阅读说明：本技术 一种低损耗lcp材料及其制备方法 (Low-loss LCP material and preparation method thereof ) 是由 张东宝 于冉 徐良 于 2021-08-06 设计创作，主要内容包括：本发明公开了一种低损耗LCP材料及其制备方法,其制备方法包括：(1)将碳纳米管依次在氢氟酸溶液和硝酸溶液中浸泡处理,得到预处理碳纳米管；(2)将预处理碳纳米管与混合酸液回流,得到纯化碳纳米管；(3)将纯化碳纳米管、邻甲基对苯二酚与1,2-二氯乙烷超声搅拌混合,冰水浴中加入三乙胺,搅拌,得到混合液；(4)在保护气氛下加入向混合液中加入4,4一二苯醚二甲酸,依次冰水浴和室温下搅拌,加入丙酮,过滤,得到低损耗LCP材料。本发明通过对多壁碳纳米管复合前进行纯化处理,有效去除填料中的杂质以及碳纳米管中的非晶碳结构。再将纯化后的多壁碳纳米管在LCP合成过程中进行复合,从而有效的降低LCP材料的介电常数及介电损耗。(The invention discloses a low-loss LCP material and a preparation method thereof, wherein the preparation method comprises the following steps: (1) sequentially soaking the carbon nano tube in hydrofluoric acid solution and nitric acid solution to obtain a pretreated carbon nano tube; (2) refluxing the pretreated carbon nano tube and the mixed acid solution to obtain a purified carbon nano tube; (3) ultrasonically stirring and mixing the purified carbon nano tube, the o-methyl hydroquinone and the 1, 2-dichloroethane, adding triethylamine into an ice water bath, and stirring to obtain a mixed solution; (4) and adding 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the protective atmosphere, stirring in an ice-water bath at room temperature in sequence, adding acetone, and filtering to obtain the low-loss LCP material. According to the invention, impurities in the filler and amorphous carbon structures in the carbon nanotubes are effectively removed by purifying the multi-walled carbon nanotubes before compounding. And compounding the purified multi-walled carbon nanotubes in the LCP synthesis process, thereby effectively reducing the dielectric constant and dielectric loss of the LCP material.)

1. A preparation method of a low-loss LCP material is characterized by comprising the following steps:

(1) sequentially soaking the carbon nano tube in hydrofluoric acid solution and nitric acid solution, washing and drying to obtain a pretreated carbon nano tube;

(2) heating the pretreated carbon nano tube and the mixed acid liquor to boiling, refluxing, washing and drying to obtain a purified carbon nano tube;

(3) ultrasonically stirring and mixing the purified carbon nano tube, the o-methyl hydroquinone and the 1, 2-dichloroethane, adding triethylamine into an ice water bath, and stirring to obtain a mixed solution;

(4) and adding 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under a protective atmosphere, stirring in an ice water bath at room temperature in sequence, adding acetone, filtering, washing and drying to obtain the low-loss LCP material.

2. The method for preparing low-loss LCP material according to claim 1, wherein the weight percentage of the hydrofluoric acid solution is 25-35%, and the soaking time in the hydrofluoric acid solution is 12-24 h;

the mass fraction of the nitric acid solution is 30-40%, and the soaking time in the nitric acid solution is 24-36 h.

3. The method for preparing the low-loss LCP material according to claim 1, wherein the mass ratio of the pre-treated carbon nanotubes to the mixed acid solution is 1: 40-60.

4. The method for preparing the low-loss LCP material according to claim 1, wherein the mixed acid solution comprises 95% sulfuric acid solution by mass, 65% nitric acid solution by mass and water; wherein the volume ratio of the sulfuric acid solution to the nitric acid solution to the water is 5:3:2-0:2: 8.

5. The method for preparing LCP materials with low loss as claimed in claim 1, wherein the stirring speed of triethylamine in step (3) is 500-800rpm, and the stirring time is 5-30 min.

6. The method for preparing LCP materials with low loss as claimed in claim 1, wherein the rotation speed of the ice-water bath stirring in step (4) is 800-1000rpm, and the stirring time is 1-2 h;

the rotation speed of stirring at room temperature is 400-600rpm, and the stirring time is 4-6 h.

7. The method for preparing low-loss LCP material according to claim 1, wherein the mass fraction of carbon nanotubes in the low-loss LCP material is 1-15%.

