25. Bisphenol A epoxy resin (E51 liquid epoxy resin), bisphenol F epoxy resin (Epikote 862 liquid bisphenol F epoxy resin), polyamide curing agent, and accelerator DMP-30 were mixed at a mass ratio of 10:5:7:1 at a speed of 600 r / min. The resin phase is obtained by stirring at 600 r / min until homogeneous. Aqueous filler is added to the resin phase at 600 r / min and stirring is continued at 600 r / min until homogeneous, thus obtaining epoxy resin material for resin molds. The polyamide curing agent is composed of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 mixed in a mass ratio of 4:3. The mass ratio of bisphenol A epoxy resin, bisphenol F epoxy resin, polyamide curing agent, accelerator DMP-30 and aqueous filler is 10:5:7:1:65.
[0071] Comparative Example 5
[0072] Comparative Example 5 is basically the same as Example 3, except that:
[0073] ② The vanillin monoglyceride, selenocysteine, and cystamine obtained in step ① were reacted at a molar ratio of 1:0.25:0.25. At room temperature (25°C), the vanillin monoglyceride was dissolved in dichloromethane, and then selenocysteine and cystamine were added and mixed evenly. The resulting mixture was reacted at 25°C for 6 hours under magnetic stirring at 600 r / min. After the reaction, the mixture was filtered and washed three times with water. Subsequently, it was dried with sodium sulfate and then vacuum dried to obtain the self-healing agent. The mass ratio of dichloromethane to vanillin monoglyceride was 15:1. This self-healing agent was used instead of the epoxy resin self-healing agent in Example 3 for subsequent steps ③.
[0074] Comparative Example 6
[0075] ① Cystamine dihydrochloride was added to a mixed solution of ethanol and tetrahydrofuran. Then, triethylamine and octadecyl acrylate were added to the mixture. The mixture was stirred at 35°C for 12 hours. After the reaction, the mixture was washed with deionized water to obtain a pale yellow precipitate. The precipitate was then placed in a vacuum oven at 50°C for 24 hours to obtain an aliphatic disulfide monomer. The molar ratio of cystamine dihydrochloride, triethylamine, and octadecyl acrylate was 1:2:2, the volume ratio of ethanol to tetrahydrofuran was 1:1, and the mass of the mixed solution of ethanol and tetrahydrofuran was 25 times the mass of cystamine dihydrochloride. ② 2,5-hexanedione was added to ethanol, then ethanolamine was added to the mixture. The mixture was stirred at 25°C for 4 hours, then ethylenediamine was added and the reaction continued for another 4 hours. The reaction was terminated. After the reaction, the mixture was subjected to vacuum distillation to remove ethanol, finally obtaining a ketimine. The molar ratio of 2,5-hexanedione, ethanolamine, and ethylenediamine was 2:1:1, and the mass of ethanol was [missing information]. The mass of 2,5-hexanedione was 25 times that of the other ingredient. Polypropylene glycol 2000, dibutyltin dilaurate catalyst, and N,N-dimethylformamide were placed in a three-necked flask and reacted at 120°C for 1 hour. The temperature was then lowered to 85°C, isophorone diisocyanate was added, and the reaction continued for 1 hour. Then, 1,4-butanediol was added, and the reaction continued for 2 hours. The temperature was then lowered to 70°C, aliphatic disulfide monomer was added, and the reaction continued for 2 hours. The temperature was then lowered to 60°C, and ketoimine was added to block the remaining isocyanate groups. The reaction was continued for 2 hours. The reaction terminates after h, and an epoxy resin modifier containing disulfide and imine bonds is finally obtained during the reaction. The molar ratio of polypropylene glycol 2000, isophorone diisocyanate, 1,4-butanediol, ketoimine and aliphatic disulfide monomer is 1:5.6:1:5:1. The mass of dibutyltin dilaurate is 3% of the sum of the mass of isophorone diisocyanate and aliphatic disulfide monomer. The mass of N,N-dimethylformamide is 25 times the mass of polypropylene glycol 2000.
[0076] ② Hydrophilic fumed silica, precipitated silica, and nano-titanium dioxide are mixed evenly with water at a speed of 600 r / min to obtain an aqueous filler. The mass ratio of hydrophilic fumed silica, precipitated silica, nano-titanium dioxide, and water is 20:10:10:25. Bisphenol A epoxy resin (E51 liquid epoxy resin), bisphenol F epoxy resin (Epikote 862 liquid bisphenol F epoxy resin), polyamide curing agent, accelerator DMP-30, and the epoxy resin modifier containing disulfide bonds and imine bonds obtained in step ① are mixed at a mass ratio of 10:5:7:1:5 at a speed of [missing information - likely a speed measurement]. The mixture is stirred at 600 r / min until homogeneous to obtain a resin phase. Aqueous filler is added to the resin phase at 600 r / min, and the mixture is stirred at 600 r / min until homogeneous to obtain an epoxy resin material for resin molds. The polyamide curing agent is composed of polyamide epoxy curing agent 5140 and polyamide epoxy curing agent 2636 mixed at a mass ratio of 4:3. The mass ratio of bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyamide curing agent, accelerator DMP-30, epoxy resin modifier containing disulfide and imine bonds, and aqueous filler is 10:5:7:1:5:65.
