Aramid fiber reinforced polyurea / epoxy matrix hybrid laminate and preparation method and application thereof

Abstract

The present invention provides an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate and a preparation method and application thereof, and relates to the technical field of armor materials. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate provided by the present invention comprises a stacked aramid / polyurea mixed fiber board and an aramid / epoxy resin mixed fiber board; the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board are bonded by polyurea. Compared with the traditional aramid / epoxy resin mixed fiber board, the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate provided by the present invention has both good stiffness and deformation ability, and can play a good protective effect.

Description

Technical Field

[0001] The invention relates to the technical field of armor materials, and in particular to an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate and a preparation method and application thereof. Background Art

[0002] Composite armor is a type of non-homogeneous tank armor composed of two or more layers of protective materials with different properties. Generally speaking, it is composed of one or more materials with different physical properties, compounded in a certain layer ratio. It relies on the differences in physical properties between each layer to interfere with the penetration of incoming projectiles, consume their energy, and ultimately achieve the purpose of preventing projectiles from penetrating.

[0003] Traditional composite armor is made of aramid fiber and thermosetting materials such as epoxy resin. Thermosetting resin matrix materials such as epoxy resin have poor toughness. After curing, a tight cross-linked network structure is formed between molecules. The material has high rigidity but poor toughness. When subjected to ballistic impact, it is difficult for the matrix material to absorb and dissipate the impact energy by deformation and other means, and brittle fracture is prone to occur, which greatly limits the elongation of the fiber. Summary of the invention

[0004] The object of the present invention is to provide an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate and its preparation method and application. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate provided by the present invention has good rigidity and deformation ability and can play a good protective effect.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, comprising a stacked aramid / polyurea mixed fiber board and an aramid / epoxy resin mixed fiber board; the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board are bonded by polyurea;

[0007] The aramid / polyurea hybrid fiber board is composed of alternately stacked first aramid fiber woven bare cloth and polyurea layers, and the outermost layer of the aramid / polyurea hybrid fiber board is the first aramid fiber woven bare cloth;

[0008] The aramid / epoxy resin mixed fiber board is composed of alternately stacked second aramid fiber woven bare cloth and epoxy resin layers, and the outermost layer of the aramid / epoxy resin mixed fiber board is the second aramid fiber woven bare cloth.

[0009] Preferably, the thickness ratio of the aramid / polyurea mixed fiberboard to the aramid / epoxy resin mixed fiberboard is (1-3):1.

[0010] Preferably, the thickness ratio of the aramid / polyurea mixed fiberboard to the aramid / epoxy resin mixed fiberboard is 3:1.

[0011] Preferably, the thickness of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate is 8 to 16 mm.

[0012] Preferably, one layer of the first aramid fiber woven bare cloth and one adjacent polyurea layer are recorded as one polyurea / fiber layer, and the thickness of each polyurea / fiber layer is independently 0.34-0.36 mm.

[0013] Preferably, one layer of the second aramid fiber woven bare cloth and one adjacent epoxy resin layer are recorded as one epoxy resin / fiber layer, and the thickness of each epoxy resin / fiber layer is independently 0.34-0.36 mm.

[0014] The present invention provides a method for preparing the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate described in the above scheme, comprising the following steps:

[0015] Coating polyurea on the surface of the first aramid fiber bare fabric and then covering it with the first aramid fiber bare fabric, alternately coating and covering until the last layer of the first aramid fiber bare fabric is covered, to obtain an aramid fiber / polyurea intermediate;

[0016] The aramid / polyurea intermediate is subjected to a first hot pressing to obtain an aramid / polyurea mixed fiber board;

[0017] Coating epoxy resin material on the surface of the second aramid fiber bare cloth and then covering it with the second aramid fiber bare cloth, and alternately coating and covering until the last layer of the second aramid fiber bare cloth is covered to obtain an aramid / epoxy intermediate;

[0018] The aramid / epoxy intermediate is subjected to a second hot pressing to obtain an aramid / epoxy resin mixed fiberboard;

[0019] A polyurea adhesive is coated on the contact surface of the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board, and a third hot pressing is performed to obtain the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate.

[0020] Preferably, the polyurea is obtained by reacting aniline-terminated polyether with isocyanate.

