Explosion-proof elastomer coating material containing secondary doped polyaniline and preparation method thereof

Abstract

This invention provides an explosion-proof elastomer coating material containing secondary doped polyaniline and its preparation method, relating to the field of flame-retardant and explosion-proof composite materials. The invention involves simultaneously adding graphene and carbon nanotubes to the explosion-proof elastomer coating material. The amino groups in the carbon nitride hybrid composite material containing secondary doped polyaniline react with the molecular chains of the polyurea explosion-proof elastomer coating material, generating a strong interfacial effect that reduces the surface energy of the coating material. Furthermore, the carbon nitride hybrid material in the graphene and carbon nanotubes and the carbon nitride hybrid composite material is uniformly dispersed in the polyurea explosion-proof elastomer coating material, forming a maze effect. The presence of ammonium polyphosphate further enhances the maze effect, thereby improving the hydrophobicity of the coating surface while simultaneously hindering the heat transfer performance of the coating. The synergistic effect with polyphosphoric acid (APP) improves the flame-retardant performance of the polyurea explosion-proof elastomer coating material and suppresses the release of smoke and toxic gases.

Description

Technical Field

[0001] This invention relates to the field of explosion-proof elastomer composite materials, and in particular to an explosion-proof elastomer coating material containing secondary doped polyaniline and its preparation method. Background Technology

[0002] Polyurea explosion-proof elastomer coatings are widely used due to their advantages such as good flexibility, high strength, fast curing speed, insensitivity to environmental temperature and humidity, and the ability to achieve thick coatings in a single application. However, this coating is composed of a semi-prepolymer formed by the reaction of isocyanate and hydroxyl-terminated polyether, as well as amino-terminated polyether and amine curing agents. As a polymer material, it is easily ignited and combustible, releasing a large amount of toxic gases. Therefore, the research and development of flame-retardant explosion-proof elastomer coatings is particularly important.

[0003] Existing flame-retardant materials mainly include organophosphorus and inorganic phosphorus flame retardants. However, using ammonium polyphosphate (APP) as a phosphorus-based flame retardant still has drawbacks: First, using only APP results in low flame-retardant efficiency; existing technologies only provide the necessary flame-retardant safety to polymers when the addition amount reaches a certain level. Second, when APP exerts its flame-retardant effect in the gas phase, the release of ·PO free radicals interrupts the combustion chain reaction, leading to the generation of more smoke and toxic gases during actual use. Third, while the main condensed-phase flame-retardant mechanism of APP is to promote the formation of a porous char layer in the polymer, studies show that the addition of APP increases the polymer's fluidity in the molten state, resulting in a char layer with low strength and poor ablation resistance. Fourth, as a polar material, APP has poor compatibility with polymers; its introduction into composite materials, while providing flame retardancy, reduces the mechanical properties of the polymer composite, affecting its practicality.

[0004] In existing technologies, methods to overcome the aforementioned defects of ammonium polyphosphate (APP) can generally be divided into two types based on the operational methods: one is to perform surface modification treatment on ammonium polyphosphate (APP), and the other is to use ammonium polyphosphate (APP) in combination with synergists. However, many drawbacks still exist. Surface-modified ammonium polyphosphate (APP) suffers from complex processes and high costs, and has a long time cycle from design to production, which is not conducive to market application and promotion. The method of using ammonium polyphosphate (APP) in combination with synergists has defects such as easy agglomeration of carbon nitride materials during use, which greatly reduces the flame retardant effect of ammonium polyphosphate. Summary of the Invention

[0005] This invention provides an explosion-proof elastomer coating material containing secondary doped polyaniline. The secondary doped polyaniline and ammonium polyphosphate are modified with layered nano-carbon materials to achieve a synergistic effect, thereby improving the flame retardant effect of ammonium polyphosphate in the explosion-proof elastomer coating material.

[0006] In a first aspect, the present invention provides an explosion-proof elastomer coating material containing secondary doped polyaniline, comprising a semi-prepolymer component A and a component B, wherein the semi-prepolymer component A comprises the following raw materials in weight percentages: 40-60% polyether diol or polyester diol, 8-10% polyisocyanate, 2-12% graphene and carbon nanotubes with secondary doped polyaniline carbon nitride hybrid composite material, and 2-12% ammonium polyphosphate; the component B comprises the following raw materials in weight percentages: terminal amino poly... The composition includes 50-70% ether or carboxyl-terminated polyether, 10-30% diamine chain extender, 0.5-1% molecular sieve powder slurry, 0.5-1% color paste, 6-16% graphene and carbon nanotubes and secondary doped polyaniline carbon nitride hybrid composite material, and 6-16% ammonium polyphosphate. The graphene and carbon nanotubes and secondary doped polyaniline carbon nitride hybrid composite material is formed by secondary doping of polyaniline, graphene, carbon nanotubes and carbon nitride in a mass ratio of 15-25:1:1.

[0007] Optionally, the mass percentage of graphene and carbon nanotubes and the carbon nitride hybrid composite material of secondary doped polyaniline in component A is 10-15:85-90; the mass percentage of graphene and carbon nanotubes and the carbon nitride hybrid composite material of secondary doped polyaniline in component B is 10-15:85-90.

[0008] Optionally, the graphene and carbon nanotube-carbon nitride hybrid composite material with secondary doped polyaniline is prepared by the following method:

[0009] (1) Take two equal volumes of 1 mol / L doped acid solution and add aniline-graphene mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-graphene mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-graphene composite material; wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 15-25:1.

[0010] (2) Add excess ammonia to the primary doped polyaniline-graphene composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-graphene composite material.

[0011] (3) Take two equal volumes of 1 mol / L doped acid solution and add aniline-carbon nanotube mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-carbon nanotube mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-carbon nanotube composite material; wherein the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 15-25:1.

[0012] (4) Add excess ammonia to the primary doped polyaniline-carbon nanotube composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-carbon nanotube composite material.

[0013] (5) The intrinsic polyaniline-graphene composite material and the intrinsic polyaniline-carbon nanotube composite material were added to a 1 mol / L mixed solution of carbon nitride and doped acid at a mass ratio of 1:1. After mixing and stirring, the mixture was allowed to stand for 20-26 hours. After filtration, the mixture was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotube and secondary doped polyaniline.

