Polyphenyl ether filler as well as preparation method and application thereof

Abstract

The invention relates to a polyphenyl ether filler and a preparation method and application thereof, and the method comprises the following steps: S1, taking poly 2, 6-diphenyl polyphenyl ether, and dissolving the poly 2, 6-diphenyl polyphenyl ether in a mixed solution composed of an aprotic polar solvent and organic amine to obtain a polymer solution; s2, dropwise adding concentrated hydrochloric acid into the polymer solution in the step S1, stirring, standing in an environment of 10 DEG C below zero to 10 DEG C, and precipitating to obtain a polymer precipitate; and S3, adding methanol into the completely precipitated system in the step S2, stirring, filtering, and drying the filtered product to obtain the polyphenyl ether filler. The mass ratio of the poly 2, 6-diphenyl polyphenyl ether to the aprotic polar solvent to the organic amine to the concentrated hydrochloric acid to the methanol is (10-60): (30-130): (1-4): (3-6): (20-500). According to the method, the operation process is greatly simplified, the equipment investment and the production cost are reduced, and the problems of rapid and random precipitation of the product caused by adding a large amount of poor solvent are solved, so that the obtained polyphenyl ether filler is regular in morphology, a large amount of micropores with uniform structures are formed on the surface, and the polyphenyl ether filler is suitable for being used as a chromatographic filler.

Description

Technical Field

[0001] This application relates to the field of chromatographic packing technology, specifically to a polyphenylene ether packing material, its preparation method, and its application. Background Technology

[0002] Polyphenylene ether polymers synthesized using poly(2,6-diphenylphenylene ether) resin as a precursor possess low dielectric constants, excellent thermal stability, good anti-adhesion properties, outstanding mechanical properties, and high dimensional stability, thus they are often used as engineering structural materials and insulating plastics. Furthermore, poly(2,6-diphenylphenylene ether) resin exhibits significant adsorption capacity for organic compounds, especially organic solvents, making it widely applicable as a commercial adsorbent in chromatographic separation and environmental pollution control.

[0003] Internationally, the thermal desorption packing material Tenax-TA, produced by Buchem in the Netherlands, has been widely adopted and is listed by the US Environmental Protection Agency (EPA) and the National Institute for Occupational Safety and Health (NIOSH) as the designated adsorption medium for several standard analytical methods. Existing methods for preparing poly(2,6-diphenylpolyphenylene ether) packing materials involve adding unsuitable solvents to the reaction solution to precipitate the solid.

[0004] For example, patent CN201410840831.X discloses a method for preparing poly(2,6-diphenyl-p-phenylene ether) spherical particles. The method involves thoroughly mixing a good solvent solution of poly(2,6-diphenyl-p-phenylene ether) with a poor solvent to form a poly(2,6-diphenyl-p-phenylene ether) suspension. This suspension is then added to a hardening solvent for hardening treatment, resulting in a precipitate. The precipitate is then filtered and dried to obtain poly(2,6-diphenyl-p-phenylene ether) spherical particles. However, this method requires a peristaltic pump and a special hardening processor, placing high demands on equipment and making the preparation process cumbersome.

[0005] Patent CN03803170.1 discloses a method for precipitating polyphenylene ether (PPE) particles. This method involves circulating a mixture comprising a good solvent, a poor solvent, and PPE particles using rotating stirring blades. PPE solution is simultaneously added to this mixture through a solution supply port, and a poor solvent is added through a poor solvent supply port, thereby further precipitating the PPE particles. This method requires the use of a large amount of poor solvent to precipitate the PPE particles and is not suitable for preparing poly(2,6-diphenylphenyl) ether, which has a more rigid structure.

[0006] Existing methods for preparing polyphenylene ether chromatographic packings have problems such as difficulty in precipitating the product in unsuitable solvents, complex preparation processes, and high equipment requirements. Furthermore, the resulting packings have small surface areas, uneven pore structures, and less than ideal physical morphology. Summary of the Invention

[0007] Based on this, the purpose of this application is to provide a method for preparing polyphenylene ether chromatographic packing material that is easy to mold, simple to operate, low in cost, and easy to industrialize.

