A ballistic-resistant composite material and a method of making the same

Abstract

The application discloses a bulletproof composite material and a preparation method thereof, and relates to the technical field of bulletproof composite materials.The bulletproof composite material is composed of aramid fiber and a resin matrix, wherein the resin matrix comprises the following raw materials in parts by weight: 60-70 parts of epoxy resin, 5-8 parts of a modified toughening agent, 4-5 parts of a curing agent, 1-2 parts of a heat stabilizer, 1-2 parts of an inorganic filler, 0.5-1 parts of a coupling agent and 2-5 parts of a wetting agent;the intermediate 1 is generated by the reaction of cyanuric chloride and 4-hydroxyphenylboronic acid;the intermediate 2 is generated by the reaction of the intermediate 1 and 3-amino-1,2-epoxypropane;the intermediate 3 is generated by the reaction of the intermediate 2 and cystamine;and the modified toughening agent is generated by the reaction of the intermediate 3 and dopamine.The bulletproof composite material prepared by the application has good ballistic protection performance, anti-multiple impact performance and self-repairing performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bulletproof composite materials, in particular to a bulletproof composite material and a preparation method thereof. BACKGROUND

[0002] Bulletproof composite materials are key materials in the fields of national security and public safety, and the core requirement is to effectively protect high-speed bullet bodies under the premise of lightweight, which are widely used in bulletproof vests, armored vehicles, security shields and other scenes. Traditional metal armor (such as steel and aluminum alloy) is difficult to meet the comprehensive requirements of "high specific strength, impact resistance and weather resistance" due to its high density and poor flexibility. High-performance fiber reinforced resin matrix composite materials gradually become the mainstream of bulletproof materials due to their low density and high tensile strength. However, the existing technology still has the following problems: (1) The resin matrix has high brittleness and insufficient energy dissipation capacity. Traditional epoxy resin has high crosslinking density and low elongation at break, which is prone to brittle fracture under high-speed impact of bullets, and cannot effectively absorb impact energy, resulting in excessive indentation on the back of the composite material. (2) The interface between the fiber and the resin is weak, and the delamination failure is serious. The surface of aramid fiber is smooth, and the chemical inertness is strong, and the interface between the resin matrix and the resin mainly depends on physical adsorption, and the interlaminar shear strength is small. The fiber and the resin are prone to interfacial peeling under impact, which leads to rapid crack propagation and poor multi-impact resistance. (3) Self-repairing and weather resistance are poor, and the service life is short. The current bulletproof composite materials lack certain self-repairing performance, and the micro-cracks generated during impact cannot be healed, and the protective performance is irreversible after multiple uses, and the moisture resistance and heat resistance also need to be improved. The above problems seriously limit the practical application of bulletproof composite materials.

[0003] Chinese invention patent with publication number CN102604320A discloses a flexible bulletproof composite material with a new resin matrix and a processing method. The composite material processed by the new matrix resin has no pollution in the entire production process of molding, good aging resistance and yellowing resistance, and small decline in bulletproof performance at high temperature, but its impact resistance, interface bonding performance is poor, and it lacks self-repairing ability. Therefore, it is urgent to develop a bulletproof composite material with impact resistance, interface enhancement and self-repairing function. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a bulletproof composite material and a preparation method thereof.

[0005] To achieve the above-mentioned purpose, the technical scheme is as follows:

[0006] A bulletproof composite material is composed of aramid fiber and resin matrix; the resin matrix comprises the following raw materials in parts by weight:

[0007] Epoxy resin: 60-70 parts;

[0008] Modified toughening agent: 5-8 parts;

[0009] Curing agent: 4-5 parts;

[0010] Thermal stabilizer: 1-2 parts;

[0011] Inorganic filler: 1-2 parts;

[0012] Coupling agent: 0.5-1 part;

[0013] Wetting agent: 2-5 parts;

[0014] The chemical structure of the modified toughening agent is as follows:

[0015] .

[0016] The modified toughening agent is prepared by the following method:

[0017] S1: Under nitrogen protection, mix chloroformic nitrile, 4-hydroxyphenylboric acid and anhydrous acetonitrile uniformly, add triethylamine dropwise, react for 4-5h, and obtain intermediate 1 after treatment;

[0018] S2: Under nitrogen protection, mix intermediate 1, 3-amino-1, 2-epoxypropane and anhydrous tetrahydrofuran (THF) uniformly, add N,N-diisopropyl ethylamine, react for 10-12h, and obtain intermediate 2 after treatment;

[0019] S3: Under nitrogen protection, mix intermediate 2, cystamine and anhydrous THF uniformly, add N,N-diisopropyl ethylamine, react for 5-6h, and obtain intermediate 3 after treatment;

[0020] S4: Under nitrogen protection, mix intermediate 3, dopamine and anhydrous DMF uniformly, react for 10-12h, and obtain the modified toughening agent after treatment.

