Method for preparing self-repairing epoxy-based vitreous material and material prepared thereby

Abstract

The application relates to the field of epoxy vitreous materials, and discloses a preparation method of a self-repairing epoxy vitreous material and the prepared material, and the preparation method comprises the following steps: performing a first reaction on an epoxy resin copolymer, a modified curing agent and an organic acid catalyst, wherein the molar ratio of the epoxy resin copolymer and the modified curing agent is 2:0.5-5, and the molar ratio of the organic acid catalyst and the epoxy resin copolymer is 1-10:20; the self-repairing epoxy vitreous material provided by the application has high self-repairing efficiency and short self-repairing time; moreover, the preparation raw materials of the self-repairing epoxy vitreous material in the application have wide sources, and the formula is flexible and changeable; the raw material ratio can be adjusted according to actual needs to regulate the mechanical properties of the material; the material can be recycled and reused under certain conditions, environmental pollution is reduced, and the self-repairing epoxy vitreous material has great application potential in products such as structural parts required by space shuttles and automobile industries.

Description

Technical Field

[0001] This invention relates to the field of epoxy vitreous materials, and more specifically to a method for preparing a self-healing epoxy vitreous material and the material itself. Background Technology

[0002] Epoxy compounds have excellent mechanical and electrical insulation properties, leading to their widespread application in various fields. However, damaged epoxy resins are often difficult to repair and degrade after disposal, causing significant resource and environmental problems.

[0003] Self-healing polymers and composites based on dynamic covalent bonds repair damage through the reversible breaking and recombination of chemical bonds. Compared to externally-assisted self-healing materials, dynamic covalent bond-based self-healing materials offer the significant advantage of multiple repair cycles; compared to non-covalent bond-based self-healing materials, they exhibit significantly improved mechanical strength, thus broadening their application range. Diels-Alder reactions (DA reactions), disulfide bonds, and ester bonds are common examples of dynamic covalent bonds. The DA reaction is a thermally reversible dynamic chemical reaction, meaning that multiple repetitive forward and reverse reactions can be achieved by changing the temperature. Its reaction conditions are mild and do not require the addition of a catalyst. Based on the characteristic that disulfide bonds in epoxy resins easily break to form sulfur radicals and thiol groups, and that disulfide bond exchange occurs through oxidation reactions, the disulfide exchange reaction can be triggered by various stimuli such as heat, light, and external free radicals, making it very popular in the design of self-healing and recyclable networks. Ester bonds can undergo transesterification under the action of a catalyst, with a relatively high response temperature (e.g., several hours at 150°C or several minutes at 240°C). Under external force, the ester bonds in the cross-linked network will break and regenerate, bringing the original covalent cross-linked network to a dynamic equilibrium, thus allowing the material to be reshaped into other shapes. Currently, there is no material that simultaneously possesses the self-healing functions of all three of these thermally reversible bonds.

[0004] Therefore, expanding the repair response temperature range of intrinsic self-healing materials is an urgent issue that needs to be addressed, and it is of great significance for the promotion and application of intrinsic self-healing materials. Summary of the Invention

[0005] The purpose of this invention is to overcome the problem of narrow self-healing temperature range of existing epoxy resin materials, and to provide a method for preparing a self-healing epoxy glass material and the prepared material. This material has strong self-healing ability, short repair time, wide repair response temperature range, and excellent mechanical properties.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a self-healing epoxy vitreous material, characterized in that the preparation method includes: subjecting an epoxy resin copolymer, a modified curing agent, and an organic acid catalyst to a first reaction, wherein the molar ratio of the epoxy resin copolymer to the modified curing agent is 2:0.5-5, and the molar ratio of the organic acid catalyst to the epoxy resin copolymer is 1-10:20.

[0007] Preferably, the first reaction process includes: mixing the epoxy resin copolymer and the organic acid catalyst to obtain a resin mixture;

[0008] The modified curing agent is added to the resin mixture and reacted at 60-100℃ for 0.5-2 hours, then the temperature is raised to 130-180℃ and the reaction continues for 1-3 hours.