[0008] To achieve the above objectives, this application provides a method for preparing polyphenylene ether filler, comprising the following steps: S1. Take poly(2,6-diphenylpolyphenyl ether), dissolve it in a mixture of aprotic polar solvent and organic amine, and stir at a speed of 80-250 rpm to obtain a polymer solution; S2. Under a stirring speed of 80~250 rpm, concentrated hydrochloric acid is added dropwise at a rate of 5~10 mL / min to the polymer solution in step S1. After the addition is complete, the solution is allowed to stand in an environment of -10~10℃ to precipitate the polymer precipitate. S3. Add methanol to the system after complete precipitation in step S2, stir, filter, and dry the filtered product to obtain the polyphenylene ether filler; The mass ratio of the poly(2,6-diphenylpolyphenyl ether), the aprotic polar solvent, the organic amine, the concentrated hydrochloric acid, and the methanol is 10~60:30~130:1~4:3~6:20~500.

[0009] Preferably, in step S1, the mixture is stirred at 35~100℃ for 0.5~5 hours.

[0010] More preferably, in step S2, the settling time is 5 to 120 hours.

[0011] Preferably, the aprotic polar solvent is one of hexamethylphosphoric triamine, N-methylpyrrolidone, and N,N-dimethylacetamide.

[0012] More preferably, the organic amine is triethylamine or tetramethylethylenediamine.

[0013] Preferably, in step S3, a vibrating screener is also used to screen the polyphenylene ether filler.

[0014] This application also provides a polyphenylene ether filler, which is prepared by the method described in any of the above claims.

[0015] Preferably, the specific surface area of ​​the polyphenylene ether filler is 80~130 cm³ / g.

[0016] Preferably, the particle size of the polyphenylene ether filler is 35-100 mesh.

[0017] More preferably, the number-average molecular weight of the polyphenylene ether filler is between 150,000 and 200,000.

[0018] This application also provides an application of the above-mentioned polyphenylene ether packing material in chromatographic techniques.

[0019] The technical solution claimed in this application has the following beneficial effects: The entire process can be completed using only conventional heating, stirring, and settling equipment, eliminating the need for peristaltic pumps, spray drying, or special hardening devices. This greatly simplifies the operation process, reduces equipment investment and production costs, and is highly beneficial for large-scale industrial production.

[0020] The precipitation is "triggered" by neutralization with concentrated hydrochloric acid. The process is mild, slow and controllable, which overcomes the problem of rapid and random precipitation of products caused by the direct addition of a large amount of poor solvent. The resulting polyphenylene ether packing has a regular morphology and a large number of uniform micropores on its surface, resulting in high adsorption performance and making it suitable for use as a chromatographic packing. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 Scanning electron microscope image of the polyphenylene ether filler prepared in Example 1 (magnification: 30X).

[0023] Figure 2 Scanning electron microscope image of the polyphenylene ether filler prepared in Example 1 (magnification: 10.00 KX).

[0024] Figure 3 The number-average / weight-average molecular weights of the polyphenylene ether filler prepared in Example 1. Detailed Implementation

[0025] To make the objectives, technical solutions, and beneficial effects of the embodiments in this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] This application provides a method for preparing polyphenylene ether chromatographic packing material. The core of this method lies in controlling the polymer precipitation process through a "dissolution-acidification-low-temperature precipitation" process, thereby forming an adsorption resin with high specific surface area and suitable pore structure. The method includes the following steps: Dissolution: Dissolve the poly(2,6-diphenyl)polyphenylene ether raw material in a mixed solution composed of an aprotic polar solvent and an organic amine, and heat and stir at 40-100°C for 0.5-5 hours to form a homogeneous and clear polymer solution; Precipitation: Concentrated hydrochloric acid was added dropwise at a uniform rate to the homogeneous polymer solution. The uniform addition of concentrated hydrochloric acid neutralized the organic amine, eliminating its solubilizing effect on the polymer, and simultaneously inducing polymer chain aggregation and phase separation. Subsequently, the mixed solution was placed in a low-temperature environment of -10 to 10°C and allowed to stand for 5 to 120 hours. Under these low-temperature conditions, the polymer precipitated slowly and in a controlled manner, forming a precipitate with a well-developed microporous structure. Post-treatment: Methanol was added to the system after complete precipitation as a washing and displacement solvent. After thorough stirring, the mixture was filtered, dried, and sieved to obtain the target product—a polyphenylene ether adsorption resin with high adsorption performance used as a chromatographic packing material.

[0027] In the above method, the aprotic polar solvent is one of hexamethylphosphoric triamine (HMPA), N-methylpyrrolidone (NMP), and N,N-dimethylacetamide (DMAC), and the organic amine is one of triethylamine and tetramethylethylenediamine.

[0028] In the above method, the mass ratio of poly(2,6-diphenylpolyphenyl ether), aprotic polar solvent, organic amine, concentrated hydrochloric acid and methanol is 10~60:30~130:1~4:3~6:20~500.