[0021] In step S1, the molar ratio of the chloroformic nitrile and 4-hydroxyphenylboric acid is 1:(1-1.2).

[0022] In step S2, the molar ratio of the intermediate 1 and 3-amino-1, 2-epoxypropane is 1:(1.05-1.1).

[0023] In step S3, the molar ratio of the intermediate 2 and cystamine is (2.05-2.1):1.

[0024] In step S4, the molar ratio of the intermediate 3 and dopamine is 1:(2-2.1).

[0025] The heat stabilizer is 2,6-di-tert-butyl-4-methylphenol; the coupling agent is KH-560 silane coupling agent; the wetting agent is polyether modified silicone oil; the curing agent is one of hexanediamine, diethylenetriamine and triethylenetetramine; the inorganic filler is one of nano silicon dioxide and nano montmorillonite; the aramid fiber is Kevlar K129 fiber; and the epoxy resin is E51 epoxy resin.

[0026] A preparation method of a bulletproof composite material, comprising the following steps:

[0027] S1: 60-70 parts by weight of epoxy resin, 200 parts by weight of N-methyl pyrrolidone are added into a reaction kettle, and the temperature is raised to 60 DEG C, and then stirring, 5-8 parts by weight of modified toughening agent, 1-2 parts by weight of heat stabilizer, 0.5-1 parts by weight of coupling agent, 2-5 parts by weight of wetting agent are added in turn, 1-2 parts by weight of inorganic filler is added after stirring for 20 min, high-speed stirring is carried out at 1500 rpm for 30 min, finally 4-5 parts by weight of curing agent is added and stirred for 20 h, and then resin glue solution is obtained;

[0028] S2: aramid fiber is dried at 120 DEG C for 2 h, and is laid on the unwinding device of the resin impregnator, the resin glue solution is added into the resin tank, the fiber tension is set to 4-6 N / cm, the resin tank temperature is set to 60 DEG C, the impregnation speed is set to 1-2 m / min, the content of the resin glue solution is controlled to 50 wt% by the scraper, and then the impregnated fiber is dried in a 50 DEG C oven for 12 h, and aramid / resin prepreg is prepared.

[0029] S3: the prepreg is cut according to [0° / 90°]8 alternating layering, and is put into a hot press to obtain the bulletproof composite material.

[0030] Due to the above technical scheme, the beneficial effects of the present application include:

[0031] (1) In the modified toughening agent prepared by the present application, the benzene boronic acid can form a borate ester bond with the surface of the fiber to dynamically build, which can reversibly break under impact load to absorb energy first; the disulfide bond is broken and recombined through redox reaction to further absorb energy; at the same time, the trichloro cyanuric triazine ring (rigid core) undergoes bond angle deformation to absorb additional energy. The synergistic effect of the three can increase the total energy absorption rate of the resin matrix, thereby greatly improving the ballistic limit of the composite material and effectively improving the bulletproof performance of the bulletproof composite material. In addition, the dynamic bond (borate ester bond / disulfide bond) preferentially breaks and dissipates energy under impact, while the triazine ring core remains intact, realizing the characteristics of "local sacrificial bond breakage-intact structure", and improving the fracture toughness of the composite material. At the same time, the existence of the dynamic bond significantly improves the self-repairing performance of the bulletproof composite material.

[0032] (2) The prepared modified toughening agent has a multi-hydroxyl structure of terminal grafted dopamine, which can form hydrogen bond action and pi-pi stacking with amide groups on the surface of aramid fiber, enhances the interface bonding of the fiber and the resin, effectively inhibits the impact crack along the interface, and improves the anti-multiple impact performance of the bulletproof composite material. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 NMR spectrum of the modified toughening agent prepared in Example 1. DETAILED DESCRIPTION

[0034] The application will be further described in conjunction with examples, but the application is not limited to these examples.