[0009] After the addition of the curing agent, a cross-linking reaction will occur between the resin mixture and the modified curing agent. The initial reaction temperature of the cross-linking reaction can be 60℃, 70℃, 80℃, 90℃, 100℃, etc., and the time can be 0.5h, 1h, 1.5h, 2h, etc. The temperature for the continued reaction can be 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, etc., and the time can be 1h, 1.5h, 2h, 2.5h, 3h, etc.

[0010] In some embodiments, preferably, the organic acid catalyst is anhydrous zinc acetate.

[0011] In some embodiments, preferably, the molar ratio of the epoxy resin copolymer to the modified curing agent is 2:1. The molar ratio of the epoxy resin copolymer to the modified curing agent directly affects the mechanical properties of the material after self-healing, and the molar ratio can be 2:0.5, 2:1, 2:1.5, 2:2, 2:3, 2:4, 2:5, etc.

[0012] The molar ratio of organic acid catalyst to epoxy resin copolymer can be 1:20, 2:20, 3:20, 4:20, 5:20, 8:20, 10:20, etc.

[0013] In some embodiments, preferably, the mixing temperature is 100-110°C and the time is 0.5-2 hours. The purpose of mixing is to completely dissolve the organic acid catalyst. The mixing temperature can be 100°C, 105°C, 110°C, etc., and the mixing time can be 0.5 hours, 1 hour, 1.5 hours, 2 hours, etc.

[0014] In some embodiments, preferably, the resin mixture is cooled to the reaction temperature before the modified curing agent is added to initiate the reaction. After cooling and adding the modified curing agent and stirring until homogeneous, further vacuum stirring can be performed to remove bubbles.

[0015] In some embodiments, preferably, the method for preparing the epoxy resin copolymer includes: subjecting an epoxy resin monomer and furfurylamine to a third reaction to obtain the epoxy resin copolymer.

[0016] In some embodiments, preferably, the method for preparing the epoxy resin copolymer includes: carrying out a second reaction of epoxy resin monomer and octanoic acid in the presence of a quaternary ammonium salt catalyst to obtain an epoxy resin with β-hydroxy esters capped with epoxy groups.

[0017] The β-hydroxy ester-containing epoxy resin is dissolved in a first solvent, and furfurylamine is added to carry out a third reaction. The first solvent is then removed to obtain an epoxy resin copolymer.

[0018] This invention does not have any particular requirements for the specific type of epoxy resin monomer. For example, the epoxy resin monomer can be any one or more of bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, 1,6-hexanediol diglycidyl ether and resorcinol diglycidyl ether, or it can be other types of epoxy resin monomer.

[0019] Furfurylamine, also known as 2-furanmethylamine, has the chemical formula C5H7NO.

[0020] There are no special requirements for the type of the first solvent, as long as it can dissolve epoxy resin containing β-hydroxy ester and furfurylamine, and there is no reaction between it and the raw materials. For example, the first solvent can be toluene.

[0021] The process of removing the first solvent includes: placing the product obtained from the third reaction in a rotary evaporator and evaporating until no liquid droplets fall; the remaining product is the epoxy resin copolymer.

[0022] In some embodiments, preferably, the molar ratio of the epoxy resin monomer to octanoic acid is 10:0.1-5.

[0023] In some embodiments, preferably, the molar ratio of the epoxy resin monomer to octanoic acid is 10:2.

[0024] The molar ratio of oxyresin monomer to octanoic acid is directly related to the mechanical properties of the material after self-healing. The molar ratio can be 10:0.1, 10:1, 10:2, 10:3, 10:4, 10:5, etc.

[0025] In some embodiments, preferably, the molar ratio of furfurylamine to epoxy resin monomer is 1-2:1. The molar ratio of furfurylamine to epoxy resin monomer can be 1:1, 1.5:1, 2:1, etc.

[0026] In some embodiments, preferably, the amount of the quaternary ammonium salt catalyst is 0.5-1.5 wt% based on the total amount of the epoxy resin monomers. The amount of the quaternary ammonium salt catalyst affects the catalytic reaction time and yield, and the amount of the quaternary ammonium salt catalyst can be 0.5 wt%, 1 wt%, 1.5 wt%, etc., of the amount of epoxy resin monomers.

