Polyurethane-derived porous c@ni / nip3 composite material, and preparation method and application thereof

Abstract

The application provides a polyurethane-derived porous C@Ni / Ni3P composite material and a preparation method and application thereof, utilizes polyurethane sponge as a raw material, in-situ chemically deposits a Ni / Ni3P layer on the surface of the polyurethane sponge through electroless plating, and finally obtains the polyurethane-derived porous C@Ni / Ni3P composite material through high-temperature carbonization in a protective atmosphere, and the polyurethane-derived porous C@Ni / Ni3P composite material has high efficient electromagnetic wave absorption performance. Compared with the prior art, the preparation method of the composite material has the characteristics of stability, controllability, simplicity and easy operation, and the prepared composite material has the characteristics of strong absorption, wide effective absorption frequency band, low density and low cost, and meets the current requirements for electromagnetic wave absorption materials. Therefore, the application provides a novel idea for the design and synthesis of electromagnetic wave absorption materials derived from industrial production waste polyurethane.

Description

Technical Field

[0001] This invention relates to electromagnetic absorbing materials in the field of functional materials, and in particular to a polyurethane-derived porous C@Ni / Ni3P composite material, its preparation method, and its application. Background Technology

[0002] With the rapid development of 5G technology and electronic communications, human technological civilization continues to advance. Precision electronic instruments, wireless communications, and autonomous driving technologies have made tremendous progress and are widely used. Electromagnetic waves, as an important carrier of information, have driven the continuous development and upgrading of various fields, benefiting our daily lives, but also presenting certain negative impacts. The most typical is electromagnetic pollution, which poses a significant threat to information security and public health. In addition to preventing the serious consequences of electromagnetic pollution, countries are also striving to improve their national defense capabilities and increase research efforts in new weapons. Therefore, materials with efficient electromagnetic wave absorption or shielding properties are in high demand in both civilian and military fields, and the preparation of new electromagnetic wave absorbing materials has become a current research hotspot.

[0003] Carbon materials, due to their low density, large specific surface area, strong electronic conductivity, and stable properties, have long been at the forefront of electromagnetic wave absorption, with wide applications, such as carbon nanotubes and graphene. However, their relatively complex fabrication processes limit their application in electromagnetic wave absorption. Many waste materials in industrial production are discarded or disposed of, polluting the environment or releasing toxic and harmful gases during the process. In fact, many of these waste materials containing carbon elements can be carbonized and used as derived carbon-based materials for wave absorption. However, the relatively high complex permittivity of pure carbon materials leads to impedance mismatch, which is detrimental to achieving high electromagnetic wave absorption performance, and the carbonization process requires certain methods to preserve the original structure. An effective approach is to combine carbon materials with other dielectric or magnetic materials, improving impedance matching and attenuation capabilities through rational structural design.

[0004] Polyurethane foam is a common waste product in industrial production. Its porous structure makes it an ideal template for preparing porous carbon materials. By controlling the appropriate carbonization temperature, a matrix with certain wave absorption properties can be obtained. However, pure carbon materials have poor impedance matching characteristics, and direct carbonization can lead to structural collapse, requiring further improvement. Summary of the Invention

[0005] In view of the problem that direct carbonization of waste polyurethane sponge in the prior art is prone to structural collapse, the present invention provides a polyurethane-derived porous C@Ni / Ni3P composite material, its preparation method and application.

[0006] The composite material provided by this invention can be obtained through simple chemical deposition and subsequent high-temperature carbonization, and has stable and excellent electromagnetic wave absorption performance.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] This invention provides a method for preparing a polyurethane-derived porous C@Ni / Ni3P composite material, comprising the following steps: using polyurethane sponge as raw material, chemically depositing a Ni / Ni3P layer on the surface of the polyurethane sponge in situ by electroless plating, and then carbonizing it at high temperature under a protective atmosphere to finally obtain a polyurethane-derived porous C@Ni / Ni3P composite material with high-efficiency electromagnetic wave absorption performance.

