CN107011648A - A kind of Kevlar fiber cloths enhancing polyureas based composites and preparation method thereof - Google Patents

Abstract

A Kevlar fiber cloth reinforced polyurea-based composite material and a preparation method thereof relate to a Kevlar fiber cloth reinforced polyurea-based composite material and a preparation method thereof. The invention aims to solve the problems of low strength of a single polyurea elastomer material and material failure caused by lateral pull-out of fibers when the Kevlar fiber cloth is in service. Kevlar fiber cloth-reinforced polyurea-based composite materials use Kevlar fiber cloth as a reinforcement and polyurea as a matrix for bonding. 1. Preparation of polyurea elastomer; 2. Fiber cloth cutting and immersion in polyurea; 3. Vacuuming; 4. Fiber cloth laying; 5. Die-casting. The fiber cloth reinforced polyurea-based composite material prepared by the invention can be used in military fields, such as bulletproof armor backboards, aircraft, missile structural materials, protective helmets, etc.; in the field of civil structural materials, such as building structural materials such as pipes and wall panels.

Description

A kind of Kevlar fiber cloth reinforced polyurea-based composite material and preparation method thereof

technical field

The invention relates to a Kevlar fiber cloth reinforced polyurea-based composite material and a preparation method thereof.

Background technique

As a polymer material, polyurea elastomer has low density and price. The excellent physical and chemical properties of polyurea include extremely high tensile impact strength, flexibility, wear resistance, anti-slip, anti-aging, anti-corrosion, etc. .

The U.S. Air Force first applied polyurea coatings to building blast protection, and then the U.S. Navy applied polyurea to the outer armor plate of the High Mobility Multipurpose Vehicle (HMMWV) in order to reduce the hazards of ballistic fragments and bullets. Experimental studies have shown that the polyurea layer has a good protective effect and can significantly enhance the penetration resistance of the armor plate against gunfire and explosion fragments. Polyurea elastomer will undergo glass transition under high-speed impact, the strength modulus of the material will be greatly improved, and at the same time dissipate a large amount of energy to achieve the purpose of bulletproof. Elastic materials are often used as back plates to form steel plates/ceramic/elastic materials (German Leopard-2, Russian T90 tank) composite bulletproof structure.

In addition to having good application prospects in the field of military bulletproof, polyurea is also widely used in the field of large-scale infrastructure construction due to its waterproof, anti-corrosion and wear-resistant properties. Such as pipeline anticorrosion, tunnel waterproofing, bridge protection, etc.

High-strength fibers mainly include carbon fiber, glass fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, etc. These fibers are widely used in civil and military fields due to their ultra-high strength and modulus. Fiber-reinforced polymer matrix composites are also widely used due to their excellent properties.

Fiber-reinforced composites have properties superior to pure fibers and matrices. First of all, the matrix can keep the position and direction of the fiber pairs unchanged during the impact, and can disperse the stress between the fibers; secondly, the existence of the matrix can protect the fibers and avoid the degradation of fiber performance caused by environmental factors, such as in The reduction of impact resistance of pure fibers under high humidity conditions and the decrease of mechanical properties caused by ultraviolet radiation photodegradation; delamination caused by matrix rupture is also an energy absorption mechanism. The impregnated aramid fiber fabric has better dynamic anti-intrusion performance. When used as lightweight ballistic or soft armor, the lower fiber-to-matrix adhesion allows the fibers to achieve greater deformation and thus absorb more impact energy.

Fiber cloth reinforced polyurea-based composite laminates combine the common advantages of fibers and polyurea elastomers. Through the design of different layers and fiber volume fractions, high strength, high toughness, low density, corrosion resistance, waterproof, and Fiber cloth reinforced polyurea-based composite laminates, especially anti-ballistic cutting performance. It can be used in large-scale infrastructure construction fields, such as pipeline anticorrosion, tunnel waterproofing, bridge protection, house explosion protection, etc.; it can be used in civilian protection fields, such as helmets, knee pads and other protective equipment; it can also be used in military fields, such as bulletproof vests and bulletproof plates , aircraft structures and other fields.

Contents of the invention

The invention aims to solve the problems of low strength of a single polyurea elastomer material and material failure caused by lateral pull-out of fibers when Kevlar fiber cloth is in service, and provides a Kevlar fiber cloth reinforced polyurea-based composite material and a preparation method thereof.

A Kevlar fiber cloth-reinforced polyurea-based composite material is combined with Kevlar fiber cloth as a reinforcement and polyurea as a matrix, wherein the volume percentage of the fiber cloth is 50% to 90%; the material of the fiber cloth is natural fiber or chemical fiber; the polyurea is prepared from diisocyanate and diamine.

