Porous poly (arylene ether ketone) pressure-resistant filter material for chromatographic column and preparation method thereof

Abstract

The present application relates to polyaryletherketone material processing technical field, specifically to porous polyaryletherketone pressure-resistant filter material for chromatographic column and preparation method thereof, which is formed by cold pressing and sintering of inorganic filler, low-melting-index polyaryletherketone core-shell structure microspheres and high-melting-index polyaryletherketone material; the present application is compounded by selecting different melting-index PAEK, and the inorganic filler is coated by low-melting-index PAEK, which increases the compression strength of the filter material on one hand, and the high-melting-index PAEK plays the role of bonding low-melting-index PAEK by its fast fluidity during sintering, further improves the compression strength and further reduces the risk of particle drop-off.

Description

Technical Field

[0001] This invention relates to the field of polyaryletherketone material processing technology, specifically to porous polyaryletherketone pressure-resistant filter material for chromatographic columns and its preparation method. Background Technology

[0002] The chromatographic column is the core component of a high-performance liquid chromatography (HPLC) system. The sieve plates fixed at both ends of the column function to support the stationary phase packing, uniformly distribute the mobile phase, and prevent packing leakage. Typical sieve plate pore sizes range from 2 to 5 μm. There are three common types of sieve plate filter media: metal sieve plates, ceramic sieve plates, and polymer sieve plates. Metal sieve plates, represented by stainless steel, have excellent properties such as uniform pore size and high pressure resistance, but are not suitable for samples and reagents sensitive to metals. Ceramic sieve plates have excellent high-temperature resistance and chemical corrosion resistance, but due to their brittleness, they are unsuitable for high-pressure working environments. Polymer sieve plates are a relatively recent development, currently mainly consisting of polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE). Polymer sieve plates have excellent chemical inertness, low dissolution, and low adsorption, making them widely applicable. However, these materials have insufficient mechanical properties and pressure resistance, usually requiring a supporting structure.

[0003] Polyaryletherketone (PAEK) has a long-term operating temperature up to 260℃, is resistant to acid, alkali, and organic solvent corrosion, and exhibits good biocompatibility. It maintains good mechanical properties under high temperature and pressure while also meeting the requirements for long-term contact with biological reagents such as proteins. PAEK is a relatively ideal sieve plate material; however, there are still few reports on the preparation of porous PAEK using sintering methods. Conventional PAEK, after sintering near its melting point, has limited interpowder bonding strength, leading to the risk of powder shedding. Furthermore, sintered products are brittle, have poor pressure resistance, and are difficult to use in high-pressure environments.

[0004] Patent CN117693551A describes the preparation of a substantially monodisperse group of generally spherical particles (micrometer-sized) of polyaryl ketone polymers or their sulfide-containing analogues, which are then fused together by sintering or other methods to create a porous device. The prepared porous device exhibits low axial compressive strength and an effective pore size of less than 2.5 μm. However, this method for obtaining micrometer-sized spherical particles is difficult to implement, has low yield, and is difficult to industrialize; furthermore, there are currently no commercially available spherical polymer powders of this particle size. Additionally, the sintering temperature of this porous device is 340°C, slightly lower than the melting point of PEEK. Although the resulting structure appears as a monolithic structure, powder shedding may still occur. Summary of the Invention

[0005] To address the technical problems of powder shedding, low axial compressive strength, and small effective pore size in the aforementioned PAEK porous devices, this invention provides a porous polyaryletherketone (PAEK) pressure-resistant filter material for chromatographic columns and its preparation method. This invention utilizes a blend of PAEKs with different melt flow indices and employs low melt flow index PAEK to coat the inorganic packing material. This increases the compressive strength of the filter material on one hand, and on the other hand, during sintering, the rapid flowability of high melt flow index PAEK helps bind the low melt flow index PAEK, further enhancing the compressive strength and reducing the risk of particle shedding.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] The first aspect of this invention provides a porous polyaryletherketone pressure-resistant filter material for chromatographic columns, comprising the following materials cold-pressed and sintered: inorganic packing material@low melt index polyaryletherketone core-shell structured microspheres and high melt index polyaryletherketone material;