[0009] In one embodiment of the present invention, the preparation method of polyurethane-derived porous C@Ni / Ni3P composite material specifically includes the following steps:

[0010] (1) Pretreatment of polyurethane foam;

[0011] (2) Preparation of polyurethane-derived porous C@Ni / Ni3P composite material: The pretreated polyurethane sponge was soaked in a solution containing nickel sulfate hexahydrate, sodium hypophosphite, trisodium citrate dihydrate, ammonium chloride and deionized water to carry out the reaction;

[0012] (3) After the reaction, take out the polyurethane sponge, squeeze out the solution, wash it, and then dry it.

[0013] (4) The polyurethane sponge obtained after drying is heat-treated, then washed and dried to obtain polyurethane-derived porous C@Ni / Ni3P composite material.

[0014] In one embodiment of the present invention, the method for pretreating the polyurethane foam in step (1) is as follows:

[0015] (1.1) Cut the polyurethane foam into blocks and soak them in a solution containing SnCl2, H2SO4 and deionized water and sonicate them.

[0016] (1.2) After the polyurethane sponge treated in step (1.1) is taken out, it is soaked in a solution containing PbCl2, HCl and deionized water and sonicated.

[0017] (1.3) After the polyurethane sponge is treated in step (1.2), it is soaked in a solution containing NaH2PO2·2H2O and deionized water and sonicated.

[0018] In one embodiment of the present invention, in step (1.1), the amounts of SnCl2, H2SO4 and deionized water in the solution are in the following order: 2g: 10m: 90m.

[0019] In one embodiment of the present invention, in step (1.1), the ultrasound time is 60 min.

[0020] In one embodiment of the present invention, in step (1.2), the amounts of PbCl2, HCl and deionized water in the solution are in the following order: 25mg: 0.25ml: 99.75ml.

[0021] In one embodiment of the present invention, in step (1.2), the ultrasound time is 60 minutes.

[0022] In one embodiment of the present invention, in step (1.3), the amount of NaH2PO2·2H2O and deionized water in the solution is in the following relationship: 1g: 100ml.

[0023] In one embodiment of the present invention, in step (1.3), the ultrasound time is 10 minutes.

[0024] In one embodiment of the present invention, in step (2), the mass ratio of nickel sulfate hexahydrate, sodium hypophosphite, trisodium citrate dihydrate, ammonium chloride and deionized water in the solution is 12:6:30:15:300.

[0025] In one embodiment of the present invention, the reaction conditions in step (2) are: reaction temperature: 60°C, holding time: 1 hour; heating method: water bath heating.

[0026] In one embodiment of the present invention, in step (2), the pH is adjusted to 9 with ammonia before the reaction.

[0027] In one embodiment of the present invention, step (2) is repeated three times.

[0028] In one embodiment of the present invention, in step (3), the polyurethane sponge is taken out, the solution is squeezed dry, and then it is squeezed and cleaned with deionized water and alcohol and placed in an oven to dry for 12 hours.

[0029] In one embodiment of the present invention, in step (4), the conditions for heat treatment of the polyurethane sponge obtained after drying are as follows: heat treatment in a nitrogen or argon atmosphere, heating rate: 5℃ / min, heat treatment temperature: 700℃, and holding time: 120min.

[0030] In one embodiment of the present invention, the washing and drying conditions in step (4) are as follows: the product is washed by filtering with deionized water and anhydrous ethanol respectively, and then placed in an oven at 60°C for 24 hours to dry.

[0031] In one embodiment of the present invention, the polyurethane foam is selected as waste polyurethane foam.

[0032] The present invention further provides a polyurethane-derived porous C@Ni / Ni3P composite material prepared based on the above preparation method.

[0033] The present invention further provides the application of the polyurethane-derived porous C@Ni / Ni3P composite material prepared by the above preparation method as a microwave absorbing material.

[0034] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects:

[0035] Chemical plating can uniformly deposit a metal coating on the surface of non-conductive materials. This invention utilizes chemical plating to deposit a magnetic Ni / Ni3P coating in situ on the surface of polyurethane, which improves the impedance matching of the composite material and introduces magnetic loss, thus improving the single loss mechanism of carbon materials and enhancing the ability to attenuate electromagnetic waves. Therefore, the polyurethane template method provides a new approach for the tunable composition and controllable structure design of composite wave materials.