[0029] The following embodiments are a more specific presentation of the solution of this application.

[0030] <Example 1> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 10 g of poly(2,6-diphenylpolyphenylene ether) in 20 g of NMP solution, then add 0.5 g of tetramethylethylenediamine and stir at 60 °C for 1 hour at a stirring speed of 150 rpm. Continue to add 2 g of concentrated hydrochloric acid dropwise at a rate of 5 mL / min to the above mixture while stirring at 150 rpm. After thorough stirring, place at 4 °C for 24 hours. Then add 35 g of methanol to the system and mechanically stir at 250 rpm for 10 minutes. After filtration, dry in a 60 °C forced-air oven for 24 hours. Sieve using a vibrating sieve to obtain polyphenylene ether filler with a mesh size of 35-100 mesh.

[0031] The specific surface area of ​​the obtained polyphenylene ether filler was measured using a Micromeritics ASAP 2460 fully automated specific surface area and porosity analyzer (USA). Nitrogen adsorption-desorption tests were performed on the samples under liquid nitrogen conditions at 77 K. After the instrument completed the analysis, isothermal adsorption-desorption curves were obtained, and the total specific surface area of ​​the material was obtained using the BET method. The tests showed that the specific surface area of ​​the prepared filler reached 10³ cm². 3 / g.

[0032] <Example 2> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 5 g of poly(2,6-diphenylpolyphenylene ether) in 50 g of HMPA solution, then add 0.8 g of triethylamine and stir at 40 °C for 5 hours at a stirring speed of 150 rpm. Continue to add 1.5 g of concentrated hydrochloric acid dropwise at a rate of 5 mL / min to the above mixture while stirring at 150 rpm. After thorough stirring, place at 10 °C for 5 hours. Then add 12.5 g of methanol to the system and mechanically stir at 250 rpm for 15 minutes. After filtration, dry in a 60 °C forced-air oven for 24 hours. Sieve using a vibrating sieve to obtain polyphenylene ether filler with a mesh size of 35-100 mesh.

[0033] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1, and the specific surface area of ​​the prepared filler was 85 cm³ / g.

[0034] <Example 3> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 25 g of poly(2,6-diphenylpolyphenylene ether) in 50 g of DMAC solution, then add 2.0 g of tetramethylethylenediamine and stir at 80 °C for 0.5 hours at a stirring speed of 150 rpm. Continue to add 5 g of concentrated hydrochloric acid dropwise at a rate of 5 mL / min to the above mixture while stirring at 150 rpm. After thorough stirring, place at -10 °C for 120 hours. Then add 250 g of methanol to the system and mechanically stir at 150 rpm for 20 minutes. After filtration, dry in a 60 °C forced-air oven for 24 hours. Sieve using a vibrating sieve to obtain polyphenylene ether filler with a mesh size of 35-100 mesh.

[0035] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1, and the specific surface area of ​​the prepared filler was as high as 120 cm³ / g.

[0036] <Example 4> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 15 g of poly(2,6-diphenylpolyphenylene ether) in 30 g of HMPA solution, then add 1.2 g of tetramethylethylenediamine and stir at 70 °C for 1.5 hours at a stirring speed of 250 rpm. Continue to add 3 g of concentrated hydrochloric acid dropwise at a rate of 10 mL / min to the above mixture while stirring at 250 rpm. After thorough stirring, place at -5 °C for 72 hours. Then add 30 g of methanol to the system and mechanically stir at 250 rpm for 12 minutes. After filtration, dry in a 60 °C forced-air oven for 24 hours. Sieve using a vibrating sieve to obtain polyphenylene ether filler with a mesh size of 35-100 mesh.

[0037] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1, and the specific surface area of ​​the prepared filler was 110 cm³ / g.

[0038] <Example 5> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 6 g of poly(2,6-diphenylpolyphenylene ether) in 60 g of NMP solution, then add 0.7 g of tetramethylethylenediamine and stir at 55 °C for 3 hours at a stirring speed of 200 rpm. Continue to add 1.7 g of concentrated hydrochloric acid dropwise at a rate of 5 mL / min to the above mixture while stirring at 200 rpm. After thorough stirring, place at -8 °C for 96 hours. Then add 75 g of methanol to the system and mechanically stir at 200 rpm for 8 minutes. After filtration, dry in a 60 °C forced-air oven for 24 hours. Sieve using a vibrating sieve to obtain polyphenylene ether filler with a mesh size of 35-100 mesh.

