阅读说明：本技术 一种破片收敛型防弹复合材料的制备方法 (Preparation method of fragment convergence type bulletproof composite material ) 是由 李忠盛 吴护林 黄安畏 牛犇 李晓晖 孙彩云 程时雨 尹仕攀 于 2020-06-24 设计创作，主要内容包括：一种破片收敛型防弹复合材料的制备方法,所述复合材料依次包括破片约束层、共混改性弹性体层、改性阻尼橡胶层,所述破片约束层是将芳纶纤维进行预处理,然后采用机织编织出浅交联2.5D编织结构,最后固化成型。本发明制备的破片收敛型防弹复合材料,具有高防破片性能、低散射角、阻燃、阻尼减振降噪、辐射屏蔽性能优异等优点,共振状态下结构损耗因子0.033~0.062、降噪量在10dB(A)以上、氧指数可达40%、中子辐射屏蔽系数1.63~1.87、破片散射角可低至5.6~12.9°。(The fragment convergence type bulletproof composite material sequentially comprises a fragment restraint layer, a blending modified elastomer layer and a modified damping rubber layer, wherein the fragment restraint layer is formed by pretreating aramid fibers, weaving a shallow cross-linking 2.5D braided structure by a machine, and finally curing and forming. The fragment convergence type bulletproof composite material prepared by the invention has the advantages of high fragment prevention performance, low scattering angle, flame retardance, damping vibration attenuation and noise reduction, excellent radiation shielding performance and the like, the structural loss factor is 0.033-0.062 in a resonance state, the noise reduction amount is more than 10dB (A), the oxygen index can reach 40%, the neutron radiation shielding coefficient is 1.63-1.87, and the fragment scattering angle can be as low as 5.6-12.9 degrees.)

1. A preparation method of a fragment convergence type bulletproof composite material comprises a fragment restraint layer, a blending modified elastomer layer and a modified damping rubber layer in sequence, and is characterized in that: the fragment restraint layer is formed by pretreating aramid fibers, weaving a shallow cross-linked 2.5D woven structure by using a machine, and finally curing and forming, wherein the curing and forming specifically comprises the steps of dissolving a double resin consisting of polyurethane resin and epoxy resin and a curing agent by using acetone to form a mixed solution, dissolving ammonium polyphosphate in deionized water, adding the ammonium polyphosphate into the mixed solution, stirring at the speed of 200-220 r/min for 15-20 min, uniformly mixing, performing auxiliary dispersion by using ultrasonic waves, controlling the temperature of an ultrasonic medium at 32 ℃, and dispersing for 10min, wherein the mass ratio of the double resin, the curing agent and the ammonium polyphosphate is 10:1:1, pressing the mixture into a fiber layer of the aramid fiber woven structure under the negative pressure condition of 0.095MPa, and curing to form the aramid fiber plate.

2. The method of making a fragment converging ballistic composite of claim 1 wherein: the polyurethane resin and the epoxy resin are composed according to a volume ratio of 1.5-4: 1, and the curing agent is composed of thermosetting phenolic resin and salicylic acid according to a volume ratio of 1: 1.

3. A method of making a fragment converging ballistic composite material according to claim 1 or 2 wherein: the pretreatment method specifically comprises the steps of putting aramid fibers into a sodium hydroxide solution with the mass fraction of 0.5%, soaking for 1-1.5 hours, taking out, washing to be neutral by using deionized water, putting into acetone, soaking for 12 hours, taking out, washing by using deionized water, putting into deionized water, boiling for 15min, taking out, putting into an oven, drying, setting the temperature to be 110 ℃, keeping the time to be 20min, taking out, and putting into a sealing bag for later use.

4. A method of making a fragment converging ballistic composite of claim 1, 2 or 3 wherein: the shallow cross-linking 2.5D weaving structure is characterized in that pretreated para-aramid fibers are divided into warps and wefts which are perpendicular to each other to be woven, the warps are in a bending state, the wefts are in a linear state, the warps are cross-linked with the wefts in the vertical plane and the thickness direction of a fabric, every 2 strands of the warps and the wefts are cross-linked once in the vertical plane direction of the fabric, and every 4 strands of the warps and the wefts are cross-linked once in the thickness direction of the fabric, so that the weaving structure is prepared.

