Polyurethane-liquid filling type explosion protection structure

Abstract

The invention relates to a polyurethane-liquid filling type explosion protection structure, and belongs to the technical field of public safety defense equipment. Comprising a flexible shell, polyurethane foam balls and liquid, the polyurethane foam ball and the liquid are filled in the flexible shell, the cylindrical explosive is positioned in the center of the flexible shell, one end of the detonator is inserted into the explosive, and the other end of the detonator extends out of the flexible shell. Polyurethane and liquid with proper density are selected, the volume ratio of the polyurethane and the liquid is controlled, and the polyurethane and the liquid are filled in a flexible shell; the explosive is located in the center of the shell, oxygen can be effectively isolated, secondary energy release generated by explosion is reduced, and the explosion reaction degree and the aftereffect reaction are reduced; meanwhile, the polyurethane and the liquid are matched to form a multi-cavity flexible protection structure, so that the energy absorption density of the structure in unit protection volume is effectively improved, and the energy absorption efficiency is high.

Description

Technical Field

[0001] The invention relates to a polyurethane-liquid filled explosion protection structure, belonging to the technical field of public safety protection equipment. Background Art

[0002] Current protective structures, such as explosion-proof tanks and explosion-proof balls, are generally made of metal steel, ceramics, aluminum alloys and other materials, and their diameters are generally 0.4m to 1.2m. During disposal, the explosives are placed inside the explosion-proof container structure at a certain distance from the wall of the protective structure. Generally speaking, the farther the wall of the rigid protective structure is from the center of the explosion, the less likely it is to break and disintegrate. This will waste more protective space and greatly increase the weight of the protective structure. If the explosives are placed directly close to the wall of the rigid protective structure, the structure will break and scatter, causing damage.

[0003] Polyurethane foam is a type of high molecular polymer with a three-dimensional network structure. It is widely used in impact-resistant protective structures due to its low density, high specific strength, and low cost. Compared with traditional high-strength dense explosion-proof materials, polyurethane foam is light in weight, has no secondary damage after explosion, and has a high degree of designability in microstructure. It has broad research prospects in explosion-proof structure design.

[0004] Patent ZL202111123230.3 discloses an explosion-proof and impact-resistant structure based on a flexible sphere and a method for preparing an explosion-proof and impact-resistant flexible sphere. The flexible sphere is mainly filled in annular wall structures such as flexible explosion-proof barrels. The filling liquid is mainly water, so as to achieve the effect of shock wave absorption. The protective structure is not in direct contact with the explosive, and the structure is a certain distance away from the explosion center. Patent ZL202210110946.8 discloses an intrinsically safe explosive disposal and protection device and a method of use. The explosion-proof filling material layer on the support plate in the explosion-proof barrel is filled with polyurethane foam balls. The liquid is also water, dry water, and shear thickening liquid. The material itself is not in direct contact with the explosive. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a polyurethane-liquid filled explosion protection structure.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows.

[0007] A polyurethane-liquid filled explosion protection structure comprises a flexible shell, a polyurethane foam ball and a liquid; the polyurethane foam ball and the liquid are filled in the flexible shell, and the density of the polyurethane foam ball is 100-300kg / m 3 , the density of the liquid is 1550~1650kg / m 3The volume of the polyurethane foam ball in the flexible shell accounts for 30% to 70%, and the volume of the liquid accounts for 30% to 70%; the explosive is located at the center of the flexible shell, one end of the detonator is inserted into the explosive, and the other end extends outside the flexible shell.

[0008] Preferably, nanoporous particles are mixed in the liquid; more preferably, the nanoporous particles include sodium bicarbonate and zeolite; and the mass ratio of the nanoporous particles to the liquid is 1:100 to 5:100.

[0009] Preferably, the flexible shell is a sphere or a cylinder, and the diameter of the flexible shell is 5 to 10 times the diameter of the explosive.

[0010] Preferably, the density of the flexible shell is 1000-2000 kg / m 3 ; More preferably, the material of the flexible shell is thermoplastic polyurethane (TPU) or polyvinyl chloride (PVC); the flexible shell contains fiber fabric as a reinforcement structure.

[0011] Preferably, the thickness of the flexible shell is 0.2-2 mm.

[0012] Preferably, the liquid is perfluorohexanone.

[0013] Preferably, the volume of the polyurethane foam balls in the flexible shell accounts for 40% to 50%, and the volume of the liquid accounts for 50% to 60%.

[0014] Preferably, the diameter of the polyurethane foam ball is 0.2 to 2 times the diameter of the explosive; more preferably, the diameter of the polyurethane foam ball is consistent with the diameter of the explosive.

