Self-repairing composite foam material and preparation method thereof

Abstract

The invention discloses a self-repairing foam material and a preparation method thereof, and the method comprises the following steps: dispersing self-repairing microcapsules and a catalyst in a polymerization raw material solution, carrying out a polymerization reaction under certain conditions to form a polymer, and carrying out high temperature foaming on the polymer to obtain the self-repairing foam material, and dicyclopentadiene is contained in the self-repairing microcapsule. The method is adaptive to a PMI material preparation process, the problem that damage is difficult to self-repair when PMI is used as a thermosetting material can be solved, and the service life of PMI is prolonged.

Description

Technical Field

[0001] This application relates to the field of materials preparation technology, and in particular to a composite foam material with self-healing function. Background Technology

[0002] In aerospace, new energy equipment, transportation, and high-end industrial equipment, polymethacrylamide (PMI) foam, with its lightweight, high specific strength, and excellent temperature resistance, has become a key basic material for various core structures or functional components. Its service reliability and durability are directly related to the overall operational safety and life cycle of the equipment. As the performance requirements for materials in these fields continue to upgrade, such as the need for long-term service under fatigue loads, impacts, extreme temperature and humidity, or corrosive environments, traditional PMI foam, as a thermosetting material, is increasingly unable to fully meet the demands of specific environments because it is difficult to repair itself once microcracks, delamination, or localized damage occur. It requires manual inspection and post-incident maintenance.

[0003] Existing methods for treating PMI foam damage are not only complex to operate and costly to maintain, but also suffer from slow identification of minor or hidden damage. Furthermore, the repair process often requires interrupting equipment operation, further impacting efficiency. Simultaneously, traditional repair methods struggle to fully restore the material's original mechanical properties and structural integrity. Long-term accumulated damage can lead to a continuous decline in the mechanical properties of PMI foam, shortening its service life and even posing safety hazards to equipment operation. This severely restricts the application of PMI foam in high-end scenarios with more stringent requirements for reliability, durability, and operational efficiency. Therefore, developing PMI materials with self-repair capabilities is a key direction for overcoming these technical bottlenecks and meeting the material performance upgrade needs of high-end fields. Summary of the Invention

[0004] This application provides a composite sandwich foam material with self-healing capabilities to enable PMI foam material to self-repair damage and expand the application scenarios of the material.

[0005] Specifically, this application provides a method for preparing a self-healing foam material, which includes: Self-healing microcapsules and catalysts are dispersed in a polymerization raw material solution, and a polymerization reaction occurs under certain conditions to form a polymer. The polymer is subjected to high-temperature foaming to obtain the self-healing foam material. The self-healing microcapsule contains dicyclopentadiene.

[0006] Furthermore, the self-healing microcapsules are prepared by the following method: After mixing and reacting diamine monomer, dianhydride monomer, and capping agent with an organic solvent, sodium dodecylbenzenesulfonate and dicyclopentadiene are added to form an emulsion. The emulsion is then reacted at high temperature to obtain a suspension containing microcapsules. After washing and filtration, the self-healing microcapsules are obtained.

[0007] Furthermore, the diamine monomer is an aromatic diamine.

[0008] Furthermore, the aromatic diamine is selected from at least one of m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, and p-phenylenediamine sulfonate.

[0009] Furthermore, the dianhydride monomer is an aromatic dianhydride.

[0010] Furthermore, the aromatic dianhydride is selected from at least one of pyromellitic dianhydride, biphenyl dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride.

[0011] Furthermore, the end-capping agent is selected from one or more of aniline, p-methylaniline, 4-chloroaniline, phthalic anhydride, and trimellitic anhydride monomethyl ester.

[0012] Furthermore, the molar ratio of the diamine monomer, dianhydride monomer, and capping agent is 1:(0.1-1):(0.01-0.5).

[0013] Furthermore, the organic solvent is m-cresol, sulfolane, or a mixed solvent thereof in any proportion.

[0014] Furthermore, in the process of preparing the self-healing microcapsules, the diamine monomer, dianhydride monomer, and capping agent are mixed with an organic solvent at a temperature of 40-80°C for 1-5 hours. Then, sodium dodecylbenzenesulfonate is added, and dicyclopentadiene is added under stirring until a stable emulsion is formed. The temperature is then slowly raised to 180°C and reacted for 1-10 hours to obtain the suspension containing the microcapsules.