5. A process for the preparation of a fragment converging ballistic composite according to any one of claims 1 to 4 wherein: the cold pressing compounding is that the aramid fiber fiberboard and the end face of the blending modified elastomer layer are polished by 400-mesh sand paper, an automatic glue spreader is used for coating an A-type adhesive after the aramid fiber fiberboard and the end face of the blending modified elastomer layer are cleaned by acetone, the pressure is maintained for 24 hours in a four-column hydraulic machine under the condition of room temperature under the pressure of 0.1-0.3 MPa, after the adhesive is completely cured, the blending elastomer surface is compounded with the modified damping rubber layer, and then holes are cut to the specified size through high-pressure water cutting.

6. A process for the preparation of a fragment converging ballistic composite according to any one of claims 1 to 5 wherein: the blending modified elastomer layer is specifically samarium oxide/polyurethane blending elastomer, and the modified damping rubber layer is specifically butyl damping rubber modified by sodium stearate.

7. The preparation method of the fragment convergence type bulletproof composite material is characterized by comprising the following steps of:

s1 preparation of aramid fiber woven structure

(1) Pretreating aramid fibers: putting aramid fibers into a sodium hydroxide solution with the mass fraction of 0.5%, soaking for 1-1.5 h, taking out, washing to be neutral by using deionized water, putting into acetone, soaking for 12h, taking out, washing by using deionized water, putting into deionized water, boiling for 15min, taking out, putting into an oven, drying, setting the temperature at 110 ℃, keeping the time at 20min, taking out, and putting into a sealing bag for later use;

(2) shallow cross-linked 2.5D braided structure: dividing the pretreated para-aramid fibers into warps and wefts which are mutually vertical to each other, weaving, wherein the warps are in a bent state, the wefts are in a linear state, the warps are crosslinked with the wefts along the vertical plane and the thickness direction of the fabric, every 2 strands of the warps and the wefts are crosslinked once in the vertical plane direction of the fabric, and every 4 strands of the warps and the wefts are crosslinked once in the thickness direction of the fabric, so that a woven structure is prepared;

s2 preparation of fragment restraint layer of aramid fiber board

(1) Double-resin system configuration: (1) double-resin system configuration: dissolving a bis-resin consisting of polyurethane resin and epoxy resin and a curing agent by using acetone to form a mixed solution, dissolving ammonium polyphosphate in deionized water, adding the deionized water into the mixed solution, uniformly mixing the mixture by stirring at the speed of 200-220 r/min for 15-20 min, and performing auxiliary dispersion by using ultrasonic waves, wherein the temperature of an ultrasonic medium is controlled to be 30 +/-2 ℃, the dispersion is performed for 10-15 min, the mass ratio of the bis-resin, the curing agent and the ammonium polyphosphate in the mixed solution is 10:1:1, the volume ratio of the polyurethane resin to the epoxy resin is 1.5-4: 1, and the curing agent consists of thermosetting phenolic resin and salicylic acid according to the volume ratio of 1: 1;

(2) solidifying and forming the fragment restraint layer of the aramid fiber board: pressing the aramid fiber board into a fiber layer of an aramid fiber woven structure under the negative pressure condition of 0.095MPa for curing to form an aramid fiber board;

s3 cold pressing compounding

The method comprises the steps of polishing the end faces of an aramid fiber board and a samarium oxide/polyurethane blended elastomer by using 400-mesh sand paper, respectively coating an A-type adhesive by using an automatic gluing machine after cleaning with acetone, maintaining the pressure for 24 hours in a four-column hydraulic press under the pressure of 0.1-0.3 MPa at room temperature, uniformly processing semi-through holes with the aperture of 2mm and the hole spacing of 8mm on the surface of damping rubber, compounding a modified butyl damping rubber layer on the surface of the elastomer by using the A-type adhesive at normal temperature and normal pressure, and cutting and opening holes to an appointed size by using high-pressure water cutting after the adhesive is completely cured.

Technical Field

The invention relates to the technical field of bulletproof materials, in particular to a preparation method of a fragment convergence type bulletproof composite material.

