Interpenetrating network and functional fiber coupled enhanced polyurea composite material and preparation method and application thereof

Abstract

The application provides an interpenetrating network and functional fiber coupled reinforced polyurea composite material and a preparation method and application thereof, and belongs to the technical field of explosion-proof materials.The polyurea composite material is prepared through the following steps: S1, preparing a polyurea prepolymer;S2, preparing a reinforcing filler;S3, preparing a polyurea composite material base material, adding the reinforcing filler into the polyurea composite material base material and stirring and mixing to obtain a dispersion liquid;S4, adding an amine curing agent into the dispersion liquid to obtain a reverse mold liquid, pouring the reverse mold liquid into a preheated mold for high-temperature curing to obtain the interpenetrating network and functional fiber coupled reinforced polyurea composite material.The polyurea composite material provided by the application can effectively improve the strength and toughness of the material by adding epoxy resin into the polyurea to form a non-covalent entanglement network, and the attenuation performance of the peak value of the explosion shock wave overpressure of the material can be further improved by adding the reinforcing filler, so that the polyurea composite material is an ideal material for explosion shock wave protection devices and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of explosion-proof materials technology, specifically to a polyurea composite material, its preparation method, and its application. Background Technology

[0002] Explosive shock waves are a major cause of casualties in current military conflicts and explosion accidents. Through extremely high instantaneous overpressure, explosive shock waves cause an imbalance in the internal pressure gradient of the human body, leading to rupture, tearing, or severe compression of tissues such as the lungs, stomach, and brain, resulting in injury. Attenuating the overpressure of shock waves through materials can minimize its damage to the human body. Polyurea, due to its customizable molecular structure and tunable mechanical properties, exhibits excellent tear resistance, impact resistance, and dynamic response characteristics, making it currently recognized as the most effective material for attenuating the peak overpressure of shock waves. Mechanical properties play a crucial role in determining the attenuation performance of polyurea materials in attenuating the peak overpressure of shock waves; however, the relatively low strength of commonly used polyurea materials limits their application in explosive shock wave protection.

[0003] Reinforcing and toughening polyurea materials is an important means to improve their protection performance against overpressure peaks from explosive shock waves. However, achieving high strength, large deformation, and high fracture toughness simultaneously remains a significant challenge, especially in applications involving short-term, high overpressure peaks under shock wave loads. This challenge stems from the fact that improving the mechanical strength of materials usually requires increasing the crosslinking density of polymer chains or introducing nanofillers, but this often sacrifices the material's deformability and toughness. For example, Chinese invention patent CN116284663A prepares a material with high mechanical strength by non-covalently bonding polyurethane-polyimide materials, but this preparation process is extremely complex; at the same time, polyurea modification usually requires the addition of a large amount of solvent, making it difficult to prepare samples with large thicknesses. Another example is Chinese invention patent CN114032016B, which strengthens the polyurea coating by adding modified silica particles. While this improves mechanical properties, it weakens the material's toughness while increasing strength, and the prepared coating is difficult to achieve a certain thickness.

[0004] In view of this, how to simultaneously improve the strength and toughness of polyurea materials and enable them to be manufactured into explosion-proof equipment with large thickness has become one of the current challenges in the research and development of explosion-proof materials. Summary of the Invention

[0005] The purpose of this invention is to provide a polyurea composite material that has both high strength and high toughness and can be prepared into thick materials.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for preparing an interpenetrating network and functionalized fiber-coupled reinforced polyurea composite material for explosion shock wave protection, specifically including the following steps: S1: Take amine oligomers and isocyanates, respectively, and vacuum dry them at 100~120℃ to dehydrate them. Then cool them to 70~85℃, mix them at 70~85℃ and add a catalyst. Stir and react for 2~5 hours to obtain polyurea prepolymer. S2: Take the reinforcing material and obtain the reinforcing filler after surface modification treatment; S3: Add epoxy resin prepolymer to the polyurea prepolymer, stir and mix at 100~1000 rpm for 1~60 min to obtain polyurea composite material substrate, add reinforcing filler to polyurea composite material substrate, stir and mix at 500~2000 rpm for 10~40 min to obtain dispersion; S4: Add an amine curing agent to the dispersion, stir evenly under vacuum to obtain a molding liquid, pour the molding liquid into a preheated mold for high-temperature curing, and obtain an interpenetrating network and functionalized fiber coupled reinforced polyurea composite material.