[0036] This invention utilizes waste polyurethane sponge as raw material, chemically depositing a Ni / Ni3P layer on the polyurethane surface in situ via electroless plating, followed by high-temperature carbonization under a protective atmosphere to ultimately obtain a polyurethane-derived porous C@Ni / Ni3P composite material with highly efficient electromagnetic wave absorption performance. Experiments demonstrate that this composite material preparation method is stable, controllable, simple, and easy to operate. Furthermore, the prepared composite material exhibits strong absorption, a wide effective absorption bandwidth, low density, and low cost, meeting current requirements for electromagnetic wave absorbing materials.

[0037] Therefore, this invention provides a novel approach for the design and synthesis of electromagnetic wave absorbing materials derived from industrial waste, which is of great significance for the development and production of wave absorbing materials. Attached Figure Description

[0038] Figure 1 Compare the XRD patterns of Examples 1-2 and Example 1.

[0039] Figure 2 Comparative SEM images of Examples 1-2 and Example 1, wherein (a) and (d) are comparative examples of Example 1, (b) and (e) are comparative examples of Example 2, and (c) and (f) are SEM images of Example 1.

[0040] Figure 3Comparative absorption performance diagrams of Examples 1-2 and Example 1. (a) is Comparative Example 1, (b) is Comparative Example 2, and (c) is Example 1. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments described below are intended to facilitate the understanding of the present invention and do not limit it in any way.

[0042] This invention provides the following specific embodiments, discloses the performance of various combined embodiments, and analyzes the role of each experimental parameter in the system. Therefore, it should be considered that this patent specifically describes and discloses all possible combinations of the described technical solutions.

[0043] Comparative Example 1:

[0044] In this embodiment, the product obtained is a pure polyurethane-derived carbon (PPU) microwave absorbing material.

[0045] The preparation method of the above-mentioned PPU absorbing material is as follows:

[0046] (1) Clean the pure polyurethane sponge with deionized water and anhydrous ethanol three times, each time for 10 minutes, and then place it in a 60℃ oven to dry for 24 hours.

[0047] (2) The polyurethane sponge obtained in step (1) is heat-treated in an argon atmosphere. The heat treatment temperature is 700℃, the holding time is 120min, the heating rate is 5℃ / min, and the sponge is cooled to room temperature in the furnace.

[0048] (3) The sample prepared in step (2) was filtered and washed with deionized water and anhydrous ethanol respectively, and then placed in a 60°C oven to dry for 24 hours to obtain PPU microwave absorbing material.

[0049] The product obtained above was subjected to the following tests:

[0050] (A) Using Cu-Kα irradiation source X-ray diffraction (XRD) is used to determine the crystal structure of a sample.

[0051] (B) The morphology of the sample was observed using a scanning electron microscope (SEM).

[0052] (C) Electromagnetic parameters, including the complex permittivity and complex permeability, were determined using a coaxial line method with a Siyi 3672B-S vector network analyzer within the frequency range of 2-18 GHz. Sample preparation: The product was uniformly dispersed in paraffin wax, accounting for 25% of the total weight, and then pressed into a ring (outer diameter: 7.0 mm, inner diameter: 3.04 mm).

[0053] Comparative Example 2:

[0054] In this embodiment, the product obtained is a Ni / Ni3P (PNP) microwave absorbing material.

[0055] The preparation method of the above-mentioned PNP absorbing material is as follows:

[0056] (1) Take a piece of iron plate of appropriate size, polish the surface with coarse sandpaper and clean it with deionized water and alcohol using ultrasonic cleaning, and then put it in an oven to dry for 12 hours.

[0057] (2) Soak the dried iron plate in a solution containing 6g nickel sulfate hexahydrate, 3g sodium hypophosphite, 15g trisodium citrate dihydrate, 7.5g ammonium chloride and 150ml deionized water, adjust the pH to 9 with ammonia water, and bathe in a 60℃ water bath for 1 hour.