[0008] The high melt index polyaryletherketone material accounts for 5wt%-40wt% of the filter material;

[0009] The low melt index polyaryletherketone material in the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres has a melt index of 0.05-3 g / 10 min at 400℃ and 2.16 kg load;

[0010] The high melt index polyaryletherketone material has a melt index of 10-30 g / 10 min at 400℃ and 2.16 kg load.

[0011] Furthermore, the particle size of the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres is 50-100 micrometers; the particle size of the high melt index polyaryletherketone material is in the range of 3-50 micrometers. That is, the particle size of the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres is larger than the particle size of the high melt index polyaryletherketone material.

[0012] Furthermore, in the porous polyaryletherketone pressure-resistant filter material, the high melt index polyaryletherketone material accounts for 5wt%-40wt%.

[0013] Furthermore, in the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres, the proportion of inorganic filler is in the range of 0.5%-25%.

[0014] Furthermore, the inorganic filler is selected from at least one of metal powder, metal oxide powder, and inorganic non-metallic powder, and the particle size of the inorganic filler is 0.5-50 micrometers. Examples include stainless steel microparticles, titanium microparticles, zirconium oxide microparticles, and silica microparticles.

[0015] Furthermore, the method for obtaining the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres includes the following steps:

[0016] S1. Dissolve or swell low melt index polyaryletherketone material in a hot, good organic solvent to form a homogeneous polymer solution;

[0017] S2. Add inorganic filler to the polymer solution and mix to form a dispersion;

[0018] S3. Add a hot phase separation solvent to the dispersion and stir continuously to form an emulsion, so that the polymer encapsulates the inorganic filler to form microspheres that precipitate in the system. After separation, washing and drying, inorganic filler@low melt index polyaryletherketone core-shell structure microspheres are obtained.

[0019] Furthermore, the polymer solution has a mass percentage of 1.5%-20%; the stirring rate in S2 and S3 is 1000-15000 rpm.

[0020] Furthermore, the organic solvent does not react with the inorganic filler, and the organic solvent is selected from one or more of diphenyl sulfone, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, tetrahydrofuran, and dimethyl sulfoxide; the temperature of the organic solvent is higher than 250°C.

[0021] Furthermore, the phase separation solvent has a boiling point higher than 250°C and lower than the melting point temperature of the low melt index polyaryletherketone material, and is also a poor solvent for the low melt index polyaryletherketone material, including but not limited to dioctyl phthalate, glycerol, polyether silicone oil, high molecular weight silicone oil, etc.

[0022] The amount of the phase separation solvent used is 1%-20% of the weight of the dispersion.

[0023] Furthermore, after obtaining inorganic filler@low melt index polyaryletherketone core-shell structured microspheres, the process also includes density screening to obtain microparticles with a density greater than that of the low melt index polyaryletherketone material, and annealing the screened microparticles at 300-350°C for at least 1 hour to make the microparticles more spherical under the action of surface tension.

[0024] Furthermore, the cold pressing pressure is in the range of 0-20 MPa and the cold pressing time is at least 1 minute.

[0025] Furthermore, the sintering is carried out in a sintering furnace under vacuum or with a protective gas filling. The sintering conditions are to heat to 340-380°C at a heating rate of 2-20°C / min and hold at that temperature for at least 30 minutes.

[0026] Furthermore, after sintering, a subsequent heat treatment is also included; the heat treatment is carried out in an oven under vacuum or with a protective gas filling, and the heat treatment temperature is 180-300℃, with a holding time of 1-8 hours.

[0027] Furthermore, the filter material has an average pore size of 2.5-5.5 micrometers, a porosity of 10%-30%, and an axial compressive strength of at least 100 MPa.