[0007] In the technical solution provided by this invention, the invention first forms a polyurea composite material substrate by utilizing the non-covalent entanglement network structure of epoxy resin and polyurea in step S3. This polyurea composite material substrate has a non-covalent network, which can effectively avoid the brittleness caused by crosslinking density.

[0008] The entangled network structure has a significant positive impact on the attenuation performance of polyurea composites against explosive shock waves, mainly due to its multiple synergistic optimization effects on the material's mechanical properties and microscopic energy absorption mechanisms. Because the entangled network structure forms a continuous three-dimensional network with topologically interlocked relationships between the phases, this spatial interlocking enhances resistance to interfacial debonding and significantly improves damage tolerance. Therefore, by controlling the velocity mismatch between loading and unloading waves generated by microphase separation in the soft and hard segments, and by constructing a mechanically interlocked three-dimensional network between the phases to achieve damage suppression and coordinated stress transfer, the attenuation efficiency of polyurea composites against explosive shock waves is systematically improved from multiple levels, including strength-toughness matching and shock wave propagation path control.

[0009] The present invention also adds a specific reinforcing filler to the polyurea composite material matrix. The reinforcing filler is a modified material that can significantly improve the strength and toughness of the final polyurea composite material. In addition, the addition of the reinforcing filler can further improve the overpressure peak attenuation performance of the explosion shock wave of the final product.

[0010] Preferably, the amine oligomer is a polyether diamine with a molecular weight of 400-5000.

[0011] Preferably, the isocyanate is a diisocyanate, which is selected from any one or more of toluene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

[0012] Preferably, the epoxy resin prepolymer is an epoxy resin polymer with a number average molecular weight of 300 to 700.

[0013] Preferably, in step S2, the surface modification is selected from any one of plasma treatment, polydopamine surface deposition, and silane coupling agent surface treatment.

[0014] Preferably, the reinforcing material is selected from any one or more of chopped carbon fibers, glass fibers, and polyethylene fibers.

[0015] Introducing surface-modified fiber reinforcements into a polyurea matrix can significantly and positively promote the material system in multiple dimensions, including interfacial bonding strength, mechanical properties, energy dissipation mechanisms, and structural stability. Chemical modification of the fiber surface enables both chemical bonding and physical entanglement between the fiber and the polyurea matrix, significantly enhancing their compatibility and wettability. This effectively suppresses fiber agglomeration in the composite material and provides strong interfacial protection for stress transfer. Regarding the attenuation performance of explosive shock waves, carbon nanofiber-reinforced polyurea / polyurethane composites exhibit excellent ultra-high peak overpressure attenuation rates under explosive loads. The introduction of carbon nanofibers effectively enhances the composite material's ability to reflect and scatter stress waves, thereby allowing for more complete dissipation of impact energy between multiple interfacial layers.

[0016] Preferably, in step S1, the catalyst is dibutyltin dilaurate.

[0017] Preferably, the amine curing agent is selected from any one or more of 4-4'-methylenebis(2-chloroaniline), dimethylthiotoluene diamine, and polyether diamine with a molecular weight of 400-1000.

[0018] Furthermore, a second aspect of the present invention provides an interpenetrating network and functionalized fiber coupled reinforced polyurea composite material, the polyurea composite material being prepared by the preparation method described in the first aspect.