[0027] In some embodiments, preferably, the quaternary ammonium salt catalyst is tetrabutylammonium bromide.

[0028] In some embodiments, preferably, the epoxy equivalent of the epoxy resin monomer is 182-192 g / eq.

[0029] In some embodiments, preferably, the temperature of the second reaction is 90-110°C. The temperature of the second reaction can be 90°C, 100°C, 110°C, etc., and the reaction time is 1-3 hours, such as 1 hour, 2 hours, 3 hours, etc.

[0030] In some embodiments, preferably, the third reaction temperature is 100-120°C and the time is 1-3 hours. The third reaction temperature can be 100°C, 110°C, 120°C, etc., and the time can be 1 hour, 2 hours, 3 hours, etc.

[0031] In some embodiments, preferably, the preparation method of the modified curing agent includes: dissolving maleic anhydride and 4',4-diaminodiphenyl disulfide separately in a second solvent, adding the second solvent containing the 4',4-diaminodiphenyl disulfide dropwise to the second solvent containing the maleic anhydride, reacting at 80-100°C for 1-3 hours, then sequentially adding a dehydrating agent, an acid-binding agent, and a nickel salt catalyst to continue the reaction for 2-4 hours, and removing the second solvent to obtain the modified curing agent.

[0032] The present invention does not have any particular requirements for the type of the second solvent, as long as it can dissolve the corresponding compound without causing a reaction. For example, the second solvent can be N,N-dimethylformamide.

[0033] The reaction temperature for preparing the modified curing agent can be 180℃, 90℃, 100℃, etc., the reaction time for the first reaction can be 1h, 2h, 3h, etc., and the reaction time for the next reaction can be 2h, 3h, 4h, etc.

[0034] The process of removing the second solvent includes: placing the reaction product in a rotary evaporator, evaporating until no liquid drips, removing the product, dissolving the residue in chloroform, washing it several times (e.g., 3 times) with a saturated sodium hydroxide solution, filtering the chloroform solution with an organic filter membrane (0.22 μm pore size), and drying the filtered residue under vacuum at 60 °C for 6 h to obtain the modified curing agent.

[0035] In some embodiments, preferably, the molar ratio of 4',4-diaminodiphenyl disulfide to maleic anhydride is 1:1-2. The molar ratio of 4',4-diaminodiphenyl disulfide to maleic anhydride can be 1:1, 1:1.5, 1:2, etc.

[0036] In some embodiments, preferably, the amount of the dehydrating agent is 15-25 wt% based on the total amount of maleic anhydride. The amount of the dehydrating agent can be 15 wt%, 20 wt%, 25 wt% of the mass of maleic anhydride, etc.

[0037] In some embodiments, preferably, the amount of the acid-binding agent is 90-110 wt% based on the total amount of maleic anhydride. The acid-binding dosage can be 90 wt%, 100 wt%, 110 wt% of the mass of maleic anhydride, etc.

[0038] In some embodiments, preferably, the amount of the nickel salt catalyst is 3-5 wt% based on the total amount of maleic anhydride. The nickel salt catalyst may be 3 wt%, 4 wt%, 5 wt% of the mass of maleic anhydride, etc.

[0039] In some embodiments, preferably, the dehydrating agent is acetic anhydride.

[0040] In some embodiments, the acid-binding agent is preferably triethylamine.

[0041] In some embodiments, preferably, the nickel salt catalyst is nickel acetate tetrahydrate.

[0042] A second aspect of the present invention provides a self-healing epoxy vitreous material, wherein it is prepared according to the preparation method described in the first aspect of the present invention.

[0043] The reaction principle of this invention is as follows:

[0044] like Figure 1 As shown, epoxy resin monomers (EP), octanoic acid (SA), and furfurylamine (FA) react in the presence of a quaternary ammonium salt catalyst to obtain an epoxy resin copolymer.

[0045] Maleic anhydride (MA) and 4',4-diaminodiphenyl disulfide (4-AFD) react in the presence of a nickel salt catalyst to obtain a modified curing agent.

