Flexible high-power microwave protection material and preparation method and application thereof

Abstract

The invention provides a flexible high-power microwave protection material as well as a preparation method and application thereof, and relates to the technical field of microwave protection materials. The flexible high-power microwave protection material is composed of a composite filler and a flexible resin matrix, the composite filler comprises SiOC ceramic powder and MXene powder, and the mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1): (0.5-1). According to the flexible high-power microwave protection material, the tensile elongation rate is larger than 30%, the high-power microwave strength is larger than 100 MW, and a human body or equipment can be effectively prevented from being damaged by microwaves. Meanwhile, by means of the UV-assisted extrusion 3D printing technology, accurate forming of the material is achieved, the requirements of customization and batch production are met, and the method has important scientific significance and application value in the field of microwave protection.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave protection materials, and in particular to a flexible high-power microwave protection material and a preparation method and application thereof. Background Art

[0002] High-power microwave (HPM) refers to strong electromagnetic pulses with a frequency range of 1 GHz to 300 GHz and a peak power of more than 100 MW. High-power microwaves have the characteristics of high frequency, short pulse, high power and high efficiency, and are widely used in military, industrial, communication, aerospace and other fields. However, the development of high-power microwave technology also brings potential hazards. For example, high-power microwaves not only damage electronic equipment, but also cause harm to personnel. At present, high-power microwave protection of electronic equipment has received more and more attention, but protecting personnel from damage caused by high-power microwaves has become an important issue.

[0003] At present, common protection measures for high-power microwave protection of electronic equipment include design and site selection, electrical equipment protection, power line protection, underground facility construction and staying away from electromagnetic radiation sources. The protection measures for personnel are mostly physical isolation, the use of protective materials, and taking other necessary protective measures. Among them, carbon materials, graphene and other materials are more common protective materials. Carbon materials and graphene can attenuate electromagnetic waves through electrical loss, but they can also cause strong reflection of electromagnetic waves rather than absorption. In a high-power microwave environment, reflection may aggravate electromagnetic interference and even cause secondary damage to surrounding equipment or personnel. Graphene and carbon nanomaterials are also easy to agglomerate in a composite matrix (such as stacking of graphene sheets), resulting in a weakening of the interface polarization effect. Therefore, the protection effect of these traditional materials against high-power microwaves needs to be improved. In addition, these traditional high-power microwave protection materials are inconvenient to use.

[0004] In summary, it is necessary to develop a new flexible high-power microwave protection material to solve the many problems existing in traditional high-power microwave protection materials. Summary of the invention

[0005] In view of this, the present invention provides a flexible high-power microwave protective material and a preparation method and application thereof. The protective material of the present invention has the characteristics of flexibility and resistance to high-power microwaves and a simple preparation process, and has important scientific significance and application value in the field of microwave protection.

[0006] The first aspect of the present invention is to provide a flexible high-power microwave protection material, which is composed of a composite filler and a flexible resin matrix;

[0007] The composite filler includes SiOC ceramic powder and MXene powder, and the mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1):(0.5-1).

[0008] Preferably, the method for preparing the SiOC ceramic powder comprises the following steps:

[0009] The polysiloxane is added to a curing agent, stirred evenly and then thermally cured to obtain a polysiloxane block, and the polysiloxane block is cracked under a vacuum environment to obtain a SiOC ceramic powder.

[0010] Preferably, the molecular weight of the polysiloxane is 20,000 to 200,000; the pyrolysis temperature is 1,200° C. to 1,600° C., and the pyrolysis time is 0.5 to 2 hours.

[0011] Preferably, the particle size of the SiOC ceramic powder is 100 nm to 20 μm.

[0012] Preferably, the particle size of the MXene powder is 100 nm to 5 μm.

[0013] Preferably, the viscosity of the flexible resin matrix is ​​1000mPa·s to 2000mPa·s, and the molecular weight is 3000 to 30000.

[0014] The second aspect of the present invention is to provide a method for preparing a flexible high-power microwave protection material, which specifically comprises the following steps:

[0015] SiOC ceramic powder and MXene powder are evenly mixed in proportion and a photoinitiator is added to obtain a composite filler. The composite filler is then added to a flexible resin matrix and ball-milled to obtain a mixed slurry. The mixed slurry is cured and molded by UV ultraviolet light-assisted extrusion 3D printing to obtain a flexible high-power microwave protective material.

[0016] Preferably, the mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1):(0.5-1).

[0017] Preferably, the SiOC ceramic powder and the MXene powder account for 10 wt.% to 60 wt.% in the mixed slurry.

[0018] Preferably, the power of the UV light is 5000-10000 mW / cm 2 The printing layer thickness is 50-100 μm, the diameter of the printing nozzle is 0.5-5 mm, and the printing speed is 0.05-0.5 m / s.

