Epoxy resin self-repairing material with dynamic covalent bonds for large-span steel bridge deck and preparation method of epoxy resin self-repairing material

Abstract

The invention relates to the technical field of bridge engineering materials, in particular to an epoxy resin self-repairing material with dynamic covalent bonds for a large-span steel bridge deck and a preparation method of the epoxy resin self-repairing material. According to modified bisphenol A epoxy resin, flexible chain segments and rigid groups are introduced into an epoxy resin molecular chain, so that the toughness and heat resistance of the material are improved; the modified aliphatic amine curing agent and the modified epoxy resin matrix have good compatibility, the formed network structure is more compact, the hardness and the heat resistance of the material are improved, the dynamic covalent bond cross-linking agent adopts a furan-maleimide system containing Diels-Alder reaction, and the dynamic covalent bond cross-linking agent has good mechanical properties and mechanical properties. Wherein a furan group and a maleimide group can be subjected to reversible addition reaction under a mild condition to form a dynamic covalent bond, so that rapid and effective self-repairing of the material when the material is damaged is realized, the self-repairing material adopting the technical scheme has an excellent self-repairing function, a repairing process can be triggered without external stimulation, and the self-repairing material has a good application prospect. And the applicability is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering materials, and in particular to an epoxy resin self-repairing material with dynamic covalent bonds for a bridge deck of a long-span steel bridge and a preparation method thereof. Background Art

[0002] As an important part of modern transportation infrastructure, the choice of bridge deck materials for long-span steel bridges is directly related to the safety, durability and maintenance cost of the bridges. Traditional epoxy resin materials are widely used due to their good mechanical properties, chemical corrosion resistance and processing convenience, but they are susceptible to the accumulation of micro-damage such as microcracks and scratches during long-term use, affecting the overall performance and life of the bridge.

[0003] Although there have been some studies on self-healing materials in the prior art, these materials often require external stimulation to trigger the repair process, which limits their application in complex environments. Summary of the invention

[0004] The purpose of the present invention is to provide an epoxy resin self-healing material with dynamic covalent bonds for a long-span steel bridge deck and a preparation method thereof, so as to solve the problem that the self-healing materials used for long-span steel bridge decks in the prior art often require external stimulation to trigger the repair process during actual use, which limits their application in complex environments.

[0005] To achieve the above-mentioned purpose, the present invention provides an epoxy resin self-repairing material with dynamic covalent bonds for a bridge deck of a long-span steel bridge. The epoxy resin self-repairing material with dynamic covalent bonds for a bridge deck of a long-span steel bridge comprises the following in percentage: 60%-75% of a modified epoxy resin matrix, 15%-30% of a modified curing agent, 2%-10% of a dynamic covalent bond cross-linking agent and additives. The modified epoxy resin matrix is ​​preferably a modified bisphenol A epoxy resin, the modified curing agent is preferably a modified fatty amine curing agent, the dynamic covalent bond cross-linking agent adopts a furan-maleimide system containing a Diels-Alder reaction, the additives include a toughening agent, an anti-ultraviolet agent and a flame retardant, the toughening agent accounts for 1%-3% of the total mass, the anti-ultraviolet agent accounts for 0.1%-0.5% of the total mass, and the flame retardant accounts for 0.5%-2% of the total mass.

[0006] Among them, the toughening agent is preferably carboxyl-terminated nitrile rubber, the anti-ultraviolet agent is preferably a benzophenone compound, and the flame retardant is preferably melamine phosphate.

[0007] The present invention also provides a method for preparing an epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck, which is used to prepare the epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck as described above, comprising the following steps:

[0008] Accurately weigh the modified epoxy resin matrix, the modified curing agent, the dynamic covalent bond crosslinking agent and the additive according to a predetermined ratio, and place them in a dry and clean container for later use;

[0009] Use a high-speed stirrer to mix the weighed raw materials evenly;

[0010] Place the mixed materials in a preheating device and heat to 40-60°C for 1-2 hours;

[0011] The preheated material is poured into a mold, placed in a vacuum oven, and subjected to a curing reaction under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material;

[0012] The cured epoxy resin self-healing material is post-processed to further optimize its microstructure and performance.