[0035] Example 1: Preparation of modified toughening agent

[0036] S1: In a reaction bottle, 0.1 mol of cyanuric chloride and 300 ml of anhydrous acetonitrile were added, and nitrogen protection was performed for 30 min; 0.1 mol of 4-hydroxyphenylboronic acid was dissolved in 300 ml of anhydrous acetonitrile, and 0.12 mol of triethylamine was prepared into a mixed solution; under ice bath, the mixed solution was slowly added to the reaction bottle, and the dropping was performed for 30 min, and the reaction was performed at 0℃ for 5 h; after the reaction was completed, filtration was performed, and 50℃ reduced pressure distillation was performed for 1.5 h; 250 ml of anhydrous ether was recrystallized, filtration was performed, the filter cake was washed with deionized water until neutral, and 40℃ vacuum drying was performed for 8 h to obtain the intermediate 1; the reaction equation is as follows:

[0037] ;

[0038] The nuclear magnetic resonance hydrogen spectrum data are as follows:

[0039] 1 H NMR (500 MHz, Chloroform- d ) δ 7.46-7.41 (m, 2H), 7.32 (s, 2H),6.58-6.52 (m, 2H).

[0040] S2: Under nitrogen protection, 0.1 mol of intermediate 1 and 300 ml of anhydrous THF were added to a reaction bottle, and stirring was performed for 30 min; 0.105 mol of 3-amino-1,2-epoxypropane was dissolved in 300 ml of anhydrous THF, and 0.1 mol of N,N-diisopropyl ethylamine was prepared into a mixed solution; under ice bath, the mixed solution was slowly added to the reaction bottle, and the dropping was performed for 30 min, and the reaction was performed at 30℃ for 12 h. After the reaction was completed, 40℃ reduced pressure distillation was performed for 2 h, 100 ml of 0.1M hydrochloric acid was added, after sufficient stirring, filtration was performed, the filter cake was washed with deionized water until neutral, and 40℃ vacuum drying was performed for 8 h to obtain the intermediate 2; the reaction equation is as follows:

[0041] ;

[0042] Its nuclear magnetic hydrogen spectrum data are as follows:

[0043] 1 H NMR (500 MHz, Chloroform-d) δ 7.47-7.41 (m, 2H), 7.32 (s, 2H),6.58-6.52 (m, 2H), 6.35 (s, 1H), 3.94 (d, J = 12.4 Hz, 2H), 3.90-3.83 (m,1H), 2.90 (q, J = 5.0 Hz, 2H).

[0044] S3: Under nitrogen protection, 0.205 mol of intermediate 2 and 350 ml of anhydrous THF were added to a reaction bottle and stirred for 30 min; 0.1 mol of cystamine was dissolved in 350 ml of anhydrous THF to prepare a mixed solution, and 0.21 mol of N,N-diisopropyl ethylamine was added to prepare a mixed solution; under ice bath, the mixed solution was slowly added to the reaction bottle, and the dropping was 30 min, and the reaction was carried out at 60°C for 6 h. After the reaction was completed, 2 was distilled under reduced pressure at 40°C for 2 h, 100 ml of 0.1M hydrochloric acid was added, and after stirring, the filter cake was washed with deionized water until neutral, and vacuum dried at 50°C for 8 h to obtain intermediate 3; the reaction equation is as follows:

[0045] ;

[0046] Its nuclear magnetic hydrogen spectrum data are as follows:

[0047] 1 H NMR (500 MHz, Chloroform-d) δ 7.47-7.41 (m, 4H), 7.32 (s, 4H),6.58-6.52 (m, 4H), 5.77 (s, 2H), 4.49-4.34 (m, 4H), 4.00 (s, 2H), 3.79 (s,4H), 3.05-2.85 (m, 8H).

[0048] S4: Under nitrogen protection, 500 ml of anhydrous DMF, 0.1 mol of intermediate 3 and 0.1 mol of triethylamine were added to a reaction bottle and stirred for 30 min, then 0.01 mol of BHT was added, and 300 ml of a DMF solution containing 0.2 mol of dopamine was slowly added, and the dropping was 30 min, and the reaction was carried out at 70°C for 12 h in the dark, and the reaction liquid was cooled in an ice bath, and the pH was adjusted to 4 with 0.5M HCl, and the reaction liquid was purified by Sephadex LH-20 gel column chromatography (eluent: methanol / water V / V=1:1), -50°C freeze-drying for 48h to obtain the modified toughening agent; the reaction equation is shown as follows:

[0049] ;

[0050] The nuclear magnetic resonance hydrogen spectrum data are as follows:

[0051] 1 H NMR (500 MHz, Chloroform-d) δ 7.47-7.41 (m, 4H), 7.32 (s, 4H),6.70-6.64 (m, 4H), 6.62-6.52 (m, 6H), 6.22 (d, J = 79.5 Hz, 4H), 5.77 (s,2H), 4.17 (d, J = 2.4 Hz, 4H), 3.98 (d, J = 5.2 Hz, 2H), 3.79 (s, 4H), 3.47(d, J = 5.2 Hz, 2H), 3.41 (s, 2H), 3.05-2.74 (m, 16H).