[0015] Preferably, the polyurethane foam ball is obtained by curing and molding component A and component B; component A is a mixture of the following components in parts by weight: 100 parts of high-functionality and high-hydroxyl polyether polyol, 2 to 5 parts of a crosslinking agent, 0.5 to 2 parts of a chemical foaming agent, 5 to 20 parts of a physical foaming agent, 0.2 to 2 parts of a foam stabilizer, 0.5 to 2 parts of a catalyst, 20 to 50 parts of an inorganic nanopowder material, and 8 to 12 parts of a flame retardant; component B is polyphenylmethane polyisocyanate (PAPI); and the molar ratio of -OH groups in component A to -NCO groups in component B is 1.2 to 1.5:1.

[0016] Preferably, the functionality of the high-functionality and high-hydroxyl polyether polyol is greater than or equal to 4, and the hydroxyl value is 400-500 mgKOH / g; the cross-linking agent is one or more of triethanolamine, dimethylenetriamine and trimethylenetetramine; the chemical foaming agent is H2O; the physical foaming agent is monochlorotrifluoromethane, dichlorodifluoroethane, n-pentane or cyclopentane; the foam stabilizer is a foam stabilizer with a brand of AK-8805 or AK-8806 produced by Jiangsu Meside Company; the catalyst The agent is one or more of A33 (a liquid catalyst containing 33% triethylenediamine), T12 (dibutyltin dimethyl silicate), PC-41 (tris(dimethylaminopropyl)hexahydrotriazine) and DMP30 (2,4,6-tris(dimethylaminomethyl)phenol); the inorganic nano-powder material is one or more of nano-aluminum hydroxide with a particle size of 20 to 100 nm, nano-magnesium hydroxide with a particle size of 20 to 100 nm, and nano-calcium carbonate; the flame retardant is expandable graphite.

[0017] Preferably, the brand of the high-functionality and high-hydroxyl value polyether polyol is one or more of 8010, 4110, 8205 and 8305; the cross-linking agent is triethanolamine; the physical foaming agent is monofluorotrichloromethane or difluorodichloroethane; the foam stabilizer is the foam stabilizer with the brand AK-8805 of Jiangsu Meside Company; the catalyst is a mixture of A33, T12 and DMP30; and the inorganic nanopowder material is nano aluminum hydroxide with a particle size of 20 to 30 nm.

[0018] Preferably, the preparation method of the polyurethane foam ball comprises the following steps:

[0019] (1) uniformly mixing a high-functionality and high-hydroxyl polyether polyol, a crosslinking agent, a chemical foaming agent, a physical foaming agent, a foam stabilizer, a catalyst, an inorganic nanopowder and a flame retardant to obtain a component A;

[0020] (2) Component A and component B are mixed and poured into a mold, foamed, and cured to obtain a polyurethane foam ball.

[0021] Beneficial Effects

[0022] The present invention provides a polyurethane-liquid filled explosion protection structure, which is filled in a flexible shell by selecting polyurethane and liquid of suitable density and controlling the volume ratio of the two; the explosive is located at the center of the shell, which can effectively isolate oxygen, reduce the secondary energy release caused by the explosion, reduce the degree of explosion reaction and its after-effect reaction; at the same time, the polyurethane and the liquid cooperate to form a multi-cavity flexible protection structure, which effectively improves the structural energy absorption density within the unit protection volume, has high energy absorption efficiency and low secondary explosion damage; in addition, different wave impedance structures are formed inside the protection structure, which can more efficiently make the shock wave form multiple reflections and refractions inside the protection structure, thereby consuming and absorbing the shock wave energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1-2 It is a schematic diagram of the protective structure of the present invention.

[0024] 1-explosive; 2-polyurethane foam ball; 3-liquid; 4-flexible shell;

[0025] Figure 3 It is the high-speed photography picture when exploding in Example 1 and the comparative example.

[0026] Figure 4 It is a comparison chart of flame duration in Example 1 and the comparative example.

[0027] Figure 5 It is a comparison diagram of the shock wave peak values ​​in Example 1 and the comparative example. DETAILED DESCRIPTION

[0028] The present invention will be further described in detail below in conjunction with specific embodiments.