[0014] Optionally, the mass ratio of aniline to graphene in the aniline-graphene mixture is equal to the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture, wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 18–22:1, and the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture is 18–22:1.

[0015] Optionally, the mass ratio of aniline to graphene in the aniline-graphene mixture is 20:1, and the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture is 20:1.

[0016] Optionally, the isocyanate mixture includes at least one of 4,4'-diphenylmethane diisocyanate (MDI-100), 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, or naphthalene diisocyanate; the hydroxyl-terminated polyether includes at least one of PTMG1000, PTMG2000, and polyester diol; wherein PTMG1000 has a relative molecular mass of 1000±50 and a hydroxyl value of 107-118 mgkoH / g; PTMG2000 has a relative molecular mass of 2000±50 and a hydroxyl value of 54.7-57.5 mgkoH / g.

[0017] On the other hand, embodiments of the present invention provide a method for preparing an explosion-proof elastomer coating material containing secondary doped polyaniline, the method comprising:

[0018] (1) Take two equal volumes of 1 mol / L doped acid solution and add aniline-graphene mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-graphene mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-graphene composite material; wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 15-25:1.

[0019] (2) Add excess ammonia to the primary doped polyaniline-graphene composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-graphene composite material.

[0020] (3) Take two equal volumes of 1 mol / L doped acid solution and add aniline-carbon nanotube mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-carbon nanotube mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-carbon nanotube composite material; wherein the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 15-25:1.

[0021] (4) Add excess ammonia to the primary doped polyaniline-carbon nanotube composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-carbon nanotube composite material.

[0022] (5) The intrinsic polyaniline-graphene composite material and the intrinsic polyaniline-carbon nanotube composite material were added to a 1 mol / L doped acid solution at a mass ratio of 1:1. After mixing and stirring, the mixture was allowed to stand for 20-26 h. After filtration, the mixture was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline.

[0023] (6) Under an inert environment, the polyether diol or polyester diol is stirred and heated to 100℃~130℃, and dehydrated under vacuum of -0.1MPa for 2~3 hours until the moisture content is less than 0.5%. Then the vacuum is released, the temperature is lowered to below 60℃, and polyisocyanate is added. The reaction is carried out at 80~90℃ for 2~4 hours. After the reaction is completed, the NCO value is measured and the material is discharged. The material is filtered to obtain the isocyanate-terminated semi-prepolymer.

[0024] (7) Under an inert environment, the prepared isocyanate-terminated semi-prepolymer, graphene and carbon nanotubes are mixed with the carbon nitride hybrid composite material of secondary doped polyaniline and ammonium polyphosphate. Then, the mixture is ultrasonically dispersed at 50-60°C for 24 hours. After the reaction is completed, the NCO value is measured and the mixture is discharged. The semi-prepolymer component A is obtained by filtration.

[0025] (8) In an inert environment, the premix of component B is obtained by dispersing, stirring and filtering the terminal amino polyether or terminal hydroxy polyether, diamine chain extender, molecular sieve powder slurry and color paste in a mass percentage of 50-70%: 10-30%: 0.5-1%: 0.5-1%. Then, the premix of component B and the nitride carbon hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline and ammonium polyphosphate are mixed together in a mass ratio of 210: 0.2-10: 0.02-1 and dispersed and filtered by ultrasonication.

[0026] (9) Before spraying, the semi-prepolymer component A and component B are mixed together in a volume ratio of 1:1 to obtain the explosion-proof composite material modified with hydroxyl and amino groups.

[0027] The present invention has the following beneficial technical effects:

[0028] This invention provides an explosion-proof elastomer coating material containing secondary-doped polyaniline and its preparation method. The explosion-proof elastomer coating material simultaneously incorporates a graphene and carbon nanotube-carbon nitride hybrid composite material with secondary-doped polyaniline, and ammonium polyphosphate. The amino groups in the graphene and carbon nanotube-carbon nitride hybrid composite material react with the molecular chains of the polyurea explosion-proof elastomer coating material, generating a strong interfacial effect that reduces the surface energy of the coating material. Furthermore, the carbon nitride hybrid material in the graphene and carbon nanotube-carbon nitride hybrid composite material is uniformly dispersed within the polyurea explosion-proof elastomer coating material. The presence of ammonium polyphosphate can further enhance the maze effect, thereby improving the hydrophobicity of the coating surface while hindering the heat transfer performance of the coating. The nitride-carbon hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline and polyphosphate (APP) improves the flame retardant performance of polyurea explosion-proof elastomer coating material through synergistic effect and inhibits the release of smoke and toxic gases. When used in solvent-free coatings, it can achieve a 1+1+1>3 effect, thereby solving the agglomeration and dispersion problem of polyaniline, while avoiding the self-agglomeration problem of carbon nanotubes and graphene, and obtaining a solvent-free epoxy coating with excellent comprehensive performance. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a scanning electron microscope image of an explosion-proof elastomer coating material containing polyaniline;

[0031] Figure 2 This is a scanning electron microscope (SEM) image of an explosion-proof elastomer coating material containing secondary doped polyaniline according to an embodiment of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is apparent that the embodiments described are only some, not all, of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0033] In view of the above-mentioned defects in the prior art, the technical problem to be solved by the embodiments of the present invention is that the existing ammonium polyphosphate (APP) flame retardant materials have the defect of easy agglomeration of carbon nitride materials when using synergists, resulting in poor flame retardant effect, and the defect of ammonium polyphosphate (APP) flame retardant materials easily generating a large amount of smoke and toxic gases during actual use, which is not conducive to environmental protection.

