Composite material for improving elastic recovery capability of on-site mixed emulsion explosive

Abstract

The invention relates to a composite material for improving the elastic recovery capability of an on-site mixed emulsion explosive. The composite material is prepared from the following raw materials in parts by mass: 80 to 100 parts of salt-resistant hydrogel, 5 to 10 parts of tetramethylguanidine ionic liquid, 2 to 5 parts of polymer betaine dispersing agent and 2 to 5 parts of viscoelastic nano-microspheres. The composite material provided by the invention can effectively improve the elastic recovery capability of the on-site mixed loading emulsion explosive, so that the on-site mixed loading emulsion explosive has better pumpable performance in the pumping process, and meanwhile, the on-site mixed loading emulsion explosive can quickly show the elastic property and recover to the initial state after the pumping is finished. Therefore, the emulsion explosive has relatively high pumpability and structural stability. And after high-speed shearing, the viscosity rise amplitude is low, the ammonium nitrate precipitation rate is low, and the detonation velocity is kept at a relatively high level.

Description

Technical Field

[0001] The present invention belongs to the technical field of emulsion explosives, and particularly relates to a composite material for improving the elastic recovery ability of on-site mixed emulsion explosives. Background Art

[0002] On-site mixed emulsion explosives are the key emulsion explosive varieties to be promoted. Due to their convenient production, flexible use and good safety, their annual output has been steadily increasing in recent years and their status in industrial explosives is becoming more and more important. Different from traditional packaged emulsion explosives, on-site mixed emulsion explosives are generally used immediately after preparation and have a short storage time, so the long-term static storage stability is not as strict as that required for packaged emulsion explosives. However, before the on-site mixed emulsion explosives are used, their matrix often needs to undergo a long pumping process. During this process, the emulsion matrix will be subjected to external forces for a long time, and its microstructure will undergo deformation or even damage. Therefore, the dynamic stability of the on-site mixed emulsion explosive matrix under external forces is very important.

[0003] On-site mixed emulsion explosives are a typical type of viscoelastic non-Newtonian fluid. Their elastic deformation often includes irreversible viscous deformation, and there is also recoverable elastic deformation in viscous flow. Elastic and viscous deformations coexist and will transform under certain conditions. For example, when the external force is large, it undergoes large deformation and can exhibit the properties of a shear-thinning fluid; when the external force is small or removed, it exhibits elastic effects. Viscoelasticity is one of the important indicators for measuring the pumpability and dynamic stability of on-site mixed emulsion explosives. On the one hand, the matrix of on-site mixed emulsion explosives often undergoes a long pumping process, and during this process, the matrix needs to have high pumpability and its pumping pressure should be as low as possible, which requires the on-site mixed emulsion explosives to have a low viscosity under external forces. On the other hand, after the on-site mixed emulsion explosives are pumped into the blast hole, they also need good elastic recovery ability so that the deformation of the dispersed droplets and the destruction of the water-in-oil structure caused by the previous pumping can be repaired in time to ensure that the on-site mixed emulsion explosives have reliable explosive performance. Therefore, the elastic recovery ability of on-site mixed emulsion explosives after experiencing external forces is not only an important property of them, but also an important indicator for whether their dynamic stability and explosive performance can be improved. However, there are few technical methods to improve their dynamic stability and explosive performance from the perspective of the elastic recovery ability of on-site mixed emulsion explosives. Summary of the Invention

[0004] In view of the fact that there is little prior art that improves the dynamic stability and explosive performance of on-site mixed emulsion explosives from the perspective of their elastic recovery ability, the present invention proposes a composite material that can improve the elastic recovery ability of on-site mixed emulsion explosives. This composite material can effectively improve the elastic recovery ability of on-site mixed emulsion explosives, enabling the on-site mixed emulsion explosives to have excellent pumpability during the pumping process and, after the pumping is completed, quickly exhibit elastic properties and return to the initial state. Thus, the emulsion explosives have both high pumpability and structural stability. To achieve the above object, the present invention adopts the following technical solutions:

[0005] A composite material for improving the elastic recovery ability of on-site mixed emulsion explosives, comprising the following raw materials in parts by mass: 80-100 parts of salt-tolerant hydrogel, 5-10 parts of tetramethylguanidine ionic liquid, 2-5 parts of polymer betaine dispersant, and 2-5 parts of viscoelastic nanospheres.