A kind of preparation method of Kevlar fiber cloth reinforced polyurea-based composite material is completed according to the following steps:

1. Put the diamine in the reaction bottle, stir magnetically for 1h~6h at a vacuum degree below 100Pa until there are no bubbles, and obtain the reaction solution A; put the diisocyanate in the reaction bottle, and magnetically stir for 1h at a vacuum degree below 100Pa ~6h until there is no air bubbles, and the reaction solution B is obtained;

2. Mix the reaction solution A and the reaction solution B, stir for 2-10 minutes to obtain a polyurea elastomer; the molar ratio of the diamine in the reaction solution A to the diisocyanate in the reaction solution B is 1:(0.8-1.2) ;

3. Immerse the Kevlar fiber cloth in the polyurea elastomer, and vacuumize it for 2-10 minutes to obtain the Kevlar fiber cloth soaked in polyurea;

4. Lay the polyurea-impregnated Kevlar fiber cloth in the mold layer by layer. Under normal pressure or vacuum atmosphere, use a press to apply pressure to the uppermost layer of polyurea-impregnated Kevlar fiber cloth. When the pressure increases to 10~ When the pressure is 100kN, the pressure is maintained at a pressure of 10-100kN for 0.1-2h, and the polyurea is solidified and released from the mold to obtain a Kevlar fiber cloth reinforced polyurea-based composite material.

Advantages of the present invention:

The preparation process of the invention is simple, without heating, and the obtained material has the characteristics of high strength and high toughness. Its tensile strength can reach 100-800MPa. During service, due to the good combination of polyurea and fiber, it is difficult for the fiber to be pulled out laterally and fail.

Description of drawings

Fig. 1 is the laminated board photo that adopts the Kevlar fiber cloth that embodiment one obtains to strengthen the polyurea-based composite material to make;

Fig. 2 is the low-magnification micro-morphological figure of the Kevlar fiber cloth reinforced polyurea-based composite material obtained in Example 1;

Fig. 3 is the high-magnification micro-morphological figure of the Kevlar fiber cloth reinforced polyurea-based composite material obtained in Example 1;

Fig. 4 is the exploded structural schematic diagram of described mould;

Fig. 5 is a structural schematic diagram of the lower bottom with holes.

detailed description

Specific embodiment 1: In this embodiment, a Kevlar fiber cloth reinforced polyurea-based composite material is combined with Kevlar fiber cloth as a reinforcement and polyurea as a matrix, wherein the volume percentage of the fiber cloth is 50% to 90%; The fiber cloth is made of natural fiber or chemical fiber; the polyurea is prepared from diisocyanate and diamine.

In this embodiment, the fibers are well combined with the polyurea, and the polyurea in the material completely or partially penetrates into the individual fibers in the fiber bundle.

Embodiment 2: This embodiment is different from Embodiment 1 in that: the form of the Kevlar fiber cloth is one or a mixture of woven cloth and unidirectional cloth. Others are the same as the first embodiment.

Embodiment 3: This embodiment is different from Embodiment 1 or Embodiment 2 in that the molar ratio of the diamine to diisocyanate is 1:(0.8-1.2). Others are the same as those in Embodiment 1 or 2.

Embodiment 4: This embodiment is different from Embodiment 1 to Embodiment 3 in that the molar ratio of diamine to diisocyanate is 1:1. Others are the same as one of the specific embodiments 1 to 3.

Embodiment 5: The difference between this embodiment and Embodiments 1 to 4 is that the diisocyanate is toluene diisocyanate, diphenylmethane-4,4'-diisocyanate and modified diphenylmethane diisocyanate one or a mixture of several of them. Others are the same as one of the specific embodiments 1 to 4.

Embodiment 6: The difference between this embodiment and one of Embodiments 1 to 5 is that the diamine is poly-1,4-butanediol bis(4-aminobenzoate), amino-terminated polyoxygen One of propylene ether and amino-terminated polyoxyethylene ether or a mixture of several of them, when the diamine is a mixture, its molecular weight is 230-5000. Others are the same as one of the specific embodiments 1 to 5.