[0034] Based on this, the present invention provides an explosion-proof elastomer coating material containing secondary doped polyaniline, comprising a semi-prepolymer component A and a component B, wherein the semi-prepolymer component A comprises the following raw materials in mass percentage: 40-60% polyether diol or polyester diol, 8-10% polyisocyanate, 2-12% graphene and carbon nanotubes with secondary doped polyaniline carbon nitride hybrid composite material, and 2-12% ammonium polyphosphate; the component B comprises the following raw materials in mass percentage: amino-terminated polyether... Alternatively, the composition may include 50-70% terminal carboxyl polyether, 10-30% diamine chain extender, 0.5-1% molecular sieve powder slurry, 0.5-1% color paste, 6-16% graphene and carbon nanotubes and secondary doped polyaniline carbon nitride hybrid composite material, and 6-16% ammonium polyphosphate. The graphene and carbon nanotubes and secondary doped polyaniline carbon nitride hybrid composite material is formed by secondary doping of polyaniline, graphene, carbon nanotubes and carbon nitride in a mass ratio of 15-25:1:1.

[0035] In component A, a composite material of graphene and carbon nanotubes with secondary doped polyaniline, along with ammonium polyphosphate, is added as a flame retardant. The mass percentage of this composite material in component A is 2%–12%. Similarly, in component B, the same composite material is added as a flame retardant. The mass percentage of this composite material in component B is 6%–16%. In this flame retardant mixture, the mass percentage (g) of ammonium polyphosphate (APP) is 10%–15%, and within this range, the synergistic effect is optimal.

[0036] Furthermore, in component A, the mass percentage of graphene and carbon nanotubes and the carbon nitride hybrid composite material of secondary doped polyaniline to ammonium polyphosphate is 10-15:85-90; in component B, the mass percentage of graphene and carbon nanotubes and the carbon nitride hybrid composite material of secondary doped polyaniline to ammonium polyphosphate is 10-15:85-90.

[0037] The graphene and carbon nanotube-carbon nitride hybrid composite material of secondary doped polyaniline used in the embodiments of the present invention is prepared by the following method:

[0038] (1) Take two equal volumes of 1 mol / L doped acid solution and add aniline-graphene mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-graphene mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-graphene composite material; wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 15-25:1.

[0039] (2) Add excess ammonia to the primary doped polyaniline-graphene composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-graphene composite material.

[0040] (3) Take two equal volumes of 1 mol / L doped acid solution and add aniline-carbon nanotube mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-carbon nanotube mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-carbon nanotube composite material; wherein the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 15-25:1.

[0041] (4) Add excess ammonia to the primary doped polyaniline-carbon nanotube composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-carbon nanotube composite material.

[0042] (5) The intrinsic polyaniline-graphene composite material and the intrinsic polyaniline-carbon nanotube composite material were added to a 1 mol / L mixed solution of carbon nitride and doped acid at a mass ratio of 1:1. After mixing and stirring, the mixture was allowed to stand for 20-26 hours. After filtration, the mixture was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotube and secondary doped polyaniline.

[0043] Furthermore, the mass ratio of aniline to graphene in the aniline-graphene mixture is equal to the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture. Preferably, the mass ratio of aniline to graphene in the aniline-graphene mixture is 18–22:1, and the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture is 18–22:1. By controlling the ratio of graphene to aniline and the ratio of carbon nanotubes to aniline within this range, the product morphology is improved, with polyaniline encapsulating carbon nanotubes neatly arranged on the graphene surface, exhibiting uniform size and fiber lengths exceeding 800 nm.

[0044] Optionally, the mass ratio of aniline to graphene in the aniline-graphene mixture is 20:1, and the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture is 20:1.

[0045] Optionally, the doped acid solution is one of an inorganic acid solution, an organic acid solution, and a composite acid, wherein the molar concentration ratio of the inorganic acid to the organic acid in the composite acid is 1:1 to 1:6.

[0046] The doped acid solution used in this embodiment of the invention is one of an inorganic acid solution, an organic acid solution, and a composite acid, wherein the molar ratio of inorganic acid to organic acid in the composite acid is 1:1 to 1:6. Organic acids include, but are not limited to, formic acid, acetic acid, propionic acid, butyric acid, octanoic acid, adipic acid, oxalic acid, malonic acid, succinic acid, tartaric acid, benzoic acid, phenylacetic acid, perchloric acid, sulfuric acid, phosphoric acid, hydrochloric acid, and molybdic acid, or a mixture of one or more of these. Preferably, the embodiment of the invention uses a tartaric acid solution. Furthermore, the preparation method of this embodiment of the invention can also use a composite acid formed from organic and inorganic acids. The composite acid used in this embodiment of the invention is mainly composed of a mixture of inorganic and organic acids, wherein the inorganic acids are mainly: perchloric acid, sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, molybdic acid, etc. The organic acids are mainly acetic acid, oxalic acid, citric acid, tartaric acid, tannic acid, p-toluenesulfonic acid, phytic acid, tannic acid, etc. The molar ratio of the composite acid is between 1:1 and 1:6.

[0047] The graphene and carbon nanotube-carbon nitride hybrid composite material prepared by the method of this invention exhibits a corrosion inhibition efficiency greater than 78%, an impedance value greater than 1500 Ω*cm², and a fiber length greater than 800 nm. Under optimal conditions, the graphene and carbon nanotube-carbon nitride hybrid composite material can achieve a corrosion inhibition efficiency greater than 80%, an impedance value greater than 1800 Ω*cm², and a fiber length greater than 850 nm.

[0048] In the graphene and carbon nanotube composite material with secondary doped polyaniline used in the embodiments of the present invention, CNTs1:15RGO1:5 represents that the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 20:1, and the mass ratio of aniline CNTs to graphene RGO in the aniline-graphene mixture is 20:1.

[0049] Table 1. Polarization curve fitting results

[0050]

[0051]

[0052] Table 1 shows the fitting results of its polarization curves. When the mass ratio of carbon nanotubes (CNTs) to aniline (ANI) is controlled at 1:15, and the ratio of graphene RGO to aniline (ANI) is changed, the corrosion current gradually decreases as the amount of RGO decreases. When the ratio of RGO to ANI is 1:20, the corrosion current reaches its minimum value, and the corrosion resistance of the product reaches its best, with a corrosion inhibition efficiency of 78.68%. When the amount of RGO is further reduced, the corrosion current begins to increase gradually. This is because the morphology of the product changes after adding different amounts of RGO. When the ratio of RGO to ANI is 1:25, the RGO content is low and cannot play a good template role. It does not change the polyaniline agglomeration phenomenon, and the corrosion current is relatively high. When the amount of RGO is gradually increased, RGO begins to play a barrier role and provides a good template for polyaniline, allowing the PANI encapsulating CNTs to grow uniformly on RGO, with the largest specific surface area, sufficient electrode interaction, and the passivation effect of PANI to a great extent.