[0028] A second aspect of the present invention provides a method for preparing the above-mentioned porous polyaryletherketone pressure-resistant filter material for chromatographic columns, comprising the following steps:

[0029] Inorganic filler @ low melt index polyaryletherketone core-shell structured microspheres and high melt index polyaryletherketone material are mixed evenly, placed in a mold, cold-pressed and then sintered, and finally heat-treated and cooled to obtain porous polyaryletherketone pressure-resistant filter material for chromatographic columns.

[0030] The low melt index polyaryletherketone material in the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres has a melt index of 0.05-3 g / 10 min at 400℃ and 2.16 kg load;

[0031] The high melt index polyaryletherketone material has a melt index of 10-30 g / 10 min at 400℃ and 2.16 kg load.

[0032] Beneficial technical effects:

[0033] This invention uses low melt index polyaryletherketone (PAEK) to coat inorganic fillers to form core-shell structured microspheres. These microspheres are then mixed with high melt index PAEK and pressed and sintered to form filter media. On the one hand, the inorganic fillers are coated and do not directly contact the solvent, thus not affecting the function of the filter media. On the other hand, when the sintering temperature is near or above the melting point of the low melt index PAEK, the core-shell structured microspheres fuse at only the contact points, while the high melt index PAEK flows and fills between the core-shell structured microspheres. This not only fixes the spacing between the core-shell structured microspheres to control the pore size and pore diameter, but also bonds the core-shell structured microspheres to reduce the risk of particle detachment and improves the strength of the porous filter media.

[0034] Through subsequent annealing heat treatment after sintering, the interfaces between core-shell microspheres and the interfaces between core-shell microspheres and high melt flow index polyaryletherketone undergo molecular chain rearrangement to improve regularity and crystallinity, thereby enhancing the mechanical properties of the contact fusion interface and further improving the strength of the porous filter material. Attached Figure Description

[0035] Figure 1 The pore size distribution curve is shown for the porous polyaryletherketone pressure-resistant filter material molded part of Example 1. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Unless otherwise specifically stated, the numerical values ​​set forth in these embodiments do not limit the scope of the invention. Techniques and methods known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques and methods should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that values ​​expressed, for example, as "within the range of ab" or "between the range of ab," do not include the endpoint values ​​a and b; values ​​expressed as "for ab," "is ab," or "ab" include the endpoint values ​​a and b.

[0038] Experimental methods not specified in the following examples are generally performed according to national standards; if there is no corresponding national standard, they are performed according to general standard requirements or general methods.

[0039] The following term is abbreviated as melt index. All particle sizes mentioned in the following examples are D50.

[0040] Preparation Example 1

[0041] This case study describes the fabrication of zirconia@low melt index PEEK core-shell structured microspheres, including the following process:

[0042] S1. Dissolve 20g of low melt index polyether ether ketone powder (model 9600P, produced by Shandong Junhao, powder particle size 50μm) with a melt index of 0.2g / 10min (tested at 400℃ and 2.16kg load) in 200g of diphenyl sulfone solvent at 320℃ and form a homogeneous polymer solution by continuous stirring at 2000rpm.

[0043] S2. Add 5g of zirconium oxide powder with a particle size of 20μm to the polymer solution and stir continuously at a speed of 5000rpm to form a dispersion.

[0044] S3. Add 10g of dioctyl phthalate at 320℃ to the dispersion and stir continuously for 1h. During this process, the polymer encapsulates the inorganic filler to form microspheres that precipitate in the system. Then, cool naturally to room temperature to obtain an emulsion. Centrifuge the emulsion in a centrifuge, discard the supernatant, add ethanol to wash the precipitate, repeat the washing 4 times, then wash with deionized water, repeat the washing 4 times, and dry the washed precipitate at 80℃ for 4h.