[0052] Example 2 Preparation of modified toughening agent:

[0053] S1: In a reaction bottle, 0.1 mol of cyanuric chloride and 300 ml of anhydrous acetonitrile were added, and stirred for 30 min under nitrogen protection; 0.11 mol of 4-hydroxyphenylboronic acid was dissolved in 300 ml of anhydrous acetonitrile, and 0.2 mol of triethylamine was added to prepare a mixed solution; the mixed solution was slowly added to the reaction bottle under ice bath, and the dropping was carried out for 30 min, and the reaction was carried out at 0°C for 5 h; 250 ml of anhydrous ether was recrystallized, filtered, and the filter cake was washed with deionized water until neutral, and vacuum dried at 40°C for 8 h to obtain intermediate 1;

[0054] S2: Under nitrogen protection, 0.1 mol of intermediate 1 and 300 ml of anhydrous THF were added to a reaction bottle, and stirred for 30 min; 0.108 mol of 3-amino-1,2-epoxypropane was dissolved in 300 ml of anhydrous THF, and 0.1 mol of N,N-diisopropyl ethylamine was added to prepare a mixed solution; the mixed solution was slowly added to the reaction bottle under ice bath, and the dropping was carried out for 30 min, and the reaction was carried out at 35°C for 11 h. After the reaction was completed, 100 ml of 0.1M hydrochloric acid was added, and stirred thoroughly, then filtered, and the filter cake was washed with deionized water until neutral, and vacuum dried at 40°C for 8 h to obtain intermediate 2;

[0055] S3: Under nitrogen protection, 0.208 mol of intermediate 2 and 350 ml of anhydrous THF were added into a reaction bottle and stirred for 30 min; 0.1 mol of cystamine was dissolved in 350 ml of anhydrous THF to prepare a mixed solution, and 0.21 mol of N,N-diisopropyl ethylamine was added to prepare a mixed solution; under ice bath, the mixed solution was slowly added into the reaction bottle, and the dropping was performed for 30 min, and the reaction was performed at 65°C for 5.5 h. After the reaction was completed, 2 h of distillation was performed at 40°C under reduced pressure, 100 ml of 0.1M hydrochloric acid was added, and after sufficient stirring, filtration was performed, the filter cake was washed with deionized water until neutral, and vacuum drying was performed at 50°C for 8 h to obtain intermediate 3;

[0056] S4: Under nitrogen protection, 500 ml of anhydrous DMF, 0.1 mol of intermediate 3 and 0.1 mol of triethylamine were added into a reaction bottle and stirred for 30 min, and then 0.01 mol of BHT was added, 300 ml of a DMF solution containing 0.205 mol of dopamine was slowly added dropwise, the dropping was performed for 30 min, the reaction was performed at 75°C in the dark for 11 h, ice bath cooling was performed, the reaction solution was adjusted to pH=4 with 0.5M hydrochloric acid, Sephadex LH-20 gel column chromatography purification was performed (eluent: methanol / water V / V =1:1), and freeze drying was performed at -50°C for 48 h to obtain the modified toughening agent.

[0057] Example 3: Preparation of a modified toughening agent

[0058] S1: In a reaction bottle, 0.1 mol of cyanuric chloride and 300 ml of anhydrous acetonitrile were added, nitrogen protection was performed, and stirring was performed for 30 min; 0.12 mol of 4-hydroxyphenylboronic acid was dissolved in 300 ml of anhydrous acetonitrile to prepare a mixed solution, and 0.2 mol of triethylamine was added to prepare a mixed solution; under ice bath, the mixed solution was slowly added into the reaction bottle, the dropping was performed for 30 min, the reaction was performed at 5°C for 4 h, after the reaction was completed, filtration was performed under suction, 1.5 h of distillation was performed at 50°C under reduced pressure, recrystallization was performed with 250 ml of anhydrous ether, filtration was performed, the filter cake was washed with deionized water until neutral, and vacuum drying was performed at 40°C for 8 h to obtain intermediate 1;

[0059] S2: Under nitrogen protection, 0.1 mol of intermediate 1 and 300 ml of anhydrous THF were added into a reaction bottle and stirred for 30 min; 0.11 mol of 3-amino-1,2-epoxypropane was dissolved in 300 ml of anhydrous THF to prepare a mixed solution, and 0.1 mol of N,N-diisopropyl ethylamine was added to prepare a mixed solution; under ice bath, the mixed solution was slowly added into the reaction bottle, the dropping was performed for 30 min, and the reaction was performed at 40°C for 10 h. After the reaction was completed, 2 h of distillation was performed at 40°C under reduced pressure, 100 ml of 0.1M hydrochloric acid was added, and after sufficient stirring, filtration was performed, the filter cake was washed with deionized water until neutral, and vacuum drying was performed at 40°C for 8 h to obtain intermediate 2;