8. The method for preparing low-loss LCP material according to claim 1, wherein the mass ratio of the o-methyl hydroquinone, the triethylamine and the 4, 4-diphenyl oxide dicarboxylic acid is 1-3:1-4: 2-5.

9. The method for preparing low-loss LCP material according to claim 1, wherein the carbon nanotubes are multi-walled carbon nanotubes.

10. A low loss LCP material prepared by the method of any one of claims 1 to 9; the dielectric constant of the low-loss LCP material is 2.5-2.9K/20GHz, and the dielectric loss is 0.002-0.004.

Technical Field

The invention relates to the technical field of liquid crystal polymers, in particular to a low-loss LCP material and a preparation method thereof.

Background

Liquid Crystal Polymer (LCP) is a thermoplastic with unique structural and physical properties. When the liquid crystal flows during processing, the rigid portions of the molecules align one after the other along the direction of shear flow. Once this orientation is formed, the orientation and structure of the molecules will no longer change, even when the LCP is cooled to a temperature below the melting temperature. Due to its unique structure, LCP has a combination of electrical, thermal, mechanical, and chemical properties not found in other engineering polymers. LCP is often used as a substrate for space and military electronic systems due to its excellent performance and stability. For example, LCP can be used as a high performance carrier for radio frequency electromagnetic components such as antennas, and the like. The results of high frequency testing showed that LCPs had fairly uniform relative dielectric constants in the range of 0.5GHz to 40GHz and that they had very low dielectric losses.

In the prior art, reinforcing materials such as glass fiber and carbon fiber are added into LCP or inorganic fillers such as graphite and mica are added, so that the strength of the welded joint of the product can be improved, the anisotropy of the product is reduced, the high-temperature mechanical property of the material is improved, and the use value is improved. On the other hand, the mineral filler is adopted for filling, so that the cost can be reduced, the market competitiveness can be improved, and the actual industrial production and application are obtained at present. However, the inorganic filler, whether made by itself or sold in the market, has catalyst and impurity residues of different degrees, which largely affects the porosity of the porous material and also causes a higher dielectric constant.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention provides a low loss LCP material, which is intended to reduce the dielectric constant and dielectric loss of LCP.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a preparation method of a low-loss LCP material comprises the following steps:

(1) sequentially soaking the carbon nano tube in hydrofluoric acid solution and nitric acid solution, washing and drying to obtain a pretreated carbon nano tube;

(2) heating the pretreated carbon nano tube and the mixed acid liquor to boiling, refluxing, washing and drying to obtain a purified carbon nano tube;

(3) ultrasonically stirring and mixing the purified carbon nano tube, the o-methyl hydroquinone and the 1, 2-dichloroethane, adding triethylamine into an ice water bath, and stirring to obtain a mixed solution;

(4) and adding 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under a protective atmosphere, stirring in an ice water bath at room temperature in sequence, adding acetone, filtering, washing and drying to obtain the low-loss LCP material.

The preparation method of the low-loss LCP material comprises the following steps of (1) preparing a hydrofluoric acid solution, wherein the mass fraction of the hydrofluoric acid solution is 25-35%, and the soaking time in the hydrofluoric acid solution is 12-24 hours;

the mass fraction of the nitric acid solution is 30-40%, and the soaking time in the nitric acid solution is 24-36 h.

The preparation method of the low-loss LCP material comprises the step of pretreating carbon nanotubes, wherein the mass ratio of the pretreated carbon nanotubes to the mixed acid liquid is 1: 40-60.

The preparation method of the low-loss LCP material comprises the following steps of mixing an acid solution with a mass fraction of 95% with a sulfuric acid solution, a mass fraction of 65% with a nitric acid solution and water; wherein the volume ratio of the sulfuric acid solution to the nitric acid solution to the water is 5:3:2-0:2: 8.

The preparation method of the low-loss LCP material comprises the step (3), wherein the stirring speed of triethylamine in the step (3) is 500-800rpm, and the stirring time is 5-30 min.

The preparation method of the low-loss LCP material comprises the following steps of (1) stirring the LCP material in an ice-water bath at the rotation speed of 800-1000rpm for 1-2 h;

the rotation speed of stirring at room temperature is 400-600rpm, and the stirring time is 4-6 h.

The preparation method of the low-loss LCP material comprises the following step of preparing the low-loss LCP material, wherein the mass fraction of carbon nanotubes in the low-loss LCP material is 1-15%.

The preparation method of the low-loss LCP material comprises the following steps of mixing o-methyl hydroquinone, triethylamine and 4, 4-diphenyl ether dicarboxylic acid in a mass ratio of 1-3:1-4: 2-5.