[0046] The epoxy resin copolymer and the modified curing agent react in the presence of an organic acid catalyst to obtain a self-healing epoxy-based glassy material, the network structure of which is as follows: Figure 1 As shown, from Figure 1 As can be seen, the prepared material contains multiple functional bonds, including DA bonds, ester bonds, disulfide bonds, etc.

[0047] When a material is damaged, its network structure is disrupted. Heating (80-160℃) can then cause the damaged material to re-crosslink, achieving self-repair. The process is as follows: Figure 2 As shown in the figure, the material is broken down into a chain structure. After heating, the ester bonds (green and purple parts), disulfide bonds (orange-red parts), and DA bonds (yellow parts) in the chain structure are broken and reconnected to each other.

[0048] The preparation method provided by this invention involves a cross-linking reaction during the curing process. Specifically, the furan groups of the epoxy resin copolymer and the maleimide groups of the modified curing agent undergo a "click" reaction, rapidly forming an epoxy-like glass network polymer. This invention utilizes the exchange interaction of the formed DA bonds, the ester bonds of the epoxy resin copolymer itself, and the disulfide bonds of the modified curing agent itself, causing the network topology of the epoxy-like glass material to change and rearrange under thermal stimulation, enabling the polymer to achieve self-healing, reprocessing, and shape memory functions. Because these three thermally reversible covalent bonds can be exchanged at different temperatures, the epoxy-like glass material provided by this invention has a wide repair temperature range, achieving self-healing within the range of 80-160℃.

[0049] In addition, the ester bonds and hydroxyl groups formed by the reaction of active groups will form hydrogen bonds in the network, which effectively improves the mechanical properties of epoxy glass polymer materials.

[0050] The self-healing epoxy vitreous material provided by this invention exhibits high self-healing efficiency and short self-healing time. Furthermore, the raw materials for preparing this self-healing epoxy vitreous material are widely available, and the formulation is flexible and adaptable. The proportions of raw materials (such as the molar ratio of epoxy resin monomer to succinic acid) can be adjusted according to actual needs to control the mechanical properties of the material. It can be recycled and reused under certain conditions, reducing environmental pollution. This invention introduces aromatic disulfide bonds, and the aromatic disulfide exchange reaction requires no additional stimulation and can be carried out under mild conditions or even at room temperature. Moreover, the material's molecular chain contains a small amount of hydroxyl groups, which easily form hydrogen bonds between molecular chains, enhancing the material's strength. This invention combines the thermally reversible characteristics of aromatic disulfide bonds, DA bonds, and ester bonds, enabling the self-healing epoxy vitreous material to possess a certain degree of repair capability at disulfide exchange reaction temperatures (80℃ or even room temperature), DA reaction temperatures (around 80℃ for the forward reaction and around 130℃ for the reverse reaction), and ester exchange reaction temperatures (around 150℃). Attached Figure Description

[0051] Figure 1 This is a synthesis route diagram and a network structure diagram of the material obtained in Example 1;

[0052] Figure 2This is a schematic diagram of the dynamic covalent bond (disulfide bond, ester bond, DA bond) exchange reaction of the material obtained in Example 3;

[0053] Figure 3 The bar graph shows the tensile strength, fracture strain, and toughness values ​​of the self-healing epoxy vitreous material samples (with different epoxy resin matrix / octanoic acid ratios) from Examples 1-6.

[0054] Figure 4 This is a bar chart showing the tensile strength, fracture strain, and toughness values ​​of the self-healing epoxy vitreous material samples (with different ratios of epoxy resin copolymer / modified curing agent) from Examples 7-10.

[0055] Figure 5 This is a bar graph showing the tensile strength, fracture strain, and toughness values ​​of the self-healing epoxy vitreous material sample in Example 3 under different repair conditions.

[0056] Figure 6 These are optical microscope images of the self-healing epoxy vitreous material sample from Example 3 under different repair conditions. Detailed Implementation

[0057] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. The terms "first," "second," etc., are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited. For example, the first object can be one or more.

[0058] Furthermore, the term "and / or" in the specification and claims is used to describe the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the related objects before and after are in an "or" relationship. In the description of this application, unless otherwise stated, "multiple" means two or more. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0059] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0060] Unless otherwise specified, the raw materials used in the following examples and comparative examples are all commercially available products well known in the art.