[0015] Furthermore, by weight, the total weight of the diamine monomer, dianhydride monomer, and capping agent is 15-30 parts by weight, the solvent is 40-80 parts by weight, the sodium dodecylbenzenesulfonate is 3-10 parts by weight, and the dicyclopentadiene is 5-30 parts by weight.

[0016] Furthermore, in the preparation method of the self-healing foam material, the catalyst is a Grubb catalyst.

[0017] Furthermore, the Grubb catalyst is selected from one or more of di-tricyclohexylphosphine-benzylmethyl-ruthenium dichlorotri ...

[0018] Furthermore, the polymerization raw material solution includes methacrylic acid, methacrylonitrile, initiator, foaming agent, and crosslinking agent.

[0019] Furthermore, the initiator is selected from one or more of tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, benzoyl peroxide lauroyl peroxide, tert-butyl peroxide, tert-butyl peroxy-2-ethylhexanoate, or bis(4-tert-butylcyclohexyl) peroxide dicarbonate.

[0020] Furthermore, the foaming agent is selected from one or more of isopropanol, glycerol, isobutanol, tert-butanol, n-heptane, methyl ethyl ketone, urea, or tert-butyl methyl ether.

[0021] Furthermore, the crosslinking agent is selected from one or more of calcium oxide, magnesium oxide, acrylamide (AM), methacrylamide (MAM), triallyl cyanurate, allyl methacrylate, metal salt of methacrylate, metal salt of acrylate, allyl acrylate, allyl methacrylate, allyl acrylamide, or allyl methacrylamide.

[0022] Furthermore, in the polymer, the ratio of the self-healing microcapsule, catalyst, methacrylic acid, methacrylonitrile, initiator, foaming agent, and crosslinking agent, by weight, is (5-15):(1-20):(0-80):(30-70):(0.1-3):(3-10):(0.1-5).

[0023] Furthermore, in the preparation method, the polymerization reaction temperature is 30-150℃ and the reaction time is 24-240h.

[0024] Furthermore, in the preparation method, the foaming temperature of the high-temperature foaming is 160-250℃, and the reaction time is 2-7h.

[0025] This application also provides a self-healing foam material, wherein the foam material comprises PMI foam material and self-healing microcapsules. Furthermore, the self-healing microcapsules contain dicyclopentadiene.

[0026] Furthermore, the foam material is prepared by the preparation method described above.

[0027] This application also provides the application of the self-healing foam material in aerospace, new energy equipment, and transportation materials.

[0028] The effects of the invention The self-healing foam material and its preparation method provided in this application involve pre-dispersing microcapsules containing a repair agent (dicyclopentadiene) and a catalyst in a PMI material matrix. When cracks occur in the PMI material, the microcapsules rupture under stress, and the released repair agent undergoes a ring-opening metathesis polymerization reaction under the action of the catalyst. The generated polymer then bonds the cracks, thus achieving self-healing of the PMI material.

[0029] This technical solution solves the problem that PMI materials, as thermosetting materials, are difficult to repair damage on their own, significantly improving their service life and reliability. It is adapted to the PMI material preparation process, enhances the interfacial bonding between the repair product and the PMI matrix, and enables the repaired material to maintain excellent performance. It is suitable for fields with high requirements for material durability, such as aerospace and new energy, and has broad application prospects. Detailed Implementation

[0030] The present application will now be described in further detail with reference to specific embodiments. The embodiments given are intended to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0031] It should be noted that the terms "comprising" or "including" used throughout the specification and appendices are open-ended and should be interpreted as "comprising but not limited to". The subsequent descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appendices.

[0032] This application provides a self-healing foam material and its preparation method. By adding microcapsules containing a specific repair agent during the polymerization preparation process of the foam material, the microcapsules rupture under certain stress to release the repair agent, thereby repairing polymer cracks.

[0033] In a specific embodiment, the preparation method provided in this application includes the following steps: Self-healing microcapsules and catalysts are dispersed in a polymerization raw material solution, and a polymerization reaction occurs under certain conditions to form a polymer. The polymer is foamed at high temperature to obtain the self-healing foam material.

[0034] In a specific embodiment, the self-healing microcapsule contains dicyclopentadiene.