Embodiment 7: In this embodiment, a method for preparing a Kevlar fiber cloth reinforced polyurea-based composite material is completed in the following steps:

1. Put the diamine in the reaction bottle, stir magnetically for 1h~6h at a vacuum degree below 100Pa until there are no bubbles, and obtain the reaction solution A; put the diisocyanate in the reaction bottle, and magnetically stir for 1h at a vacuum degree below 100Pa ~6h until there is no air bubbles, and the reaction solution B is obtained;

2. Mix the reaction solution A and the reaction solution B, stir for 2-10 minutes to obtain a polyurea elastomer; the molar ratio of the diamine in the reaction solution A to the diisocyanate in the reaction solution B is 1:(0.8-1.2) ;

3. Immerse the Kevlar fiber cloth in the polyurea elastomer, and vacuumize it for 2-10 minutes to obtain the Kevlar fiber cloth soaked in polyurea;

4. Lay the polyurea-impregnated Kevlar fiber cloth in the mold layer by layer. Under normal pressure or vacuum atmosphere, use a press to apply pressure to the uppermost layer of polyurea-impregnated Kevlar fiber cloth. When the pressure increases to 10~ When the pressure is 100kN, the pressure is maintained at a pressure of 10-100kN for 0.1-2h, and the polyurea is solidified and released from the mold to obtain a Kevlar fiber cloth reinforced polyurea-based composite material.

The degree of vacuum described in step 3 of this embodiment is below 1000 Pa.

Embodiment 8: The difference between this embodiment and Embodiment 7 is that the diisocyanate described in step 1 is toluene diisocyanate, diphenylmethane-4,4'-diisocyanate and modified diphenylmethane diisocyanate one or a mixture of several of them. Others are the same as the seventh embodiment.

Specific embodiment nine: the difference between this embodiment and specific embodiment seven or eight is that the diamine is poly-1,4-butanediol bis(4-aminobenzoate), amino-terminated polyoxypropylene One of ether and amino-terminated polyoxyethylene ether or a mixture of several of them, when the diamine is a mixture, its molecular weight is 230-5000. Others are the same as the seventh or eighth specific embodiment.

Specific Embodiment 10: The difference between this embodiment and one of specific embodiments 7 to 9 is that the way of layer-by-layer laying described in step 4 is [0°/22.5°] _n laying, [0°/45°] _n Lay, [0°/67.5°] _nlay , [0°/90°] _nlay , [0°/30°] _nlay , [0°/60°] _nlay , [-30°/30°] _n laying, [-60°/60°] _n laying, [0°/22.5°/45°/67.5°/90°] _n laying, and [0°/45°/90°/135°] _n laying one or a combination of several of them. Others are the same as one of the seventh to ninth specific embodiments.

Embodiment 11: This embodiment differs from Embodiment 7 to Embodiment 11 in that: the mold described in step 4 is composed of an upper indenter 1, a mold body 2 and a lower bottom 3 with holes; the mold body 2 There is a through hole in the middle, the lower bottom 3 with holes is arranged on one side of the through hole, the upper indenter 1 is pressed in from the other side, and the lower bottom 3 with holes is in interference connection with the mold main body 2 , The interference size is 0.01mm ~ 1mm. Others are the same as one of the seventh to tenth specific embodiments.

Embodiment 12: This embodiment differs from Embodiment 7 to Embodiment 11 in that the molar ratio of the diamine in the reaction solution A to the diisocyanate in the reaction solution B in step 2 is 1:1. Others are the same as one of the seventh to eleventh specific embodiments.

Adopt the following examples to verify the beneficial effects of the present invention:

Embodiment one: a kind of preparation method of Kevlar fiber cloth reinforced polyurea-based composite material is completed according to the following steps:

1. Put the diamine in the reaction bottle, stir magnetically for 3 hours at a vacuum degree below 10Pa until there is no bubble, and obtain the reaction solution A; put the diisocyanate in the reaction bottle, and stir magnetically for 3 hours at a vacuum degree below 10Pa until there is no air bubbles. bubbles to obtain reaction solution B; the molar ratio of the diamine to diisocyanate is 1;

2. Mix the reaction solution A and the reaction solution B, and stir for 3 minutes to obtain a polyurea elastomer;

3. Immerse the Kevlar woven fiber cloth in the polyurea elastomer, and vacuumize it for 3 minutes to obtain the Kevlar fiber cloth soaked in polyurea;

4. Lay the polyurea-impregnated Kevlar fiber cloth in [0°]n layers in the mold. Under normal pressure atmosphere, use a press to apply pressure to the uppermost polyurea-impregnated Kevlar fiber cloth. When When the pressure was increased to 50kN, the pressure was kept at 50kN for 1h, and the polyurea was solidified and released from the mold to obtain a Kevlar fiber cloth reinforced polyurea-based composite material.

Fig. 1 is the laminated board photo that adopts the Kevlar fiber cloth reinforced polyurea-based composite material that embodiment one obtains to make; Fig. 2 is the low-magnification microscopic topography figure of the Kevlar fiber cloth reinforced polyurea-based composite material that embodiment one obtains; Fig. 3 is a high-magnification microscopic morphology diagram of the Kevlar fiber cloth reinforced polyurea-based composite material obtained in Example 1. It can be seen from Figure 2 and Figure 3 that the laminated composite material is dense, and the fiber monofilament is well combined with polyurea.