[0019] Furthermore, a third aspect of the present invention provides an application of the interpenetrating network and functionalized fiber coupled reinforced polyurea composite material described in the second aspect, the application including the use of the interpenetrating network and functionalized fiber coupled reinforced polyurea composite material in the preparation of explosion-proof equipment for protection against explosive shock waves.

[0020] Compared with the prior art, the present invention has the following beneficial effects: 1. The preparation method provided by this invention effectively avoids the brittleness caused by the increase in crosslinking density in traditional methods by utilizing the non-covalent entanglement network of epoxy resin, thus endowing the polyurea composite material substrate with high strength and high toughness. At the same time, the introduction of reinforcing fillers provided by this invention further enables the final composite material to have excellent shock wave overpressure peak attenuation performance, making it suitable for the manufacture of high-performance explosion-proof equipment.

[0021] 2. The polyurea composite material provided by this invention does not use any organic solvents in the preparation process, which overcomes the problem of thickness limitation caused by the need to use organic solvents in the preparation of polyurea coatings. It can realize the casting and molding of explosion-proof equipment with large thickness polyurea composite material, and can meet the needs of various complex explosion-proof scenarios. 3. The preparation method of polyurea composite material provided by the present invention has clear steps, mild reaction conditions and is easy to implement. It not only broadens the structural design ideas of explosion-proof materials, but also has extremely high industrial mass production prospects and broad application prospects in explosion-proof equipment. Attached Figure Description

[0022] Figure 1 The tensile strength of each specimen strip in Test Example 1 of this invention was measured at 100 kN and a tensile speed of 5 mm / min. Figure 2 The elongation at break was measured for each specimen strip in Test Example 1 of this invention at 100 kN and a tensile speed of 5 mm / min. Figure 3 The results of overpressure peak detection for each sample in Test Example 2 of this invention; Figure 4 The results are the overpressure peak decay rate test results for each sample in Test Example 2 of this invention. Detailed Implementation

[0023] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0024] It should be noted that 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.

[0025] As described in the background section, while polyurea materials are effective at attenuating the overpressure peak of shock waves, it is difficult to balance strength and toughness simultaneously, and it is also difficult to fabricate them in large thicknesses, which severely restricts the development of explosion shock wave protection equipment. Based on this, a specific embodiment of the present invention provides a method for preparing an interpenetrating network and functionalized fiber-reinforced polyurea composite material for explosion shock wave protection, comprising the following steps: S1: Take amine oligomers and isocyanates, respectively, and vacuum dry them at 100~120℃ to dehydrate them. Then cool them to 70~85℃, mix them at 70~85℃ and add a catalyst. Stir and react for 2~5 hours to obtain polyurea prepolymer. S2: Take the reinforcing material and obtain the reinforcing filler after surface modification treatment; S3: Add epoxy resin prepolymer to the polyurea prepolymer, stir and mix at 100~1000 rpm for 1~60 min to obtain polyurea composite material substrate, add reinforcing filler to polyurea composite material substrate, stir and mix at 500~2000 rpm for 10~40 min to obtain dispersion; S4: Add an amine curing agent to the dispersion, stir evenly under vacuum to obtain a molding liquid, pour the molding liquid into a preheated mold for high-temperature curing, and obtain an interpenetrating network and functionalized fiber coupled reinforced polyurea composite material.

[0026] More specifically, in step S1 of the above embodiments, the mass ratio of amine oligomer to isocyanate is 1:(1~5).

[0027] More specifically, in step S3 of the above embodiment, the amount of epoxy resin prepolymer added is 10% to 70% of the polyurea prepolymer by weight.

[0028] More specifically, in step S3 of the above embodiment, the amount of reinforcing filler added is 0.1% to 10% by weight.

[0029] More specifically, in step S4 of the above embodiments, the amount of amine curing agent added is 15% to 40% of the dispersion by weight.

[0030] More specifically, in step S4 of the above embodiment, the temperature of the high-temperature curing is preferably 100~120°C, and the curing time of the high-temperature curing is preferably 10~14h.