[0035] Dicyclopentadiene has a bridged ring olefin (norbornene) structure. Under the action of Grubbs catalysts, it undergoes ring-opening metathesis polymerization. Through a microcapsule-triggered polymerization filling process, crack repair and performance restoration of materials can be achieved.

[0036] In a specific embodiment, the self-healing microcapsules can be prepared by the following method: After mixing and reacting diamine monomer, dianhydride monomer, and capping agent with an organic solvent, sodium dodecylbenzenesulfonate and dicyclopentadiene are added to form an emulsion. The emulsion is then reacted at high temperature to obtain a suspension containing microcapsules. After washing and filtration, the self-healing microcapsules are obtained.

[0037] In the preparation of self-healing microcapsules, diamine monomers, dianhydride monomers, and end-capping agents are used to form the shell structure of polyimide (PI), which encapsulates dicyclopentadiene during suspension polymerization. The PI shell exhibits good heat resistance, ensuring the integrity of the microcapsule structure during subsequent polymerization and foaming processes.

[0038] In a specific embodiment, the diamine monomer is an aromatic diamine.

[0039] In a specific embodiment, the aromatic diamine is selected from at least one of m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, and p-phenylenediamine sulfonate.

[0040] In a specific embodiment, the dianhydride monomer is an aromatic dianhydride.

[0041] In a specific embodiment, the aromatic dianhydride is selected from at least one of pyromellitic dianhydride, biphenyl dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride.

[0042] In a specific embodiment, the end-capping agent is selected from one or more of aniline, p-methylaniline, 4-chloroaniline, phthalic anhydride, and trimellitic anhydride monomethyl ester.

[0043] In a specific embodiment, the molar ratio of the diamine monomer, dianhydride monomer, and capping agent is 1:(0.1-1):(0.01-0.5).

[0044] In some specific embodiments, the molar ratio of the diamine monomer, dianhydride monomer, and capping agent is 1:(0.2-0.8):(0.05-0.2).

[0045] In some specific embodiments, the molar ratio of the diamine monomer, dianhydride monomer, and capping agent is 1:(0.1-0.5):(0.1-0.2).

[0046] In some specific embodiments, the organic solvent is m-cresol, sulfolane, or a mixed solvent thereof in any proportion.

[0047] In some specific embodiments, during the preparation of the self-healing microcapsules, the diamine monomer, dianhydride monomer, and capping agent are mixed with an organic solvent at a temperature of 40-80°C for 1-5 hours. Then, sodium dodecylbenzenesulfonate is added, and dicyclopentadiene is added under stirring until a stable emulsion is formed. The temperature is then slowly raised to 180°C and reacted for 1-10 hours to obtain the suspension containing the microcapsules.

[0048] In some specific embodiments, the total weight of the diamine monomer, dianhydride monomer and capping agent is 15-30 parts by weight, the solvent is 40-80 parts by weight, the sodium dodecylbenzenesulfonate is 3-10 parts by weight, and the dicyclopentadiene is 5-30 parts by weight.

[0049] In some specific embodiments, the total weight of the diamine monomer, dianhydride monomer and capping agent is 25-25 parts by weight, the solvent is 50-70 parts by weight, the sodium dodecylbenzenesulfonate is 5-8 parts by weight, and the dicyclopentadiene is 10-20 parts by weight.

[0050] In a specific embodiment, the catalyst in the preparation method of the self-healing foam material is a Grubb catalyst.

[0051] Grubbs catalysts are ruthenium carbene complex catalysts used for olefin metathesis, enyne metathesis, and olefin-carbonyl metathesis. They maintain catalytic activity in the presence of water, acids, alcohols, or other solvents and exhibit strong tolerance to functional groups on olefins.

[0052] In some specific embodiments, the Grubb catalyst is selected from one or more of di-tricyclohexylphosphine-benzylmethyl-ruthenium dichlorotri ...

[0053] In a preferred embodiment, the catalyst is di-tricyclohexylphosphine-benzylmethyl-ruthenium dichloroethylene.

[0054] In a specific embodiment, the polymerization raw material solution includes methacrylic acid, methacrylonitrile, initiator, foaming agent and crosslinking agent.