[0021] Preferably, the molar ratio of the aniline-terminated polyether to the isocyanate is 1:(0.9-1).

[0022] The present invention provides the use of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate described in the above scheme or the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate prepared by the preparation method described in the above scheme in composite armor.

[0023] The present invention utilizes the deformation mechanism of composite materials in terms of impact resistance to design an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, which has higher energy absorption and anti-ballistic performance compared with traditional aramid / epoxy resin mixed fiber boards. Specifically, polyurea has excellent impact resistance, elongation and tear strength, and has excellent chemical resistance, water resistance and corrosion resistance. Under ballistic impact loads, the elastomer matrix composite material with polyurea elastomer as the matrix and aramid fiber as the reinforcing material will deform with the elongation of the fiber, giving full play to the elongation ability of the fiber, thereby absorbing higher energy. Finally, the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board are compounded into a hybrid laminate, wherein the aramid / epoxy resin mixed fiber board is located on the bullet-facing surface, so that it can take into account both rigidity and deformation ability.

[0024] The results of the embodiments show that compared with the traditional aramid / epoxy resin mixed fiber board, the present invention shows a higher overall ballistic limit. For the mixed laminate with a total thickness of 8.4 mm composed of a 2.1 mm thick aramid / epoxy resin mixed fiber board and a 6.3 mm thick aramid / polyurea mixed fiber board, the ballistic limit is improved by 12% compared with the traditional aramid / epoxy resin mixed fiber board, which can provide better protection.

[0025] The present invention provides a method for preparing the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate described in the above scheme. The preparation process of the present invention is simple, the production efficiency is high, and it has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, wherein A is an epoxy resin layer, B is an aramid fiber woven bare cloth, and C is a polyurea layer;

[0027] Figure 2 This is a schematic diagram of the structure of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate of Example 1;

[0028] Figure 3 This is a schematic diagram of the structure of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate of Example 2;

[0029] Figure 4 This is a physical picture of the tension and compression standard specimens of aramid / polyurea mixed fiberboard and aramid / epoxy mixed fiberboard. DETAILED DESCRIPTION

[0030] The invention provides an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, comprising a stacked aramid / polyurea mixed fiber board and an aramid / epoxy resin mixed fiber board; the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board are bonded by polyurea.

[0031] In the present invention, the aramid / polyurea hybrid fiber board is composed of alternately stacked first aramid fiber woven bare cloth and polyurea layers, and the outermost layer of the aramid / polyurea hybrid fiber board is the first aramid fiber woven bare cloth.

[0032] In the present invention, the volume fraction of the polyurea layer in the aramid / polyurea mixed fiberboard is preferably 18-20%. In the present invention, a layer of the first aramid fiber woven bare cloth and an adjacent layer of polyurea layer are recorded as a polyurea / fiber layer, and the thickness of each polyurea / fiber layer is independently preferably 0.34-0.36 mm, more preferably 0.35 mm. In the present invention, the polyurea layer is composed of polyurea well known in the art, for example, the polyurea in the polyurea layer is formed by the reaction of aniline-terminated polyether and isocyanate, and the molar ratio of the aniline-terminated polyether to isocyanate is preferably 1: (0.9-1). The present invention has no special requirements for the specific types of the aniline-terminated polyether and isocyanate, and the aniline-terminated polyether and isocyanate well known in the art can be used. In the embodiment of the present invention, the manufacturer of the aniline-terminated polyether is Qingdao Ocean New Materials Co., Ltd., brand P650; the manufacturer of the isocyanate is Yantai Wanhua Polyurethane Co., Ltd., brand MDI100LL.

[0033] In the present invention, the aramid / epoxy resin mixed fiber board is composed of alternately stacked second aramid fiber woven bare cloth and epoxy resin layers, and the outermost layer of the aramid / epoxy resin mixed fiber board is the second aramid fiber woven bare cloth.

