CN115716925A - Preparation method of a ternary interpenetrating network high conductivity thermogel composite material with synergistic effect - Google Patents

Abstract

The invention discloses a method for preparing a ternary interpenetrating network high-conductivity hydrogel composite material with synergistic effect. Boron nitride and carbon nanotubes are used as fillers, and good synergy can be produced by utilizing the similar crystal structures of the two Function, the present invention adopts the step-by-step interpenetrating polymerization method, adds boron nitride and carbon nanotubes with different content ratios, and uniformly disperses them into the ternary interpenetrating hydrogel matrix to prepare a hydrogel composite material with high thermal conductivity , the whole preparation process flow is clear, and the operation is relatively simple. The present invention enables several polymers with different functions to form a stable combination through the form of network interpenetration, thereby realizing the complementarity of properties between components and having good mechanical properties. The composite material is flexible while taking into account the high thermal conductivity of the material, and can be widely used in the fields of heat dissipation of electronic components and heat conduction of nanocomposite materials.

Description

A synergistic ternary interpenetrating network high conductivity thermogel composite Preparation

technical field

The invention relates to a conductive thermogel, in particular to a method for preparing a ternary interpenetrating network high-conductivity thermogel composite material with synergistic effect.

Background technique

With the rapid development of small microelectronics and high integration, the thermal conductivity of materials has become a key technology in the microelectronics manufacturing process. It is difficult for electronic devices to dissipate heat quickly, resulting in a sharp rise in chip temperature, resulting in low efficiency and low lifetime of devices. Therefore, it is urgent to study materials with good thermal conductivity and excellent mechanical properties.

Hydrogel is a new type of polymer material with a three-dimensional network structure. Due to its good flexibility and biocompatibility, it has been widely used in industry, agriculture, biomedicine and other fields. However, the mechanical properties of traditional hydrogels are relatively poor. Poor, low strength, prone to permanent fracture, and their internal structure is single, low thermal conductivity, which largely limits their application range. In order to improve these problems, the present invention utilizes the interpenetrating network structure to prepare hydrogel, so that the mechanical properties of the material are significantly improved, and by adding thermally conductive fillers, the thermal conductivity of the hydrogel composite material is effectively increased by synergistic effect.

Contents of the invention

The invention provides a method for preparing a ternary interpenetrating network high-conductivity thermogel composite material with synergistic effect. The present invention selects boron nitride and carbon nanotubes as thermal conductive fillers, improves the thermal conductivity of the hydrogel through the synergistic effect of the two, utilizes the ternary interpenetrating network structure to enhance the mechanical properties of the hydrogel, and obtains the hydrogel composite material It has excellent mechanical properties and good thermal conductivity.

The preparation method of the ternary interpenetrating network high conductivity thermogel composite material with synergistic effect of the present invention comprises the following steps:

Step 1: Pretreatment of thermally conductive filler

Weigh the thermally conductive filler and disperse it in 50mL of n-hexane, ultrasonically disperse it evenly to reduce agglomeration, and then remove the n-hexane to obtain the pretreated thermally conductive filler for later use;

Step 2: Preparation of semi-IPN hydrogel

Weigh 1-2 parts of PVA into deionized water, stir until completely dissolved, then add 15-20 parts of AMPS into deionized water to dissolve, add the obtained AMPS solution into the PVA solution, and add 0.03-0.05 parts of cross-linking agent at the same time And 0.04-0.06 parts of initiator, react at constant temperature (60°C) for 2-4 hours under the protection of _N2 to obtain PVA-PAMPS semi-interpenetrating network structure hydrogel;

Step 3: Preparation of ternary interpenetrating network highly conductive thermogel composites

Add the PVA-PAMPS semi-interpenetrating network structure hydrogel obtained in step 2 into the aqueous solution (10ml deionized water) dissolved with 8-10 parts of AA, and add the thermally conductive filler pretreated in step 1, 0.06-0.08 parts of initiator React with 0.08-0.1 part of cross-linking agent in a closed reactor at 30°C for 2-3 hours, so that acrylic acid, boron nitride and multi-walled carbon nanotubes can be uniformly diffused in the gel, and fully washed to remove unreacted monomers and Impurities were removed to obtain a PVA-PAMPS-PAA ternary interpenetrating network conductive hydrogel composite material.