[0061] The epoxy resin monomer has the following structural formula: Its epoxy equivalent is 185 g / eq.

[0062] Tensile strength was measured using the method specified in GB / T1040.2-2008;

[0063] Fracture strain was measured using the method specified in GB / T1040.2-2008.

[0064] Toughness is obtained by calculating the enclosing area of ​​the specimen.

[0065] Based on the stress (σ)-strain (ε) curve, using the formula:

[0066]

[0067] Where τ is the toughness of the specimen, ε is the strain of the specimen, σ is the stress of the specimen, and ε max The elongation at which the sample breaks is the elongation.

[0068] Tensile strength repair rate = (Tensile strength of the material after self-repair / Tensile strength of the material before failure) × 100%;

[0069] Fracture strain repair rate = fracture strain of the material after self-repair / fracture strain of the material before it was damaged × 100%;

[0070] Toughness repair rate = (Toughness value of the material after self-repair / Toughness value of the material before it was damaged) × 100%.

[0071] Example 1

[0072] S100, Preparation of epoxy resin copolymer, as detailed below:

[0073] Weigh furfurylamine and epoxy resin monomers at a molar ratio of 2:1 and set aside.

[0074] The epoxy resin monomer was stirred in an ice bath under nitrogen protection until it was completely dissolved in toluene. The furfurylamine was added dropwise and the temperature was rapidly raised to 110°C. The mixture was refluxed for 2 hours. The resulting product was then placed in a rotary evaporator and evaporated until no liquid dripped down. The remaining product was the epoxy resin copolymer.

[0075] S200, Prepare the modified curing agent, as follows:

[0076] (1) Weigh 4',4-diaminodiphenyl disulfide and maleic anhydride in a molar ratio of 1:2 for later use;

[0077] (2) The maleic anhydride was completely dissolved in N,N-dimethylformamide and heated to 90°C. The 4'4-diaminodiphenyl disulfide was completely dissolved in N,N-dimethylformamide and then added dropwise to N,N-dimethylformamide containing maleic anhydride. The mixture was kept at 90°C and stirred for 2 hours.

[0078] (3) Acetic anhydride, triethylamine and nickel acetate tetrahydrate were added to the reaction in step (2) in sequence, and the temperature was maintained and the reaction was stirred for 3 hours. The amount of acetic anhydride, triethylamine and nickel acetate tetrahydrate added were 15wt%, 100wt% and 3wt% of the mass of maleic anhydride, respectively.

[0079] (4) Place the product from step (3) in a rotary evaporator and evaporate until no liquid drips. Remove the product, dissolve the residue in chloroform, wash it three times with saturated sodium hydroxide solution, and finally filter the solution with an organic filter membrane (0.22 μm pore size).

[0080] (5) The residue filtered in step (4) is dried under vacuum at 60°C for 6 hours to obtain the modified curing agent.

[0081] S300, Preparation of self-healing epoxy-based glass materials, as detailed below:

[0082] Weigh the epoxy resin copolymer and anhydrous zinc acetate in a molar ratio of 10:0.5, and weigh the epoxy resin copolymer and the modified curing agent in a molar ratio of 2:1 for later use.

[0083] The epoxy resin copolymer and anhydrous zinc acetate were heated and mixed at 105°C for 1 hour until the anhydrous zinc acetate was completely dissolved to obtain a resin mixture. The resin mixture was then cooled to 80°C, the modified curing agent was added, and the mixture was stirred evenly. The mixture was then vacuum stirred at 80°C to remove bubbles and cured at 80°C for 1 hour. The temperature was then raised to 150°C and cured for 2 hours to obtain a self-healing epoxy glass material.

[0084] Example 2

[0085] S100, Preparation of epoxy resin copolymer, as detailed below:

[0086] (1) Weigh furfurylamine and epoxy resin monomers at a molar ratio of 2:1, weigh epoxy resin monomers and octanoic acid at a molar ratio of 10:1, and weigh tetrabutylammonium bromide at 1 wt% of the mass of epoxy resin monomers for later use.