[0039] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1, and the specific surface area of ​​the prepared filler was 115 cm³ / g.

[0040] <Comparative Example 1> A method for preparing polyphenylene ether chromatographic packing material is provided: 25 g of poly(2,6-diphenylpolyphenylene ether) was dissolved in 50 g of water (with 4 g of sodium dodecyl sulfate added), and the mixture was heated to 80 °C and reacted for 24 hours. Then, 250 g of methanol was added to the system, and the mixture was mechanically stirred at 250 rpm for 20 minutes. After filtration, the mixture was dried in a 60 °C oven for 24 hours. The resulting polyphenylene ether filler was sieved using a vibrating sieve to obtain a mesh size of 100-200 mesh.

[0041] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1. The specific surface area of ​​the prepared filler was 65 cm³ / g. However, due to the addition of sodium dodecyl sulfate as an emulsifier, the particle size of the filler was too small, resulting in a large back pressure during gas phase detection, which could not meet the detection requirements.

[0042] <Comparative Example 2> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 15 g of poly(2,6-diphenylpolyphenylene ether) in 30 g of HMPA solution, then add 1.2 g of tetramethylethylenediamine and stir at 70 °C for 1.5 hours at a speed of 150 rpm; then add 30 g of methanol to the system and mechanically stir at 150 rpm for 12 minutes; after filtration, dry in a 60 °C forced-air oven for 24 hours; and obtain 35-100 mesh polyphenylene ether filler by sieving with a vibrating screen.

[0043] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1. The specific surface area of ​​the prepared filler was 30 cm³ / g, and the filler showed severe agglomeration.

[0044] <Comparative Example 3> A method for preparing polyphenylene ether chromatographic packing material is provided: Dissolve 6 g of poly(2,6-diphenylpolyphenylene ether) in water and heat to 80°C for 12 hours. Then add 0.7 g of tetramethylethylenediamine and stir at room temperature for 3 hours at 150 rpm. Continue to add 1.7 g of concentrated hydrochloric acid dropwise to the above mixture at a rate of 5 mL / min, stir thoroughly, and place at -8°C for 96 hours. Then add 75 g of methanol to the system and mechanically stir at 150 rpm for 8 minutes. After filtration, dry in a 60°C oven for 24 hours. Sieve using a vibrating sieve to obtain polyphenylene ether filler of 35-100 mesh.

[0045] The specific surface area of ​​the obtained polyphenylene ether filler was tested using the same method as in Example 1. The specific surface area of ​​the prepared filler was approximately 43 cm³ / g. The filler was in the form of a lightweight powder and had a relatively large back pressure.

[0046] <Test Example 1> This test example uses scanning electron microscopy to examine the size and morphology of the polyphenylene ether filler obtained in Example 1. The results are as follows: Figure 1 and 2 As shown. The average molecular weight of the polyphenylene ether packing material in Example 1 was determined by gel permeation chromatography (GPC, Agilent PL-GPC220, USA). The mobile phase was chloroform (trichloromethane). The test results are shown below. Figure 3 As shown.

[0047] Depend on Figure 1 and Figure 2 The results showed that the precipitated polyphenylene ether particles had a size between 35 and 100 mesh, a relatively regular shape, and formed a large number of micropores with a uniform pore structure, making it suitable for use as a chromatographic packing material. Figure 3 The results show that the number-average molecular weight of the polyphenylene ether filler is approximately 163,500.

[0048] <Test Example 2> This test example examines the recovery rates of compounds in thermal desorption experiments using polyphenylene ether packing materials obtained from Examples 1 to 5, Comparative Examples 1 to 3, and commercially available Tenax-TA packing materials.

[0049] The test method refers to Appendix E of GB50325-2020 (Standard for Indoor Environmental Pollution Control of Civil Building Engineering). Specifically, the sample was aged for half an hour before injection (nitrogen flow rate: 150 ml / min, 350℃ aging), followed by purging and injection (nitrogen flow rate: 100 ml / min, injection volume: 1 μL, purging for 5 min). After the flow rate stabilized, 1 μL (100 ppm) of standard was drawn through the injection needle and injected quickly, and the time was set for 5 min. During this process, the heating knob of the thermal desorption device was adjusted to 3-4, and the heating mode was selected as low (low frequency heating). The recovery rate was calculated as the ratio of the peak area of ​​the compound passing through the synthetic packing material to the peak area of ​​the compound passing through the standard packing material. The test results are shown in Table 1.