[0055] In some specific embodiments, the initiator is selected from one or more of tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, benzoyl peroxide lauroyl peroxide, tert-butyl peroxide, tert-butyl peroxy-2-ethylhexanoate, or bis(4-tert-butylcyclohexyl) peroxide dicarbonate.

[0056] In some specific embodiments, the foaming agent is selected from one or more of isopropanol, glycerol, isobutanol, tert-butanol, n-heptane, methyl ethyl ketone, urea, or tert-butyl methyl ether.

[0057] In some specific embodiments, the crosslinking agent is selected from one or more of calcium oxide, magnesium oxide, acrylamide (AM), methacrylamide (MAM), triallyl cyanurate, allyl methacrylate, metal salt of methacrylate, metal salt of acrylate, allyl acrylate, allyl methacrylate, allyl acrylamide, or allyl methacrylamide.

[0058] In a specific embodiment, the ratio of the self-healing microcapsule, catalyst, methacrylic acid, methacrylonitrile, initiator, foaming agent, and crosslinking agent in the polymer, by weight, is (5-15):(1-20):(0-80):(30-70):(0.1-3):(3-10):(0.1-5).

[0059] In some specific embodiments, the ratio of the self-healing microcapsule, catalyst, methacrylic acid, methacrylonitrile, initiator, foaming agent, and crosslinking agent is (8-12):(1-20):(0-80):(30-70):(0.1-3):(3-10):(0.1-5).

[0060] In a specific embodiment, the polymerization reaction is carried out at a temperature of 30-150°C and for a reaction time of 24-240 h.

[0061] In some specific embodiments, the polymerization reaction is carried out at a temperature of 100-140°C and for a reaction time of 120-240 h.

[0062] In a specific embodiment, the preparation method involves a high-temperature foaming temperature of 160-250℃ and a reaction time of 2-7 hours.

[0063] In some specific embodiments, the high-temperature foaming temperature is 200-240℃, and the reaction time is 4-6 hours.

[0064] This application further provides a self-healing foam material, wherein the foam material includes PMI foam material and self-healing microcapsules. In a specific embodiment, the self-healing microcapsule contains dicyclopentadiene.

[0065] In a specific embodiment, the foam material is prepared by the preparation method provided in this application.

[0066] This application further provides the application of the self-healing foam material in aerospace, new energy equipment, and transportation materials.

[0067] Example This application provides a general and / or specific description of the materials and experimental methods used in the experiments. In the following examples, unless otherwise specified, all quantities are by weight. Among the main materials used in the examples, o-phenylenediamine was purchased from Zhejiang Anno Chemical Co., Ltd., pyromellitic dianhydride from Shijiazhuang Haopu Technology Co., Ltd., p-methylaniline from Hubei Kesai Chemical Co., Ltd., dicyclopentadiene from Nanjing Yuangang Fine Chemical Co., Ltd., and di-tricyclohexylphosphine-phenylmethylene-ruthenium dichlorohydrate from Xinxiang Runyu New Materials Technology Co., Ltd. Other reagents or instruments used, unless otherwise specified, are all commercially available conventional reagents or conventional laboratory instruments.

[0068] Example 1: Preparation of self-healing foam material (1) Preparation of self-healing microcapsules: 8.8 parts by weight of diamine monomer (o-phenylenediamine), 12.4 parts by weight of dianhydride monomer (pyromellitic dianhydride), 0.8 parts by weight of capping agent (p-methylaniline), and 78 parts by weight of organic solvent (reophenol) were mixed and reacted at 65°C for 2 hours. Then, 6 parts by weight of sodium dodecylbenzenesulfonate were added, and 18 parts by weight of dicyclopentadiene were added while stirring. The mixture was emulsified for 2 hours to form a stable emulsion. The temperature was slowly increased to 180°C, and the reaction was carried out for 1.5 hours to obtain a suspension containing microcapsules. After washing, filtering, and drying, the self-healing microcapsules were obtained.

[0069] (2) Preparation of polymerization raw material solution: 60 parts by weight of methacrylic acid, 40 parts by weight of methacrylonitrile, 0.3 parts by weight of initiator (azobisisobutyronitrile), 10 parts by weight of foaming agent (isopropanol), and 0.5 parts by weight of crosslinking agent (acrylamide) are mixed to obtain a polymerization raw material solution.