[0053] (1) The morphology of the carbon nitride hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline was more uniform and the nanofibers were more uniform. The product morphology was best when the ratio of RGO to ANI was 1:20 and the ratio of CNTs to ANT was 1:20. PANI wrapped CNTs neatly arranged on the graphene surface with uniform size and fiber length reached 850 nm.

[0054] (2) Analysis of Tafel curves and electrochemical impedance spectroscopy shows that polyaniline with different ratios has a certain anti-corrosion effect on metals. When the ratio of RGO to ANI is 1:20 and the ratio of CNTs to ANI is 1:20, the anti-corrosion effect of the graphene and carbon nanotube-carbon nitride hybrid composite material prepared by the secondary doping method of polyaniline is significantly better than that of other ratios. The corrosion current is the lowest, the corrosion inhibition efficiency reaches 81.79%, and the impedance value is 1893.6Ω.

[0055] (3) The method of secondary doping of polyaniline to prepare carbon nitride hybrid composite materials of graphene and carbon nanotubes with secondary doped polyaniline can avoid the agglomeration of nanomaterials and effectively improve the various properties of the product, which is better than the single composite material with single doping or secondary doping. It is a breakthrough in the preparation of composite materials of graphene / carbon nanotubes with polyaniline at the same time. The product performance is significantly lower than that of composite products of graphene alone or carbon nanotubes alone with polyaniline.

[0056] Preferably, in the coating material prepared in the embodiments of the present invention, the isocyanate mixture includes at least one of 4,4'-diphenylmethane diisocyanate (MDI-100), 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, or naphthalene diisocyanate; the hydroxyl-terminated polyether includes at least one of PTMG1000, PTMG2000, and polyester diol; wherein, PTMG1000 has a relative molecular mass of 1000±50 and a hydroxyl value of 107-118 mgkoH / g; PTMG2000 has a relative molecular mass of 2000±50 and a hydroxyl value of 54.7-57.5 mgkoH / g.

[0057] Based on the same inventive concept, embodiments of the present invention also provide a method for preparing an explosion-proof elastomer coating material containing secondary doped polyaniline, the method comprising:

[0058] (1) Take two equal volumes of 1 mol / L doped acid solution and add aniline-graphene mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-graphene mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-graphene composite material; wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 15-25:1.

[0059] (2) Add excess ammonia to the primary doped polyaniline-graphene composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-graphene composite material.

[0060] (3) Take two equal volumes of 1 mol / L doped acid solution and add aniline-carbon nanotube mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-carbon nanotube mixture to ammonium persulfate is 0.8:1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-carbon nanotube composite material; wherein the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 15-25:1.

[0061] (4) Add excess ammonia to the primary doped polyaniline-carbon nanotube composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-carbon nanotube composite material.

[0062] (5) The intrinsic polyaniline-graphene composite material and the intrinsic polyaniline-carbon nanotube composite material were added to a 1 mol / L doped acid solution at a mass ratio of 1:1. After mixing and stirring, the mixture was allowed to stand for 20-26 h. After filtration, the mixture was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline.

[0063] (6) Under an inert environment, the polyether diol or polyester diol is stirred and heated to 100℃~130℃, and dehydrated under vacuum of -0.1MPa for 2~3 hours until the moisture content is less than 0.5%. Then the vacuum is released, the temperature is lowered to below 60℃, and polyisocyanate is added. The reaction is carried out at 80~90℃ for 2~4 hours. After the reaction is completed, the NCO value is measured and the material is discharged. The material is filtered to obtain the isocyanate-terminated semi-prepolymer.

[0064] (7) Under an inert environment, the prepared isocyanate-terminated semi-prepolymer, graphene and carbon nanotubes are mixed with the carbon nitride hybrid composite material of secondary doped polyaniline and ammonium polyphosphate. Then, the mixture is ultrasonically dispersed at 50-60°C for 24 hours. After the reaction is completed, the NCO value is measured and the mixture is discharged. The semi-prepolymer component A is obtained by filtration.

[0065] (8) In an inert environment, the premix of component B is obtained by dispersing, stirring and filtering the terminal amino polyether or terminal hydroxy polyether, diamine chain extender, molecular sieve powder slurry and color paste in a mass percentage of 50-70%: 10-30%: 0.5-1%: 0.5-1%. Then, the premix of component B and the nitride carbon hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline and ammonium polyphosphate are mixed together in a mass ratio of 210: 0.2-10: 0.02-1 and dispersed and filtered by ultrasonication.

[0066] (9) Before spraying, the semi-prepolymer component A and component B are mixed together in a volume ratio of 1:1 to obtain the explosion-proof composite material modified with hydroxyl and amino groups.

[0067] This invention provides an explosion-proof elastomer coating material containing secondary-doped polyaniline, which can be easily sprayed onto the surface of various materials, greatly improving the flame-retardant and explosion-proof effect of objects; it is conducive to industrial promotion and cost reduction; it uses layered graphene and carbon nanotubes and secondary-doped polyaniline carbon nitride hybrid composite material for modification, which effectively solves the problem of easy agglomeration of carbon nitride material in ammonium polyphosphate (APP) flame retardant materials when using synergists, and greatly improves flame retardant performance while maintaining the original mechanical strength; the modification of components A and B with layered graphene and carbon nanotubes and secondary-doped polyaniline carbon nitride hybrid composite material, in synergy with ammonium polyphosphate, can effectively avoid the generation of a large amount of smoke and toxic gases during actual use; it is beneficial to environmental protection and green application, and is conducive to widespread application.