The above-mentioned proportions are all parts by mass.

In step 1, the thermally conductive filler is boron nitride and multi-walled carbon nanotubes, the proportion of boron nitride in the thermally conductive filler is 60% to 90%, and the balance is carbon nanotubes.

The size of the boron nitride is 100nm, the inner diameter of the multi-walled carbon nanotube is 5-8nm, and the outer diameter is 10-15nm.

In step 3, the amount of the pretreated thermally conductive filler is 1-3 wt%, calculated on the basis of the total mass of the monomers. The total mass of the monomers refers to the total mass of PVA, AMPS and AA.

The crosslinking agent includes any one of ethylene glycol dimethacrylate and N,N-methylenebisacrylamide.

The initiator includes any one of ammonium persulfate and potassium persulfate.

Compared with prior art, the beneficial effect of the present invention is:

1. Compared with the current technology, the network structure obtained by ternary interpenetration is denser and more stable, and the mechanical strength of the prepared hydrogel is significantly higher than that of ordinary hydrogel products;

2. Since the crystal structures of boron nitride and carbon nanotubes are very similar, they can produce good synergy and effectively improve the thermal conductivity of hydrogel materials;

3. The preparation method of the present invention is simple in process and low in cost, and at the same time, the preparation conditions are easy to control and the efficiency is high.

Description of drawings

Fig. 1 Comparison of thermal conductivity structures of hydrogels obtained in different embodiments and Comparative Example 1.

Figure 2 The stress-strain curves of the hydrogels obtained in different embodiments and Comparative Example 1.

Fig. 3 Comparison results of elastic modulus of hydrogels obtained in different examples and Comparative Example 1.

specific implementation plan

The following is a further description of the present invention in conjunction with the examples, but the embodiments of the present invention are not limited thereto.

Example 1:

In this embodiment, the preparation of the ternary interpenetrating network high conductivity thermogel composite material with synergistic effect includes the following steps:

1. Weigh boron nitride and carbon nanotubes with a ratio of 9:1 (the total addition amount is 3wt%), dissolve them in 50mL of n-hexane, and disperse the two groups evenly by ultrasonic dispersion for 30 minutes to reduce the phenomenon of agglomeration , and then remove n-hexane to obtain treated boron nitride and carbon nanotubes for later use.

2. Weigh 1.6g of PVA and add 10ml of deionized water into the three-necked flask, stir until it is completely dissolved, then add 16g of AMPS into the beaker and dissolve it with 20ml of deionized water, then add it into the three-necked flask, and at the same time Add 0.09g of N,N'-methylenebisacrylamide and 0.07g of ammonium persulfate, protect with _N2 , and react at constant temperature (60°C) for 3h to obtain a semi-interpenetrating PVA-PAMPS hydrogel .

3. Put the semi-interpenetrating PVA-PAMPS hydrogel into the dissolved 9g AA aqueous solution (10ml deionized water), and add boron nitride and carbon nanotubes (0.72g: 0.08g), 0.04g ammonium persulfate and 0.05g N,N'-methylenebisacrylamide, in a closed three-necked flask at 30°C for 3 hours, to make acrylic acid, boron nitride and carbon nanotubes diffuse evenly in the gel, and fully wash to remove unreacted monomers and impurities to obtain a PVA-PAMPS-PAA ternary interpenetrating network conductive hydrogel composite material.

Example 2:

In this embodiment, the preparation of the ternary interpenetrating network high conductivity thermogel composite material with synergistic effect includes the following steps:

1. Weigh boron nitride and carbon nanotubes with a ratio of 8:2, dissolve them in 50mL of n-hexane, and disperse the two groups more evenly by ultrasonic dispersion for 30 minutes to reduce agglomeration, and then remove the n-hexane to obtain Treated boron nitride and carbon nanotubes ready for use.