[0070] (3) Polymerization reaction: The self-healing microcapsules and catalyst (di-tricyclohexylphosphine-benzylmethyl-ruthenium dichloroethylene) obtained in step (1) were uniformly dispersed in the polymerization solution obtained in step (2) and a polymerization reaction was carried out to form a polymer. The mass ratio of the self-healing microcapsules, catalyst and polymerization solution was 10:13:110, the temperature was gradually increased to 125℃, and the reaction time was 200h. (4) High-temperature foaming: The polymer obtained in step (3) is reacted at 220°C for 5 hours to produce high-temperature foam, thus obtaining the self-healing PMI foam board.

[0071] Example 2 The only difference from Example 1 is that in step (1), the amount of dicyclopentadiene added is 28 parts by weight.

[0072] Example 3 The only difference from Example 1 is that in step (1), the amount of dicyclopentadiene added is 6 parts by weight.

[0073] Example 4 The only difference from Example 1 is that in step (1), the proportions of the diamine monomer, dianhydride monomer and capping agent added are 10 parts by weight, 15 parts by weight and 1.5 parts by weight, respectively.

[0074] Example 5 The only difference from Example 1 is that in step (3), the mass ratio of self-healing microcapsules, catalyst, and polymerization solution is 14:13:110.

[0075] Example 6 The only difference from Example 1 is that in step (3), the mass ratio of self-healing microcapsules, catalyst, and polymerization solution is 6:13:110.

[0076] Comparative Example 1: Preparation of PMI Foam Material 60 parts by weight of methacrylic acid, 40 parts by weight of methacrylonitrile, 0.3 parts by weight of initiator (azobisisobutyronitrile), 10 parts by weight of foaming agent (isopropanol), and 0.5 parts by weight of crosslinking agent (acrylamide) were mixed to obtain a polymerization raw material solution. The solution was gradually heated to 125°C and reacted for 200 hours to obtain a polymer. Then, the polymer was foamed at 220°C for 5 hours to obtain a self-healing PMI foam board.

[0077] Comparative Example 2 (1) Preparation of self-healing microcapsules: 8.8 parts by weight of diamine monomer (o-phenylenediamine), 12.4 parts by weight of dianhydride monomer (pyromellitic dianhydride), 0.8 parts by weight of capping agent (p-methylaniline), and 78 parts by weight of organic solvent (reophenol) were mixed and reacted at 65°C for 2 hours. Then, 6 parts by weight of sodium dodecylbenzenesulfonate were added, and 18 parts by weight of dicyclopentadiene were added while stirring. The mixture was emulsified for 2 hours to form a stable emulsion. The temperature was slowly increased to 180°C, and the reaction was carried out for 1.5 hours to obtain a suspension containing microcapsules. After washing, filtering, and drying, the self-healing microcapsules were obtained.

[0078] (2) Preparation of polymerization raw material solution: 60 parts by weight of methacrylic acid, 40 parts by weight of methacrylonitrile, 0.3 parts by weight of initiator (azobisisobutyronitrile), 10 parts by weight of foaming agent (isopropanol), and 0.5 parts by weight of crosslinking agent (acrylamide) are mixed to obtain a polymerization raw material solution.

[0079] (3) Polymerization reaction: The self-healing microcapsules and catalyst (di-tricyclohexylphosphine-benzylmethyl-ruthenium dichloroethylene) obtained in step (1) were uniformly dispersed in the polymerization solution obtained in step (2) and a polymerization reaction was carried out to form a polymer. The mass ratio of the self-healing microcapsules, catalyst and polymerization solution was 3:13:110, the temperature was gradually increased to 125℃, and the reaction time was 200h. (4) High-temperature foaming: The polymer obtained in step (3) is reacted at 220°C for 5 hours to produce high-temperature foam, thus obtaining the self-healing PMI foam board.

[0080] Comparative Example 3: Preparation of PMI Foam Material (1) Preparation of polyurea-formaldehyde microcapsules: 12.4 parts by weight of urea and 24.8 parts by weight of formaldehyde aqueous solution were stirred and reacted at 65°C for 1 hour. Then, 6 parts by weight of sodium dodecylbenzenesulfonate aqueous solution and 20 parts by weight of dicyclopentadiene were added. After emulsification for 2 hours, the temperature was slowly raised to 60°C and reacted for 2.5 hours. After drying, polyurea formaldehyde-coated dicyclopentadiene microcapsules were obtained.