[0060] S3: 0.21 mol of intermediate 2 and 350 ml of anhydrous THF were added into a reaction bottle under nitrogen protection and stirred for 30 min; 0.1 mol of cystamine was dissolved in 350 ml of anhydrous THF to prepare a mixed solution with 0.21 mol of N,N-diisopropyl ethylamine; the mixed solution was slowly added into the reaction bottle under ice bath, and the dropping was performed for 30 min, and the reaction was performed at 75°C for 5 h. After the reaction was completed, 100 ml of 0.1 M hydrochloric acid was added under 40°C and reduced pressure distillation for 2 h, and then the filter cake was washed with deionized water until neutral, and vacuum dried at 50°C for 8 h to obtain intermediate 3;

[0061] S4: 500 ml of anhydrous DMF, 0.1 mol of intermediate 3 and 0.1 mol of triethylamine were added into a reaction bottle under nitrogen protection and stirred for 30 min, and then 0.01 mol of BHT was added, and 300 ml of a DMF solution containing 0.21 mol of dopamine was slowly added dropwise, the dropping was performed for 30 min, and the reaction was performed at 80°C in the dark for 10 h, and the reaction liquid was cooled in an ice bath, and the reaction liquid was adjusted to pH = 4 with 0.5 M hydrochloric acid, and then purified by Sephadex LH-20 gel column chromatography (eluent: methanol / water = 1:1), and then freeze-dried at -50°C for 48 h to obtain the modified toughening agent. V / V

[0062] Example 4: Preparation of bulletproof composite material

[0063] The following were weighed by weight: epoxy resin (E51 epoxy resin) 600 g, modified toughening agent (prepared in Example 1) 50 g, curing agent (hexanediamine) 40 g, thermal stabilizer (2,6-di-tert-butyl-4-methylphenol) 10 g, inorganic filler (nano-silicon dioxide) 10 g, coupling agent (KH-560 silane coupling agent) 5 g, wetting agent (polyether modified silicone oil) 20 g.

[0064] S1: 600 g of epoxy resin, 2000 ml of N-methyl pyrrolidone were added into a reaction kettle, stirred, and heated to 60°C, and stirred for 10 min, and then 50 g of modified toughening agent, 10 g of thermal stabilizer, 5 g of coupling agent, and 20 g of wetting agent were added in sequence, and stirred for 20 min, and then 10 g of inorganic filler was added, and stirred at 1500 rpm for 30 min, and finally 40 g of curing agent was added and stirred for 20 h to obtain a viscous resin glue solution.

[0065] S2: Kevlar K129 aramid fiber was vacuum dried at 120°C for 2 h, and laid on the unwinding device of the resin impregnator, and the resin glue solution was added into the resin tank, and the fiber tension was set to 4 N / cm, the resin tank temperature was set to 60°C, and the impregnation speed was set to 1 m / min, and the resin glue solution content was controlled to 50 wt% by a scraper, and then the impregnated fiber was dried in a 50°C oven for 12 h to prepare aramid / resin prepreg.

[0066] ​S3: After cutting the prepreg according to the [0° / 90°]8 alternate layering (a total of 16 layers), the prepreg was placed in a hot press, and the temperature was raised to 90°C at a rate of 2°C / min, and maintained for 1 h (pressure 5 MPa); the temperature was continued to be raised to 120°C, and maintained for 2 h (pressure increased to 10 MPa); the temperature was again raised to 150°C, and maintained for 1 h (pressure 15 MPa), and the pressure was released after natural cooling to below 60°C, to obtain the bulletproof composite material.

[0067] Example 5 Preparation of bulletproof composite material:

[0068] The following were weighed by weight: epoxy resin (E51 epoxy resin) 650 g, modified toughening agent (prepared in Example 2) 65 g, curing agent (diethylene triamine) 45 g, thermal stabilizer (2,6-di-tert-butyl-4-methylphenol) 15 g, inorganic filler (nano-montmorillonite) 15 g, coupling agent (KH-560 silane coupling agent) 8 g, wetting agent (polyether modified silicone oil) 35 g.