[0034] In the present invention, the volume fraction of the epoxy resin layer in the aramid / epoxy resin mixed fiberboard is preferably 18-20%. In the present invention, a layer of the second aramid fiber woven bare cloth and an adjacent layer of epoxy resin layer are recorded as an epoxy resin / fiber layer, and the thickness of each epoxy resin / fiber layer is independently preferably 0.34-0.36 mm, more preferably 0.35 mm. In the present invention, the raw materials for preparing the epoxy resin layer preferably include epoxy resin, curing agent and accelerator. The present invention has no special requirements for the types of epoxy resin, curing agent and accelerator, and epoxy resins, curing agents and accelerators known in the art can be used. In an embodiment of the present invention, the epoxy resin is ERL-4221 epoxy resin, the curing agent is methyltetrahydrophthalic anhydride, and the accelerator is NN dimethylbenzylamine. The present invention has no special requirements for the ratio of the epoxy resin, curing agent and accelerator, and the ratio known in the art can be used. In an embodiment of the present invention, the mass ratio of the epoxy resin, curing agent and accelerator is 1:1:0.02.

[0035] The present invention has no special requirements for the first aramid fiber woven bare cloth and the second aramid fiber woven bare cloth, and any aramid fiber woven bare cloth known in the art can be used. In an embodiment of the present invention, the first aramid fiber woven bare cloth and the second aramid fiber woven bare cloth are both aramid II plain weave fabrics produced by Sinochem High Performance Fiber Materials Co., Ltd., and the thickness before hot pressing is 0.4 mm.

[0036] In the present invention, the thickness ratio of the aramid / polyurea mixed fiber board to the aramid / epoxy resin mixed fiber board is preferably (1-3): 1, more preferably 3: 1. The present invention is beneficial to improving the ballistic limit of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate by controlling the thickness ratio of the two.

[0037] In the present invention, the aramid / polyurea mixed fiberboard and the aramid / epoxy resin mixed fiberboard are bonded by polyurea; the type of polyurea used for bonding is preferably the same as the composition of the polyurea in the aramid / polyurea mixed fiberboard.

[0038] In the present invention, the thickness of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate is preferably 8-16 mm, specifically 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, which are not listed here. In the embodiment of the present invention, the thickness is 8.4 mm.

[0039] Figure 1 Schematic diagram of the structure of an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, wherein A is an epoxy resin layer, B is an aramid fiber woven bare cloth, and C is a polyurea layer.

[0040] The present invention provides a method for preparing the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate described in the above scheme, comprising the following steps: firstly preparing an aramid / polyurea mixed fiber board and an aramid / epoxy resin mixed fiber board respectively.

[0041] The preparation of the aramid / polyurea mixed fiberboard is first described below.

[0042] The present invention coats polyurea on the surface of a first aramid fiber woven bare cloth and then covers the first aramid fiber woven bare cloth, and the coating and covering are performed alternately until the last layer of the first aramid fiber woven bare cloth is covered to obtain an aramid fiber / polyurea intermediate;

[0043] The aramid / polyurea intermediate is subjected to a first hot pressing to obtain an aramid / polyurea mixed fiber board.

[0044] Before use, the present invention preferably firstly ultrasonically cleans the first aramid fiber bare cloth with alcohol, and then dries the cleaned aramid fiber bare cloth.

[0045] In the present invention, when the polyurea is obtained by reacting aniline-terminated polyether with isocyanate, the preparation method of the polyurea preferably comprises the following steps: mixing the aniline-terminated polyether with isocyanate, and stirring for 1.5 minutes using a vacuum degassing machine to obtain an uncured polyurea. The present invention has no special requirements for the coating method of the polyurea, and any coating method known in the art can be used, such as evenly applying the polyurea with a scraper.

[0046] In the present invention, the first hot pressing preferably includes: maintaining the aramid / polyurea intermediate at a pressure of 13 MPa and a temperature of 25° C. for 30 minutes, and then increasing the temperature to 80° C. and maintaining it for 12 hours. The present invention utilizes the first hot pressing to fully react the aniline-terminated polyether with the isocyanate, while extruding the excess polyurea.

[0047] The preparation of the aramid / epoxy resin mixed fiberboard is described below.

[0048] The present invention coats epoxy resin material on the surface of the second aramid fiber woven bare cloth and then covers the second aramid fiber woven bare cloth, and the coating and covering are performed alternately until the last layer of the second aramid fiber woven bare cloth is covered to obtain an aramid / epoxy intermediate;

[0049] The aramid / epoxy intermediate is subjected to a second hot pressing to obtain an aramid / epoxy resin mixed fiberboard.