[0050] Table 1. Recovery results of compounds in thermal desorption experiments

[0051] As can be seen from the above results, the polyphenylene ether packing obtained in Examples 1 to 5 has a recovery rate of more than 85% for most compounds, indicating that almost all compounds adsorbed on the polyphenylene ether medium can be thermally desorbed. There is no obvious residue or retention in the desorption process. Therefore, the obtained polyphenylene ether packing is suitable for recycling and the results are highly reliable.

[0052] The results in Table 1 also show that the polyphenylene ether packing material obtained in the examples has a better recovery rate for some compounds than commercially available Tenax. ® The TA filler, due to the advantages of simple operation, low cost and more environmental protection of the preparation method in the embodiments of this application, has more commercial application prospects for the method and the obtained polyphenylene ether filler.

[0053] The difference between Comparative Example 1 and Example 3 is that Comparative Example 1 did not use aprotic polar solvents or hydrochloric acid in its preparation process; instead, water was used as the solvent. The polyphenylene ether was redissolved and granulated by increasing the temperature. The polyphenylene ether particles obtained in Comparative Example 1 were smaller, and the back pressure during injection was too high after the packing material was assembled into a thermal desorption tube, failing to meet testing requirements. Furthermore, its specific surface area was lower than that of the polyphenylene ether in Example 3, resulting in a significantly lower recovery rate.

[0054] The difference between Comparative Example 2 and Example 4 is that hydrochloric acid was not added during the preparation process of Comparative Example 2. This difference caused the polymer obtained in Comparative Example 2 to precipitate rapidly and uncontrollably, failing to form polymer particles with a well-developed microporous structure. This resulted in a low specific surface area of ​​the filler and a recovery rate far lower than that of the polyphenylene ether filler in Example 4.

[0055] Compared with Example 5, the difference in Comparative Example 3 is that water was used as a solvent to dissolve polyphenylene ether in the preparation process. Although it was heated, the solubility of water in polyphenylene ether was poor, which affected the subsequent precipitation of the filler. As a result, the precipitated polyphenylene ether particles had poor uniformity, small specific surface area, and a lower recovery rate than the polyphenylene ether filler obtained in Example 5.

[0056] The embodiments and application examples described above are merely illustrative descriptions of this application and are not intended to limit the scope of this application. Any modifications and improvements made to the technical solutions of this application by those skilled in the art without departing from the spirit of this application should fall within the protection scope defined by the claims of this application.

Claims

1. A method for preparing polyphenylene ether filler, characterized in that, Includes the following steps: S1. Take poly(2,6-diphenylpolyphenyl ether), dissolve it in a mixture of aprotic polar solvent and organic amine, and stir at 80-250 rpm for 0.5-5 hours at 40-100℃ to obtain a polymer solution; S2. Under a stirring speed of 80~250 rpm, concentrated hydrochloric acid is added dropwise at a rate of 5~10 mL / min to the polymer solution in step S1. After the addition is complete, the solution is allowed to stand in an environment of -10~10℃ to precipitate the polymer precipitate. S3. Add methanol to the system after complete precipitation in step S2, stir, filter, and dry the filtered product to obtain the polyphenylene ether filler; The mass ratio of the poly(2,6-diphenylpolyphenyl ether), the aprotic polar solvent, the organic amine, the concentrated hydrochloric acid, and the methanol is 10~60:30~130:1~4:3~6:20~500; The aprotic polar solvent is one of hexamethylphosphoric triamine, N-methylpyrrolidone, and N,N-dimethylacetamide; The organic amine is triethylamine or tetramethylethylenediamine.

2. The preparation method according to claim 1, characterized in that, In step S2, the settling time is 5 to 120 hours.

3. The preparation method according to claim 1, characterized in that, In step S3, a vibrating screener is also used to screen the polyphenylene ether filler.

4. A polyphenylene ether filler, characterized in that, The polyphenylene ether filler is prepared by the preparation method according to any one of claims 1 to 3.

5. The polyphenylene ether filler according to claim 4, characterized in that, The specific surface area of ​​the polyphenylene ether filler is 80~130 cm³ / g.

6. The polyphenylene ether filler according to claim 4, characterized in that, The particle size of the polyphenylene ether filler is 35~100 mesh.

7. The polyphenylene ether filler according to claim 4, characterized in that, The number-average molecular weight of the polyphenylene ether filler is between 150,000 and 200,000.

8. The application of a polyphenylene ether packing material according to any one of claims 4 to 6 in chromatographic techniques.

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