[0045] Density screening: Immerse the dried precipitate in a solution with a density of 1.3 g / cm³. 3 In a potassium iodide aqueous solution, floating and suspended particles were poured out, and settled particles were collected to obtain zirconium oxide@low melt index PEEK core-shell structured microspheres.

[0046] Finally, the zirconia@low melt index PEEK core-shell structured microspheres were spread out in a container, placed in a vacuum furnace, and vacuum heat-treated at 345℃ for 2 hours. After cooling, the microspheres were taken out and sieved to obtain 50-100μm zirconia@low melt index PEEK core-shell structured microspheres.

[0047] Example 1

[0048] This case study describes the preparation method of porous polyaryletherketone pressure-resistant filter media for chromatographic columns, including the following steps:

[0049] Zirconia@low melt flow index PEEK core-shell structured microspheres with a diameter of 50-100 μm prepared in Example 1 were mixed with high melt flow index polyetheretherketone powder (model 3600P, produced by Shandong Junhao, with a particle size of 10 μm) with a melt flow index of 20 g / 10 min (tested at 400℃ and 2.16 kg load) at a mass percentage ratio of 90%:10% to form a mixture.

[0050] 0.1g of the mixture is loaded into a φ5mm mold and cold-pressed at 2MPa for 5min on a press. Then, the cold-pressed material and the mold are placed in a nitrogen-protected sintering furnace, heated to 345℃ at a rate of 10℃ / min, and sintered at that temperature for 2h. The material is then cooled to 60℃ at a rate of 10℃ / min and removed.

[0051] The sintered sample was placed in a nitrogen-protected oven and heat-treated at 250°C for 6 hours. After natural cooling, it was removed to obtain the finished porous polyaryletherketone pressure-resistant filter material.

[0052] Example 2

[0053] This case study describes the preparation method of porous polyaryletherketone pressure-resistant filter media for chromatographic columns, including the following steps:

[0054] Zirconia@low melt flow index PEEK core-shell structured microspheres with a diameter of 50-100 μm from Preparation Example 1 were mixed with high melt flow index polyetheretherketone powder (model 3600, produced by Shandong Junhao, with a particle size of 10 μm) with a melt flow index of 20 g / 10 min (tested at 400℃ and 2.16 kg load) at a mass percentage ratio of 80%:20% to form a mixture.

[0055] 0.1g of the mixture is loaded into a φ5mm mold and cold-pressed at 2MPa for 5min on a press. Then, the cold-pressed material and the mold are placed in a nitrogen-protected sintering furnace, heated to 345℃ at a rate of 10℃ / min, and sintered at that temperature for 2h. The material is then cooled to 60℃ at a rate of 10℃ / min and removed.

[0056] The sintered sample was placed in a nitrogen-protected oven and heat-treated at 250°C for 6 hours. After natural cooling, it was removed to obtain the finished porous polyaryletherketone pressure-resistant filter material.

[0057] Example 3

[0058] This case study describes the preparation method of porous polyaryletherketone pressure-resistant filter media for chromatographic columns, including the following steps:

[0059] Zirconia@low melt flow index PEEK core-shell structured microspheres with a diameter of 50-100 μm from Preparation Example 1 were mixed with high melt flow index polyetheretherketone powder (model 3600, produced by Shandong Junhao, with a particle size of 10 μm) with a melt flow index of 20 g / 10 min (tested at 400℃ and 2.16 kg load) at a mass percentage ratio of 80%:20% to form a mixture.

[0060] 0.1g of the mixture is loaded into a φ5mm mold and cold-pressed at 5MPa for 5min on a press. Then, the cold-pressed material and the mold are placed in a nitrogen-protected sintering furnace, heated to 345℃ at a rate of 10℃ / min, and sintered at that temperature for 2h. The material is then cooled to 60℃ at a rate of 10℃ / min and removed.