[0081] (2) Preparation of polymerization raw material solution: 60 parts by weight of methacrylic acid, 40 parts by weight of methacrylonitrile, 0.3 parts by weight of initiator (azobisisobutyronitrile), 10 parts by weight of foaming agent (isopropanol), and 0.5 parts by weight of crosslinking agent (acrylamide) are mixed to obtain a polymerization raw material solution.

[0082] (3) Polymerization reaction: The microcapsules and catalyst (di-tricyclohexylphosphine-benzylmethyl-ruthenium dichloroethylene) obtained in step (1) were uniformly dispersed into the polymerization solution obtained in step (2) and a polymerization reaction was carried out to form a polymer. The mass ratio of the self-healing microcapsules, catalyst and polymerization solution was 10:13:110, the temperature was gradually increased to 125℃, and the reaction time was 200h. (4) High-temperature foaming: The polymer obtained in step (3) is reacted at 220°C for 5 hours to produce high-temperature foam, thus obtaining the self-healing PMI foam board.

[0083] Comparative Example 4: Preparation of Self-Healing Foam Material (1) Preparation of self-healing microcapsules: 8.8 parts by weight of diamine monomer (o-phenylenediamine), 12.4 parts by weight of dianhydride monomer (pyromellitic dianhydride), 0.8 parts by weight of capping agent (p-methylaniline), and 78 parts by weight of organic solvent (reophenol) were mixed and reacted at 65°C for 2 hours. Then, 6 parts by weight of sodium dodecylbenzenesulfonate were added, and 18 parts by weight of dicyclopentadiene were added while stirring. The mixture was emulsified for 2 hours to form a stable emulsion. The temperature was slowly increased to 150°C, and the reaction was carried out for 2.5 hours to obtain a suspension containing microcapsules. After washing, filtering, and drying, the self-healing microcapsules were obtained.

[0084] (2) Preparation of polymerization raw material solution: 60 parts by weight of methacrylic acid, 40 parts by weight of methacrylonitrile, 0.3 parts by weight of initiator (azobisisobutyronitrile), 10 parts by weight of foaming agent (isopropanol), and 0.5 parts by weight of crosslinking agent (acrylamide) are mixed to obtain a polymerization raw material solution.

[0085] (3) Polymerization reaction: The self-healing microcapsules and catalyst (di-tricyclohexylphosphine-benzylmethyl-ruthenium dichloroethylene) obtained in step (1) were uniformly dispersed in the polymerization solution obtained in step (2) and a polymerization reaction was carried out to form a polymer. The mass ratio of the self-healing microcapsules, catalyst and polymerization solution was 10:13:110, the temperature was gradually increased to 125℃, and the reaction time was 200h. (4) High-temperature foaming: The polymer obtained in step (3) is reacted at 220°C for 5 hours to produce high-temperature foam, thus obtaining the self-healing PMI foam board.

[0086] Experimental Example 1 Repair performance tests were conducted on the foam material samples obtained in the above embodiments and comparative examples. The specific methods are as follows: The samples of each example / comparative example were divided into two groups. One group was subjected to conventional tensile property testing, while the other group was subjected to tensile testing using a universal testing machine with a loading rate of 0.5 mm / min and a tensile time of 30-40 s. The samples were then placed at room temperature for 5 days before tensile property testing.

[0087] The testing standards are as follows: apparent density is determined according to GB / T 6343-2009 Determination of apparent density of foamed plastics and rubber; tensile strength is determined according to ASTM-D638-2010 Tensile strength of plastics.

[0088] The specific experimental results are shown in Table 1.

[0089] Table 1. Material performance test results

[0090] The experimental results show that microcracks appeared inside the foam after a fixed tensile stress was applied. After a period of time, the foam with self-healing microcapsules added using the method of this application embodiment has significantly better mechanical properties than ordinary foam materials. This indicates that the microcapsules in the material can restore the material defects after stress failure.

[0091] The above description is merely a preferred embodiment of this application and is not intended to limit the application in any other way. Any person skilled in the art may make changes or modifications to the disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the protection scope of this application.