[0050] In the present invention, the second aramid fiber woven bare cloth is preferably washed and dried before use. The washing and drying steps are the same as those of the first aramid fiber woven bare cloth, and will not be described in detail here.

[0051] In the present invention, the epoxy resin, the curing agent and the accelerator are preferably mixed and stirred for 10 minutes using a vacuum degassing machine to obtain the epoxy resin material.

[0052] In the present invention, the conditions of the second hot pressing are preferably determined according to the type of epoxy resin, and the epoxy resin is ensured to be cured. In the present invention, when the epoxy resin is ERL-4221 epoxy resin, the conditions of the second hot pressing are: maintaining a pressure of 13MPa, increasing the temperature from 25°C to 100°C, and then keeping it at 100°C for 6h; increasing the temperature from 100°C to 120°C, and keeping it at 120°C for 2h; then increasing the temperature from 120°C to 150°C, and keeping it at 150°C for 2h, and finally cooling naturally to room temperature.

[0053] After obtaining the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board, the present invention coats the contact surface of the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board with a polyurea adhesive, and performs a third hot pressing to obtain the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate.

[0054] In the present invention, the conditions of the third hot pressing are the same as those of the first hot pressing, and will not be described in detail here.

[0055] The present invention provides the use of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate described in the above scheme or the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate prepared by the preparation method described in the above scheme in composite armor.

[0056] The present invention utilizes the deformation mechanism of composite materials in terms of impact resistance to design an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, which has higher energy absorption and anti-ballistic performance compared with traditional aramid / epoxy resin mixed fiber boards. Specifically, polyurea has excellent impact resistance, elongation and tear strength, and has excellent chemical resistance, water resistance and corrosion resistance. Under ballistic impact loads, the elastomer matrix composite material with polyurea elastomer as the matrix and aramid fiber as the reinforcing material will deform with the elongation of the fiber, giving full play to the elongation ability of the fiber, thereby absorbing higher energy. Finally, the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board are compounded into a hybrid laminate, wherein the aramid / epoxy resin mixed fiber board is located on the bullet-facing surface, so that it can take into account both rigidity and deformation ability.

[0057] The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate provided by the present invention and its preparation method and application are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0058] The raw materials involved in the following examples and comparative examples are: aramid fiber woven fabric, epoxy resin, curing agent, accelerator, aniline-terminated polyether, and isocyanate.

[0059] Among them, the aramid fiber woven fabric is aramid II plain weave fabric produced by Sinochem High Performance Fiber Materials Co., Ltd., with a thickness of 0.4mm before hot pressing;

[0060] The epoxy resin is ERL-4221 epoxy resin, the chemical name is 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate, and the manufacturer is Macklin; the curing agent is methyltetrahydrophthalic anhydride, and the manufacturer is Macklin; the accelerator is NN dimethylbenzylamine, and the manufacturer is Macklin.

[0061] The manufacturer of aniline-terminated polyether is Qingdao Ocean New Materials Co., Ltd., with the brand name P650; the manufacturer of isocyanate is Yantai Wanhua Polyurethane Co., Ltd., with the brand name MDI100LL.

[0062] Example 1

[0063] 1. Use a cutting machine to cut the material into 24 pieces of 330mm×330mm aramid fiber woven bare cloth, then use an ultrasonic machine to clean it with alcohol for 30 minutes to remove impurities such as surface oil and dirt, and put the cleaned aramid fiber bare cloth into an oven for drying.

[0064] 2. 300 g of aniline-terminated polyether and 109 g of isocyanate (the molar ratio of aniline-terminated polyether to isocyanate is 1.05:1) were mixed and stirred for 1.5 min using a vacuum degassing machine to obtain uncured polyurea.

[0065] 3. Select 12 pieces of cut aramid fiber woven bare cloth, apply uncured polyurea between every two layers of aramid fiber woven bare cloth, apply 15g between every two layers, and use a scraper to evenly apply polyurea on the surface of the bare cloth to obtain an aramid / polyurea intermediate.