[0006] Before use, the on-site mixed emulsion explosive matrix often needs to undergo a long pumping process. During this process, the emulsion matrix will be subjected to long-term external forces, and its microstructure will deform or even be damaged. If the damaged microstructure cannot recover, it may lead to a decline in the performance and stability of the on-site mixed emulsion explosives, and in severe cases, the explosives may lose their use value. Therefore, improving the structural recovery ability of on-site mixed emulsion explosives is an effective way to improve the structural stability of on-site mixed emulsion explosives. However, there is little prior art in this regard.

[0007] In the present invention, a salt-tolerant hydrogel is used as the main component, in combination with a tetramethylguanidine ionic liquid plasticizer, a polymeric betaine dispersant, and viscoelastic nanospheres, in the aqueous phase of an on-site mixed emulsion explosive to improve the structural recovery ability of the on-site mixed emulsion explosive. Hydrogels generally have good elastic recovery effects, and the on-site mixed emulsion explosive prepared therefrom has relatively good elasticity. However, since the aqueous phase in the on-site mixed emulsion explosive is a high-salt concentration system, if the salt tolerance of the hydrogel is poor, it may degrade or precipitate, and a relatively stable system cannot be formed, thus losing its function. Therefore, it is more suitable to select a salt-tolerant hydrogel for the aqueous phase system of the emulsion explosive. In addition, even if a small amount of hydrogel is added, the viscosity of the matrix of the on-site mixed emulsion explosive will increase, which will increase the pumping pressure of the matrix of the on-site mixed emulsion explosive and reduce the safety of its transportation process. To solve this problem, we add a small amount of ionic liquid plasticizer to endow the hydrogel and the matrix of the on-site mixed emulsion explosive after its addition with good fluidity, so that the pressure during pumping does not increase too much. On this basis, a small amount of viscoelastic nanospheres + polymeric dispersant is further added to make the viscoelastic nanospheres uniformly dispersed in the on-site mixed emulsion explosive system. On the one hand, the viscoelastic nanospheres also help to improve the viscoelastic properties of the emulsion matrix, further improving its structural recovery ability. On the other hand, when these microsphere materials with rich functional groups on the surface are at the oil-water interface of the emulsion explosive, they have a positive effect on improving the strength of the oil film on the surface of the dispersed phase droplets in the emulsion explosive and the recovery effect of the oil film after being damaged by external forces during pumping. Therefore, the structural stability and recovery effect can be further improved.

[0008] The lowest critical solution temperature (LCST) of the salt-tolerant hydrogel is 30 - 50 °C, and the viscosity-average molecular weight is 150,000 - 250,000. Specifically, it is selected from at least one of cyclodextrin-based poly(N-isopropylacrylamide) hydrogel, N-isopropylacrylamide-β-cyclodextrin-tetraphenylethylene polymer hydrogel, and β-cyclodextrin polymer / acrylamide / acrylic acid copolymer hydrogel. The mechanism by which the above hydrogel can tolerate salt is not yet clear, and it may be the synergistic effect of host-guest interaction, hydrophobic interaction, and multiple physical crosslinking networks.

[0009] The tetramethylguanidine ionic liquids are selected from any one of tetramethylguanidine hydrochloride, tetramethylguanidine nitrate, tetramethylguanidine hydrogen sulfate, and tetramethylguanidine dihydrogen phosphate.

[0010] The polymeric betaine dispersants are selected from at least one of poly(methacrylic acid sulfobetaine), poly(carboxybetaine methacrylate), poly(methacryloylethyl sulfobetaine), and poly(carboxybetaine acrylamide); further, the number-average molecular weight of the polymeric betaine dispersants is 4500–7000 g / mol.