The preparation method of the low-loss LCP material comprises the step of preparing a porous carbon nanotube.

Meanwhile, the invention also provides a low-loss LCP material which is prepared by the method; the dielectric constant of the low-loss LCP material is 2.5-2.9K/20GHz, and the dielectric loss is 0.002-0.004.

Has the advantages that: the invention discloses a low-loss LCP material and a preparation method thereof. And compounding the purified multi-walled carbon nanotubes in the LCP synthesis process, thereby effectively reducing the dielectric constant and dielectric loss of the LCP material.

Detailed Description

The invention provides a low-loss LCP material and a preparation method thereof, and the invention is further described in detail below in order to make the purpose, technical scheme and effect of the invention clearer and more clear. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Specifically, the invention provides a preparation method of a low-loss LCP material, which comprises the following steps:

(1) placing the carbon nano tube in 25-35% of hydrofluoric acid by mass for soaking for 12-24h, and removing the catalyst carrier in the preparation process of the filler; and then placing the carbon nano tube in a nitric acid solution with the mass fraction of 30-40% for soaking for 24-36h, removing residual catalyst particles in the preparation process of the filler, washing to be neutral, and drying at the temperature of 100-130 ℃ for 3-6h to obtain the pretreated carbon nano tube.

(2) Mixing the pretreated carbon nano tube with mixed acid liquor according to the mass ratio of 1:40-60, heating to boiling, refluxing for 0.5-3h, washing to neutrality, and drying at the temperature of 100-;

wherein the mixed acid solution comprises a sulfuric acid solution with the mass fraction of 95%, a nitric acid solution with the mass fraction of 65% and water; wherein the volume ratio of the sulfuric acid solution to the nitric acid solution to the water is 5:3:2-0:2: 8.

(3) Ultrasonically stirring the purified carbon nano tube, the o-methyl hydroquinone and the 1, 2-dichloroethane until the mixture is uniformly mixed, cooling the mixture to 0 ℃ in ice water bath, adding triethylamine, and stirring the mixture for 5 to 30 minutes at 800rpm to obtain a mixed solution;

(4) adding 4, 4-diphenyl oxide dicarboxylic acid into the mixed solution under the protective atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 1000rpm for 1-2h, stirring at 600rpm at room temperature of 400 ℃ for 4-6h, adding acetone, filtering and washing the precipitate, and drying at 80-100 ℃ to obtain the low-loss LCP material.

Wherein, the mass fraction of the carbon nano-tubes in the low-loss LCP material is 1-15%.

The mass ratio of the o-methyl hydroquinone to the triethylamine to the 4, 4-diphenyl ether dicarboxylic acid is 1-3:1-4: 2-5.

The carbon nanotube is a multi-walled carbon nanotube.

Meanwhile, the invention also provides a low-loss LCP material which is prepared by the method; the dielectric constant of the low-loss LCP material is 2.5-2.9K/20GHz, and the dielectric loss is 0.002-0.004.

The low-loss LCP material and the preparation method thereof of the invention are further explained by the following specific examples:

example 1

One embodiment of the invention provides a preparation method of a low-loss LCP material, which comprises the following steps:

(1) placing the multi-walled carbon nano-tube in hydrofluoric acid with the mass fraction of 25% for soaking for 12 hours, and removing a catalyst carrier in the filler preparation process; and then placing the carbon nano tube in a nitric acid solution with the mass fraction of 30% for soaking for 24 hours, removing catalyst particles remained in the preparation process of the filler, washing the carbon nano tube to be neutral by using deionized water, and drying the carbon nano tube in a drying oven at the temperature of 110 ℃ for 4 hours to obtain the pretreated carbon nano tube.

(2) Mixing 95% sulfuric acid, 65% nitric acid and water according to the volume ratio of 4: 3 to obtain the mixed acid liquid. Mixing 1g of the pretreated carbon nanotube with 40mL of mixed acid solution, heating to boiling, refluxing for 1h, washing with deionized water to neutrality, and drying in an oven at 110 ℃ for 12h to obtain the purified carbon nanotube.

(3) Carrying out ultrasonic treatment on 0.1g of purified carbon nano tube, 1.24g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane, stirring until the mixture is uniformly mixed, cooling to 0 ℃ in ice water bath, adding 1.39g of triethylamine, and stirring for 10min at 600rpm to obtain a mixed solution;

(4) adding 2.95g of 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 800rpm for 2h, slowly raising to room temperature, stirring at 400rpm at room temperature for 6h, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the low-loss LCP material.