[0068] In summary, the explosion-proof elastomer coating material containing secondary doped polyaniline disclosed in this invention uses a layered graphene and carbon nanotube hybrid composite material with secondary doped polyaniline carbon nitride to modify components A and B, preventing the agglomeration of ammonium polyphosphate (APP) in the explosion-proof elastomer coating material, which is beneficial to improving the flame retardant and explosion-proof effect of the material; it does not produce smoke or toxic gases in actual use, which is beneficial to high efficiency and energy saving, cost reduction, environmental protection, and widespread industrial application.

[0069] In this invention, components A and B are modified with a layered graphene and carbon nanotube hybrid composite material of secondary-doped polyaniline and carbon nitride. The amino groups in this composite material react with the molecular chains of the polyurea explosion-proof elastomer coating material, generating a strong interfacial effect that reduces the surface energy of the coating material. Furthermore, the graphene and carbon nanotube hybrid composite material is uniformly dispersed within the polyurea explosion-proof elastomer coating material, forming a maze effect. The presence of ammonium polyphosphate enhances this maze effect, thereby improving hydrophobicity while simultaneously hindering heat transfer. When the coating material is exposed to flame, ammonium polyphosphate (APP) and the graphene and carbon nanotube hybrid composite material decompose at relatively low temperatures. Ammonium polyphosphate (APP) promotes the formation of carbon in the polyurea explosion-proof elastomer coating material and generates a large amount of non-flammable water vapor, causing the polyurea explosion-proof elastomer coating material to foam and expand into a carbon layer. The amino groups in the graphene and carbon nanotube-carbon nitride hybrid composite material with secondary-doped polyaniline react with the polyurea explosion-proof elastomer coating material, promoting the formation of the elastomer coating network. Meanwhile, the self-carbonization of this composite material further promotes the cross-linking and carbonization of the polyurea explosion-proof elastomer coating material, ultimately forming a dense, continuous porous protective carbon layer. This porous, expanding protective carbon layer not only insulates against heat but also creates a labyrinth effect, prolonging the pathway for flammable and toxic gases to escape into contact with the flame. Therefore, the graphene and carbon nanotube-carbon nitride hybrid composite material, in synergy with polyphosphoric acid (APP), improves the flame-retardant properties of the polyurea explosion-proof elastomer coating material and inhibits the release of smoke and toxic gases.

[0070] In this embodiment of the invention, components A and B can also be prepared by the following method: the hydroxyl-terminated polyether is heated to 90°C and stirred under vacuum for 1-2 hours to remove the moisture. It is then cooled to a certain temperature under nitrogen protection. The isocyanate monomer is then added to the reaction vessel, and the temperature is raised to (80±4)°C and maintained for 2 hours to ensure complete reaction. The entire reaction must be carried out under nitrogen protection, and the generated prepolymer must also be sealed by purging with nitrogen to obtain component A. A certain amount of pigment, filler, flame retardant, additives and an appropriate amount of terminal amino polyether are mixed and ground on a three-roll mill to achieve a certain fineness. The ground slurry is then put into a reaction vessel, and amino polyether and chain extender are added. After mixing evenly, the material is discharged. During the discharge process, the material is filtered through a 100-mesh sieve. Isocyanate prepolymer is used as component A, polyether polyol and amino chain extender are used as component B. Graphene and carbon nanotubes and secondary doped polyaniline nitride carbon hybrid composite material and ammonium polyphosphate (APP) are added as flame retardants to components A and B respectively. Flame-retardant explosion-proof elastomer coating material is prepared using special spraying equipment.

[0071] Example 1

[0072] Preparation of carbon nitride hybrid composites of graphene and carbon nanotubes with secondary doped polyaniline:

[0073] (1) Prepare a 1 mol / L perchloric acid solution as a doped acid system. Take two 20 ml perchloric acid solutions, add aniline (ANI) and a certain amount of g-C3N4 nanosheets to one solution, and add ammonium persulfate (APS) to the other solution. The molar ratio of aniline to ammonium persulfate is n(ANI):n(APS) = 0.8:1. Mix the two solutions evenly with a magnetic stirrer for 1-2 h, and let them stand at room temperature for 24 h. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a first-doped polyaniline (PANI).

[0074] (2) Graphene RGO and carbon nanotubes were added to the aniline system. The mass ratio of graphene RGO, carbon nanotubes and aniline ANI was set to 1:1:5 to 1:1:25. The above preparation steps were repeated to prepare a first-doped graphene and carbon nanotube carbon nitride hybrid material.

[0075] (3) The primary doped graphene and carbon nanotube carbon nitride hybrid material obtained in (2) was dedoped by adding excess ammonia water, stirred with a magnetic stirrer for 1-2 hours, and left to stand at room temperature for 24 hours. The obtained product was washed with ethanol and deionized water until neutral, and finally dried and ground to obtain the intrinsic state polyaniline carbon nitride hybrid material of graphene and carbon nanotube.

[0076] (4) Graphene, carbon nanotubes and intrinsic polyaniline carbon nitride hybrid material of graphene and carbon nanotubes were added to 1 mol / L perchloric acid solution in a ratio of 1:1:20. After mixing and stirring, the mixture was allowed to stand for 24 h. After filtration, it was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline.

[0077] Example 2

[0078] Preparation of explosion-resistant elastomer coating materials modified with graphene and carbon nanotube hybrid composites of secondary doped polyaniline and carbon nitride.

[0079] In a specific embodiment, the basic formulation (parts by mass) of the explosion-proof elastomer coating material modified with a graphene and carbon nanotube-carbon nitride hybrid composite material of secondary doped polyaniline is as follows:

[0080] Component A (NCO mass fraction 17%) is formulated as isocyanate semi-prepolymer 89.4% and flame retardant 10.6%.

[0081] Component B is formulated with polyoxypropylene triamine (amino-terminated polyether) T-500036.6, polyether amine (amino-terminated polyether) D-200028, diethyltoluene diamine (chain extender) E-10020, and flame retardant 15.4.

[0082] The specific steps are as follows:

[0083] I. Preparation of Component A (Prepolymer):

[0084] 1. Dehydration process of end capping materials

[0085] (1) Check whether the reactor, auxiliary devices, and vacuum system are operating normally;

[0086] (2) Weigh 36g of terminal hydroxyl polyether PTMG1000 and add it to the reactor for dehydration process.