[0031] More specifically, in step S4 of the above embodiment, the vacuum degree of the vacuum stirring is preferably (-2.0~-0.8)×10⁻⁶. 5 Pa, the preferred speed of vacuum stirring is 2500~3500 rpm, and the preferred time of vacuum stirring is 1~10 min.

[0032] More specifically, in the above embodiments, the polyethylene fiber is preferably ultra-high molecular weight polyethylene fiber.

[0033] More specifically, in the above embodiments, the molecular weight of the ultra-high molecular weight polyethylene fiber is preferably 2 million to 5 million.

[0034] In the above embodiments, the amine oligomer is a polyether diamine with a molecular weight of 400-5000.

[0035] In the above embodiments, the isocyanate is a diisocyanate, which is selected from any one or more of toluene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

[0036] In the above embodiments, the epoxy resin prepolymer is an epoxy resin polymer with a number average molecular weight of 300 to 700.

[0037] In the above embodiments, the surface modification is selected from any one of plasma treatment, polydopamine surface deposition, and silane coupling agent surface treatment.

[0038] In the above embodiments, the reinforcing material is selected from any one or more of chopped carbon fibers, glass fibers, and polyethylene fibers.

[0039] In step S1 of the above embodiment, the catalyst is preferably dibutyltin dilaurate.

[0040] More specifically, in the above embodiments, the amount of catalyst added is 0.15% to 0.5% of the total mass of the dried amine oligomer and the dried isocyanate.

[0041] In the above embodiments, the length of the reinforcing material is 5~25mm and the diameter is 10~100μm.

[0042] In the above embodiments, the amine curing agent is selected from any one or more of 4-4'-methylenebis(2-chloroaniline), dimethylthiotoluene diamine, and polyether diamine with a molecular weight of 400-1000.

[0043] More specifically, in the above embodiments, the reinforcing filler is prepared by the following steps: SA1: Take the reinforcing material, clean and dry it, and then place the reinforcing material into the working chamber of the plasma treatment instrument; SA2: Start the plasma treatment instrument, introduce the reaction gas, and perform plasma treatment on the reinforcing material to obtain the reinforcing filler.

[0044] In the above embodiments, the plasma processing power is preferably 50~200W.

[0045] In the above embodiments, the reaction gas is selected from any one or more of oxygen, air, and argon.

[0046] In the above embodiments, the plasma treatment time is preferably 1 to 10 minutes.

[0047] More specifically, in the above embodiments, the reinforcing filler can also be prepared by the following steps: SB1: Take the reinforcing material, clean and dry it for later use; SB2: Dissolve dopamine hydrochloride in Tris-HCl buffer solution with pH=8~9 to prepare a dopamine hydrochloride solution with a concentration of 1~5mg / mL for later use; SB3: Place the reinforcing material in a dopamine hydrochloride solution, stir and react for 12-24 hours, remove the reinforcing material, wash and dry it to obtain the reinforcing filler.

[0048] More specifically, in the above embodiments, the reinforcing filler can also be prepared by the following steps: SC1: Take the reinforcing material, clean and dry it for later use; SC2: Prepare an aqueous solution of silane coupling agent with a mass fraction of 1%~5% for later use; SC3: Immerse the reinforcing material in an aqueous solution of silane coupling agent, stir and react at 50~80℃ for 2~6h. After the reaction is complete, remove the reinforcing material, wash it with anhydrous ethanol, and dry it to obtain the reinforcing filler.

[0049] In the above embodiments, the silane coupling agent is selected from any one or more of KH550, KH560, and KH570.

[0050] The interpenetrating network and functionalized fiber coupled reinforced polyurea composite material prepared by the above embodiments has the advantages of high strength and high toughness, which can effectively attenuate the overpressure peak of the explosion shock wave. At the same time, since the polyurea composite material does not use organic solvents in the preparation process, it can obtain explosion-proof equipment of any thickness by casting, which has a wide range of applications and can effectively promote the development of explosion shock wave protection equipment.