[0077] To evaluate the performance of the epoxy resin material for resin molds prepared according to this invention, the epoxy resin materials for resin molds prepared in each embodiment and each comparative example were cured at 35°C for 12 hours to obtain cured samples of epoxy resin materials for resin molds. Then, the bending strength, hardness, tensile strength (tensile strength before breakage), and self-healing efficiency were tested, and the results are shown in Table 1. In this invention, the self-healing efficiency was tested as follows: the cured sample of epoxy resin material for resin molds was broken and then spliced together, and then placed in a 50°C oven for repair for 12 hours. Then, the repaired sample was subjected to a tensile test, and the ratio of the tensile strength after repair to the tensile strength before breakage was taken as the self-healing efficiency.
[0078] Table 1
[0079]
[0080] In Table 1, the symbol "-" indicates that the performance metric was not tested.
[0081] As shown in Table 1, the epoxy resin material for resin molds prepared using the epoxy resin self-healing agent of this invention can significantly improve the mechanical properties and self-healing performance of the material. In some preferred embodiments of this invention, the flexural strength of the epoxy resin material for resin molds prepared using the epoxy resin self-healing agent is as high as 14 MPa or more, indicating that it has better structural integrity and bending resistance when subjected to external pressure, indicating that the epoxy resin material for resin molds has high toughness, and the hardness is as high as 68D or more, indicating that the epoxy resin material for resin molds has high hardness and wear resistance, making it suitable for manufacturing ceramic molds that can withstand large mechanical loads, and enabling the self-healing efficiency of the prepared epoxy resin material for resin molds to reach 90-98.9%.
[0082] The parts of this invention not described in detail are techniques known to those skilled in the art.
[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. The application of an epoxy resin self-healing agent in the preparation of epoxy resin materials for resin molds, characterized in that, The preparation method of the epoxy resin self-healing agent includes the following steps: (1) Vanillin is reacted with epichlorohydrin to obtain vanillin monoglyceride; (2) Vanillin monoglyceride and selenocysteine are mixed evenly with dichloromethane and reacted. After filtration, washing and drying, the reactants obtained by the reaction of vanillin monoglyceride and cysteine and acetonitrile are added and mixed evenly. The mixture is reacted at a temperature of 50~60℃ for 4~8h to obtain epoxy resin self-healing agent. The epoxy resin material for the resin mold comprises bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyamide curing agent, accelerator, epoxy resin self-healing agent and aqueous phase filler in a mass ratio of 10:(2~8):(3~8):(0.5~1.5):(3~5):(50~80).
2. The application according to claim 1, characterized in that: The aqueous filler comprises hydrophilic fumed silica, precipitated silica, nano titanium dioxide and water in a mass ratio of (15~25):(5~15):(5~15):(20~30); The polyamide curing agent is polyamide epoxy curing agent 5140 and / or polyamide epoxy curing agent 2636; and / or The accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.
3. The application according to claim 1, characterized in that, In step (1): The reaction was carried out in the presence of benzyltriethylammonium chloride and an aqueous solution of sodium hydroxide. The reaction is as follows: first, vanillin, epichlorohydrin and benzyltriethylammonium chloride are mixed evenly and reacted at 70~90℃ for 1~3h, then the temperature is lowered to 15~35℃ and sodium hydroxide aqueous solution is added and reacted at 15~35℃ for 0.5~1.5h to obtain vanillin monoglyceride; The mass ratio of vanillin, epichlorohydrin, benzyltriethylammonium chloride, and sodium hydroxide aqueous solution is 2:(4~6):(0.05~0.15):(5~8); The sodium hydroxide aqueous solution contains 25-35% sodium hydroxide by mass.
4. The application according to claim 1, characterized in that: The molar ratio of vanillin monoglyceride to selenocysteine is 1:(0.4~0.6); and / or The mass ratio of dichloromethane to vanillin monoglyceride is (10~20):
1.
5. The application according to claim 1, characterized in that, In step (2): In the reaction of vanillin monoglyceride with selenocysteine, the reaction temperature is 15-35°C; and / or In the reaction of vanillin monoglyceride with selenocysteine, the reaction time is 4-8 hours.
6. The application according to claim 1, characterized in that: The mass ratio of the reactant obtained by the reaction of vanillin monoglyceride with cystamine to acetonitrile is 1:(10~20). In the reaction of vanillin monoglyceride with cystamine, the molar ratio of vanillin monoglyceride to cystamine is 1:(0.4~0.6); and / or In the reaction of vanillin monoglyceride with selenocysteine and the reaction of vanillin monoglyceride with cysteine, the molar ratio of selenocysteine to cysteine is 1:(0.8~1.2).
7. An epoxy resin material for resin molds, characterized in that, The epoxy resin material for the resin mold comprises bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyamide curing agent, accelerator, epoxy resin self-healing agent and aqueous phase filler in a mass ratio of 10:(2~8):(3~8):(0.5~1.5):(3~5):(50~80). The preparation method of the epoxy resin self-healing agent includes the following steps: (1) Vanillin is reacted with epichlorohydrin to obtain vanillin monoglyceride; (2) Vanillin monoglyceride and selenocysteine are mixed evenly with dichloromethane and reacted. After filtration, washing and drying, the reactants obtained by the reaction of vanillin monoglyceride and cysteine and acetonitrile are added and mixed evenly. The mixture is reacted at a temperature of 50~60℃ for 4~8h to obtain epoxy resin self-healing agent.