[0029] like Figure 1-2 As shown, a polyurethane-liquid filled explosion protection structure includes a flexible shell 4, a polyurethane foam ball 2 and a liquid 3; the polyurethane foam ball 2 and the liquid 3 are filled in the flexible shell 4, and the density of the polyurethane foam ball 2 is 100-300kg / m 3 , the density of liquid 3 is 1550~1650kg / m 3 The volume of the polyurethane foam ball 2 in the flexible shell 4 accounts for 30% to 70%, and the volume of the liquid accounts for 30% to 70%; the columnar explosive 1 is located at the center of the flexible shell 4, one end of the detonator is inserted into the explosive 1, and the other end extends to the outside of the flexible shell 4.

[0030] Preferably, nanoporous particles are mixed in the liquid; more preferably, the nanoporous particles include sodium bicarbonate and zeolite; and the mass ratio of the nanoporous particles to the liquid is 1:100 to 5:100.

[0031] Preferably, the flexible shell 4 is a sphere or a cylinder, and the diameter of the flexible shell is 5 to 10 times the diameter of the explosive.

[0032] Preferably, the density of the flexible shell 4 is 1000-2000 kg / m 3 ; More preferably, the material of the flexible shell 4 is thermoplastic polyurethane (TPU) or polyvinyl chloride (PVC); the flexible shell contains fiber fabric as a reinforcement structure.

[0033] Preferably, the thickness of the flexible shell 4 is 0.2-2 mm.

[0034] Preferably, the volume of the polyurethane foam balls in the flexible shell accounts for 40% to 50%, and the volume of the liquid accounts for 50% to 60%.

[0035] Preferably, the liquid 3 is perfluorohexanone.

[0036] Preferably, the diameter of the polyurethane foam ball 2 is 0.2 to 2 times the diameter of the explosive 1 ; more preferably, the diameter of the polyurethane foam ball 2 is consistent with the diameter of the explosive 1 .

[0037] The polyurethane foam ball 2 is obtained by curing component A and component B; component A is a mixture of the following components in parts by mass: 100 parts of high-functionality and high-hydroxyl polyether polyol, 2-5 parts of a crosslinking agent, 0.5-2 parts of a chemical foaming agent, 5-20 parts of a physical foaming agent, 0.2-2 parts of a foam stabilizer, 0.5-2 parts of a catalyst, 20-50 parts of an inorganic nanopowder material, and 8-12 parts of a flame retardant; component B is polyphenylmethane polyisocyanate (PAPI); the molar ratio of -OH groups in component A to -NCO groups in component B is 1.2-1.5:1. The polyurethane foam ball is prepared by selecting high-functionality low-molecular-weight polyether polyol and high-functionality cross-linking agent, reacting with excessive polymerized MDI curing agent, and using H2O as a chemical foaming agent. By increasing the cross-linking point density of the generated polyurethane foam matrix and forming isocyanate trimer and urea-based rigid structures, the hardness and brittleness of the polyurethane foam matrix are improved. In addition, a certain amount of inorganic nano powder material is added to further improve the strength and brittleness of the polyurethane foam. Adding a certain amount of flame retardant can improve the overall flame retardant effect. The raw materials required for preparing the easily crushed polyurethane foam are weighed and mixed in proportion and then poured into a mold for foaming and curing to obtain an explosion shock wave easily crushed polyurethane rigid foam structure.

[0038] The functionality of the high-functionality and high-hydroxyl polyether polyol is greater than or equal to 4, and the hydroxyl value is 400-500 mgKOH / g. For example, the high-hydroxyl polyether polyol with a functionality of more than 4 produced by using small molecules containing 4 or more active hydrogens such as sucrose, sorbitol, diethylenetriamine, triethylenetetramine as initiators, such as polyether polyols with grades 8010, 4110, 8205, 8305, etc. Preferably, the polyether polyol is a polyether polyol with a functionality greater than 4 and a hydroxyl value in the range of 400-500 mgKOH / g using sucrose and sorbitol as initiators, and the optional grades are 8010 and 4110 polyether polyols.

[0039] The cross-linking agent is one or more small molecular compounds containing 3 or more active hydrogen atoms such as triethanolamine, dimethylenetriamine and trimethylenetetramine; preferably triethanolamine.

[0040] The chemical foaming agent is H2O.

[0041] The physical foaming agent is trichloromonofluoromethane, dichlorodifluoroethane, n-pentane or cyclopentane; preferably trichloromonofluoromethane or dichlorodifluoroethane.

[0042] The foam stabilizer is a foam stabilizer with the brand number AK-8805 or AK-8806 produced by Jiangsu Meside Company; preferably, it is a foam stabilizer with the brand number AK-8805 produced by Jiangsu Meside Company.