Claims

1. A method for producing a self-repairable foam material, characterized by, The preparation method comprises the following steps: dispersing the self-repairing microcapsule and the catalyst in a polymer raw material solution, and polymerizing under certain conditions to form a polymer, foaming the polymer at high temperature to obtain the self-repairing foam material, The self-repairing microcapsule is prepared by the following method: After mixing and reacting the diamine monomer, the dianhydride monomer and the end-capping agent with an organic solvent, sodium dodecyl benzene sulfonate and dicyclopentadiene are added to form an emulsion, and a suspension containing microcapsules is obtained by high-temperature reaction, and the self-repairing microcapsule is obtained after washing and filtering.

2. The production method according to claim 1, characterized by, The diamine monomer is aromatic diamine, and the aromatic diamine is at least one selected from m-phenylenediamine, o-phenylenediamine, p-phenylenediamine and p-phenylenediamine sulfonic acid; and / or the dianhydride monomer is aromatic dianhydride, and the aromatic dianhydride is at least one selected from pyromellitic dianhydride, biphenyl tetracarboxylic dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride; and / or the end-capping agent is selected from one or more than two of aniline, p-methyl aniline, 4-chloro aniline, phthalic anhydride and monomethyl trimellitate anhydride.

3. The production method according to claim 1, characterized by, The molar ratio of the diamine monomer, the dianhydride monomer and the end-capping agent is 1:(0.1-1):(0.01-0.5).

4. The method of claim 1, wherein, The organic solvent is m-cresol, sulfolane or a mixed solvent formed by mixing the two in any ratio.

5. The preparation method according to claim 1, characterized in that, After the mixing reaction is performed at a temperature of 40-80℃ for 1-5h, sodium dodecyl benzene sulfonate is added, and dicyclopentadiene is added under stirring until a stable emulsion is formed, then the temperature is slowly raised to 180℃, and the reaction is performed for 1-10h to obtain the suspension containing microcapsules.

6. The production method according to claim 5, wherein The total weight of the diamine monomer, the dianhydride monomer and the end-capping agent is 15-30 parts by weight, the solvent is 40-80 parts by weight, the sodium dodecyl benzene sulfonate is 3-10 parts by weight, and the dicyclopentadiene is 5-30 parts by weight.

7. The preparation method according to claim 1, characterized in that, The catalyst is Grubbs catalyst, and the Grubbs catalyst is selected from one or more than two of di-tricyclohexylphosphine-benzylidene-ruthenium dichloride and benzylidene[1,3-(trimethylphenyl)-2-imidazolinylidene]dichloro(tricyclohexylphosphine)ruthenium.

8. The method of claim 1, wherein, The polymer raw material solution comprises methyl methacrylate, methyl acrylate, an initiator, a foaming agent and a crosslinking agent, The initiator is selected from one or more than two of tert-butyl peroxybenzoate, azobisisobutyronitrile, dibenzoyl peroxide, lauryl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy-2-ethylhexanoate and bis(4-tert-butyl cyclohexyl ester)peroxydicarbonate, The foaming agent is selected from one or more than two of isopropyl alcohol, glycerol, isobutyl alcohol, tert-butyl alcohol, n-heptane, methyl ethyl ketone, urea and tert-butyl methyl ether, The crosslinking agent is selected from one or more than two of calcium oxide, magnesium oxide, acrylamide, methacrylamide, triallyl cyanurate, allyl methacrylate, metal methacrylate, metal acrylate, allyl acrylate, allyl methacrylate, allyl acrylamide and allyl methacrylamide.

9. The production method according to claim 8, characterized by, The ratio of the self-repairing microcapsule, catalyst, methacrylic acid, methacrylonitrile, initiator, foaming agent, crosslinking agent is (5-15) : (1-20) : (40-80) : (30-70) : (0.1-3) : (3-10) : (0.1-5) by weight.

10. The method of claim 1, wherein, The reaction temperature of the polymerization reaction is 30-150℃, and the reaction time is 24-240h.

11. The method of claim 1, wherein, The foaming temperature of the high-temperature foaming is 160-250℃, and the reaction time is 2-7h.

12. A self-repairable foam material, characterized in that, The foam material is prepared by the preparation method of any one of claims 1-11.

13. The foam material of claim 12 is used in aerospace, new energy equipment, and transportation materials.

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