[0087] (2) At 105°C, the epoxy resin monomer and the octanoic acid undergo an addition reaction with the carboxylic acid under the catalysis of tetrabutylammonium bromide to obtain an epoxy resin with β-hydroxy esters capped by epoxy groups. The reaction time is 2 hours.

[0088] (3) Take the product from step (2) and stir it in an ice bath under nitrogen protection until it is completely dissolved in toluene. Add the furfurylamine dropwise and heat it rapidly to 110°C. Then reflux the mixture for 2 hours.

[0089] (4) Take the product from step (3) and place it in a rotary evaporator. Evaporate until no liquid drops fall. The remaining product is the epoxy resin copolymer.

[0090] S200, Prepare the modified curing agent, as follows:

[0091] (1) Weigh 4',4-diaminodiphenyl disulfide and maleic anhydride in a molar ratio of 1:2 for later use;

[0092] (2) The maleic anhydride was completely dissolved in N,N-dimethylformamide and heated to 90°C. The 4'4-diaminodiphenyl disulfide was completely dissolved in N,N-dimethylformamide and then added dropwise to N,N-dimethylformamide containing maleic anhydride. The mixture was kept at 90°C and stirred for 2 hours.

[0093] (3) Acetic anhydride, triethylamine and nickel acetate tetrahydrate were added to the reaction in step (2) in sequence, and the temperature was maintained and the reaction was stirred for 3 hours. The amount of acetic anhydride, triethylamine and nickel acetate tetrahydrate added were 15wt%, 100wt% and 3wt% of the mass of maleic anhydride, respectively.

[0094] (4) Place the product from step (3) in a rotary evaporator and evaporate until no liquid drips. Remove the product, dissolve the residue in chloroform, wash it three times with saturated sodium hydroxide solution, and finally filter the solution with an organic filter membrane (0.22 μm pore size).

[0095] (5) The residue filtered in step (4) is dried under vacuum at 60°C for 6 hours to obtain the modified curing agent.

[0096] S300, Preparation of self-healing epoxy-based glass materials, as detailed below:

[0097] Weigh the epoxy resin copolymer and anhydrous zinc acetate in a molar ratio of 10:0.5, and weigh the epoxy resin copolymer and the modified curing agent in a molar ratio of 2:1 for later use.

[0098] The epoxy resin copolymer and anhydrous zinc acetate were heated and mixed at 105°C for 1 hour until the anhydrous zinc acetate was completely dissolved to obtain a resin mixture. The resin mixture was then cooled to 80°C, the modified curing agent was added, and the mixture was stirred evenly. The mixture was then vacuum stirred at 80°C to remove bubbles and cured at 80°C for 1 hour. The temperature was then raised to 150°C and cured for 2 hours to obtain a self-healing epoxy glass material.

[0099] Example 3

[0100] The procedure was carried out in accordance with Example 2, except that the molar ratio of epoxy resin monomer to octanoic acid was 10:2.

[0101] Example 4

[0102] The procedure was carried out in accordance with Example 2, except that the molar ratio of epoxy resin monomer to octanoic acid was 10:3.

[0103] Example 5

[0104] The procedure was carried out in accordance with Example 2, except that the molar ratio of epoxy resin monomer to octanoic acid was 10:4.

[0105] Example 6

[0106] The procedure was carried out in accordance with Example 2, except that the molar ratio of epoxy resin monomer to octanoic acid was 10:5.

[0107] Example 7

[0108] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the modified curing agent was 2:0.5.

[0109] Example 8

[0110] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the modified curing agent was 2:1.5.

[0111] Example 9

[0112] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the modified curing agent was 2:2.

[0113] Example 10

[0114] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the organic acid catalyst was 10:1.25.

[0115] Example 11

[0116] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the organic acid catalyst was 10:2.5.

[0117] Example 12

[0118] The reaction was carried out in accordance with Example 3, except that the resin mixture and the modified curing agent were first reacted at 60°C for 2 hours, and then the temperature was raised to 180°C to continue the reaction for 1 hour.