[0011] The viscoelastic nano-microspheres are selected from any one of poly(N-isopropylacrylamide)-b-polyacrylic acid nano-microspheres, dimeric lactic acid polyethylene glycol nano-microspheres, and poly-N-isopropylacrylamide nano-microspheres; the particle size of the viscoelastic nano-microspheres is 10-50 nm, and the storage modulus (G’) is 1000-2000 Pa; preferably, the particle size of the viscoelastic nano-microspheres is 20-35 nm, and the storage modulus (G’) is 1000-1500 Pa.

[0012] Furthermore, the composite material further comprises the following raw materials in parts by mass: 2-4 parts of perfluoropolyether silicone oil, 0.5-0.8 part of carboxylated nano-cellulose.

[0013] Furthermore, the viscosity of the perfluoropolyether silicone oil at 25 °C is 40-60 mm 2 / s; the length of the carboxylated nano-cellulose is 0.5-1 μm, the diameter is 10-30 nm, and the carboxyl content is 1-3 mmol / g.

[0014] The composite material provided by the present invention can improve the elastic recovery ability of the on-site mixed emulsion explosive, but there is a certain loss in the anti-freeze-thaw cycle ability of the emulsion explosive. The emulsion explosive is water-in-oil type, and the aqueous phase contains ammonium nitrate. The crystallization of salt and the phase change of water during freeze-thaw will cause structural damage, thereby affecting the detonation velocity. The inventor unexpectedly found that adding a small amount of perfluoropolyether silicone oil and carboxylated nano-cellulose to the composite material can significantly improve the anti-freeze-thaw cycle ability of the emulsion explosive. The high detonation velocity of the explosive can still be maintained after freeze-thaw cycles.

[0015] The present invention also provides a preparation method of the above composite material, comprising the following steps: adding a tetramethylguanidine ionic liquid plasticizer and a polymeric betaine dispersant to a salt-tolerant hydrogel, stirring at 30-50 °C, and then adding viscoelastic nano-microspheres, and continuously stirring and mixing evenly to obtain the composite material.

[0016] Furthermore, the preparation method of the composite material comprises the following steps: adding a tetramethylguanidine ionic liquid plasticizer, a polymeric betaine dispersant, and perfluoropolyether silicone oil to a salt-tolerant hydrogel, stirring at 30-50 °C, and then adding viscoelastic nano-microspheres and carboxylated nano-cellulose, and continuously stirring and mixing evenly to obtain the composite material.

[0017] An emulsion explosive comprises the following raw materials in parts by mass: 70-80 parts of ammonium nitrate, 12-18 parts of water, 4-8 parts of oil, 1-3 parts of surfactant, 0.1-3 parts of sensitizer, and 0.2-1.5 parts of the above composite material.

[0018] Further, the emulsion explosive comprises the following raw materials in parts by mass: 70 - 80 parts of ammonium nitrate, 13 - 15 parts of water, 5 - 6 parts of oil, 1.5 - 2 parts of surfactant, 1 - 2 parts of sensitizer, and 0.5 - 1 part of the above composite material.

[0019] Further, the oil is selected from at least one of diesel oil and machine oil, such as 46# mechanical oil, 0# diesel oil, naphthenic oil, and a small amount of biodiesel; the surfactant is a non-ionic surfactant, specifically selected from at least one of span, tween, sorbitan sesquioleate, fatty alcohol polyoxyethylene ether sulfate, and fatty alcohol polyoxyethylene ether phosphate; the sensitizer is at least one of sodium nitrite, diatomite, and glass microspheres.

[0020] The present invention actually also provides a use of viscoelastic nanospheres for improving the elastic recovery ability of on-site mixed emulsion explosives. The viscoelastic nanospheres are selected from any one of poly(N-isopropylacrylamide)-b-polyacrylic acid nanospheres, dimeric lactic acid polyethylene glycol nanospheres, and poly N-isopropylacrylamide nanospheres, with a particle size of 10 - 50 nm and a storage modulus (G') of 1000 - 2000 Pa.

[0021] By adding a small amount of the composite material provided by the present invention to the emulsion explosive, the elastic recovery ability of the on-site mixed emulsion explosive can be significantly improved. After high-speed shearing, the viscosity of the emulsion matrix increases slightly, the ammonium nitrate precipitation rate is low, the detonation velocity of the explosive is basically unaffected, and the dynamic stability and explosion performance of the on-site mixed emulsion explosive are improved. The raw materials used in the preparation of the composite material of the present invention are environmentally friendly and easily available, and the addition amount in the emulsion explosive is small, which has high promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is the macroscopic picture of the emulsion explosive in Example 1 after being sheared for 1000S -1 and placed for 12 h.