[0087] (3) Turn on the stirrer (gradually adjust to medium speed, 600 rpm) and heating device, control the temperature to rise to 105℃ within 30 minutes, turn on the vacuum system, continue to heat to 110℃, maintain the temperature at 115±3℃, maintain the vacuum degree above 0.075MPa, and vacuum dehydrate for more than 2 hours.

[0088] (4) Close the vacuum system and open the vent valve, purge with nitrogen to restore atmospheric pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat (3) until the polyether moisture content is lower than 0.5‰.

[0089] (5) After the moisture content is qualified, close the vacuum system and open the vent valve, fill with nitrogen to restore the pressure to normal, and cool to a material temperature of <60℃ for later use.

[0090] 2. Preparation of semi-prepolymer

[0091] (1) Turn on the stirrer and heating device, add 4g of dehydrated hydroxyl-terminated polyether PTMG650, 2g of graphene and carbon nanotubes and secondary doped polyaniline carbon nitride hybrid composite material, 0.3g of ammonium polyphosphate (APP), and 60g of iso-MDI-50; control the feeding speed, and it must be added slowly and uniformly within 30 minutes. The feeding should be completed before the material temperature rises to 60℃.

[0092] (2) After the material is added, the temperature is raised to 75℃ within 20 minutes, and the temperature is controlled at 75±2℃ for 2 hours of reaction; then the temperature is raised to 82℃ within 10 minutes, and the temperature is controlled at 82±2℃ for 2 hours of reaction, and the material temperature is strictly controlled not to exceed 86℃.

[0093] (3) After the reaction is complete, stop heating and turn on the cooling device. Control the cooling rate to reduce the material temperature to below 60°C within 20 minutes, and continue stirring for 30 minutes.

[0094] (4) After filtering with a 100-mesh copper mesh, the product is filled. After filling, the packaging drum must be filled with nitrogen for protection to ensure that the packaging container is well sealed, thus obtaining component A. At the same time, samples are taken to determine the NCO index of the semi-prepolymer.

[0095] The isocyanate index was measured to be 1.08.

[0096] II. Preparation of Component B:

[0097] (1) Check whether the reactor and its accessories are operating normally;

[0098] (2) Metering the materials and adding them to the reactor for dehydration process:

[0099] First, add 60g of high molecular weight (1000-8000) terminal amino polyether (T-5000) and 15g of flame retardant (including 13g of graphene and carbon nanotubes and secondary doped polyaniline carbon nitride hybrid composite material, and 2g of ammonium polyphosphate (APP)) and mix. Turn on the stirrer (gradually adjust to medium speed, 600rpm) and heating device. Then add low molecular weight (100-800) D-2000 and 22g of chain extender E-100. Control the temperature to rise to 105℃ within 30min, turn on the vacuum system, continue to rise to 110℃, maintain the temperature at 110±3℃, maintain the vacuum degree above 0.075MPa, and dehydrate under vacuum for more than 2h.

[0100] (3) Close the vacuum system and open the vent valve, fill with nitrogen to restore normal pressure, take a sample and measure the moisture content. If the moisture content is still higher than 0.5‰, repeat the operation in (2) until the moisture content is lower than 0.5‰.

[0101] (4) After the moisture content is qualified, close the vacuum system and open the vent valve, and fill with nitrogen to restore the pressure to normal.

[0102] (5) 1.8g of pigment titanium dioxide and 1.2g of filler kaolin after metering and grinding were added to the reactor and stirred at high speed (1000rpm) for 1h.

[0103] (6) Turn on the vacuum system, maintain the vacuum level at 0.075MPa, keep the temperature at 80±2℃, and degas for 15 minutes.

[0104] (7) Turn off the vacuum system and heating device, stir at low speed, then fill with nitrogen to remove the vacuum, cool to a material temperature of <60℃, filter with a 100-mesh copper mesh and fill. After filling, the packaging barrel must be filled with nitrogen for protection to ensure the packaging container is well sealed and obtain component B.

[0105] In the preparation of component A, the reaction process is carried out with strict control of stepwise heating and temperature maintenance. This prevents the isocyanate in component A from undergoing accelerated self-polymerization due to excessively high temperatures, thus avoiding excessive consumption of NCO and effectively maintaining the NCO content in the system to ensure product performance. Simultaneously, the strict control of stepwise heating and temperature maintenance effectively prevents the reaction from failing to reach the endpoint due to excessively low temperatures, avoiding the presence of large amounts of unreacted hydroxyl groups and NCO in the system, effectively ensuring flame retardancy and explosion resistance. In the preparation of component B, a process is adopted where high molecular weight amino polyethers are first mixed with the flame retardant, and then low molecular weight amino polyethers are added. This effectively avoids the problem of reduced amine value caused by the volatilization loss of low molecular weight amino polyethers, greatly increasing the stability of the system and the performance of the product.

[0106] Example 3

[0107] Spraying Sample Preparation

[0108] The explosion-resistant elastomer coating material modified with a carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline obtained in Example 2 was applied. The spraying equipment used was an H-xp3 main unit and a Fusion-AP spray gun manufactured by Graco Corporation (USA). The main process parameters were: hydraulic pressure 2000–2500 psi, material temperature 60–66°C, and a mixing volume ratio of component A to component B of 1:1. The substrate was PVC board, and the coating thickness was 1.5–2.0 mm. The sprayed samples were cured at 50°C for 2 days for later use.

[0109] Comparative Example 4

[0110] The only difference between Comparative Example 4 and Example 3 is that the graphene and carbon nanotube-carbon nitride hybrid composite material with secondary doped polyaniline was not used, and ammonium polyphosphate was used as the flame retardant. Both the explosion-proof elastomer coating material obtained in Comparative Example 4 and the explosion-proof elastomer coating material modified with the graphene and carbon nanotube-carbon nitride hybrid composite material with secondary doped polyaniline obtained in Example 2 were subjected to electron microscopy scanning. The results are as follows:

[0111] like Figure 1 As shown, when only the ammonium polyphosphate anti-explosion elastomer coating material is used, a small amount of polyaniline is attached to the surface of the polyaniline, and the fiber length is relatively short, forming agglomerates; Figure 2As shown, the explosion-proof elastomer coating material modified with a carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline shows a significant improvement in polyaniline agglomeration. The wrinkles of graphene can be faintly seen, and a small amount of polyaniline is attached to the surface of graphene. In addition, polyaniline is also attached to the surface of carbon nanotubes, forming a network structure. The product morphology is the best, and graphene plays a good role as a template. The length of polyaniline fibers can reach about 850 nm. Polyaniline and carbon nanotubes are neatly arranged on the surface of graphene.