[0069] S1: 650 g of epoxy resin, 2000 ml of N-methyl pyrrolidone were added to the reaction kettle, stirred, and the temperature was raised to 60°C, stirred for 10 min, and then 65 g of modified toughening agent, 15 g of thermal stabilizer, 8 g of coupling agent, and 35 g of wetting agent were added in sequence, stirred for 20 min, and then 15 g of inorganic filler was added, stirred at 1800 rpm for 30 min, and finally 45 g of curing agent was added and stirred for 20 h, to obtain a viscous resin glue solution.

[0070] S2: The Kevlar K129 aramid fiber was vacuum dried at 120°C for 2 h, and was laid on the unwinding device of the resin impregnator, the resin glue solution was added to the resin tank, the fiber tension was set to 5 N / cm, the resin tank temperature was set to 60°C, and the impregnation speed was set to 1.5 m / min, the resin glue solution content was controlled to 50 wt% by a scraper, and then the impregnated fiber was dried in a 50°C oven for 12 h, to obtain an aramid / resin prepreg.

[0071] S3: After cutting the prepreg according to the [0° / 90°]8 alternate layering (a total of 16 layers), the prepreg was placed in a hot press, and the temperature was raised to 90°C at a rate of 2°C / min, and maintained for 1 h (pressure 5 MPa); the temperature was continued to be raised to 120°C, and maintained for 2 h (pressure increased to 13 MPa); the temperature was again raised to 150°C, and maintained for 1 h (pressure 15 MPa), and the pressure was released after natural cooling to below 60°C, to obtain the bulletproof composite material.

[0072] Example 6 Preparation of bulletproof composite material:

[0073] Weigh by weight: epoxy resin (E51 epoxy resin) 700g, modified toughening agent (prepared in Example 3) 80g, curing agent (triethylene tetramine) 50g, thermal stabilizer (2,6-di-tert-butyl-4-methylphenol) 20g, inorganic filler (nano-silicon dioxide) 20g, coupling agent (KH-560 silane coupling agent) 10g, wetting agent (polyether modified silicone oil) 50g.

[0074] S1: 700g of epoxy resin, 2000ml of N-methyl pyrrolidone were added to the reaction kettle, stirred, heated to 60℃, stirred for 10min, 80g of modified toughening agent, 20g of thermal stabilizer, 10g of coupling agent, 50g of wetting agent were added in turn, stirred for 20min, then 20g of inorganic filler was added, stirred at 2000rpm for 30min, finally 50g of curing agent was added and stirred for 20h, to get viscous resin glue solution.

[0075] S2: Kevlar K129 aramid fiber was vacuum dried at 120℃ for 2h, laid on the unwinding device of the resin impregnator, the resin glue solution was added to the resin tank, the fiber tension was set to 6N / cm, the resin tank temperature was set to 60℃, the impregnation speed was set to 2m / min, the content of resin glue solution was controlled to 50wt% by scraper, then the impregnated fiber was dried in a 50℃ oven for 12h, to obtain aramid / resin prepreg.

[0076] S3: After cutting the prepreg according to the [0° / 90°]8 alternating layer (a total of 16 layers), the prepreg was put into a hot press, heated to 90℃ at a rate of 2℃ / min, kept for 1h (pressure 5MPa); continue to heat to 120℃, keep for 2h (pressure rises to 15MPa); again heat to 150℃, keep for 1h (pressure 15MPa), natural cooling to below 60℃, release pressure, to obtain bulletproof composite material.

[0077] Comparative Example 1

[0078] The raw material composition and process of the bulletproof composite material are basically the same as those of Example 5, the difference is that no modified toughening agent is added in the resin matrix component.

[0079] Comparative Example 2

[0080] The raw material composition and process of the bulletproof composite material are basically the same as those of Example 5, the difference is that the modified toughening agent is replaced by an equal weight of modified toughening agent prepared by the following method:

[0081] The preparation method of the modified toughening agent is basically the same as that of Example 2, the difference is that the cyanuric chloride in step S1 is replaced by an equal weight of 2,4,6-trichloropyrimidine.

[0082] Comparative Example 3

[0083] The raw material composition and process of the bulletproof composite material are basically the same as those of Example 5, except that the modified toughening agent is replaced with an equal weight of a modified toughening agent prepared by the following method:

[0084] The preparation method of the modified toughening agent is basically the same as that of Example 2, except that the 4-hydroxybenzoic acid in step S1 is replaced with an equal weight of 4-hydroxybenzoic acid.

[0085] Comparative Example 4

[0086] The raw material composition and process of the bulletproof composite material are basically the same as those of Example 5, except that the modified toughening agent is replaced with an equal weight of a modified toughening agent prepared by the following method:

[0087] The preparation method of the modified toughening agent is basically the same as that of Example 2, except that the cystamine in step S3 is replaced with an equal weight of 3,3'-thio-1-propylamine (CAS: 13643-20-4).