[0023] Figure 2 is the macroscopic picture of the emulsion explosive in Comparative Example 1 after being sheared for 1000S -1 and placed for 12 h.

[0024] Figure 3 is the macroscopic picture of the emulsion explosive without adding the composite material after being sheared for 1000S -1 and placed for 12 h. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be further described below through examples, but the present invention is not limited to the described examples.

[0026] Cyclodextrin-based poly (N-isopropylacrylamide) hydrogel (LCST of 37°C, viscosity-average molecular weight of 236,200) and β-cyclodextrin polymer / acrylamide / acrylic acid copolymer hydrogel (LCST of 42°C, viscosity-average molecular weight of 255,800) were purchased from Xi'an Qiyue Biological.

[0027] Poly(N-isopropylacrylamide)-b-polyacrylic acid nanoparticles (average particle size 22 nm, storage modulus G'=1454 Pa), di-lactic acid polyethylene glycol nanoparticles (average particle size 28 nm, storage modulus G'=1088 Pa), and poly(N-isopropylacrylamide) nanoparticles (average particle size 31 nm, storage modulus G'=1242 Pa) were purchased from Xi'an Qiyue Biological.

[0028] The number average molecular weight of polymethacrylate sulfobetaine is 7000 g / mol, the number average molecular weight of polycarboxylic acid betaine methacrylate is 4500 g / mol, the number average molecular weight of polymethacryloylethyl sulfobetaine is 6700 g / mol, and the number average molecular weight of polycarboxybetaine acrylamide is 5900 g / mol.

[0029] Example 1

[0030] 0.1 kg of tetramethylguanidine hydrochloride and 0.05 kg of polymethacrylate sulfobetaine were added to 0.8 kg of cyclodextrin-based poly(N-isopropylacrylamide) hydrogel, heated to 50°C and stirred, and then 0.05 kg of poly(N-isopropylacrylamide)-b-polyacrylic acid nanospheres were added, and stirring was continued for 1 hour to obtain composite material 1.

[0031] Example 2

[0032] 0.06 kg of tetramethylguanidine nitrate and 0.02 kg of polycarboxylic acid betaine methacrylate were added to 0.9 kg of N-isopropylacrylamide-β-cyclodextrin-tetraphenylethylene polymer hydrogel, heated to 50° C. and stirred, then 0.02 kg of dilactic acid polyethylene glycol nanospheres were added, and stirring was continued for 1 hour to obtain composite material 2.

[0033] Example 3

[0034] 0.08 kg of tetramethylguanidine hydrogen sulfate and 0.04 kg of polymethacryloylethyl sulfobetaine were added to 0.84 kg of β-cyclodextrin polymer / acrylamide / acrylic acid copolymer hydrogel, heated to 50°C and stirred, then 0.04 kg of poly (N-isopropylacrylamide) nanospheres were added and stirred for 1 hour to obtain composite material 3.

[0035] Example 4

[0036] Add 0.09 kg of tetramethylguanidine dihydrogen phosphate and 0.04 kg of polycarboxybetaine acrylamide to 0.82 kg of cyclodextrin-based poly(N-isopropylacrylamide) hydrogel. After heating to 50 °C, start stirring, then add 0.05 kg of dilactic acid polyethylene glycol nanospheres, and continue stirring for 1 h to obtain Composite Material 4.

[0037] Example 5

[0038] Add 0.1 kg of tetramethylguanidine hydrochloride and 0.05 kg of polymethacrylic acid sulfobetaine to 0.8 kg of N-isopropylacrylamide-β-cyclodextrin-tetraphenylethylene polymer hydrogel. After heating to 50 °C, start stirring, then add 0.05 kg of dilactic acid polyethylene glycol nanospheres, and continue stirring for 1 h to obtain Composite Material 5.