[0119] Example 13

[0120] The reaction was carried out in accordance with Example 3, except that the resin mixture and the modified curing agent were first reacted at 100°C for 0.5 hours, and then the temperature was raised to 130°C to continue the reaction for 3 hours.

[0121] Example 14

[0122] The reaction was carried out in accordance with Example 3, except that the resin mixture and the modified curing agent were first reacted at 120°C for 1 hour, and then the temperature was raised to 200°C to continue the reaction for 2 hours.

[0123] Example 15

[0124] The reaction was carried out in accordance with Example 3, except that the resin mixture and the modified curing agent were first reacted at 50°C for 1 hour, and then the temperature was raised to 100°C to continue the reaction for 2 hours.

[0125] Example 16

[0126] The procedure was carried out in accordance with Example 3, except that the molar ratio of 4',4-diaminodiphenyl disulfide and maleic anhydride was 1:4.

[0127] Example 17

[0128] The procedure was carried out in accordance with Example 3, except that the molar ratio of 4',4-diaminodiphenyl disulfide and maleic anhydride was 1:0.5.

[0129] Example 18

[0130] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the modified curing agent was 2:5.

[0131] Example 19

[0132] The procedure was carried out in accordance with Example 3, except that the molar ratio of the epoxy resin copolymer to the organic acid catalyst was 20:10.

[0133] Using the materials prepared in Examples 1-9 as test objects, their tensile strength, fracture strain, toughness, etc., were tested respectively, and the test results are as follows: Figure 3 (Materials from Examples 1-6) and 4 (Materials from Examples 3 and 7-9) are shown.

[0134] Depend on Figure 3 It is known that the material prepared with an epoxy resin monomer / octanoic acid ratio of 10:2 exhibits strong and tough properties, demonstrating the best overall performance. With further increases in the octanoic acid ratio, the fracture strain of the self-healing vitreous material gradually increases, while the tensile strength and toughness continuously decrease. The reasons for this are as follows: the epoxy resin monomer possesses a rigid benzene ring structure, enhancing the material's strength; the presence of hydrogen bonds increases intermolecular forces, making it more difficult for molecular chains to slip under stress, thus effectively improving the material's resistance to deformation and consequently enhancing its mechanical strength. Simultaneously, the hydrogen bond network can, to some extent, dissipate energy when the material is subjected to external impact, further enhancing its toughness. Octanoic acid acts as a dynamic soft segment, improving the material's toughness; however, excessive octanoic acid leads to a decrease in material strength.

[0135] Depend on Figure 4 It is evident that the epoxy resin copolymer / modified curing agent ratio (2:1) exhibits strong and tough properties, resulting in the best overall performance. However, with further increases in the proportion of modified curing agent, the tensile strength, fracture strain, and toughness of the self-healing vitreous material continuously decrease. The reason for this is that the modified curing agent in the crosslinking network contains disulfide bonds and DA bonds, acting as dynamic hard segments. As the content of modified curing agent increases, the disulfide bonds become weak and easily break, forming a soft network structure that continuously reduces its mechanical properties.

[0136] The self-healing properties of the material prepared in Example 3 (with a molar ratio of epoxy resin monomer / octanoic acid of 10:2 and a molar ratio of epoxy resin copolymer / modified curing agent of 2:1) were further tested. The specific method is as follows: the material sample was scratched with a scratch width of about 46 μm, and then placed under an optical microscope equipped with a heating stage and heated to 80°C, 130°C and 150°C respectively to observe the scratch repair.

[0137] like Figure 5 and 6 As shown, the material prepared in Example 3 was basically healed after 300 minutes at 80°C; after 75 minutes at 130°C; and after 75 minutes at 150°C.

[0138] Mechanical property testing of the repaired sample involves completely cutting the sample in the middle, aligning the fracture surfaces, heating and placing it for a period of time. This allows for the exchange reaction of reversible dynamic covalent bonds (DA bonds, disulfide bonds, and ester bonds) between the tightly joined fracture surfaces, resulting in network rearrangement and thus repairing the fracture surfaces.