[0061] The sintered sample was placed in a nitrogen-protected oven and heat-treated at 250°C for 6 hours. After natural cooling, it was removed to obtain the finished porous polyaryletherketone pressure-resistant filter material.

[0062] Comparative Example 1

[0063] In this case, the filter material was prepared by directly loading 50-100μm zirconium oxide@low melt index PEEK core-shell structured microspheres from Preparation Example 1 into a mold, cold pressing, sintering, and then heat treating with the same parameters as in Example 1.

[0064] Comparative Example 2

[0065] The filter material preparation process in this case is the same as in Example 1, except that no subsequent heat treatment was performed after sintering.

[0066] Comparative Example 3

[0067] The filter media preparation process in this case is the same as in Example 1, except that the raw materials are:

[0068] Low melt flow polyetheretherketone powder (model 9600, manufactured by Shandong Junhao, powder particle size 50μm) with a melt flow rate of 0.2g / 10min (tested at 400℃ and 2.16kg load) and high melt flow polyetheretherketone powder (model 3600, manufactured by Shandong Junhao, powder particle size 10μm) with a melt flow rate of 20g / 10min (tested at 400℃ and 2.16kg load) were mixed evenly at a mass percentage ratio of 90%:10%. The subsequent operation process was the same as in Example 1.

[0069] Comparative Example 4

[0070] The filter material preparation process in this case is the same as that in Comparative Example 3, except that the particle size of the high melt index polyether ether ketone powder is 50 micrometers.

[0071] Comparative Example 5

[0072] The filter material preparation process in this case is the same as that in Comparative Example 3, except that the particle size of the high melt index polyether ether ketone powder is 3 micrometers.

[0073] Comparative Example 6

[0074] The filter material preparation process in this case is the same as that in Comparative Example 3, except that the low melt index polyether ether ketone powder has a particle size of 30 micrometers.

[0075] Comparative Example 7

[0076] The filter material preparation process in this case is the same as that in Comparative Example 3, except that the low melt index polyether ether ketone powder has a particle size of 150 micrometers.

[0077] Comparative Example 8

[0078] In this case, the filter material was prepared by directly loading high melt flow polyetheretherketone powder (model 3600, produced by Shandong Junhao, with a particle size of 10μm) with a melt flow rate of 20g / 10min (tested at 400℃ and 2.16kg load) into a mold, cold pressing, sintering, and then heat treatment. The treatment parameters were the same as in Example 1.

[0079] Test case

[0080] The performance of the above materials was tested, and the results are shown in Table 1.

[0081] Table 1 Filter Media Performance in Each Case

[0082]

[0083] This invention utilizes zirconia@low melt index PEEK core-shell structured microspheres and high melt index PEEK, first cold-pressed, then sintered, and finally heat-treated. The resulting filter material exhibits good axial compressive strength, and its average pore size and porosity meet the requirements for chromatographic column applications. High melt index PEEK acts as a binder to bond the core-shell structured microspheres, avoiding the risk of powder shedding while improving strength. As the proportion of high melt index PEEK increases, the compressive strength further increases. Increasing the cold-pressing pressure increases axial compressive strength while reducing the pore size and porosity of the filter material. This invention uses inorganic filler@low melt index polyaryletherketone core-shell structured microspheres and high melt index PEEK as raw materials. By adjusting the cold-pressing pressure, the content of high melt index polyaryletherketone, and subsequent heat treatment, filter material products with high strength and controllable pore size can be prepared.

[0084] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A porous polyaryletherketone pressure-resistant filter material for chromatographic columns, characterized in that, The following materials are cold-pressed and sintered: inorganic fillers @ low melt index polyaryletherketone core-shell structured microspheres and high melt index polyaryletherketone materials; The high melt index polyaryletherketone material accounts for 5wt%-40wt% of the filter material; The low melt index polyaryletherketone material in the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres has a melt index of 0.05-3 g / 10 min at 400℃ and 2.16 kg load; The high melt index polyaryletherketone material has a melt index of 10-30 g / 10 min at 400℃ and 2.16 kg load.

2. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to claim 1, characterized in that, The inorganic filler@low melt index polyaryletherketone core-shell structured microspheres have a particle size of 50-100 micrometers; the high melt index polyaryletherketone material has a particle size in the range of 3-50 micrometers. In the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres, the proportion of inorganic filler is in the range of 0.5%-25%; The inorganic filler is selected from at least one of metal powder, metal oxide powder, and inorganic non-metallic powder, and the particle size of the inorganic filler is 0.5-50 micrometers.

3. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to claim 2, characterized in that, The method for obtaining the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres includes the following steps: S1. Dissolve or swell low melt index polyaryletherketone material in a hot, good organic solvent to form a homogeneous polymer solution; S2. Add inorganic filler to the polymer solution and mix to form a dispersion; S3. Add a hot phase separation solvent to the dispersion and stir continuously to form an emulsion, so that the polymer encapsulates the inorganic filler to form microspheres that precipitate in the system. After separation, washing and drying, inorganic filler@low melt index polyaryletherketone core-shell structure microspheres are obtained.

4. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to claim 3, characterized in that, The polymer solution has a mass percentage of 1.5%-20%; the stirring rate in S2 and S3 is 1000-15000 rpm; The organic solvent does not react with the inorganic filler, and the organic solvent is selected from one or more of diphenyl sulfone, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, tetrahydrofuran, and dimethyl sulfoxide; the temperature of the organic solvent is higher than 250°C.

5. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to claim 3, characterized in that, The phase separation solvent has a boiling point higher than 250°C and lower than the melting point of the low melt index polyaryletherketone material, and is also a poor solvent for the low melt index polyaryletherketone material. The amount of the phase separation solvent used is 1%-20% of the weight of the dispersion.

6. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to claim 3, characterized in that, After obtaining inorganic filler@low melt index polyaryletherketone core-shell structured microspheres, the process also includes density screening to obtain microparticles with a density greater than that of the low melt index polyaryletherketone material, and annealing the screened microparticles at 300-350°C for at least 1 hour after spreading them out.

7. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to any one of claims 1-6, characterized in that, The cold pressing pressure is in the range of 0-20MPa and the cold pressing time is at least 1min; The sintering process is carried out in a sintering furnace under vacuum or with a protective gas filling. The sintering conditions are to heat the furnace to 340-380°C at a heating rate of 2-20°C / min and hold the temperature for at least 30 minutes.

8. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to any one of claims 1-6, characterized in that, The process after sintering also includes subsequent heat treatment. The heat treatment is carried out in an oven under vacuum or with a protective gas filling. The heat treatment temperature is 180-300℃ and the heat treatment is held for 1-8 hours.

9. The porous polyaryletherketone pressure-resistant filter material for chromatographic columns according to any one of claims 1-6, characterized in that, The filter material has an average pore size of 2.5-5.5 micrometers, a porosity of 10%-30%, and an axial compressive strength of at least 100 MPa.

10. A method for preparing porous polyaryletherketone pressure-resistant filter media for chromatographic columns, applicable to the preparation of the filter media according to any one of claims 1-9, characterized in that, Includes the following steps: Inorganic filler @ low melt index polyaryletherketone core-shell structured microspheres and high melt index polyaryletherketone material are mixed evenly, placed in a mold, cold-pressed and then sintered, and finally heat-treated and cooled to obtain porous polyaryletherketone pressure-resistant filter material for chromatographic columns. The low melt index polyaryletherketone material in the inorganic filler@low melt index polyaryletherketone core-shell structured microspheres has a melt index of 0.05-3 g / 10 min at 400℃ and 2.16 kg load; The high melt index polyaryletherketone material has a melt index of 10-30 g / 10 min at 400℃ and 2.16 kg load.

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