Background

At present, in the field of bulletproof composite materials at home and abroad, fiber reinforced composite materials such as glass fibers, aramid fibers, ultra-high molecular weight polyethylene fibers and the like are mainly adopted. In the field of armor protection, tank armored vehicles face threats to advanced ammunition such as armor-piercing bombs, armor-breaking bombs, large-caliber grenades, anti-tank missiles and the like. After the ammunition punctures the steel armor of the vehicle body, the steel armor and the warhead are broken to form high-speed fragments and collapse fragments, and the high-speed fragments move forwards in a conical shape, so that large-area casualties and equipment damage in the vehicle are caused. The fragment convergence type multifunctional composite material is mainly used for effectively converging and protecting secondary fragments generated after various ammunitions puncture an armor of an infantry combat tank, and effectively controlling flame and heat effects caused by metal jet flow generated by a penetration bomb and a hollow charge bomb simultaneously, so that casualties are reduced, equipment, instruments and meters and computers in the tank are effectively protected, the battlefield viability is improved, and meanwhile, the tank armored vehicle has the characteristics of low density, flame retardance, good environmental adaptability, economy and the like, and the protection capability of the tank armored vehicle is improved.

The fiber woven cloth structure adopted in the material of the present composite material is mainly a two-dimensional or one-way fiber structure, the adopted resin is mainly thermosetting resin or other series of modified resins, such as glass fiber cloth-epoxy resin, aramid fiber-phenolic resin and the like, the main forming mode is that the resin and the fiber are primarily impregnated to form a prepreg cloth material, then the prepreg cloth material is prepared by a mould pressing or laminating forming mode of the conventional composite material and a large-scale pressure device in a high-pressure and heating mode, the materials produced by the forming process are basically laminated structures, the interlayer high-pressure pressing bonding structure is easy to delaminate or crack under a complex environment, the mechanical property is poor, the defects of high surface density, poor radiation shielding property, poor flame retardant property and the like exist, under the severe battlefield environment, the protective performance and the convergence effect on various high-speed fragments are limited, and the combat effectiveness is seriously influenced.

Disclosure of Invention

The invention aims to provide a preparation method of a fragment convergence type bulletproof composite material with excellent mechanical properties. The composite material prepared by the invention can effectively converge secondary fragments, and has high flame retardance, radiation shielding property and excellent vibration and noise reduction performance.

The purpose of the invention is realized by the following technical scheme:

a preparation method of a fragment convergence type bulletproof composite material comprises a fragment restraint layer, a blending modified elastomer layer and a modified damping rubber layer in sequence, and is characterized in that: the fragment restraint layer is formed by pretreating aramid fibers, weaving a shallow cross-linked 2.5D woven structure by using a machine, and finally curing and forming, wherein the curing and forming specifically comprises the steps of dissolving a double resin consisting of polyurethane resin and epoxy resin and a curing agent by using acetone to form a mixed solution, dissolving ammonium polyphosphate in deionized water, adding the ammonium polyphosphate into the mixed solution, stirring at the speed of 200-220 r/min for 15-20 min, uniformly mixing, performing auxiliary dispersion by using ultrasonic waves, controlling the temperature of an ultrasonic medium at 32 ℃, and dispersing for 10min, wherein the mass ratio of the double resin, the curing agent and the ammonium polyphosphate is 10:1:1, pressing the mixture into a fiber layer of the aramid fiber woven structure under the negative pressure condition of 0.095MPa, and curing to form the aramid fiber board composite material.

Furthermore, the aramid fiber is a copolymer type para-aramid fiber containing a heterocyclic ring structure, the fiber degree is 1000-1500D, the density is 1.42-1.44 g/cm3, the tensile strength is 3500-5000 MPa, the elastic modulus is 115-150 GPa, and the elongation at break is 2.8-3.5%.

Further, the polyurethane resin and the epoxy resin are composed according to a volume ratio of 1.5-4: 1, and the curing agent is composed of thermosetting phenolic resin and salicylic acid according to a volume ratio of 1: 1.