[0019] The third aspect of the present invention is to provide an application of a flexible high-power microwave shielding material, wherein the flexible high-power microwave shielding material is the flexible high-power microwave shielding material described in the above technical solution.

[0020] The flexible high-power microwave protection material of the present invention has the characteristics of flexibility and resistance to high-power microwaves and can be used to prepare high-power microwave protection products that need to be bent, stretched or fitted to complex curved surfaces to prevent microwaves from causing harm to the human body or equipment. The products include but are not limited to flexible masks, flexible protective clothing, space flexible protective stickers, etc.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are:

[0022] The flexible high-power microwave protective material of the present invention has a tensile elongation greater than 30% and a high-power microwave resistance strength greater than 100MW, and can effectively protect a human body or equipment from microwave damage.

[0023] The present invention utilizes UV ultraviolet light-assisted extrusion 3D printing technology to not only achieve precise molding of materials, but also meet the needs of customization and mass production. It has important scientific significance and application value in the field of microwave protection, especially complex curved surface microwave protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] Figure 1 The present invention is a process flow chart for preparing the flexible high-power microwave protection material. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The first aspect of the present invention is to provide a flexible high-power microwave protection material, which is composed of a composite filler and a flexible resin matrix;

[0028] The composite filler includes SiOC ceramic powder and MXene powder, and the mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1):(0.5-1).

[0029] The method for preparing SiOC ceramic powder of the present invention comprises the following steps:

[0030] Adding polysiloxane to a curing agent, stirring evenly and then thermally curing to obtain a polysiloxane block, and cracking the polysiloxane block under a vacuum environment to obtain a SiOC ceramic powder;

[0031] The molecular weight of the polysiloxane is 20000-200000; the curing agent is an amine curing agent, preferably an aliphatic amine curing agent, more preferably hexamethylenediamine, and the amount of the curing agent is 1wt.%-5wt.% of the polysiloxane; the thermal curing temperature is 80°C-120°C, preferably 80°C-100°C; the pyrolysis temperature is 1200°C-1600°C, and the pyrolysis time is 0.5-2h, preferably 1-2h; the particle size of the SiOC ceramic powder is 100nm-20μm.

[0032] In some specific embodiments of the present invention, the pyrolysis is carried out in a vacuum tube furnace, but the present invention does not strictly limit the pyrolysis method, as long as the polysiloxane block can be vacuum pyrolyzed into SiOC ceramic powder.

[0033] The particle size of the MXene powder of the present invention is 100 nm to 5 μm. The present invention does not strictly limit the type of MXene powder, and conventional MXene powders in the art can be used in the present invention.

[0034] In some specific embodiments of the present invention, the MXene powder is at least one of Ti3C2 powder, Ti2N powder, and Mo2C powder.

[0035] The viscosity of the flexible resin matrix of the present invention is 1000 mPa·s to 2000 mPa·s, and the molecular weight is 3000 to 30000. In some specific embodiments of the present invention, the flexible resin matrix is ​​polydimethylsiloxane (PDMS).

[0036] The second aspect of the present invention is to provide a method for preparing a flexible high-power microwave protection material, which specifically comprises the following steps:

[0037] SiOC ceramic powder and MXene powder are evenly mixed in proportion and a photoinitiator is added to obtain a composite filler. The composite filler is then added to a flexible resin matrix and ball-milled to obtain a mixed slurry. The mixed slurry is cured and molded by UV ultraviolet light-assisted extrusion 3D printing to obtain a flexible high-power microwave protective material.

[0038] In the preparation method of the flexible high-power microwave protection material of the present invention, the mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1):(0.5-1); the photoinitiator is a Type I free radical photoinitiator, preferably an acylphosphonate photoinitiator, more preferably 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the amount of the photoinitiator added is 1wt.% to 5wt.% of the SiOC ceramic powder and the MXene powder; the ball milling speed is 200-400rpm, preferably 400rpm, the ball milling time is 0.5-2h, and the material-ball ratio is (1-1.5):1; the proportion of the SiOC ceramic powder and the MXene powder in the mixed slurry is 10wt.% to 60wt.%; the power of the UV ultraviolet light is 5000-10000mW / cm 2 The printing layer thickness is 50-100 μm, the diameter of the printing nozzle is 0.5-5 mm, preferably 1-1.5 mm, and the printing speed is 0.05-0.5 m / s, preferably 0.05-0.25 m / s.

[0039] The third aspect of the present invention is to provide an application of a flexible high-power microwave shielding material, wherein the flexible high-power microwave shielding material is the flexible high-power microwave shielding material described in the above technical solution.