[0139] Depend on Figure 5 It can be seen that the self-healing effect is optimal at 150℃ for 75 minutes. The tensile strength of the material after self-healing is 55.76 MPa, the fracture strain is 50.28%, and the toughness is 18.16 MJ / m. 3 Calculations showed that the tensile strength repair rate was 89%, the fracture strain repair rate was 89.61%, and the toughness repair rate was 84.43%.

[0140] The tensile strength, fracture strain, and toughness of the materials prepared in Examples 1-19 were tested, and their mechanical properties after self-healing at 150℃ for 75 minutes were further tested. The repair rate was calculated, and the specific results are shown in Table 1.

[0141] Table 1 Self-healing properties of materials

[0142]

[0143] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a self-healing epoxy vitreous material, characterized in that, The preparation method includes: subjecting an epoxy resin copolymer, a modified curing agent, and an organic acid catalyst to a first reaction to obtain a self-healing epoxy glass material, wherein the molar ratio of the epoxy resin copolymer to the modified curing agent is 2:0.5-1, and the molar ratio of the organic acid catalyst to the epoxy resin copolymer is 1-5:

20. The first reaction process includes: mixing the epoxy resin copolymer and the organic acid catalyst to obtain a resin mixture; The modified curing agent is added to the resin mixture and reacted at 60-100℃ for 0.5-2 hours, then the temperature is raised to 130-180℃ and the reaction continues for 1-3 hours. The preparation method of the epoxy resin copolymer includes: carrying out a second reaction of epoxy resin monomer and octanoic acid in the presence of a quaternary ammonium salt catalyst to obtain epoxy resin with β-hydroxy ester end capping. The β-hydroxy ester-containing epoxy resin is dissolved in a first solvent, and furfurylamine is added to carry out a third reaction. The first solvent is then removed to obtain an epoxy resin copolymer. The molar ratio of the epoxy resin monomer to octanoic acid is 10:2-4; The molar ratio of furfurylamine to epoxy resin monomer is 1-2:1; The preparation method of the modified curing agent includes: independently dissolving maleic anhydride and 4',4-diaminodiphenyl disulfide in a second solvent; adding the second solvent containing the 4',4-diaminodiphenyl disulfide dropwise to the second solvent containing the maleic anhydride; reacting at 80-100℃ for 1-3 hours; then sequentially adding a dehydrating agent, an acid-binding agent, and a nickel salt catalyst and continuing the reaction for 2-4 hours; removing the second solvent to obtain the modified curing agent; the molar ratio of the 4',4-diaminodiphenyl disulfide to the maleic anhydride is 1:1-2; and the structural formula of the modified curing agent is as follows: 。 2. The preparation method according to claim 1, wherein, The organic acid catalyst is anhydrous zinc acetate.

3. The preparation method according to claim 1 or 2, wherein, The molar ratio of the epoxy resin copolymer to the modified curing agent is 2:

1.

4. The preparation method according to claim 3, wherein, Based on the total amount of the epoxy resin monomers, the amount of the quaternary ammonium salt catalyst is 0.5-1.5 wt%. And / or, the quaternary ammonium salt catalyst is tetrabutylammonium bromide; And / or, the epoxy equivalent of the epoxy resin monomer is 182-192 g / eq.

5. The preparation method according to claim 4, wherein, The molar ratio of the epoxy resin monomer to octanoic acid is 10:

2.

6. The preparation method according to claim 4 or 5, wherein, The temperature of the second reaction is 90-110℃.

7. The preparation method according to claim 6, wherein, The third reaction is carried out at a temperature of 100-120℃ for 1-3 hours.

8. The preparation method according to claim 6, wherein, Based on the total amount of maleic anhydride, the amount of the dehydrating agent is 15-25 wt%; And / or, based on the total amount of maleic anhydride, the amount of the acid-binding agent is 90-110 wt%; And / or, based on the total amount of the maleic anhydride, the amount of the nickel salt catalyst is 3-5 wt%; And / or, the dehydrating agent is acetic anhydride; And / or, the acid-binding agent is triethylamine; And / or, the nickel salt catalyst is nickel acetate tetrahydrate.

9. A self-healing epoxy vitreous material, characterized in that, Prepared according to the preparation method according to any one of claims 1-8.

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