[0013] Wherein, in the step of "using a high-speed stirrer to mix the weighed raw materials uniformly", the stirring speed is controlled at 500-1000 rpm, and the stirring time is not less than 25 minutes.

[0014] Among them, in the step of "pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material", the curing temperature is controlled at 80-100°C, the pressure is controlled at 0.3-0.5MPa, and the curing time is not less than 6 hours.

[0015] The specific steps of the step of "post-treating the cured epoxy resin self-healing material to further optimize its microstructure and performance" are:

[0016] Place the cured epoxy resin self-healing material in a heating furnace, heat to 120-150°C, and keep it for 2-4 hours;

[0017] After the heating treatment, the material is slowly cooled to room temperature;

[0018] Carry out performance tests on the post-processed materials.

[0019] The specific preparation method of the modified fatty amine curing agent is as follows: uniformly mixing fatty amine, polyether amine and alkyl glycidyl ether;

[0020] The uniformly mixed raw materials are heated to 70-100°C under stirring conditions and reacted for 1-3 hours;

[0021] After the reaction is completed, the reaction product is cooled, filtered and dried to obtain the modified fatty amine curing agent product.

[0022] Wherein, the specific preparation method of the dynamic covalent bond cross-linking agent is:

[0023] Weigh appropriate amounts of furan methanol and maleimide and place them in a reaction container;

[0024] Add dimethyl sulfoxide into the reaction vessel and heat to 60-80°C to completely dissolve the raw materials;

[0025] Under stirring conditions, slowly add the catalyst dropwise, control the dropping speed to ensure a smooth reaction, keep the reaction temperature at 60-80°C, and the reaction time is not less than 4 hours;

[0026] After the reaction is completed, the reaction solution is poured into a large amount of cold water to precipitate a solid product, which is then filtered, washed, and dried to obtain the pure dynamic covalent bond cross-linking agent.

[0027] The present invention discloses an epoxy resin self-repairing material with dynamic covalent bonds for a long-span steel bridge deck and a preparation method thereof, which comprises the following in percentage: 60%-75% of a modified epoxy resin matrix, 15%-30% of a modified curing agent, 2%-10% of a dynamic covalent bond cross-linking agent and an additive, wherein the modified epoxy resin matrix is ​​preferably a modified bisphenol A epoxy resin, and the toughness and heat resistance of the material are improved by introducing flexible segments and rigid groups into the epoxy resin molecular chain, and the modified curing agent is preferably a modified fatty amine curing agent, which has good compatibility with the modified epoxy resin matrix. The formed network structure is more compact, which improves the hardness and heat resistance of the material. The dynamic covalent bond cross-linking agent adopts a furan-maleimide system containing a Diels-Alder reaction, in which the furan group and the maleimide group can undergo a reversible addition reaction under mild conditions to form a dynamic covalent bond, thereby realizing rapid and effective self-repair of the material when damaged. The self-repairing material using this technical solution has excellent self-repairing function, can trigger the repair process without external stimulation, has stronger applicability, and can maintain stable performance under extreme environmental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a flow chart of the steps of the method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge provided by the present invention.

[0030] Figure 2It is a flow chart of the steps of the method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge provided in Example 1 of the present invention.

[0031] Figure 3 It is a flow chart of the steps of the method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge provided in Example 2 of the present invention.

[0032] Figure 4 It is a flow chart of the steps of the method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0033] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0034] The invention provides an epoxy resin self-repairing material with dynamic covalent bonds for a bridge deck of a long-span steel bridge. The epoxy resin self-repairing material with dynamic covalent bonds for a bridge deck of a long-span steel bridge comprises the following in percentage: 60%-75% of a modified epoxy resin matrix, 15%-30% of a modified curing agent, 2%-10% of a dynamic covalent bond cross-linking agent and additives. The modified epoxy resin matrix is ​​preferably a modified bisphenol A epoxy resin, the modified curing agent is preferably a modified fatty amine curing agent, the dynamic covalent bond cross-linking agent adopts a furan-maleimide system containing a Diels-Alder reaction, the additives include a toughening agent, an anti-ultraviolet agent and a flame retardant, the toughening agent accounts for 1%-3% of the total mass, the anti-ultraviolet agent accounts for 0.1%-0.5% of the total mass, and the flame retardant accounts for 0.5%-2% of the total mass.