[0112] Experimental Example 5

[0113] The explosion-proof elastomer coating material sample of Example 3, modified with the carbon nitride hybrid composite material of graphene, carbon nanotubes and secondary doped polyaniline of Example 2 of this invention, and the explosion-proof elastomer coating material sample of Comparative Example 4 were simultaneously placed in the same flame combustion environment and deflagration environment for testing, and the results were observed and recorded as follows:

[0114] In the aforementioned flame combustion and deflagration environments, the sample coated with the explosion-proof elastomer coating material of Comparative Example 4 began to burn after 15 minutes, with a flame tip height greater than 150 mm and internal combustion drippings, and burned completely after 10 minutes. The sample coated with the explosion-proof elastomer coating material modified with the graphene and carbon nanotube and secondary doped polyaniline nitride carbon hybrid composite material of Example 2 of the present invention did not burn within 60 minutes and did not release a large amount of smoke and toxic gases. This indicates that, compared with the explosion-proof elastomer coating material sample modified only with ammonium polyphosphate, the explosion-proof elastomer coating material sample modified with the graphene and carbon nanotube and secondary doped polyaniline nitride carbon hybrid composite material of the present invention has a significant flame-retardant and explosion-proof effect.

[0115] Example 6

[0116] Samples of the explosion-proof elastomer coating modified with the carbon nitride hybrid composite material of graphene, carbon nanotubes and secondary doped polyaniline of Example 2 were sprayed in Example 3; and samples of the explosion-proof elastomer coating without the addition of the carbon nitride hybrid composite material of graphene, carbon nanotubes and secondary doped polyaniline were also sprayed. Relevant mechanical properties were tested according to GB / T 528-2009 "Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber" and GB / T 529-2008 "Determination of Tear Strength of Vulcanized Rubber or Thermoplastic Rubber (Pants-shaped, Right-angled and Crescent-shaped Specimens)". The results are as follows:

[0117] The tensile strength of the explosion-proof elastomer coating sample coated with the carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline without the addition of graphene and carbon nanotubes was 23.81 MPa, the tear strength was 120.3 N / mm, and the elongation at break was 210.5%. The tensile strength of the sample of Example 3 coated with the explosion-proof elastomer coating material modified with the carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline of Example 2 of the present invention was 23.84 MPa, the tear strength was 120.5 N / mm, and the elongation at break was 211.1%.

[0118] The results show that, compared with the explosion-proof elastomer coating sample of the carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline without the addition of graphene and carbon nanotubes, the explosion-proof elastomer coating sample modified with the carbon nitride hybrid composite material of graphene and carbon nanotubes and secondary doped polyaniline of the present invention does not reduce the tensile strength, tear strength, and elongation at break mechanical strength, and still maintains the mechanical strength of the original material; it solves the problem in the prior art that ammonium polyphosphate (APP), as a polar material, has poor compatibility with polymers, and its introduction into composite materials will reduce the mechanical properties of polymer composite materials while providing flame retardancy, thus affecting practicality.

[0119] Analysis revealed a synergistic flame-retardant mechanism between the graphene and carbon nanotube hybrid composite material with secondary-doped polyaniline (APP) and ammonium polyphosphate: The amino groups in the APP react with the molecular chains of the polyurea explosion-proof elastomer coating material, generating a strong interfacial effect that reduces the surface energy of the coating material. Furthermore, the APP is uniformly dispersed within the polyurea explosion-proof elastomer coating material, creating a maze effect. The presence of ammonium polyphosphate enhances this maze effect, improving hydrophobicity while simultaneously hindering heat transfer. When the coating material is exposed to flame, both the ammonium polyphosphate (APP) and the APP decompose at relatively low temperatures. The ammonium polyphosphate (APP) promotes the formation of char in the polyurea explosion-proof elastomer coating material, generating a large amount of non-flammable water vapor that causes the coating material to foam and expand into a char layer. The reaction of amino groups in the graphene and carbon nanotube-carbon nitride hybrid composite material with secondary doped polyaniline with the polyurea explosion-proof elastomer coating material promotes the formation of the explosion-proof elastomer coating material network. Meanwhile, the self-carbonization of the graphene and carbon nanotube-carbon nitride hybrid composite material with secondary doped polyaniline promotes the crosslinking and carbonization of the polyurea explosion-proof elastomer coating material, ultimately forming a dense and continuous porous protective carbon layer.

[0120] The porous, expanded protective carbon layer not only insulates against heat but also creates a labyrinth effect, extending the pathway for flammable and toxic gases to escape into the flame. Thus, the nitride-carbon hybrid composite material of graphene and carbon nanotubes with secondary-doped polyaniline, along with polyphosphoric acid (APP), synergistically improves the flame-retardant properties of the polyurea explosion-proof elastomer coating material, suppressing the release of smoke and toxic gases.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A blast-resistant elastomer coating material containing secondary doped polyaniline, characterized in that, The explosion-proof elastomer coating material comprises a semi-prepolymer component A and a component B. Component A comprises the following raw materials in the indicated mass percentages: 40-60% polyether diol or polyester diol, 8-10% polyisocyanate, 2-12% graphene and carbon nanotubes with secondary doped polyaniline in a carbon nitride hybrid composite material, and 2-12% ammonium polyphosphate. Component B comprises the following raw materials in the indicated mass percentages: 50-70% amino-terminated polyether or carboxyl-terminated polyether, 10-30% diamine chain extender, 0.5-1% molecular sieve powder slurry, and 0.5-1% color paste. The composite material contains 6-16% graphene and carbon nanotubes with secondary-doped polyaniline and 6-16% ammonium polyphosphate. The graphene and carbon nanotubes with secondary-doped polyaniline are synthesized by secondary doping of polyaniline with a mass ratio of 15-25:1:1:

1. The composite material has a layered structure and is prepared using the following method: (1) Take two equal volumes of 1 mol / L doped acid solution and add aniline-graphene mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-graphene mixture to ammonium persulfate is 0.8:

1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-graphene composite material; wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 15-25:

1. (2) Add excess ammonia to the primary doped polyaniline-graphene composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-graphene composite material. (3) Take two equal volumes of 1 mol / L doped acid solution and add aniline-carbon nanotube mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-carbon nanotube mixture to ammonium persulfate is 0.8:

1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-carbon nanotube composite material; wherein the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 15-25:

1. (4) Add excess ammonia to the primary doped polyaniline-carbon nanotube composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-carbon nanotube composite material. (5) The intrinsic polyaniline-graphene composite material and the intrinsic polyaniline-carbon nanotube composite material were added to a 1 mol / L mixed solution of carbon nitride and doped acid at a mass ratio of 1:

1. After mixing and stirring, the mixture was allowed to stand for 20-26 hours. After filtration, the mixture was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotube and secondary doped polyaniline.

2. The explosion-proof elastomer coating material according to claim 1, characterized in that, In component A, the mass percentage of graphene and carbon nanotubes and the carbon nitride hybrid composite material of secondary doped polyaniline to ammonium polyphosphate is 10-15:85-90; in component B, the mass percentage of graphene and carbon nanotubes and the carbon nitride hybrid composite material of secondary doped polyaniline to ammonium polyphosphate is 10-15:85-90.

3. The explosion-proof elastomer coating material according to claim 2, characterized in that, The mass ratio of aniline to graphene in the aniline-graphene mixture is equal to the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture, wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 18–22:1, and the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture is 18–22:

1.

4. The explosion-proof elastomer coating material according to claim 3, characterized in that, The mass ratio of aniline to graphene in the aniline-graphene mixture is 20:1, and the mass ratio of aniline to carbon nanotubes in the aniline-carbon nanotube mixture is 20:

1.

5. The explosion-proof elastomer coating material according to claim 3, characterized in that, The isocyanate mixture includes at least one of 4,4'-diphenylmethane diisocyanate (MDI-100), 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, or naphthalene diisocyanate; the hydroxyl-terminated polyether includes at least one of PTMG1000, PTMG2000, and polyester diol; wherein PTMG1000 has a relative molecular mass of 1000±50 and a hydroxyl value of 107-118 mgkoH / g; PTMG2000 has a relative molecular mass of 2000±50 and a hydroxyl value of 54.7-57.5 mgkoH / g.

6. A method for preparing an anti-explosion elastomer coating material containing secondary doped polyaniline as described in any one of claims 1 to 5, characterized in that, The method includes: (1) Take two equal volumes of 1 mol / L doped acid solution and add aniline-graphene mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-graphene mixture to ammonium persulfate is 0.8:

1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-graphene composite material; wherein the mass ratio of aniline to graphene in the aniline-graphene mixture is 15-25:

1. (2) Add excess ammonia to the primary doped polyaniline-graphene composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-graphene composite material. (3) Take two equal volumes of 1 mol / L doped acid solution and add aniline-carbon nanotube mixture and ammonium persulfate respectively, wherein the molar ratio of aniline-carbon nanotube mixture to ammonium persulfate is 0.8:

1. Mix the two evenly with a magnetic stirrer for 1-2 hours, and let them stand at room temperature for 20-26 hours. Wash the obtained product with ethanol and deionized water until neutral, and then dry and grind to obtain a one-time doped polyaniline-carbon nanotube composite material; wherein the mass ratio of aniline to carbon nanotube in the aniline-carbon nanotube mixture is 15-25:

1. (4) Add excess ammonia to the primary doped polyaniline-carbon nanotube composite material to dedope, stir with a magnetic stirrer for 1-2 hours, let stand at room temperature for 20-26 hours, wash the obtained product with ethanol and deionized water until neutral, and finally dry and grind to obtain the intrinsic polyaniline-carbon nanotube composite material. (5) The intrinsic polyaniline-graphene composite material and the intrinsic polyaniline-carbon nanotube composite material were added to a 1 mol / L doped acid solution at a mass ratio of 1:

1. After mixing and stirring, the mixture was allowed to stand for 20-26 h. After filtration, the mixture was washed with ethanol and deionized water until neutral. Finally, it was dried and ground to obtain the carbon nitride hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline. (6) Under an inert environment, the polyether diol or polyester diol is stirred and heated to 100℃~130℃, and dehydrated under vacuum of -0.1MPa for 2~3 hours until the moisture content is less than 0.5%. Then the vacuum is released, the temperature is lowered to below 60℃, and polyisocyanate is added. The reaction is carried out at 80~90℃ for 2~4 hours. After the reaction is completed, the NCO value is measured and the material is discharged. The material is filtered to obtain the isocyanate-terminated semi-prepolymer. (7) Under an inert environment, the prepared isocyanate-terminated semi-prepolymer, graphene and carbon nanotubes are mixed with the carbon nitride hybrid composite material of secondary doped polyaniline and ammonium polyphosphate. Then, the mixture is ultrasonically dispersed at 50-60°C for 24 hours. After the reaction is completed, the NCO value is measured and the mixture is discharged. The semi-prepolymer component A is obtained by filtration. (8) In an inert environment, the premix of component B is obtained by dispersing, stirring and filtering the terminal amino polyether or terminal hydroxy polyether, diamine chain extender, molecular sieve powder slurry and color paste in a mass percentage of 50-70%: 10-30%: 0.5-1%: 0.5-1%. Then, the premix of component B and the nitride carbon hybrid composite material of graphene and carbon nanotubes with secondary doped polyaniline and ammonium polyphosphate are mixed together in a mass ratio of 210: 0.2-10: 0.02-1 and dispersed and filtered by ultrasonication. (9) Before spraying, the semi-prepolymer component A and component B are mixed together in a volume ratio of 1:1 to obtain the explosion-proof composite material modified with hydroxyl and amino groups.

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