[0043] The catalyst is one or more of A33 (liquid catalyst containing 33% triethylenediamine), T12 (dibutyltin diisocyanate), PC-41 (tris(dimethylaminopropyl)hexahydrotriazine) and DMP30 (2,4,6-tris(dimethylaminomethyl)phenol); preferably a mixture of A33, T12 and DMP30.

[0044] The inorganic nano powder material is one or more of nano aluminum hydroxide with a particle size of 20 to 100 nm, nano magnesium hydroxide with a particle size of 20 to 100 nm, and nano calcium carbonate; preferably, nano aluminum hydroxide with a particle size of 20 to 30 nm.

[0045] The flame retardant is expandable graphite. The high-temperature heat source is used to induce rapid expansion. The high-volume expanded graphite sheets occupy the surface of the polyurethane to form a dense carbon isolation layer, covering the combustion area, isolating the substrate from the external burning flame, and effectively separating oxygen from the burning substrate, thereby improving the flame retardant performance.

[0046] The preparation method of the polyurethane foam ball 2 comprises the following steps:

[0047] (1) uniformly mixing a high-functionality and high-hydroxyl polyether polyol, a crosslinking agent, a chemical foaming agent, a physical foaming agent, a foam stabilizer, a catalyst, an inorganic nanopowder and a flame retardant to obtain a component A;

[0048] (2) Component A and component B are mixed and poured into a mold, foamed, and cured to obtain a polyurethane foam ball.

[0049] Example 1

[0050] Take 80g TNT explosive protection as an example. The explosive is a φ40*40mm columnar explosive. The flexible shell is made of TPU material with a thickness of 0.3mm. Fiber fabric is added inside as a structural reinforcement. The size of the flexible shell is φ200*200mm. The diameter of the filled polyurethane foam ball is 20mm, the number is 694, and the weight of the filled liquid perfluoroacetone is 2002g. The explosive is placed in the center of the flexible shell, the polyurethane foam ball is poured in, and then the perfluoroacetone is filled.

[0051] Polyurethane foam ball is obtained by curing component A and component B, with a density of 200kg / m 3 The components and mass fractions of component A are: 100 parts of high-functionality and high-hydroxyl polyether polyol (brand 8010, 4110), 3 parts of cross-linking agent triethanolamine, 1 part of chemical foaming agent H2O, 10 parts of physical foaming agent (monochlorotrifluoromethane and dichlorodifluoroethane), 0.5 parts of foam stabilizer (foam stabilizer with brand AK-8805 of Jiangsu Meside Company), 1 part of catalyst (mixture of A33, T12 and DMP30), 30 parts of inorganic nanopowder material (nano aluminum hydroxide with a particle size of 30nm), and 10 parts of flame retardant expandable graphite; component B is polyphenylmethane polyisocyanate PAPI (polymerized MDI with brand PM200); the molar ratio of -OH group in component A to -NCO group in component B is 1.4:1 (the mass ratio of component A to component B is 1:1).

[0052] Comparative Example 1

[0053] In this comparative example, no protective structure is used, and air blasting is directly carried out.

[0054] Comparative Example 2

[0055] In this comparative example, the protective structure is filled with only polyurethane foam balls and no liquid.

[0056] In both the embodiment and the comparative example, 8# electric detonator was used for detonation, high-speed photography with a frame rate of 10000 fps was used to capture the flame duration, and a pressure sensor 1 m away from the explosion center was used to test the pressure condition after the explosion.

[0057] The high-speed photography pictures during the explosion in the embodiments and comparative examples are as follows: Figure 3 shown.

[0058] The flame duration comparison results in Example 1 and the comparative example are as follows: Figure 4 As shown, the flame duration under air explosion conditions in Comparative Example 1 is 86 ms, that in Comparative Example 2 is 2 ms, and there is almost no flame in Example 1.

[0059] After the explosion, the peak pressure of the shock wave at 1m was tested. The comparison results of the peak pressure of the shock wave in the embodiment and the comparative example are as follows: Figure 5 As shown, the maximum peak value of the shock wave pressure after the explosion of Comparative Example 1 is 133.5 kPa, the maximum peak value of the shock wave pressure in Comparative Example 2 is 72.5 kPa, and the maximum peak value of the shock wave pressure in Example 1 is 29.8 kPa.

[0060] In summary, the invention includes but is not limited to the above embodiments. Any equivalent substitution or partial improvement made under the spirit and principle of the invention shall be deemed to be within the protection scope of the invention.