[0035] In this embodiment, the modified epoxy resin matrix is ​​preferably a modified bisphenol A epoxy resin, and flexible segments and rigid groups are introduced into the epoxy resin molecular chain to improve the toughness and heat resistance of the material. The modified curing agent is preferably a modified fatty amine curing agent, which has good compatibility with the modified epoxy resin matrix, and the formed network structure is denser, thereby improving the hardness and heat resistance of the material. The dynamic covalent bond cross-linking agent adopts a furan-maleimide system containing a Diels-Alder reaction, wherein the furan group and the maleimide group can undergo a reversible addition reaction under mild conditions to form a dynamic covalent bond, thereby achieving rapid and effective self-repair of the material when damaged. The self-repairing material using this technical solution has excellent self-repairing function, can trigger the repair process without external stimulation, has stronger applicability, and can maintain stable performance under extreme environmental conditions.

[0036] Furthermore, the toughening agent is preferably carboxyl-terminated nitrile rubber, the anti-ultraviolet agent is preferably a benzophenone compound, and the flame retardant is preferably melamine phosphate.

[0037] See also Figure 1 The present invention also provides a method for preparing an epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck, which is used to prepare the epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck as described above, comprising the following steps:

[0038] S1: accurately weighing the modified epoxy resin matrix, the modified curing agent, the dynamic covalent bond cross-linking agent and the additive according to a predetermined ratio, and placing them in a dry and clean container for later use;

[0039] S2: using a high-speed stirrer to mix the weighed raw materials uniformly;

[0040] S3: Place the mixed materials in a preheating device, heat to 40-60°C, and keep for 1-2 hours;

[0041] S4: pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material;

[0042] S5: Post-process the cured epoxy resin self-healing material to further optimize its microstructure and performance.

[0043] In this embodiment, the modified epoxy resin matrix, the modified curing agent, the dynamic covalent bond cross-linking agent and the additive are first accurately weighed according to a predetermined ratio, and placed in a dry and clean container for standby use. Then, a high-speed stirrer is used to evenly mix the weighed raw materials. The evenly mixed material is placed in a preheating device, heated to 40-60°C, and maintained for 1-2 hours. Finally, the preheated material is poured into a mold, placed in a vacuum oven, and a curing reaction is carried out under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material. The cured epoxy resin self-healing material is post-processed to further optimize its microstructure and performance.

[0044] Furthermore, in the step of "using a high-speed stirrer to uniformly mix the weighed raw materials", the stirring speed is controlled at 500-1000 rpm, and the stirring time is not less than 25 minutes.

[0045] Furthermore, in the step of "pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material", the curing temperature is controlled at 80-100°C, the pressure is controlled at 0.3-0.5MPa, and the curing time is not less than 6 hours.

[0046] Furthermore, the specific steps of the step of “post-treating the cured epoxy resin self-healing material to further optimize its microstructure and performance” are:

[0047] Place the cured epoxy resin self-healing material in a heating furnace, heat to 120-150°C, and keep it for 2-4 hours;

[0048] After the heating treatment, the material is slowly cooled to room temperature;

[0049] Carry out performance tests on the post-processed materials.

[0050] Furthermore, the specific preparation method of the modified fatty amine curing agent is: uniformly mixing fatty amine, polyether amine and alkyl glycidyl ether;

[0051] The uniformly mixed raw materials are heated to 70-100°C under stirring conditions and reacted for 1-3 hours;

[0052] After the reaction is completed, the reaction product is cooled, filtered and dried to obtain the modified fatty amine curing agent product.