Claims (10)

1. a kind of Kevlar fiber cloths strengthen polyureas based composites, it is characterised in that a kind of Kevlar fiber cloths strengthen polyureas base Composite is, using Kevlar fiber cloths as reinforcement, to be combined using polyureas as matrix, wherein the volume hundred of fiber cloth Fraction is 50%~90%；The material of the fiber cloth is natural fiber or chemical fibre；The polyureas is by diisocyanate It is prepared from diamine.

2. a kind of Kevlar fiber cloths enhancing polyureas based composites according to claim 1, it is characterised in that described The form of Kevlar fiber cloths be woven cloth and unidirectional cloth in one or two kinds of mixing.

3. a kind of Kevlar fiber cloths enhancing polyureas based composites according to claim 1, it is characterised in that described two The mol ratio of first amine and diisocyanate is 1:(0.8~1.2).

4. a kind of Kevlar fiber cloths enhancing polyureas based composites according to claim 1, it is characterised in that described two Isocyanates is toluene di-isocyanate(TDI), diphenyl methane -4,4 '-diisocyanate and modified diphenylmethane diisocyanate In one kind or wherein several mixtures.

5. a kind of Kevlar fiber cloths enhancing polyureas based composites according to claim 1, it is characterised in that described two First amine is poly- 1,4- butanediols double (PABA esters), Amino End Group PPOX ether and Amino End Group polyethylene glycol oxide ether In one kind or wherein several mixtures, when diamine is mixture, its molecular weight is 230~5000.

6. a kind of Kevlar fiber cloths as claimed in claim 1 strengthen the preparation method of polyureas based composites, its feature exists The preparation method for strengthening polyureas based composites in Kevlar fiber cloths is completed according to the following steps：

First, diamine is placed in reaction bulb, vacuum be below 100Pa magnetic agitations 1h~6h to bubble-free, obtain anti- Answer liquid A；Diisocyanate is placed in reaction bulb, vacuum be below 100Pa magnetic agitations 1h~6h to bubble-free, obtain Reaction solution B；

2nd, reaction solution A and reaction solution B is mixed, stirs 2~10min, obtain SPUA；Diamine in the reaction solution A Mol ratio with diisocyanate in reaction solution B is 1:(0.8~1.2)；

3rd, Kevlar fiber cloths are immersed in SPUA, vacuumizes 2~10min, obtain being soaked with the Kevlar fibers of polyureas Cloth；

4th, the Kevlar fiber cloths for being soaked with polyureas are successively elaborated in mould, under normal pressure or vacuum atmosphere, uses pressure Machine applies pressure to the Kevlar fiber cloths for being soaked with polyureas of the superiors, when pressure increases to 10~100kN, is 10 in pressure 0.1~2h of pressurize under~100kN, the demoulding obtains Kevlar fiber cloths enhancing polyureas based composites after polyureas solidification.

7. a kind of Kevlar fiber cloths according to claim 6 strengthen the preparation method of polyureas based composites, its feature It is toluene di-isocyanate(TDI), diphenyl methane -4,4 to be diisocyanate described in step one '-diisocyanate and modified two One kind or wherein several mixtures in methylenebis phenyl isocyanate.

8. a kind of Kevlar fiber cloths according to claim 6 strengthen the preparation method of polyureas based composites, its feature It is that the diamine is poly- for poly- 1,4- butanediols double (PABA esters), Amino End Group PPOX ether and Amino End Group One kind or wherein several mixtures in ethylene oxide ether, when diamine is mixture, its molecular weight is 230~5000.

9. a kind of Kevlar fiber cloths according to claim 6 strengthen the preparation method of polyureas based composites, its feature It is [0 °/22.5 °] to be the mode successively elaborated described in step 4_nLaying, [0 °/45 °]_nLaying, [0 °/67.5 °]_nLaying, [0°/90°]_nLaying, [0 °/30 °]_nLaying, [0 °/60 °]_nLaying, [- 30 °/30 °]_nLaying, [- 60 °/60 °]_nLaying, [0 °/ 22.5°/45°/67.5°/90°]_nLaying and [0 °/45 °/90 °/135 °]_nOne kind or wherein several combinations in laying.

10. a kind of Kevlar fiber cloths according to claim 6 strengthen the preparation method of polyureas based composites, its feature It is that mould described in step 4 is made up of seaming chuck (1), die main body (2) and bottom (3) with holes；The die main body (2) Centre is provided with through hole, and the bottom (3) with holes is arranged on the side of through hole, and the seaming chuck (1) is pressed into from opposite side, the band Hole bottom (3) is connected with the die main body (2) interference, and Interference size is 0.01mm~1mm.