[0051] The technical solutions of the present invention are further described below through specific embodiments. Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art. In some cases, terms with conventional meanings are limited herein for clarification or ease of reference, and such limitations should not be construed as indicating a significant difference from conventional understanding in the art. The technical methods described or referenced herein are generally well understood by those skilled in the art and have been employed by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents, and instruments shall be performed according to the manufacturer's instructions and parameters.

[0052] Example 1

[0053] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 1 part by mass of dried toluene diisocyanate were taken, mixed, and then 0.3% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SA1: Take short-cut carbon fibers with a length of 5~10mm and a diameter of 10~50μm, clean and dry them, and then put the short-cut carbon fibers into the working chamber of the plasma treatment instrument. SA2: Start the plasma treatment instrument, introduce argon gas, and perform plasma treatment on the short-cut carbon fibers to obtain reinforcing filler. The power of the plasma treatment instrument is set to 100W, and the plasma treatment time is 10min. S3: By mass, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SA2 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0054] Example 2

[0055] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 5000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take glass fibers with a length of 10~20mm and a diameter of 70~80μm, clean and dry them for later use; SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Glass fiber is placed in a dopamine hydrochloride solution and stirred for 24 hours. The glass fiber is then removed, washed, and dried to obtain the reinforcing filler. S3: By mass, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 25% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0056] Example 3

[0057] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 1000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 5 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SC1: Take ultra-high molecular weight polyethylene fibers with a length of 10~20mm, a diameter of 80~100μm, and a molecular weight of 2 million, clean and dry them for later use. SC2: Prepare a 5% (w / w) KH550 aqueous solution for later use; SC3: Immerse ultra-high molecular weight polyethylene fiber in KH550 aqueous solution, stir and react at 70°C for 6 hours. After the reaction is completed, take out the ultra-high molecular weight polyethylene fiber, wash it with anhydrous ethanol, and dry it to obtain the reinforcing filler. S3: By mass, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 600 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SC3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 20% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0058] Example 4

[0059] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take short-cut carbon fibers with a length of 5~10mm and a diameter of 10~50μm, clean and dry them for later use; SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Short carbon fibers are placed in a hydrochloric acid dopamine solution and stirred for 24 hours. The short carbon fibers are then removed, washed, and dried to obtain the reinforcing filler. S3: By mass, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0060] Example 5

[0061] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take ultra-high molecular weight polyethylene fibers with a length of 10~20mm, a diameter of 80~100μm, and a molecular weight of 2 million, clean and dry them for later use. SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Place ultra-high molecular weight polyethylene fiber into a dopamine hydrochloride solution, stir and react for 24 hours, remove the ultra-high molecular weight polyethylene fiber, wash and dry it to obtain the reinforcing filler; S3: By mass, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0062] Example 6

[0063] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take glass fibers with a length of 10~20mm and a diameter of 70~80μm, clean and dry them for later use; SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Glass fiber is placed in a dopamine hydrochloride solution and stirred for 24 hours. The glass fiber is then removed, washed, and dried to obtain the reinforcing filler. S3: By mass, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0064] Example 7

[0065] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take glass fibers with a length of 10~20mm and a diameter of 70~80μm, clean and dry them for later use; SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Glass fiber is placed in a dopamine hydrochloride solution and stirred for 24 hours. The glass fiber is then removed, washed, and dried to obtain the reinforcing filler. S3: By mass, add 35 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 1 part of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0066] Example 8

[0067] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take glass fibers with a length of 10~20mm and a diameter of 70~80μm, clean and dry them for later use; SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Glass fiber is placed in a dopamine hydrochloride solution and stirred for 24 hours. The glass fiber is then removed, washed, and dried to obtain the reinforcing filler. S3: By mass, add 35 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 3 parts of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0068] Example 9