[0058] (3) Take out the iron plate, scrape off the metal coating deposited on the surface, clean it with deionized water and alcohol, and dry it in an oven for 12 hours to obtain PNP absorbing material.

[0059] The product obtained above was tested, and the testing methods and contents were exactly the same as those in Comparative Example 1.

[0060] Example 1:

[0061] In this embodiment, the product obtained is a polyurethane-derived porous C@Ni / Ni3P (PUNP) composite microwave absorbing material.

[0062] The preparation method of the above-mentioned polyurethane-derived porous C@Ni / Ni3P (PUNP) composite microwave absorbing material is as follows:

[0063] (1) Cut the polyurethane foam into pieces (3*3*1cm) 3 First, soak it in a solution containing 2g SnCl2, 10ml H2SO4, and 90ml deionized water, and sonicate for 60 minutes.

[0064] (2) After taking out the polyurethane sponge treated in step (1), soak it in a solution containing 25mg PbCl2, 0.25ml HCl and 99.75ml deionized water, and sonicate for 60min.

[0065] (3) Take out the polyurethane sponge after step (2) and soak it in a solution containing 1g NaH2PO2·2H2O and 100ml deionized water, and sonicate for 10min.

[0066] (4) After taking out the polyurethane sponge treated in step (3), soak it in a solution containing 6g nickel sulfate hexahydrate, 3g sodium hypophosphite, 15g trisodium citrate dihydrate, 7.5g ammonium chloride and 150ml deionized water, adjust the pH to 9 with ammonia water, and bathe in a 60℃ water bath for 1 hour.

[0067] (5) Repeat step (4) 3 times. After taking it out, squeeze the solution dry, squeeze and wash it with deionized water and alcohol, and then put it in the oven to dry for 12 hours.

[0068] (6) The polyurethane sponge obtained in step (5) is heat-treated in an argon atmosphere. The heat treatment temperature is 700℃, the holding time is 120min, the heating rate is 5℃ / min, and the sponge is cooled to room temperature in the furnace.

[0069] (7) The sample prepared in step (6) was filtered and washed with deionized water and anhydrous ethanol respectively, and then placed in an oven at 60°C for 24 hours to dry.

[0070] The product obtained above was tested, and the testing methods and contents were exactly the same as in Example 1.

[0071] The phase composition and structure of the materials obtained in Comparative Examples 1-2 and Example 1 are as follows: Figure 1 As shown, the microstructure of the prepared material is as follows Figure 2 As shown in Table 1, the absorption performance is as follows, and the results are as follows: Figure 3 .

[0072] Table 1: Heat treatment process and microwave absorption performance in Examples 1-3 and comparative examples

[0073]

[0074] The symbols in Table 1 have the following meanings:

[0075] RL—Reflection Loss; RL min —Minimum reflection loss.

[0076] Phase analysis: such as Figure 1 As shown, the phase of Comparative Example 1 was identified as amorphous carbon, exhibiting a distinct peak. The phases of Comparative Example 2 were Ni and Ni3P. The phase of Example 3 consisted of amorphous carbon, Ni, and Ni3P, and the positions of each peak and the corresponding PDF cards are marked in the figure.

[0077] Morphological analysis: such as Figure 2As shown, in Comparative Example 1, the original porous structure collapsed after high-temperature carbonization. In Example 2, the Ni / Ni3P obtained after electroless plating was granular and agglomerated. In Example 3, after electroless plating and carbonization, the Ni / Ni3P particles were uniformly attached to the polyurethane surface, thus preserving the porous structure of the carbonized polyurethane sponge. The polyurethane served as a sacrificial template, ensuring the preparation of the porous C@Ni / Ni3P composite material.