[0066] 4. The stacked aramid / polyurea intermediates are laid and fixed, and placed in a hot press for hot pressing. The molding process of the hot press is: 13MPa pressure and 25°C temperature are maintained for 30 minutes, and then the temperature of the hot press is increased to 80°C and maintained for 12 hours to fully solidify the polyurea, and finally cooled to room temperature. After cooling, a 4.2mm thick 12-layer aramid / polyurea hybrid fiber board (roughly equivalent to 12 aramid fiber / polyurea single layers) can be obtained, wherein the thickness of each polyurea / fiber layer is 0.35mm.

[0067] 5. Mix 200g of ERL-4221 epoxy resin, 200g of curing agent and 4g of accelerator and stir for 10 minutes using a vacuum degassing machine to obtain epoxy resin material.

[0068] 6. Select 12 pieces of cut aramid fiber woven bare cloth, apply the epoxy resin mixture between every two layers of aramid fiber woven bare cloth, apply 15g between every two layers, and use a scraper to evenly apply the mixture on the surface of the bare cloth to obtain an aramid / epoxy intermediate.

[0069] 7. The stacked aramid / epoxy intermediates are laid and fixed, placed in a mold, and placed in a hot press for hot pressing. The molding process of the hot press is as follows: maintain a pressure of 13 MPa, increase the temperature from 25°C to 100°C, and then keep it at 100°C for 6 hours; increase the temperature from 100°C to 120°C, and keep it at 120°C for 2 hours; then increase the temperature from 120°C to 150°C, and keep it at 150°C for 2 hours, and finally cool naturally to room temperature; after cooling, a 12-layer aramid / epoxy resin mixed fiberboard with a thickness of about 4.2 mm can be obtained; the thickness of each epoxy resin / fiber layer is 0.35 mm.

[0070] 8. The prepared aramid / polyurea mixed fiberboard and aramid / epoxy resin mixed fiberboard samples are bonded, and the bonding surfaces of the two are bonded with polyurea. The polyurea on the bonding surfaces of the two is evenly applied with a scraper. The stacked and bonded composite material is placed in a mold and placed in a hot press for hot pressing. The molding process of the hot press is: 13MPa pressure and 25°C temperature are maintained for 30 minutes, and then the hot press temperature is increased to 80°C and maintained for 12 hours to fully cure the polyurea, and finally cooled to room temperature. After cooling, an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate of about 8.4 mm thickness can be obtained, wherein the thickness ratio of the aramid / polyurea mixed fiberboard to the aramid / epoxy resin mixed fiberboard is 1:1 (see Figure 2 ).

[0071] Example 2

[0072] Consistent with the preparation method of Example 1, the total thickness of the prepared aramid fiber reinforced polyurea / epoxy matrix hybrid laminate remains unchanged, wherein the thickness ratio of the aramid / polyurea mixed fiber board to the aramid / epoxy resin mixed fiber board changes.

[0073] In this embodiment, 18 pieces of cut aramid fiber woven bare cloth are used to prepare an aramid / polyurea mixed fiber board with a thickness of about 6.3 mm, and 6 pieces of cut aramid fiber woven bare cloth are used to prepare an aramid / epoxy resin mixed fiber board with a thickness of about 2.1 mm, so that an aramid fiber reinforced polyurea / epoxy matrix hybrid laminate with a thickness of 8.4 mm can be obtained. The thickness ratio of the aramid / polyurea mixed fiber board to the aramid / epoxy resin mixed fiber board is 3:1 (see Figure 3 ).

[0074] Comparative Example 1

[0075] The preparation method of the aramid fiber / epoxy resin mixed fiber board in this comparative example is consistent with that in Example 1. 24 pieces of cut aramid fiber woven bare cloth are selected to prepare an aramid fiber / epoxy resin mixed fiber board with a thickness of about 8.4 mm.

[0076] The prepared aramid / polyurea mixed fiber board and aramid / epoxy resin mixed fiber board were cut into composite material tensile and compression standard specimens according to the dimensions required by ASTM-D3039 and ASTM-D6641 (where Figure 4 (Figure 1) The standard tensile and compressive test pieces of aramid / polyurea mixed fiberboard and aramid / epoxy resin mixed fiberboard were tested by a universal testing machine at room temperature for uniaxial tensile test and compression test on two strip specimens with different matrices. The measured parameters are shown in Table 1.