The copolymer para-aramid fabric has poor wettability with a resin matrix, and poor bonding force between resin and fiber, so that the bulletproof performance of the copolymer para-aramid fabric is reduced. According to the invention, the double-resin system is adopted, wherein the ammonium polyphosphate not only enhances the flame retardance of the system, but also enhances the compatibility of the elastic matrix of the polyurethane resin, isocyanate groups in the polyurethane resin react and crosslink with epoxy groups in the epoxy resin, hydroxymethyl groups in the thermosetting phenolic resin react with hydroxyl groups and epoxy groups in the epoxy resin, phenolic hydroxyl groups in the phenolic resin and salicylic acid react with epoxy groups of the epoxy resin to perform a ring-opening etherification reaction, so that the epoxy resin is converted from a linear type to a body type, the curing is promoted, finally, the epoxy resin and the polyurethane resin form mutually crosslinked reticular body type macromolecules, the wettability of the resin to the copolymerized para-aramid fiber is improved, the chemical bonding between the fiber and the resin is enhanced, and the bonding force between the resin and the fiber is enhanced.

In the curing process, the polyurethane is completely cured, the epoxy resin forms a semi-cured state under the action of the curing agent at the normal temperature in vacuum, and the cured and semi-cured dual-resin are mutually cooperated, so that the strength and toughness of the composite material are enhanced, and the overall performance of the composite material is improved.

Further, the pretreatment specifically comprises the steps of putting the aramid fiber into a sodium hydroxide solution with the mass fraction of 0.5%, soaking for 1-1.5 hours, taking out, washing to be neutral by using deionized water, putting into acetone, soaking for 12 hours, taking out, washing by using deionized water, putting into the deionized water, boiling for 15min, taking out, putting into an oven, drying at a set temperature of 110 ℃ for 20min, taking out, and putting into a sealing bag for later use.

Further, the shallow cross-linking 2.5D weaving structure is obtained by weaving the pretreated para-aramid fiber into warp yarns and weft yarns which are perpendicular to each other, wherein the warp yarns are in a bending state, the weft yarns are in a linear state, the warp yarns are cross-linked with the weft yarns along a vertical plane and a thickness direction of the fabric, every 2 strands of the warp yarns and the weft yarns are cross-linked once in the vertical plane direction of the fabric, and every 4 strands of the warp yarns and the weft yarns are cross-linked once in the thickness direction of the fabric.

According to the invention, by controlling the vertical cross-linking weaving of the warp yarns and the weft yarns, the fiber volume content is increased in the vertical plane direction, the gaps among the fibers are small, and the aperture left after the bullet penetrates through the fibers is small, so that the purpose of restraining fragments is achieved; the capability of transmitting stress waves of the fibers in the vertical plane direction is kept in the thickness direction, and the capability of resisting tensile damage of the fiber braided structure is fully exerted.

Further, the cold pressing compounding is that the aramid fiber fiberboard and the end face of the blending modified elastomer are polished by 400-mesh sand paper, the aramid fiber fiberboard and the end face of the blending modified elastomer are cleaned by acetone, an automatic gluing machine is used for coating an A-type adhesive, pressure maintaining is carried out in a four-column hydraulic machine for 24 hours at room temperature under the pressure of 0.1-0.3 MPa, after the adhesive is completely cured, the surface of the blending elastomer is compounded with the modified damping rubber layer, and then the blending elastomer is cut to an appointed size through high-pressure water cutting.

Further, the blending modified elastomer layer is specifically samarium oxide/polyurethane blending elastomer, and the modified damping rubber layer is specifically butyl damping rubber modified by sodium stearate.

According to the invention, the surface of the aramid fiber board is sequentially compounded with the samarium oxide/polyurethane blended elastomer and the sodium stearate modified butyl damping rubber, so that the composite material has excellent radiation resistance and vibration and noise reduction capabilities, wherein the sodium stearate modified butyl damping rubber has vibration and noise reduction capabilities, and the surface of the sodium stearate modified butyl damping rubber has remarkable adhesive property, so that the composite material has excellent binding force with the samarium oxide/polyurethane blended elastomer.

Most specifically, the preparation method of the fragment convergence type bulletproof composite material is characterized by comprising the following steps of:

s1 preparation of aramid fiber woven structure

(1) Pretreating aramid fibers: putting aramid fibers into a sodium hydroxide solution with the mass fraction of 0.5%, soaking for 1-1.5 h, taking out, washing to be neutral by using deionized water, putting into acetone, soaking for 12h, taking out, washing by using deionized water, putting into deionized water, boiling for 15min, taking out, putting into an oven, drying, setting the temperature at 110 ℃, keeping the time at 20min, taking out, and putting into a sealing bag for later use.