2. Weigh 1.6g of PVA and add 10ml of deionized water into the three-necked flask, stir until it is completely dissolved, then add 16g of AMPS into the beaker and dissolve it with 20ml of deionized water, then add it into the three-necked flask, and at the same time Add 0.09g of N,N'-methylenebisacrylamide and 0.07g of ammonium persulfate, protect with _N2 , and react at constant temperature (60°C) for 3h to obtain a semi-interpenetrating PVA-PAMPS hydrogel .

3. Put the semi-interpenetrating PVA-PAMPS hydrogel into the dissolved 9g AA aqueous solution (10ml deionized water), and add boron nitride and carbon nanotubes (0.64g: 0.16g), 0.04g ammonium persulfate and 0.05g N,N′-methylenebisacrylamide, in a closed three-necked flask at 30°C for 3 hours, to make acrylic acid, boron nitride and carbon nanotubes diffuse evenly in the gel, and fully wash to remove unreacted monomers and impurities to obtain a PVA-PAMPS-PAA ternary interpenetrating network conductive hydrogel composite material.

Example 3:

In this embodiment, the preparation of the ternary interpenetrating network high conductivity thermogel composite material with synergistic effect includes the following steps:

1. Weigh boron nitride and carbon nanotubes with a ratio of 7:3, dissolve them in 50mL of n-hexane, and disperse the two groups more evenly by ultrasonic dispersion for 30 minutes to reduce agglomeration, and then remove the n-hexane to obtain Treated boron nitride and carbon nanotubes ready for use.

2. Weigh 1.6g of PVA and add 10ml of deionized water into the three-necked flask, stir until it is completely dissolved, then add 16g of AMPS into the beaker and dissolve it with 20ml of deionized water, then add it into the three-necked flask, and at the same time Add 0.09g of N,N'-methylenebisacrylamide and 0.07g of ammonium persulfate, protect with _N2 , and react at constant temperature (60°C) for 3h to obtain a semi-interpenetrating PVA-PAMPS hydrogel .

3. Put the semi-interpenetrating PVA-PAMPS hydrogel into the dissolved 9g AA aqueous solution (10ml deionized water), and add boron nitride and carbon nanotubes (0.56g: 0.24g), 0.04g ammonium persulfate and 0.05g N,N'-methylenebisacrylamide, in a closed three-necked flask at 30°C for 3 hours, to make acrylic acid, boron nitride and carbon nanotubes diffuse evenly in the gel, and fully wash to remove unreacted monomers and impurities to obtain a PVA-PAMPS-PAA ternary interpenetrating network conductive hydrogel composite material.

Example 4:

The boron nitride and carbon nanotube proportioning in step (1) in embodiment 1 is replaced by 6:4 by 9:1, and boron nitride and carbon nanotube mass ratio are (0.48g: 0.32 The rest of g) remain unchanged.

Example 5:

The boron nitride and carbon nanotube proportioning in step (1) in embodiment 1 is replaced with 5:5 by 9:1, and boron nitride and carbon nanotube mass ratio are (0.4g:0.4 The rest of g) remain unchanged.

Embodiment 6:

The total amount of boron nitride and carbon nanotubes added in step (1) in Example 1 was replaced by 1 wt%, and the rest remained unchanged.

The embodiments of the present invention are described in detail, but the content is only a preferred embodiment of the present invention, and cannot be considered as limiting the implementation scope of the present invention. All equal changes and improvements made according to the technical scope of the present invention shall fall within the scope of this patent.

Comparative example 1:

Weigh 1.6g of PVA and 10ml of deionized water into the three-necked flask, stir evenly until completely dissolved, then weigh 16g of AMPS and 20ml of deionized water into the beaker for stirring and dissolving, and add the obtained solution to the three-necked flask In the flask, add 0.09g of N,N'-methylenebisacrylamide and 0.07g of ammonium persulfate at the same time, protect with _N2 , and react at constant temperature (60°C) for 3h to obtain semi-interpenetrating PVA - PAMPS hydrogel.