[0069] Preparation of polyurea composite materials S1: Take polyether diamine with a molecular weight of 2000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. SB1: Take glass fibers with a length of 10~20mm and a diameter of 70~80μm, clean and dry them for later use; SB2: Dissolve dopamine hydrochloride in 100mM Tris-HCl buffer solution at pH=8 to prepare a 5mg / mL dopamine hydrochloride solution for later use; SB3: Glass fiber is placed in a dopamine hydrochloride solution and stirred for 24 hours. The glass fiber is then removed, washed, and dried to obtain the reinforcing filler. S3: By mass, add 35 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at a stirring rate of 300 rpm for 10 min, then take 5 parts of the reinforcing filler obtained in step SB3 and add it to the mixture, continue stirring at a stirring rate of 1000 rpm for 10 min to obtain a dispersion. S4: Add 40% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0070] Comparative Example 1 Preparation of polyurea composites without the introduction of epoxy resin and reinforcing fillers A1: Take polyether diamine with a molecular weight of 5000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. A2: Add 25% by weight of 4,4'-methylenebis(2-chloroaniline) to the polyurea prepolymer, stir under vacuum until homogeneous, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0071] Comparative Example 2 Preparation of polyurea composites without reinforcing fillers B1: Take polyether diamine with a molecular weight of 5000 and heat it at 110℃ under a vacuum of -2.0×10⁻⁶. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. B2: By weight, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, and stir at a stirring rate of 300 rpm for 10 min to obtain a dispersion. B3: Add 25% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0072] Comparative Example 3 Preparation of polyurea composites without added modified reinforcing fillers C1: Polyether diamine with a molecular weight of 5000 is subjected to a vacuum of -2.0 × 10⁻⁶ at 110°C. 5 Vacuum drying and dehydration were carried out at Pa for 3 hours. Toluene diisocyanate was then dried at 120℃ under a vacuum of -2.0 × 10⁻⁶ Pa for 3 hours. 5 Vacuum drying and dehydration were carried out under Pa for 3 hours. 1 part by mass of dried polyether diamine and 3 parts by mass of dried toluene diisocyanate were taken, mixed, and then 0.2% by mass of dibutyltin dilaurate (total mass of dried polyether diamine and dried toluene diisocyanate) was added. The mixture was stirred and reacted at 80°C for 4 hours to obtain polyurea prepolymer. C2: By weight, add 15 parts of epoxy resin prepolymer with a number average molecular weight of 400 to 100 parts of polyurea prepolymer, stir at 300 rpm for 10 min, then add 1 part of clean glass fiber with a length of 10-20 mm and a diameter of 70-80 μm to the mixture, and continue stirring at 1000 rpm for 10 min to obtain a dispersion. C3: Add 25% of the dispersion mass of 4,4'-methylenebis(2-chloroaniline) to the dispersion, stir evenly under vacuum, and pour into a 10mm mold preheated to 110℃ to obtain a polyurea composite material specimen with a thickness of 10mm.

[0073] Test Example 1 Tensile mechanical property testing The specimens from Examples 1-9 and Comparative Examples 1-3 were processed into dumbbell-shaped strips conforming to GB / T 1040.1-2025 and subjected to tensile tests on an electronic universal testing machine. The tribological properties of each specimen were analyzed at least three times. The test conditions were: tensile speed of 5 mm / min.

[0074] Formula for calculating elongation at break: Among them, L a L is the length of the test section of the specimen when it breaks, and L0 is the initial length of the test section of the specimen.

[0075] Test results are as follows Figure 1 and Figure 2 As shown, Figure 1 The tensile strength of each specimen strip was measured at 100 kN and a tensile speed of 5 mm / min. Figure 2 The elongation at break is the measured value of each specimen strip at 100 kN and a tensile speed of 5 mm / min.