[0053] Furthermore, the specific preparation method of the dynamic covalent bond cross-linking agent is:

[0054] Weigh appropriate amounts of furan methanol and maleimide and place them in a reaction container;

[0055] Add dimethyl sulfoxide into the reaction vessel and heat to 60-80°C to completely dissolve the raw materials;

[0056] Under stirring conditions, slowly add the catalyst dropwise, control the dropping speed to ensure a smooth reaction, keep the reaction temperature at 60-80°C, and the reaction time is not less than 4 hours;

[0057] After the reaction is completed, the reaction solution is poured into a large amount of cold water to precipitate a solid product, which is then filtered, washed, and dried to obtain the pure dynamic covalent bond cross-linking agent.

[0058] Embodiment 1:

[0059] See also Figure 2 The present invention also provides a method for preparing an epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck, which is used to prepare the epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck as described above, comprising the following steps:

[0060] S101: accurately weighing 60% of the modified epoxy resin matrix accounting for 60% of the total amount of the epoxy resin self-healing material, 30% of the modified curing agent accounting for 30% of the total amount of the epoxy resin self-healing material, 8% of the dynamic covalent bond cross-linking agent accounting for 8% of the total amount of the epoxy resin self-healing material, 1% of the toughening agent accounting for 1% of the total amount of the epoxy resin self-healing material, 0.1% of the anti-ultraviolet agent accounting for 0.9% of the total amount of the epoxy resin self-healing material, and placing them in a dry and clean container for later use;

[0061] S102: using a high-speed stirrer, stirring and mixing at a stirring speed of 500 rpm for 25 minutes to mix the weighed raw materials uniformly;

[0062] S103: placing the uniformly mixed material in a preheating device, heating to 40° C., and maintaining for 1 hour;

[0063] S104: pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under the conditions of a curing temperature of 80° C. and a pressure of 0.3 MPa to obtain a cured epoxy resin self-healing material;

[0064] S105: Post-processing the cured epoxy resin self-healing material to further optimize its microstructure and performance.

[0065] Embodiment 2:

[0066] See also Figure 3The present invention also provides a method for preparing an epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck, which is used to prepare the epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck as described above, comprising the following steps:

[0067] S201: accurately weighing 68% of the modified epoxy resin matrix, 22% of the modified curing agent, 6% of the dynamic covalent bond cross-linking agent, 2% of the toughening agent, 0.3% of the anti-ultraviolet agent and 1.7% of the flame retardant, and placing them in a dry and clean container for later use;

[0068] S202: using a high-speed stirrer, stirring and mixing at a stirring speed of 750 rpm for 30 minutes to uniformly mix the weighed raw materials;

[0069] S203: placing the uniformly mixed material in a preheating device, heating to 50° C., and maintaining for 1.5 hours;

[0070] S204: pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under the conditions of a curing temperature of 100° C. and a pressure of 0.4 MPa to obtain a cured epoxy resin self-healing material;

[0071] S205: Post-processing the cured epoxy resin self-healing material to further optimize its microstructure and performance.

[0072] Embodiment 3:

[0073] See also Figure 4 The present invention also provides a method for preparing an epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck, which is used to prepare the epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck as described above, comprising the following steps:

[0074] S301: accurately weighing 75% of the modified epoxy resin matrix, 15% of the modified curing agent, 5% of the dynamic covalent bond cross-linking agent, 3% of the toughening agent, 0.5% of the anti-ultraviolet agent and 1.5% of the flame retardant, and placing them in a dry and clean container for later use;

[0075] S302: Using a high-speed stirrer, stirring and mixing at a stirring speed of 1000 rpm for 35 minutes to mix the weighed raw materials uniformly;

[0076] S303: placing the uniformly mixed materials in a preheating device, heating to 60° C., and maintaining for 2 hours;

[0077] S304: pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under the conditions of a curing temperature of 100° C. and a pressure of 0.5 MPa to obtain a cured epoxy resin self-healing material;

[0078] S305: Post-processing the cured epoxy resin self-healing material to further optimize its microstructure and performance.