Figure 1 shows the comparison results of the thermal conductivity of hydrogels obtained in Examples 1 to 6 and Comparative Example 1. From the figure, we can see that the introduction of thermally conductive fillers in Example 1 increases the network density, forms a high thermal conductivity path, and reduces the acoustic noise. Sub-scattering reduces the interfacial thermal resistance between the filler and the matrix, so that the hydrogel composite material has a good thermal conductivity (the thermal conductivity of embodiment 1 is 1.26W/m.K compared with the thermal conductivity of comparative example 1. 0.27W/m.K increased by 360 %).

Fig. 2 is the stress-strain curve figure of hydrogel obtained in different embodiments and comparative examples; the compressive strength of comparative example 1 hydrogel is 0.021MPa, and the compressive strength of the hydrogel prepared by the inventive method (embodiment 1) is 0.075MPa, which is 3.5 times that of Comparative Example 1, so it has good mechanical properties and can withstand a wider range of stress.

From Fig. 3 we can see that the elastic modulus of embodiment 1 is 0.77MPa, and the elastic modulus of comparative example 1 is 0.21MPa, and embodiment 1 has increased 260% compared with comparative example 1, mainly due to the two-step method The three monomers have a high degree of crosslinking, and the network structure is more stable. At the same time, the thermally conductive filler also plays a role in strengthening the matrix, so that the elastic modulus of the hydrogel composite material is significantly increased.

In summary, the prepared hydrogel composites have excellent mechanical properties (higher elastic modulus) and good thermal conductivity (higher thermal conductivity).

Claims (8)

1. A preparation method of a ternary interpenetrating network high-thermal conductivity hydrogel composite material with a synergistic effect is characterized by comprising the following steps: the method comprises the following steps:

step 1: pretreatment of thermally conductive fillers

Weighing heat-conducting filler, dispersing the heat-conducting filler in n-hexane, performing ultrasonic dispersion uniformly to reduce agglomeration, and then removing the n-hexane to obtain pretreated heat-conducting filler for later use;

step 2: preparation of hydrogel with semi-interpenetrating network structure

Weighing 1-2 parts of PVA, adding the PVA into deionized water, stirring until the PVA is completely dissolved, then adding 15-20 parts of AMPS into the deionized water for dissolving, adding the obtained AMPS solution into the PVA solution, and simultaneously adding 0.03-0.05 part of cross-linking agent, 0.04-0.06 part of initiator and N ₂ Reacting at constant temperature under protection to obtain PVA-PAMPS semi-interpenetrating network structure hydrogel;

and step 3: preparation of ternary interpenetrating network high-thermal-conductivity hydrogel composite material

And (3) adding the PVA-PAMPS semi-interpenetrating network structure hydrogel obtained in the step (2) into an aqueous solution in which 8-10 parts of AA are dissolved, simultaneously adding the heat-conducting filler pretreated in the step (1), 0.06-0.08 part of initiator and 0.08-0.1 part of cross-linking agent, reacting in a closed reactor, uniformly diffusing acrylic acid and the pretreated heat-conducting filler in gel, and fully washing to remove unreacted monomers and impurities to obtain the PVA-PAMPS-PAA ternary interpenetrating network heat-conducting hydrogel composite material.

2. The method of claim 1, wherein:

in the step 1, the heat-conducting filler is boron nitride and a multi-walled carbon nanotube, the proportion of the boron nitride in the heat-conducting filler is 60-90%, and the balance is the carbon nanotube.

3. The method of claim 2, wherein:

the size of the boron nitride is 100nm, the inner diameter of the multi-wall carbon nanotube is 5-8nm, and the outer diameter is 10-15nm.

4. The method of claim 1, wherein:

in the step 2, the reaction temperature is 60 ℃, and the reaction time is 2-4 h.

5. The method of claim 1, wherein:

in the step 3, the addition amount of the pretreated heat-conducting filler is 1-3 wt% based on the total mass of the monomers.

6. The method of claim 1, wherein:

in the step 3, the reaction temperature is 30 ℃ and the reaction time is 2-3 h.

7. The method of claim 1, wherein:

the cross-linking agent comprises any one of ethylene glycol dimethacrylate and N, N-methylene bisacrylamide.

8. The method of claim 1, wherein:

the initiator comprises any one of ammonium persulfate and potassium persulfate.

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