[0039] Example 6

[0040] Add 0.1 kg of tetramethylguanidine hydrochloride and 0.05 kg of polymethacrylic acid sulfobetaine to 0.8 kg of β-cyclodextrin polymer / acrylamide / acrylic acid copolymer hydrogel. After heating to 50 °C, start stirring, then add 0.05 kg of dilactic acid polyethylene glycol nanospheres, and continue stirring for 1 h to obtain Composite Material 6.

[0041] Example 7

[0042] Add 0.08 kg of tetramethylguanidine hydrochloride and 0.04 kg of poly(methacryloylethylsulfobetaine) to 0.84 kg of N-isopropylacrylamide-β-cyclodextrin-tetraphenylethylene polymer hydrogel. After heating to 50 °C, start stirring, then add 0.04 kg of poly(N-isopropylacrylamide)-b-polyacrylic acid nanospheres, and continue stirring for 1 h to obtain Composite Material 7.

[0043] Comparative Example 1

[0044] Other conditions are the same as those in Example 1, except that the cyclodextrin-based poly(N-isopropylacrylamide) hydrogel is replaced with sesbania gum.

[0045] Comparative Example 2

[0046] Other conditions are the same as those in Example 1, except that tetramethylguanidine hydrochloride is replaced with 1-butyl-3-methylimidazolium chloride.

[0047] Comparative Example 3

[0048] Other conditions are the same as those in Example 1, except that polymethacrylic acid sulfobetaine is replaced with fatty alcohol polyoxyethylene ether phosphate AEO-9P.

[0049] Comparative Example 4

[0050] The other conditions were the same as those in Example 1, except that no viscoelastic nanospheres were added.

[0051] Application Example 1

[0052] The composite material of the present invention was added to the on-site mixed emulsion explosive, and the pressure of the emulsion matrix during the screw pumping was investigated. -1 The increase in viscosity after shearing for 1 minute relative to the initial emulsified matrix viscosity, 1000S -1 The amount of ammonium nitrate precipitated after shearing for 1 min and the amount of emulsion explosive after 1000S -1 The effect of composite materials on the pumpability, structural recovery, dynamic stability and explosion performance of on-site mixed emulsion explosives was evaluated by the change of explosion performance after shearing for 1 minute. The formula of on-site mixed emulsion explosives is shown in Table 1, and the change of performance of on-site mixed emulsion explosives after shearing is shown in Table 2.

[0053] From the test results in Table 2, it can be seen that after adding the composite material of the present invention to the on-site mixed emulsion explosive, the pumpability of the emulsion matrix remains unchanged (the pumping pressure is basically the same as the emulsion matrix prepared by using a commercially available emulsifier), the elastic recovery ability of the emulsion matrix (the viscosity increase amplitude of the emulsion matrix after shearing, generally the greater the increase amplitude, the worse the elastic recovery ability) and the structural stability (ammonium nitrate precipitation rate of the emulsion matrix after shearing) are greatly improved, and at the same time, its explosive performance is maintained at a high level. It shows that the composite material provided by the present invention has a good effect of improving the elastic recovery ability and dynamic stability of the on-site mixed emulsion explosive.

[0054] Table 1: Emulsion explosive formula

[0055]

[0056] Table 2: Changes in properties of emulsion explosives after shearing

[0057]

[0058] Figure 1 The emulsion explosive of Example 1 was heated for 1000 seconds. -1 After shearing, the macroscopic picture was taken after 12 hours of storage, and no ammonium nitrate was precipitated on the surface. Figure 2 The emulsion explosive of Example 1 was subjected to 1000S -1 After shearing, the macroscopic picture was taken after 12 hours of storage, and there was obvious precipitation of ammonium nitrate on the surface. Figure 3 It is an emulsion explosive without adding composite materials after 1000S -1 After shearing, the macroscopic picture was taken after 12 hours of storage, and more ammonium nitrate was precipitated on the surface.