Claims

1. A polyurethane-liquid filled explosion protection structure, characterized in that: The invention comprises a flexible shell, a polyurethane foam ball and a liquid; the polyurethane foam ball and the liquid are filled in the flexible shell, and the density of the polyurethane foam ball is 100-300 kg / m 3 , the density of the liquid is 1550~1650kg / m 3 The volume of the polyurethane foam ball in the flexible shell accounts for 30% to 70%, and the volume of the liquid accounts for 30% to 70%; the columnar explosive is located at the center of the flexible shell, one end of the detonator is inserted into the explosive, and the other end extends outside the flexible shell.

2. A polyurethane-liquid filled explosion protection structure as claimed in claim 1, characterized in that: The liquid is mixed with nanoporous particles; preferably, the nanoporous particles include sodium bicarbonate and zeolite; the mass ratio of the nanoporous particles to the liquid is 1:100 to 5:

100.

3. A polyurethane-liquid filled explosion protection structure as claimed in claim 1, characterized in that: The flexible shell is a sphere or a cylinder, and the diameter of the flexible shell is 5 to 10 times the diameter of the explosive.

4. A polyurethane-liquid filled explosion protection structure as claimed in claim 1, characterized in that: The density of the flexible shell is 1000-2000 kg / m 3 ; Preferably, the material of the flexible shell is thermoplastic polyurethane elastomer or polyvinyl chloride; the flexible shell contains fiber fabric as a reinforcement structure; The thickness of the flexible shell 4 is 0.2-2 mm.

5. The polyurethane-liquid filled explosion protection structure according to claim 1, characterized in that: The liquid is perfluorohexanone; preferably, the volume of the polyurethane foam balls in the flexible shell accounts for 40% to 50%, and the volume of the liquid accounts for 50% to 60%.

6. A polyurethane-liquid filled explosion protection structure as claimed in claim 1, characterized in that: The diameter of the polyurethane foam ball is 0.2 to 2 times the diameter of the explosive; preferably, the diameter of the polyurethane foam ball is consistent with the diameter of the explosive.

7. A polyurethane-liquid filled explosion protection structure as claimed in claim 1, characterized in that: The polyurethane foam ball is obtained by curing and molding component A and component B; component A is a mixture of the following components in parts by mass: 100 parts of high-functionality and high-hydroxyl polyether polyol, 2-5 parts of a crosslinking agent, 0.5-2 parts of a chemical foaming agent, 5-20 parts of a physical foaming agent, 0.2-2 parts of a foam stabilizer, 0.5-2 parts of a catalyst, 20-50 parts of an inorganic nano powder material, and 8-12 parts of a flame retardant; component B is polyphenylmethane polyisocyanate (PAPI); and the molar ratio of -OH groups in component A to -NCO groups in component B is 1.2-1.5:

1.

8. A polyurethane-liquid filled explosion protection structure as claimed in claim 7, characterized in that: The functionality of the high-functionality and high-hydroxyl-value polyether polyol is greater than or equal to 4, and the hydroxyl value is 400-500 mgKOH / g; the cross-linking agent is one or more of triethanolamine, methylenetriamine and trimethylenetetramine; the chemical foaming agent is H2O; the physical foaming agent is monofluorotrichloromethane, difluorodichloroethane, n-pentane or cyclopentane; the foam stabilizer is a foam stabilizer with a brand of AK-8805 or AK-8806 produced by Jiangsu Meside Company; the catalyst is one or more of A33, T12, PC-41 and DMP30; the inorganic nanopowder material is one or more of nano aluminum hydroxide with a particle size of 20-100 nm, nano magnesium hydroxide with a particle size of 20-100 nm, and nano calcium carbonate; the flame retardant is expandable graphite.

9. A polyurethane-liquid filled explosion protection structure as claimed in claim 8, characterized in that: The brand of the high-functionality and high-hydroxyl value polyether polyol is one or more of 8010, 4110, 8205 and 8305; the cross-linking agent is triethanolamine; the physical foaming agent is monofluorotrichloromethane or difluorodichloroethane; the foam stabilizer is the foam stabilizer with the brand of AK-8805 produced by Jiangsu Meside Company; the catalyst is a mixture of A33, T12 and DMP30; the inorganic nanopowder material is nano aluminum hydroxide with a particle size of 20 to 30 nm.

10. A polyurethane-liquid filled explosion protection structure according to any one of claims 7 to 9, characterized in that: The preparation method of the polyurethane foam ball comprises the following steps: (1) uniformly mixing high-functionality and high-hydroxyl polyether polyol, a crosslinking agent, a chemical foaming agent, a physical foaming agent, a foam stabilizer, a catalyst, an inorganic nanopowder and a flame retardant to obtain component A; (2) mixing component A and component B, pouring them into a mold, foaming, and curing to obtain a polyurethane foam ball.

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