[0088] Comparative Example 5

[0089] The raw material composition and process of the bulletproof composite material are basically the same as those of Example 5, except that the modified toughening agent is replaced with an equal weight of a modified toughening agent prepared by the following method:

[0090] The preparation method of the modified toughening agent is basically the same as that of Example 2, except that the cystamine in step S3 is replaced with an equal weight of 2-(propyl dithio)-ethylamine (CAS: 81134-72-7).

[0091] The nanometer silicon dioxide used in the examples and comparative examples of the present application is a rutile type silicon dioxide with a particle size of 5-50 nm, purchased from Shanghai Yuan Ye Biological Technology Co., Ltd.; the nanometer montmorillonite is a nanometer montmorillonite with a mesh number of 2000, purchased from Shanghai Wanzhao Fine Chemical Co., Ltd.; the polyether modified silicone oil is a brand of Dow Corning DC193.

[0092] The bulletproof composite materials prepared in Examples 4-6 and Comparative Examples 1-5 were tested for bulletproof performance and self-repairing performance, and the test results are shown in Table 1.

[0093] The bulletproof performance of the bulletproof composite material is tested by the ballistic limit speed (V50) V 50) and energy absorption as evaluation indexes, ballistic impact tests were carried out according to the standard GJB4300A-2012 of China military bulletproof clothing. The ballistic impact test device was composed of fragment simulating projectile (FSP), 7.62 mm caliber fragment simulating projectile launcher, velocity measuring device, composite laminated plate and backing fixed support body; wherein the size of the composite laminated plate was 300 mm x 300 mm; the FSP was made of 45 steel, the surface hardness was HRC30, the diameter was 5.5 mm, and the mass was 1.1 g; the distance between the launcher and the laminated plate was 5 m, and each sample needed at least 6 shots. V 50 was the average value of 5 shots of complete penetration and 5 shots of non-penetration within a certain speed range (38 m / s). The energy absorption was represented by specific energy absorption (SEA), which was calculated by the following formula: SEA = (1 / 2m V 50 2 ) / Areal density, wherein m was the mass of FSP (kg), and Areal density was the areal density of the composite material (kg / m 2 ). The areal density was tested according to the standard HB 7736.2-2004.

[0094] The self-repairing performance of the bulletproof composite material was represented by the retention rate of V 50 before and after repair, and the self-repairing efficiency H = the value of V 50 after repair / the value of V 50 before repair x 100%.

[0095] Table 1 Performance indicators of bulletproof composite material

[0096]

[0097] It can be seen from the data in Table 1 that the bulletproof composite material prepared in the application has excellent ballistic protection performance, multi-impact resistance and self-repairing performance.

[0098] Comparative Example 1 was a bulletproof composite material prepared without using a modified toughening agent, and its ballistic limit speed, energy absorption and self-repairing performance were all poor, indicating that the synergistic effect of the rigid ring core and the multi-functional groups (phenylboronic acid, disulfide bond and dopamine) introduced in the modified toughening agent could significantly improve the multiple performances of the bulletproof composite material. The dopamine grafted at the end of the modified toughening agent could form hydrogen bond action and π-π stacking with the amide groups on the surface of aramid fibers, enhance the interfacial bonding between the fibers and the resin, effectively inhibit the crack propagation along the interface, and improve the multi-impact resistance of the bulletproof composite material.

[0099] The ballistic performance of the ballistic composite material prepared in Comparative Example 2 using 2,4,6-trichloropyrimidine is poor, mainly because the nitrogen atoms of the pyrimidine ring are not symmetrically distributed, the molecular conformation of the reaction product is more complex, and local stress concentration points may be generated, which easily causes crack propagation under ballistic impact. When the composite material is impacted, the bond angle of the cyanuric chloride triazine ring (rigid core) changes, additional energy is absorbed, the ballistic limit of the composite material is improved, and the presence of the rigid structure of the triazine ring core in the modified toughening agent allows the composite material to maintain the integrity of the skeleton under impact, improve the fracture toughness of the composite material, and thus improve its ballistic performance.

[0100] The self-repairing performance of the ballistic composite material prepared in Comparative Examples 3 and 4 is poorer than that of Example 5, mainly because of the lack of dynamic boronic acid groups and disulfide bonds. In a humid environment, the broken B-O bonds can be recombined through hydrolysis-esterification reaction; under thermal stimulation, the disulfide bond can be recombined through thiol-disulfide exchange, which can significantly improve the self-repairing performance of the ballistic composite material.