[0078] Wave absorption performance analysis: From Table 1 and Figure 3 It can be seen that, compared to Example 1, the sample thickness of the pure polyurethane-derived carbon (PPU) obtained ranges from 1.0 to 5.0 mm. At a frequency of 15.05 GHz and a sample thickness of 1.5 mm, RL... min The absorption band at this thickness is -17.32 dB, with a value of -28.63 dB. In contrast, the Ni / Ni3P (PNP) sample obtained in Example 2, with a thickness range of 1.0-5.0 mm, exhibits poor absorption performance within the measured range. The lowest RL value (-28.63 dB) is observed at a thickness of 2.5 mm and a frequency of 12.84 GHz, corresponding to an absorption band of 4.91 GHz. In Example 1, the polyurethane-derived porous C@Ni / Ni3P composite material (PUNP) sample, with a thickness range of 1.0-5.0 mm, shows a lower RL value at a frequency of 15.78 GHz and a sample thickness of 1.5 mm. min The absorption bandwidth (RL < -10dB) is -58.12dB, and at this thickness, the absorption bandwidth is 4.82GHz. Therefore, the product obtained in Example 3 exhibits excellent absorption performance within a relatively thin matching thickness (d = 1.5mm) and a wide frequency range (Ku band), demonstrating great application potential.

[0079] In summary, a polyurethane foam-derived porous C@Ni / Ni3P composite material with excellent microwave absorption properties can be prepared through simple heat treatment and in-situ chemical synthesis. In particular, the process parameters enable stable and efficient preparation of this composite material while effectively regulating its microwave absorption performance, thus greatly advancing industrial production and holding significant importance for the widespread application and development of microwave absorbing materials.

[0080] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a polyurethane-derived porous C@Ni / Ni3P composite material, characterized in that, Includes the following steps: (1) Pretreatment of polyurethane foam; (2) Preparation of polyurethane-derived porous C@Ni / Ni3P composite material: The pretreated polyurethane sponge was soaked in a solution containing nickel sulfate hexahydrate, sodium hypophosphite, trisodium citrate dihydrate, ammonium chloride and deionized water to carry out the reaction; (3) After the reaction, remove the polyurethane sponge, squeeze out the solution, wash it, and then dry it. (4) The polyurethane sponge obtained after drying is heat-treated, then washed and dried to obtain polyurethane-derived porous C@Ni / Ni3P composite material. The method for pretreating the polyurethane foam in step (1) is as follows: (1.1) Cut the polyurethane sponge into blocks and soak them in a solution containing SnCl2, H2SO4 and deionized water and sonicate them. (1.2) After the polyurethane sponge treated in step (1.1) is taken out, it is soaked in a solution containing PbCl2, HCl and deionized water and sonicated. (1.3) After taking out the polyurethane sponge treated in step (1.2), soak it in a solution containing NaH2PO2·2H2O and deionized water and sonicate it. In step (2), the reaction conditions are as follows: reaction temperature: 60℃, holding time: 1 hour; heating method: water bath heating; in step (2), before the reaction, the pH is adjusted to 9 with ammonia water. In step (4), the conditions for heat treatment of the polyurethane sponge obtained after drying are as follows: heat treatment in nitrogen or argon atmosphere, heating rate: 5℃ / min, heat treatment temperature: 700℃, heat treatment time: 120min. The polyurethane foam used was selected from waste polyurethane foam.

2. The method for preparing a polyurethane-derived porous C@Ni / Ni3P composite material according to claim 1, characterized in that, In step (1.1), the ratio of SnCl2, H2SO4, and deionized water in the solution is 2g:10ml:90ml. In step (1.2), the ratio of PbCl2, HCl, and deionized water in the solution is: 25mg: 0.25ml: 99.75ml. In step (1.3), the ratio of the amounts of NaH2PO2·2H2O and deionized water in the solution is 1g:100ml.

3. The method for preparing a polyurethane-derived porous C@Ni / Ni3P composite material according to claim 1, characterized in that, In step (2), the mass ratio of nickel sulfate hexahydrate, sodium hypophosphite, trisodium citrate dihydrate, ammonium chloride, and deionized water in the solution is 12:6:30:15:

300.

4. The method for preparing a polyurethane-derived porous C@Ni / Ni3P composite material according to claim 1, characterized in that, Step (2) is repeated 3 times.

5. A polyurethane-derived porous C@Ni / Ni3P composite material prepared by any one of the preparation methods described in claims 1-4.

6. The application of the polyurethane-derived porous C@Ni / Ni3P composite material prepared by any one of the preparation methods described in claims 1-4 as a microwave absorbing material.

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