(2) Shallow cross-linked 2.5D braided structure: dividing the pretreated para-aramid fibers into warps and wefts which are mutually vertical to each other, weaving, wherein the warps are in a bent state, the wefts are in a linear state, the warps are crosslinked with the wefts along the vertical plane and the thickness direction of the fabric, every 2 strands of the warps and the wefts are crosslinked once in the vertical plane direction of the fabric, and every 4 strands of the warps and the wefts are crosslinked once in the thickness direction of the fabric, so that a woven structure is prepared; the aramid fiber is a copolymer para-aramid fiber containing a heterocyclic ring structure, the fiber degree is 1000-1500D, the density is 1.42-1.44 g/cm3, the tensile strength is 3500-5000 MPa, the elastic modulus is 115-150 GPa, and the elongation at break is 2.8-3.5%;

s2 preparation of fragment restraint layer of aramid fiber board

(1) Double-resin system configuration: dissolving a bis-resin consisting of polyurethane resin and epoxy resin and a curing agent by using acetone to form a mixed solution, dissolving ammonium polyphosphate in deionized water, adding the deionized water into the mixed solution, uniformly mixing the mixture by stirring at the speed of 200-220 r/min for 15-20 min, and performing auxiliary dispersion by using ultrasonic waves, wherein the temperature of an ultrasonic medium is controlled to be 30 +/-2 ℃, the dispersion is performed for 10-15 min, the mass ratio of the bis-resin, the curing agent and the ammonium polyphosphate in the mixed solution is 10:1:1, the volume ratio of the polyurethane resin to the epoxy resin is 1.5-4: 1, and the curing agent consists of thermosetting phenolic resin and salicylic acid according to the volume ratio of 1: 1;

(2) solidifying and forming the fragment restraint layer of the aramid fiber board: pressing the aramid fiber board into a fiber layer of an aramid fiber woven structure under the negative pressure condition of 0.095MPa for curing to form an aramid fiber board;

s3 cold pressing compounding

The method comprises the steps of polishing the end faces of an aramid fiber fiberboard and a samarium oxide/polyurethane blended elastomer by 400-mesh sand paper, cleaning the end faces by acetone, coating an A-type adhesive by an automatic gluing machine, maintaining the pressure for 24 hours in a four-column hydraulic press under the condition of room temperature under the pressure of 0.1-0.3 MPa, uniformly processing semi-through holes with the aperture of 2mm and the hole spacing of 8mm on the surface of damping rubber after the adhesive is completely cured, compounding a modified butyl damping rubber layer on the surface of the elastomer by the A-type adhesive at normal temperature and normal pressure, and cutting and opening the holes to an appointed size by high-pressure water cutting after the adhesive is completely cured.

The invention has the following technical effects:

the fragment convergence type bulletproof composite material prepared by the invention has the advantages of stable structure, no phenomena of layering, cracking and the like, high fragment prevention performance, low scattering angle, flame retardance, damping vibration attenuation and noise reduction, excellent radiation shielding performance and the like, realizes multifunctional and efficient integration by adopting a function complementary structure design, and effectively solves the problem that the traditional bulletproof composite material cannot attenuate the fragment scattering angle. The thickness of the composite material prepared by the invention is 8-20 mm, and the surface density is 8-20 kg/m²The structural loss factor is 0.033-0.062 in a resonance state, the noise reduction is more than 10dB (A), the oxygen index can reach more than 42%, the neutron radiation shielding coefficient is 1.63-1.87, and the scattering angle of fragments is as low as 2.6-15.9 degrees. It is secondary to be applicable to various lightweight armoured equipmentThe protection requirement of the fragments is that the fragments are nontoxic and harmless, so that the man-machine environment is effectively improved, and the survival rate of a battlefield is improved.

Drawings

FIG. 1: scanning electron microscope images of the copolymerized para-aramid fibers before and after pretreatment.

FIG. 2: the invention relates to a solidification forming object diagram of a para-aramid fiber board fragment restraint layer.

FIG. 3: the invention discloses a structural schematic diagram of a fragment convergence type bulletproof composite material.

FIG. 4: the fragment convergence type multifunctional bulletproof composite material prepared by the invention is in a real object diagram.

Detailed Description

The present invention is described in detail below by way of examples, it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make some insubstantial modifications and adaptations of the present invention based on the above-mentioned disclosure.