[0101] The ballistic performance of the ballistic composite material prepared in Comparative Example 5 is poorer than that of Example 5, because 2-(propyldithio)-ethylamine only contains one amino group, and the prepared modified plasticizer only has one dopamine group and one phenylboronic acid group, resulting in a decrease in interfacial strength and energy absorption, which in turn affects the multi-impact resistance and ballistic protection performance of the ballistic composite material.

[0102] The above is only a preferred embodiment of the present application and is not intended to limit the present application; but for ordinary skilled persons in the art, some minor changes, modifications and equivalent changes of the above disclosed technical content without departing from the scope of the technical solutions of the present application can be made, which are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above embodiments according to the essential technology of the present application are still within the protection scope of the technical solutions of the present application.

Claims

1. A ballistic resistant composite material, characterized by, The aramid fiber is compounded with a resin matrix; The resin matrix comprises the following raw materials in parts by weight: Epoxy resin: 60-70 parts; Modified toughening agent: 5-8 parts; Curing agent: 4-5 parts; Heat stabilizer: 1-2 parts; Inorganic filler: 1-2 parts; Coupling agent: 0.5-1 part; Wetting agent: 2-5 parts; The chemical structural formula of the modified toughening agent is as follows: 。 2. A ballistic resistant composite material according to claim 1, wherein, The modified toughening agent is prepared by the following method: S1: Under nitrogen protection, mix cyanuric chloride, 4-hydroxyphenylboronic acid and anhydrous acetonitrile uniformly, add triethylamine dropwise, react for 4-5h, and then process to obtain intermediate 1; S2: Under nitrogen protection, mix intermediate 1, 3-amino-1, 2-epoxypropane and anhydrous THF uniformly, add N, N-diisopropyl ethylamine, react for 10-12h, and then process to obtain intermediate 2; S3: Under nitrogen protection, mix intermediate 2, cystamine and anhydrous THF uniformly, add N, N-diisopropyl ethylamine, react for 5-6h, and then process to obtain intermediate 3; S4: Under nitrogen protection, mix intermediate 3, dopamine and anhydrous DMF uniformly, react for 10-12h, and then process to obtain the modified toughening agent.

3. A ballistic resistant composite material according to claim 2, wherein, In step S1, the molar ratio of cyanuric chloride to 4-hydroxyphenylboronic acid is 1:(1-1.2).

4. A ballistic resistant composite material according to claim 2, wherein, In step S2, the molar ratio of intermediate 1 to 3-amino-1, 2-epoxypropane is 1:(1.05-1.1).

5. A ballistic resistant composite material according to claim 2, wherein, In step S3, the molar ratio of intermediate 2 to cystamine is (2.05-2.1):

1.

6. A ballistic resistant composite material according to claim 2, wherein, In step S4, the molar ratio of intermediate 3 to dopamine is 1:(2-2.1).

7. A ballistic resistant composite material according to claim 1 wherein, The heat stabilizer is 2, 6-di-tert-butyl-4-methylphenol; the coupling agent is KH-560 silane coupling agent; and the wetting agent is polyether modified silicone oil.

8. A ballistic resistant composite material according to claim 1 wherein, The curing agent is one of hexanediamine, diethylenetriamine and triethylenetetramine; and the inorganic filler is one of nano silicon dioxide and nano montmorillonite.

9. The ballistic resistant composite material of Claim 1 wherein, The aramid fiber is Kevlar K129 fiber, and the epoxy resin is E51 epoxy resin.

10. A method of manufacturing the ballistic resistant composite material according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1: Put 60-70 parts by weight of epoxy resin and 200 parts by weight of N-methylpyrrolidone into a reaction kettle, heat to 60℃, and then add 5-8 parts by weight of modified toughening agent, 1-2 parts by weight of heat stabilizer, 0.5-1 part by weight of coupling agent and 2-5 parts by weight of wetting agent in sequence, stir for 20min, then add 1-2 parts by weight of inorganic filler, stir at 1500rpm for 30min, finally add 4-5 parts by weight of curing agent and stir for 20h to obtain resin glue solution; S2: Dry aramid fiber at 120℃ for 2h, lay it on the unwinding device of the impregnation machine, put the resin glue solution into the resin tank, set the fiber tension to 4-6N / cm, the resin tank temperature to 60℃ and the impregnation speed to 1-2m / min, control the resin glue solution content to 50wt% by using a scraper, then dry the impregnated fiber in a 50℃ oven for 12h to obtain aramid / resin prepreg; S3: Cut the prepreg according to [0° / 90°]8 alternating layering, put it into a hot press to obtain a bulletproof composite material.

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