Another embodiment of the present invention provides a low loss LCP material made by the method of example 1; the dielectric constant of the low-loss LCP material is 2.84K/20GHz, and the dielectric loss is 0.004.

Example 2

One embodiment of the invention provides a preparation method of a low-loss LCP material, which comprises the following steps:

(1) placing the multi-walled carbon nano-tube in 35% hydrofluoric acid by mass for soaking for 18h, and removing a catalyst carrier in the filler preparation process; and then placing the carbon nano tube in a nitric acid solution with the mass fraction of 40% for soaking for 36h, removing catalyst particles remained in the preparation process of the filler, washing the carbon nano tube to be neutral by using deionized water, and drying the carbon nano tube in a drying oven at the temperature of 100 ℃ for 6h to obtain the pretreated carbon nano tube.

(2) Mixing 95% sulfuric acid, 65% nitric acid and water according to the volume ratio of 4: 3 to obtain the mixed acid liquid. Mixing 1g of the pretreated carbon nanotube with 40mL of mixed acid solution, heating to boiling, refluxing for 0.5h, washing with deionized water to neutrality, and drying in an oven at 100 ℃ for 12h to obtain the purified carbon nanotube.

(3) Carrying out ultrasonic treatment on 0.1g of purified carbon nano tube, 1.24g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane, stirring until the mixture is uniformly mixed, cooling to 0 ℃ in ice water bath, adding 1.39g of triethylamine, and stirring for 10min at 600rpm to obtain a mixed solution;

(4) adding 2.95g of 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 1000rpm for 1h, slowly raising to room temperature, stirring at 600rpm for 4h at room temperature, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the low-loss LCP material.

Another embodiment of the present invention provides a low loss LCP material made by the method of example 2; the dielectric constant of the low-loss LCP material is 2.75K/20GHz, and the dielectric loss is 0.003.

Example 3

One embodiment of the invention provides a preparation method of a low-loss LCP material, which comprises the following steps:

(1) placing the multi-walled carbon nano-tube in 35% hydrofluoric acid by mass for soaking for 18h, and removing a catalyst carrier in the filler preparation process; and then placing the carbon nano tube in a nitric acid solution with the mass fraction of 40% for soaking for 36h, removing catalyst particles remained in the preparation process of the filler, washing the carbon nano tube to be neutral by using deionized water, and drying the carbon nano tube in an oven at the temperature of 130 ℃ for 3h to obtain the pretreated carbon nano tube.

(2) Mixing sulfuric acid with the mass fraction of 95%, nitric acid with the mass fraction of 65% and water according to the volume ratio of 1: 3: 6 to obtain the mixed acid liquid. Mixing 1g of the pretreated carbon nanotube with 60mL of mixed acid solution, heating to boiling, refluxing for 1h, washing to neutrality by using deionized water, and drying in an oven at 110 ℃ for 12h to obtain the purified carbon nanotube.

(3) Carrying out ultrasonic treatment on 0.1g of purified carbon nano tube, 1.24g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane, stirring until the mixture is uniformly mixed, cooling to 0 ℃ in ice water bath, adding 1.39g of triethylamine, and stirring for 10min at 600rpm to obtain a mixed solution;

(4) adding 2.95g of 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 800rpm for 2h, slowly raising to room temperature, stirring at 400rpm at room temperature for 6h, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the low-loss LCP material.

Another embodiment of the present invention provides a low loss LCP material made by the method of example 3; the dielectric constant of the low-loss LCP material is 2.81K/20GHz, and the dielectric loss is 0.004.

Example 4

One embodiment of the invention provides a preparation method of a low-loss LCP material, which comprises the following steps:

(1) placing the multi-walled carbon nano-tube in 35% hydrofluoric acid by mass for soaking for 18h, and removing a catalyst carrier in the filler preparation process; and then placing the carbon nano tube in a nitric acid solution with the mass fraction of 40% for soaking for 36h, removing catalyst particles remained in the preparation process of the filler, washing the carbon nano tube to be neutral by using deionized water, and drying the carbon nano tube in a drying oven at the temperature of 110 ℃ for 4h to obtain the pretreated carbon nano tube.