[0040] The flexible high-power microwave protection material of the present invention has the characteristics of flexibility and resistance to high-power microwaves. Its tensile elongation is greater than 30%, and its resistance to high-power microwaves is greater than 100MW. It can be used to prepare high-power microwave protection products that need to be bent, stretched or fitted to complex surfaces to prevent microwaves from causing harm to the human body or equipment. The products include but are not limited to flexible masks, flexible protective clothing, space flexible protective stickers, etc.

[0041] In order to further illustrate the present invention, the following examples are provided for detailed description. The raw materials used in the following examples of the present invention are all commercially available.

[0042] Unless otherwise specified, all experiments were repeated 3 times and the results were expressed as mean values.

[0043] Embodiment 1 A method for preparing a flexible high-power microwave protection material, the steps are as follows:

[0044] (1) Preparation of SiOC ceramic powder

[0045] Add hexamethylenediamine curing agent to polysiloxane with a molecular weight of 20,000, the amount of the curing agent is 1 wt.% of the polysiloxane, stir evenly, and then heat cure at 80°C. Place the cured polysiloxane block in a vacuum tube furnace and decompose it at 1200°C for 0.5h in a vacuum environment to obtain SiOC ceramic powder;

[0046] (2) Preparation of SiOC / Ti3C2 / PDMS mixed slurry

[0047] SiOC ceramic powder and Ti3C2 powder were mixed and stirred in a mass ratio of 1:1, 2 wt.% of photoinitiator 2,4,6-trimethylbenzoyldiphenylphosphine oxide was added, and then added to a liquid PDMS flexible resin matrix, and ball milled for 1 h at a rotation speed of 400 rpm and a material-ball ratio of 1:1 to obtain a SiOC / Ti3C2 / PDMS mixed slurry, wherein the content of SiOC ceramic powder and Ti3C2 powder in the mixed slurry was 40 wt.%;

[0048] (3) 3D printing of protective materials

[0049] UV light-assisted extrusion 3D printing is used to cure the mixed slurry by photothermal synergy, with the UV light power of 5000mW / cm 2 , the 3D printing layer thickness is 50μm, the nozzle diameter is 1mm, and the printing speed is 0.05m / s.

[0050] According to tests, the flexible high-power microwave protection material prepared in this embodiment has a tensile elongation of 82%, a tensile breaking strength of 4.87 MPa, and a maximum microwave resistance power of 117 MW.

[0051] Example 2 A method for preparing a flexible high-power microwave protection material, the steps are as follows:

[0052] (1) Preparation of SiOC ceramic powder

[0053] Add hexamethylenediamine curing agent to polysiloxane with a molecular weight of 10,000, the amount of the curing agent is 2 wt.% of the polysiloxane, stir evenly and then heat cure at 100°C, place the cured polysiloxane block in a vacuum tube furnace, and decompose at 1400°C for 1 hour in a vacuum environment to obtain SiOC ceramic powder;

[0054] (2) Preparation of SiOC / Ti2N / PDMS mixed slurry

[0055] SiOC ceramic powder and Ti2N powder were mixed and stirred in a mass ratio of 1:0.5, 3 wt.% of photoinitiator 2,4,6-trimethylbenzoyldiphenylphosphine oxide was added, and then added to a liquid PDMS flexible resin matrix, and ball milled for 2 h at a rotation speed of 400 rpm and a material-ball ratio of 1.2:1 to obtain a SiOC / Ti2N / PDMS mixed slurry, wherein the content of SiOC ceramic powder and Ti2N powder in the mixed slurry was 50 wt.%;

[0056] (3) 3D printing of protective materials

[0057] UV light-assisted extrusion 3D printing is used to cure the mixed slurry by photothermal synergy, with the UV light power of 8000mW / cm 2 , the 3D printing layer thickness is 75μm, the nozzle diameter is 1mm, and the printing speed is 0.1m / s.

[0058] According to tests, the flexible high-power microwave protection material prepared in this embodiment has a tensile elongation of 68%, a tensile breaking strength of 4.64 MPa, and a maximum microwave resistance power of 135 MW.