[0079] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A long-span steel bridge deck epoxy resin self-repairing material with dynamic covalent bonds, characterized in that: The composition comprises the following in percentage: 60%-75% of a modified epoxy resin matrix, 15%-30% of a modified curing agent, 2%-10% of a dynamic covalent bond crosslinking agent and additives. The modified epoxy resin matrix is ​​preferably a modified bisphenol A epoxy resin, the modified curing agent is preferably a modified fatty amine curing agent, the dynamic covalent bond crosslinking agent adopts a furan-maleimide system containing a Diels-Alder reaction, and the additives include a toughening agent, an anti-ultraviolet agent and a flame retardant. The toughening agent accounts for 1%-3% of the total mass, the anti-ultraviolet agent accounts for 0.1%-0.5% of the total mass, and the flame retardant accounts for 0.5%-2% of the total mass.

2. The long-span steel bridge deck epoxy resin self-repairing material with dynamic covalent bonds as claimed in claim 1, characterized in that: The toughening agent is preferably carboxyl-terminated nitrile rubber, the anti-ultraviolet agent is preferably a benzophenone compound, and the flame retardant is preferably melamine phosphate.

3. A method for preparing an epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck, which is used to prepare the epoxy resin self-repairing material having dynamic covalent bonds on a long-span steel bridge deck as claimed in claim 1, characterized in that: The steps include: Accurately weigh the modified epoxy resin matrix, the modified curing agent, the dynamic covalent bond crosslinking agent and the additive according to a predetermined ratio, and place them in a dry and clean container for later use; Use a high-speed stirrer to mix the weighed raw materials evenly; Place the mixed materials in a preheating device and heat to 40-60°C for 1-2 hours; The preheated material is poured into a mold, placed in a vacuum oven, and subjected to a curing reaction under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material; The cured epoxy resin self-healing material is post-processed to further optimize its microstructure and performance.

4. The method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge according to claim 3, characterized in that: In the step of "using a high-speed stirrer to uniformly mix the weighed raw materials", the stirring speed is controlled at 500-1000 rpm, and the stirring time is not less than 25 minutes.

5. The method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge according to claim 4, characterized in that: In the step of "pouring the preheated material into a mold, placing it in a vacuum oven, and performing a curing reaction under controlled temperature and pressure conditions to obtain a cured epoxy resin self-healing material", the curing temperature is controlled at 80-100°C, the pressure is controlled at 0.3-0.5MPa, and the curing time is not less than 6 hours.

6. The method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge according to claim 5, characterized in that: The specific steps of the step "post-processing the cured epoxy resin self-healing material to further optimize its microstructure and performance" are: Place the cured epoxy resin self-healing material in a heating furnace, heat to 120-150°C, and keep it for 2-4 hours; After the heating treatment, the material is slowly cooled to room temperature; Carry out performance tests on the post-processed materials.

7. The method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge according to claim 6, characterized in that: The specific preparation method of the modified fatty amine curing agent is: uniformly mixing fatty amine, polyether amine and alkyl glycidyl ether; The uniformly mixed raw materials are heated to 70-100°C under stirring conditions and reacted for 1-3 hours; After the reaction is completed, the reaction product is cooled, filtered and dried to obtain the modified fatty amine curing agent product.

8. The method for preparing the epoxy resin self-repairing material with dynamic covalent bonds for the bridge deck of a long-span steel bridge according to claim 7, characterized in that: The specific preparation method of the dynamic covalent bond cross-linking agent is: Weigh appropriate amounts of furan methanol and maleimide and place them in a reaction container; Add dimethyl sulfoxide into the reaction vessel and heat to 60-80°C to completely dissolve the raw materials; Under stirring conditions, slowly add the catalyst dropwise, control the dropping speed to ensure a smooth reaction, keep the reaction temperature at 60-80°C, and the reaction time is not less than 4 hours; After the reaction is completed, the reaction solution is poured into a large amount of cold water to precipitate a solid product, which is then filtered, washed, and dried to obtain the pure dynamic covalent bond cross-linking agent.

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