[0059] As can be seen from the data in Table 1, for the composite material provided by the present invention, when a small amount is added to ammonium nitrate emulsion explosive, the elastic recovery ability of the emulsion explosive can be significantly improved, so that after the explosive passes through 1000S -1 shearing, the viscosity change is small, the precipitation of ammonium nitrate is less, the detonation velocity decreases less, and good explosive performance is maintained. When the tetramethylguanidine ionic liquid is replaced with other ionic liquids, such as imidazole-based ionic liquids; when the poly(methacryloyloxyethyl sulfobetaine) is replaced with other surfactants; or when the viscoelastic nanospheres are not added, it is impossible to maintain a high detonation velocity after high-speed shearing. If the composite material is not added, the emulsion explosive will -1 show a misfire phenomenon after 1000S shearing.

[0060] Example 8

[0061] On the basis of Example 3, perfluoropolyether silicone oil and carboxylated nanocellulose are added, specifically as follows: 0.08 kg of tetramethylguanidine hydrogensulfate, 0.04 kg of poly(methacryloyloxyethyl sulfobetaine), and 0.04 kg of perfluoropolyether silicone oil (viscosity at 25 °C is 50 mm 2 / s) are added to 0.84 kg of β-cyclodextrin polymer / acrylamide / acrylic acid copolymer hydrogel. After heating to 50 °C, stirring is started, and then 0.04 kg of poly(N-isopropylacrylamide) nanospheres and 0.008 kg of carboxylated nanocellulose (length 1 μm, diameter 20 nm, carboxyl content 1.7 mmol / g) are added, and stirring is continued for 1 h to obtain the composite material.

[0062] Example 9

[0063] Other conditions are the same as in Example 8, except that the perfluoropolyether silicone oil is replaced with an equal mass of polyether-modified silicone oil (viscosity at 25 °C is 50 mm 2 / s).

[0064] Example 10

[0065] Other conditions are the same as in Example 8, except that the carboxylated nanocellulose is replaced with an equal mass of nanocellulose (length 1 μm, diameter 20 nm).

[0066] Example 11

[0067] Other conditions are the same as in Example 8, except that the perfluoropolyether silicone oil is not added.

[0068] Example 12

[0069] Other conditions are the same as in Example 8, except that the carboxylated nanocellulose is not added.

[0070] Application Example 2

[0071] For the composite materials in Examples 8 - 12 above, emulsion explosives were prepared under the same conditions as in Application Example 1. The performance of the explosives was tested, and the results are shown in Table 3 below. For the freeze-thaw cycle, it was -25°C / 2h, 25°C / 2h for one cycle, and after 10 cycles, the detonation velocity of the explosive was retested.

[0072] Table 3: Performance of Emulsion Explosives

[0073]

[0074]

[0075] As can be seen from Table 3, adding a small amount of perfluoropolyether silicone oil and carboxylated nanocellulose to the composite material, and the two play a synergistic role, can significantly improve the freeze-thaw cycle resistance of the emulsion explosive. After 10 freeze-thaw cycles, the performance of the explosive is basically unaffected. The possible reason is that perfluoropolyether silicone oil, as a surfactant, enhances the strength and flexibility of the oil film, maintains elasticity at low temperatures, and prevents ice crystals from piercing the interface. The hydrophobicity of the fluorocarbon chain may repel water and reduce the formation of ice crystals in the aqueous phase. Carboxylated nanocellulose may interact with ions in the aqueous phase through hydrogen bonding or electrostatic interactions to inhibit the recrystallization of salts. The nanofiber structure forms a three-dimensional network that binds water molecules and reduces the expansion stress during freezing. The carboxylate groups of carboxylated nanocellulose may complex with cations, reducing the supercooling degree of the solution, making the ice crystals finer and more uniform, and reducing the damage to the structure. The combined action of the two may significantly improve the freeze-thaw resistance. However, the dosages of perfluoropolyether silicone oil and carboxylated nanocellulose cannot be too much, otherwise it will affect the detonation velocity of the explosive.

Claims

1. A composite material for improving the elastic recovery ability of on-site mixed emulsion explosive, characterized in that, It comprises the following raw materials in parts by mass: 80 - 100 parts of salt - tolerant hydrogel, 5 - 10 parts of tetramethylguanidine ionic liquid, 2 - 5 parts of polymer betaine dispersant, and 2 - 5 parts of viscoelastic nanospheres.