[0077] Table 1 Mechanical properties of aramid / polyurea mixed fiberboard and aramid / epoxy resin mixed fiberboard

[0078] Tensile modulus Tensile Strength Compression strength Elongation at break Aramid / Epoxy 19.6GPa 660MPa 168MPa 3.4％ Aramid / Polyurea 12.7GPa 633MPa 42MPa 4.8％

[0079] As can be seen from Table 1, the single aramid / epoxy resin mixed fiberboard has strong rigidity and poor toughness, with an elongation at break of only 3.4%. At the same time, it has a high tensile modulus and is not easy to deform; while the aramid / polyurea mixed fiberboard has good toughness and a low tensile modulus, and is easy to absorb energy by deformation when subjected to ballistic impact.

[0080] The ballistic limit of Example 1, Example 2, and Comparative Example 1 was 357 m / s, 332 m / s, and 319 m / s, respectively, after a 6.2 g cylindrical bullet ballistic impact test. This indicates that the present invention can provide a better protective effect by combining the aramid / polyurea mixed fiberboard and the aramid / epoxy resin mixed fiberboard into a hybrid laminate.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An aramid fiber reinforced polyurea / epoxy matrix hybrid laminate, comprising a laminated aramid / polyurea mixed fiber board and an aramid / epoxy resin mixed fiber board; the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board are bonded by polyurea; the thickness ratio of the aramid / polyurea mixed fiber board to the aramid / epoxy resin mixed fiber board is (1-3):1; The aramid / polyurea hybrid fiber board is composed of alternately stacked first aramid fiber woven bare cloth and polyurea layers, and the outermost layer of the aramid / polyurea hybrid fiber board is the first aramid fiber woven bare cloth; The aramid / epoxy resin mixed fiber board is composed of alternately stacked second aramid fiber woven bare cloth and epoxy resin layers, and the outermost layer of the aramid / epoxy resin mixed fiber board is the second aramid fiber woven bare cloth; The method for preparing the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate comprises the following steps: Coating polyurea on the surface of a first aramid fiber bare fabric and then covering the first aramid fiber bare fabric, alternately coating and covering until the last layer of the first aramid fiber bare fabric is covered, to obtain an aramid fiber / polyurea intermediate; the polyurea is obtained by reacting aniline-terminated polyether with isocyanate; The aramid / polyurea intermediate is subjected to a first hot pressing to obtain an aramid / polyurea mixed fiber board having a polyurea layer volume fraction of 18-20%; Coating epoxy resin on the surface of the second aramid fiber bare cloth and then covering it with the second aramid fiber bare cloth, alternately coating and covering until the last layer of the second aramid fiber bare cloth is covered, to obtain an aramid / epoxy intermediate; The aramid / epoxy intermediate is subjected to a second hot pressing to obtain an aramid / epoxy resin mixed fiberboard having an epoxy resin layer with a volume fraction of 18-20%; A polyurea adhesive is coated on the contact surface of the aramid / polyurea mixed fiber board and the aramid / epoxy resin mixed fiber board, and a third hot pressing is performed to obtain the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate.

2. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate according to claim 1, characterized in that: The thickness ratio of the aramid / polyurea mixed fiber board to the aramid / epoxy resin mixed fiber board is 3:

1.

3. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate according to claim 1, characterized in that: The thickness of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate is 8-16 mm.

4. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate according to claim 1, characterized in that: One layer of the first aramid fiber woven bare cloth and one adjacent polyurea layer are recorded as one polyurea / fiber layer, and the thickness of each polyurea / fiber layer is independently 0.34-0.36 mm.

5. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate according to claim 1, characterized in that: One layer of the second aramid fiber woven bare cloth and one adjacent epoxy resin layer are recorded as one epoxy resin / fiber layer, and the thickness of each epoxy resin / fiber layer is independently 0.34-0.36 mm.

6. The aramid fiber reinforced polyurea / epoxy matrix hybrid laminate according to claim 1, characterized in that: The molar ratio of the aniline-terminated polyether to the isocyanate is 1:(0.9-1).

7. Use of the aramid fiber reinforced polyurea / epoxy matrix hybrid laminate according to any one of claims 1 to 6 in composite armor.

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