[0076] Comparative Example 2 The specimens from Examples 1-9 and Comparative Examples 1-3 were processed into 130mm×130mm×10mm sample plates and subjected to an explosion shock wave overpressure peak attenuation performance test on a bio-shock tube. Each sample was tested at least three times. The test conditions were: the driving pressure emitted by the shock tube was 5.5 MPa, and the peak overpressure of the shock wave reaching the material surface was 515 kPa.

[0077] Formula for calculating the peak overpressure attenuation rate of an explosion shock wave: Among them, P 前 P represents the peak overpressure of the explosion shock wave in front of the sample plate. 后 The peak value of the explosion shock wave after attenuation by the sample plate.

[0078] The results are as follows Figure 3 and Figure 4 As shown, Figure 3 The results show the peak overpressure values ​​for each sample. Figure 4 The results show the overpressure peak decay rate test results for each sample.

[0079] As can be seen from the results of Test Example 1 and Test Example 2, the present invention can significantly improve the strength and toughness of polyurea materials by adding epoxy resin. The incorporation of specific reinforcing fillers can further improve the strength of the materials and the attenuation performance of the overpressure peak of the explosion shock wave. For the high overpressure of the explosion shock wave, which is extremely likely to cause serious injury to personnel, the polyurea composite material provided by the present invention can serve as an excellent protective material and has broad application prospects.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for preparing a polyurea composite material reinforced by interpenetrating network and functionalized fiber coupling, characterized in that, Includes the following steps: S1: Take amine oligomers and isocyanates, and vacuum dry them at 100~120℃ to remove water. Then cool them to 70~85℃. Mix the two at 70~85℃ and add a catalyst. Stir and react for 2~5 hours to obtain polyurea prepolymer. S2: Take the reinforcing material and obtain the reinforcing filler after surface modification treatment; S3: Add epoxy resin prepolymer to the polyurea prepolymer, stir and mix at 100~1000 rpm for 1~60 min to obtain polyurea composite material substrate, add reinforcing filler to polyurea composite material substrate, stir and mix at 500~2000 rpm for 10~40 min to obtain dispersion; S4: Add an amine curing agent to the dispersion, stir evenly under vacuum to obtain a molding liquid, pour the molding liquid into a preheated mold for high-temperature curing, and obtain an interpenetrating network and functionalized fiber coupled reinforced polyurea composite material.

2. The preparation method according to claim 1, characterized in that, The amine oligomer is a polyether diamine with a molecular weight of 400-5000.

3. The preparation method according to claim 1, characterized in that, The isocyanate is a diisocyanate, which is selected from any one or more of toluene diisocyanate, isophorone diisocyanate, and diphenylmethane diisocyanate.

4. The preparation method according to claim 1, characterized in that, The epoxy resin prepolymer is an epoxy resin polymer with a number average molecular weight of 300-700.

5. The preparation method according to claim 1, characterized in that, In step S2, the surface modification is selected from any one of plasma treatment, polydopamine surface deposition, and silane coupling agent surface treatment.

6. The preparation method according to claim 1, characterized in that, The reinforcing material is selected from any one or more of chopped carbon fibers, glass fibers, and polyethylene fibers.

7. The preparation method according to claim 1, characterized in that, In step S1, the catalyst is dibutyltin dilaurate.

8. The preparation method according to claim 1, characterized in that, The amine curing agent is selected from any one or more of 4-4'-methylenebis(2-chloroaniline), dimethylthiotoluene diamine, and polyether diamine with a molecular weight of 400-1000.

9. A polyurea composite material reinforced by interpenetrating network and functionalized fiber coupling, characterized in that, The interpenetrating network and functionalized fiber coupled reinforced polyurea composite material is prepared by any of the preparation methods described in claims 1 to 8.

10. An application of the interpenetrating network and functionalized fiber coupled reinforced polyurea composite material according to claim 9, characterized in that, The applications include using the interpenetrating network and functionalized fiber coupled reinforced polyurea composite material in the preparation of explosion-proof equipment.

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