[0059] Example 3 A method for preparing a flexible high-power microwave protection material, the steps are as follows:

[0060] (1) Preparation of SiOC ceramic powder

[0061] Add hexamethylenediamine curing agent to polysiloxane with a molecular weight of 20,000, the amount of the curing agent is 5 wt.% of the polysiloxane, stir evenly and then heat cure at 100°C, place the cured polysiloxane block in a vacuum tube furnace, and decompose at 1600°C for 2 hours in a vacuum environment to obtain SiOC ceramic powder;

[0062] (2) Preparation of SiOC / Mo2C / PDMS mixed slurry

[0063] SiOC ceramic powder and Mo2C powder were mixed and stirred at a mass ratio of 0.5:1, 5wt.% of photoinitiator 2,4,6-trimethylbenzoyldiphenylphosphine oxide was added, and then added to a liquid PDMS flexible resin matrix, and ball milled for 2 hours at a rotation speed of 400 rpm and a material-ball ratio of 1.5:1 to obtain a SiOC / Mo2C / PDMS mixed slurry, wherein the content of SiOC ceramic powder and Mo2C powder in the mixed slurry was 60wt.%;

[0064] (3) 3D printing of protective materials

[0065] UV light-assisted extrusion 3D printing is used to cure the mixed slurry by light and heat, with the UV light power of 10000mW / cm 2 , the 3D printing layer thickness is 100μm, the nozzle diameter is 1.5mm, and the printing speed is 0.25m / s.

[0066] According to tests, the flexible high-power microwave protection material prepared in this embodiment has a tensile elongation of 51%, a tensile breaking strength of 4.34 MPa, and a maximum microwave resistance power of 155 MW.

[0067] Comparative Example 1

[0068] Same as Example 1, except that an equal amount of SiOC ceramic powder is used to replace Ti3C2 powder.

[0069] According to tests, the flexible high-power microwave protection material prepared in this embodiment has a tensile elongation of 23%, a tensile breaking strength of 3.15 MPa, and a maximum microwave resistance power of 85 MW.

[0070] Comparative Example 2

[0071] Same as Example 1, except that the mass ratio of the SiOC ceramic powder to the Ti3C2 powder is 2:1.

[0072] According to tests, the flexible high-power microwave protection material prepared in this embodiment has a tensile elongation of 17%, a tensile breaking strength of 3.87 MPa, and a maximum microwave resistance power of 63 MW.

[0073] Comparative Example 3

[0074] Same as Example 1, except that the mass ratio of SiOC ceramic powder to Ti3C2 powder is 1:2.

[0075] According to tests, the flexible high-power microwave protection material prepared in this embodiment has a tensile elongation of 31%, a tensile breaking strength of 3.27 MPa, and a maximum microwave resistance power of 93 MW.

[0076] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A flexible high-power microwave protective material, characterized in that: The material is composed of a composite filler and a flexible resin matrix; The composite filler includes SiOC ceramic powder and MXene powder, and the mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1):(0.5-1).

2. A flexible high-power microwave protection material according to claim 1, characterized in that: The preparation method of the SiOC ceramic powder comprises the following steps: The polysiloxane is added to a curing agent, stirred evenly and then thermally cured to obtain a polysiloxane block, and the polysiloxane block is cracked under a vacuum environment to obtain a SiOC ceramic powder.

3. A flexible high-power microwave protection material according to claim 2, characterized in that: The molecular weight of the polysiloxane is 20,000 to 200,000; the pyrolysis temperature is 1,200° C. to 1,600° C.; and the pyrolysis time is 0.5 to 2 hours.

4. The flexible high-power microwave protection material according to claim 1, characterized in that: The viscosity of the flexible resin matrix is ​​1000mPa·s to 2000mPa·s, and the molecular weight is 3000 to 30000.

5. The method for preparing the flexible high-power microwave protection material according to any one of claims 1 to 4, characterized in that: The following steps are involved: SiOC ceramic powder and MXene powder are evenly mixed in proportion and a photoinitiator is added to obtain a composite filler. The composite filler is then added to a flexible resin matrix and ball-milled to obtain a mixed slurry. The mixed slurry is cured and molded by UV ultraviolet light-assisted extrusion 3D printing to obtain a flexible high-power microwave protective material.

6. The preparation method according to claim 5, characterized in that: The mass ratio of the SiOC ceramic powder to the MXene powder is (0.5-1):(0.5-1).

7. The preparation method according to claim 5, characterized in that: The SiOC ceramic powder and the MXene powder account for 10 wt.% to 60 wt.% in the mixed slurry.

8. The preparation method according to claim 5, characterized in that: The power of the UV light is 5000-10000 mW / cm 2 The printing layer thickness is 50-100 μm, the diameter of the printing nozzle is 0.5-5 mm, and the printing speed is 0.05-0.5 m / s.

9. Application of a flexible high-power microwave protection material, characterized in that: The flexible high-power microwave protection material is used to prepare high-power microwave protection products that need to be bent, stretched or fitted to complex curved surfaces. The flexible high-power microwave protection material is the flexible high-power microwave protection material described in any one of claims 1 to 4 or the flexible high-power microwave protection material prepared by the method described in any one of claims 5 to 8.

10. The use according to claim 9, characterized in that: The product is at least one of a flexible face mask, a flexible protective suit, and a space flexible protective patch.

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