2. The composite material according to claim 1, wherein The lower critical solution temperature (LCST) of the salt - tolerant hydrogel is 30 - 50 °C, and the viscosity - average molecular weight is 150,000 - 250,000; preferably, the salt - tolerant hydrogel is selected from at least one of cyclodextrin - based poly(N - isopropylacrylamide) hydrogel, N - isopropylacrylamide - β - cyclodextrin - tetraphenylethylene polymer hydrogel, and β - cyclodextrin polymer / acrylamide / acrylic acid copolymer hydrogel.

3. The composite material according to claim 1, wherein The tetramethylguanidine ionic liquid is selected from any one of tetramethylguanidine hydrochloride, tetramethylguanidine nitrate, tetramethylguanidine hydrogen sulfate, and tetramethylguanidine dihydrogen phosphate.

4. The composite material according to claim 1, wherein The polymer betaine dispersant is selected from at least one of poly(sulfobetaine methacrylate), poly(carboxybetaine methacrylate), poly(sulfobetaine ethyl methacrylate), and poly(carboxybetaine acrylamide); further, the number - average molecular weight of the polymer betaine dispersant is 4500–7000 g / mol.

5. The composite material according to claim 1, characterized in that, The viscoelastic nanospheres are selected from any one of poly(N - isopropylacrylamide)-b - polyacrylic acid nanospheres, dimeric lactic acid - polyethylene glycol nanospheres, and poly(N - isopropylacrylamide) nanospheres; the particle size of the viscoelastic nanospheres is 10 - 50 nm, and the storage modulus (G’) is 1000 - 2000 Pa; preferably, the particle size of the viscoelastic nanospheres is 20 - 35 nm, and the storage modulus (G’) is 1000 - 1500 Pa.

6. The composite material according to claim 1, characterized in that, The composite material further comprises the following raw materials in parts by mass: 2 - 4 parts of perfluoropolyether silicone oil, and 0.5 - 0.8 part of carboxylated nanocellulose.

7. The composite material according to claim 6, characterized in that The viscosity of perfluoropolyether silicone oil at 25 °C is 40-60 mm 2 / s; and / or The length of the carboxylated nanocellulose is 0.5 - 1 μm, the diameter is 10 - 30 nm, and the carboxyl content is 1 - 3 mmol / g.

8. The preparation method of the composite material according to any one of claims 1-5, comprising the following steps: The tetramethylguanidine ionic liquid plasticizer and the polymer betaine dispersant are added to the salt - tolerant hydrogel, stirred at 30 - 50 °C, and then the viscoelastic nanospheres are added, and stirring is continued until evenly mixed to obtain the composite material.

9. Use of viscoelastic nanospheres for improving the elastic recovery ability of on - site - mixed emulsion explosives, wherein the viscoelastic nanospheres are selected from any one of poly(N - isopropylacrylamide)-b - polyacrylic acid nanospheres, dimeric lactic acid - polyethylene glycol nanospheres, and poly(N - isopropylacrylamide) nanospheres, with a particle size of 10 - 50 nm and a storage modulus (G’) of 1000 - 2000 Pa.

10. An emulsion explosive, which comprises the following raw materials in parts by mass: 70 - 80 parts of ammonium nitrate, 12 - 18 parts of water, 4 - 8 parts of oil, 1 - 3 parts of surfactant, 0.1 - 3 parts of sensitizer, and 0.2 - 1.5 parts of the composite material according to any one of claims 1 - 7; Further, the emulsion explosive comprises the following raw materials in parts by mass: 70 - 80 parts of ammonium nitrate, 13 - 15 parts of water, 5 - 6 parts of oil, 1.5 - 2 parts of surfactant, 1 - 2 parts of sensitizer, and 0.5 - 1 part of the composite material according to any one of claims 1 - 7; Further, the oil is selected from at least one of diesel oil and engine oil, such as 46# mechanical oil, 0# diesel oil, and naphthenic oil; the surfactant is a non-ionic surfactant, specifically selected from at least one of span, tween, sorbitan sesquioleate, fatty alcohol polyoxyethylene ether sulfate, and fatty alcohol polyoxyethylene ether phosphate; the sensitizer is selected from at least one of sodium nitrite, diatomaceous earth, and glass microspheres.

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