(2) Mixing sulfuric acid with the mass fraction of 95%, nitric acid with the mass fraction of 65% and water according to the volume ratio of 1: 3: 6 to obtain the mixed acid liquid. Mixing 1g of the pretreated carbon nanotube with 60mL of mixed acid solution, heating to boiling, refluxing for 1h, washing to neutrality by using deionized water, and drying in an oven at 110 ℃ for 12h to obtain the purified carbon nanotube.

(3) Carrying out ultrasonic treatment on 0.9g of purified carbon nano tube, 3g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane, stirring until the mixture is uniformly mixed, cooling to 0 ℃ in ice water bath, adding 1g of triethylamine, and stirring at 600rpm for 10min to obtain a mixed solution;

(4) and adding 5g of 4, 4-diphenyl oxide dicarboxylic acid into the mixed solution under a nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 800rpm for 2h, slowly raising to room temperature, stirring at 400rpm at room temperature for 6h, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the low-loss LCP material.

Another embodiment of the present invention provides a low loss LCP material made by the method of example 4; the dielectric constant of the low-loss LCP material is 2.53K/20GHz, and the dielectric loss is 0.002.

Example 5

One embodiment of the invention provides a preparation method of a low-loss LCP material, which comprises the following steps:

(1) placing the multi-walled carbon nano-tube in 35% hydrofluoric acid by mass for soaking for 18h, and removing a catalyst carrier in the filler preparation process; and then placing the carbon nano tube in a nitric acid solution with the mass fraction of 40% for soaking for 36h, removing catalyst particles remained in the preparation process of the filler, washing the carbon nano tube to be neutral by using deionized water, and drying the carbon nano tube in a drying oven at the temperature of 100 ℃ for 6h to obtain the pretreated carbon nano tube.

(2) Mixing sulfuric acid with the mass fraction of 95%, nitric acid with the mass fraction of 65% and water according to the volume ratio of 1: 3: 6 to obtain the mixed acid liquid. Mixing 1g of the pretreated carbon nanotube with 60mL of mixed acid solution, heating to boiling, refluxing for 1h, washing to neutrality by using deionized water, and drying in an oven at 110 ℃ for 12h to obtain the purified carbon nanotube.

(3) Carrying out ultrasonic treatment on 0.6g of purified carbon nano tube, 1g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane, stirring until the mixture is uniformly mixed, cooling to 0 ℃ in an ice water bath, adding 1g of triethylamine, and stirring at 600rpm for 10min to obtain a mixed solution;

(4) adding 2g of 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 800rpm for 2h, slowly raising to room temperature, stirring at 400rpm at room temperature for 6h, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the low-loss LCP material.

Another embodiment of the present invention provides a low loss LCP material made by the method of example 5; the dielectric constant of the low-loss LCP material is 2.68K/20GHz, and the dielectric loss is 0.003.

Comparative example 1

One comparative example of the present invention provides a method for preparing an LCP material, comprising the steps of:

(1) ultrasonically stirring 1.24g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane until the o-methyl hydroquinone and the 1, 2-dichloroethane are uniformly mixed, cooling the mixture to 0 ℃ in ice water bath, adding 1.39g of triethylamine, and stirring the mixture for 10min at 600rpm to obtain a mixed solution;

(2) adding 2.95g of 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 800rpm for 2h, slowly raising to room temperature, stirring at 400rpm at room temperature for 6h, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the LCP material.

Another comparative example of the present invention provides an LCP material prepared by the method of comparative example 1; the dielectric constant of the LCP material is 3.48K/20GHz, and the dielectric loss is 0.007.

Comparative example 2

One comparative example of the present invention provides a method for preparing an LCP material, comprising the steps of:

(1) ultrasonically stirring 0.1g of multi-walled carbon nano tube, 1.24g of o-methyl hydroquinone and 70mL of 1, 2-dichloroethane until the mixture is uniformly mixed, cooling the mixture to 0 ℃ in ice water bath, adding 1.39g of triethylamine, and stirring the mixture for 10min at 600rpm to obtain a mixed solution;

(2) adding 2.95g of 4, 4-diphenyl ether dicarboxylic acid into the mixed solution under the nitrogen atmosphere, cooling to 0 ℃ in an ice water bath, stirring at 800rpm for 2h, slowly raising to room temperature, stirring at 400rpm at room temperature for 6h, adding acetone, filtering and washing precipitates, and drying at 100 ℃ to obtain the LCP material.

Another embodiment of the present invention provides an LCP material prepared by the method of comparative example 2; the dielectric constant of the LCP material is 3.05K/20GHz, and the dielectric loss is 0.005.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.