A carboxylated polyethersulfone material, its preparation method and application in the preparation of ultrafiltration membranes

Abstract

The present invention relates to the technical field of ultrafiltration membranes and their material preparation, and specifically discloses a carboxylated polyethersulfone material, a preparation method thereof, and an application thereof in the preparation of ultrafiltration membranes. The preparation method of the carboxylated polyethersulfone material comprises the following steps: (1) Dissolve polyethersulfone resin in an organic solvent, then add a carboxyl-containing compound and a photoinitiator, and stir evenly to obtain a reaction solution; (2) React the reaction solution under a nitrogen atmosphere under ultraviolet light irradiation for 2 to 3 hours to obtain the carboxylated polyethersulfone material. By carboxylating the polyethersulfone resin, the hydrophilic property of the prepared carboxylated polyethersulfone material is enhanced, and further the hydrophilic property of the polyethersulfone ultrafiltration membrane prepared by using the carboxylated polyethersulfone material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrafiltration membranes and their material preparation, and particularly relates to a carboxylated polyethersulfone material, a preparation method thereof, and an application thereof in the preparation of ultrafiltration membranes. Background Art

[0002] Artificial permeable membranes used in the ultrafiltration process are generally made of polymer materials such as cellulose acetates, cellulose acetate esters, polyethylenes, polysulfones, and polyamides. Ultrafiltration membranes are currently widely used in the concentration, purification, and separation of macromolecular substances in the chemical, food, and pharmaceutical industries.

[0003] Polyethersulfone is a thermoplastic polymer material with excellent comprehensive properties. Due to its excellent heat resistance and physical and mechanical properties, it is currently widely used in the preparation of ultrafiltration membranes. However, due to the strong superhydrophobicity of polyethersulfone, the polyethersulfone ultrafiltration membranes prepared therefrom also have strong hydrophobicity. Research shows that the stronger the hydrophobicity of the ultrafiltration membrane, the more easily it is contaminated. Therefore, hydrophilic modification of polyethersulfone to provide a polyethersulfone material with good hydrophilicity has important application value for developing polyethersulfone ultrafiltration membranes with strong anti-pollution ability. Summary of the Invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a preparation method of a carboxylated polyethersulfone material. The carboxylated polyethersulfone material prepared by this method has good hydrophilicity.

[0005] A preparation method of a carboxylated polyethersulfone material, comprising the following steps:

[0006] (1) Dissolve polyethersulfone resin in the organic solvent N,N-dimethylformamide, then add a carboxyl-containing compound and a photoinitiator, and stir evenly to obtain a reaction solution;

[0007] (2) React the reaction solution in a nitrogen atmosphere under ultraviolet light irradiation for 2-3 h to obtain a carboxylated polyethersulfone material.

[0008] By carboxylating the polyethersulfone resin, the hydrophilic property of the prepared carboxylated polyethersulfone material is enhanced, and thus the hydrophilic property of the polyethersulfone ultrafiltration membrane prepared using this carboxylated polyethersulfone material is improved.

[0009] Preferably, in step (1), the dosage ratio of the polyethersulfone resin, the carboxyl-containing compound, the photoinitiator to the organic solvent is 5-10 g: 1-2 g: 0.5-1 g: 50-100 mL.

[0010] Most preferably, in step (1), the dosage ratio of the polyethersulfone resin, the carboxyl-containing compound, the photoinitiator to the organic solvent is 8 g: 1.5 g: 0.8 g: 80 mL.

[0011] Preferably, the carboxyl group-containing compound is selected from 16-mercaptohexadecanoic acid or p-mercaptobenzoic acid.

[0012] Preferably, the carboxyl group-containing compound consists of 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid.

[0013] The inventors found in the research that in the preparation method of the present invention, there are significant differences in the hydrophilic properties of the carboxylated polyethersulfone materials prepared using different carboxyl group-containing compounds. The inventors surprisingly found in the research that the hydrophilic property of the carboxylated polyethersulfone material prepared by using both 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid as the carboxyl group-containing compound is greatly improved compared to the carboxylated polyethersulfone materials prepared by using 16-mercaptohexadecanoic acid or p-mercaptobenzoic acid alone as the carboxyl group-containing compound. Using both 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid can synergistically improve the hydrophilic property of the prepared carboxylated polyethersulfone material.

[0014] More preferably, the weight ratio of 16-mercaptohexadecanoic acid to p-mercaptobenzoic acid is 3-4:1.

[0015] Preferably, the photoinitiator consists of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate;

[0016] wherein, the weight ratio of 1-hydroxycyclohexyl phenyl ketone to methyl benzoylformate is 1-3:1-3;

[0017] Most preferably, the weight ratio of 1-hydroxycyclohexyl phenyl ketone to methyl benzoylformate is 1:1.

[0018] Preferably, the specific conditions of the ultraviolet light irradiation reaction are: reacting under ultraviolet light with a wavelength of 350-380 and an intensity of 80-120 mW / cm 2 for 2-3 h.

[0019] Most preferably, the specific conditions of the ultraviolet light irradiation reaction are: first reacting under ultraviolet light with a wavelength of 350-380 nm and an intensity of 80-120 mW / cm 2 for 1-2 h; then reacting under ultraviolet light with a wavelength of 235-250 nm and an intensity of 80-120 mW / cm 2 for 0.5-1 h.

[0020] The inventors further discovered in their research that the specific conditions of the ultraviolet light irradiation reaction also play an important role in further improving the hydrophilic properties of the prepared carboxylated polyethersulfone material. The inventors surprisingly found in their research that in the present invention, a photoinitiator composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate is used, and the irradiation reaction is carried out at two different ultraviolet light wavelengths (i.e., first reacting for 1 to 2 h under irradiation with ultraviolet light having a wavelength of 350 to 380 nm at 80 to 120 mW / cm 2 ; then reacting for 0.5 to 1 h under irradiation with ultraviolet light having a wavelength of 235 to 250 nm at 80 to 120 mW / cm 2 ) to prepare a carboxylated polyethersulfone material, which can further significantly improve the hydrophilic properties of the prepared carboxylated polyethersulfone material; its hydrophilic properties are significantly higher than those of the carboxylated polyethersulfone material prepared by irradiating and reacting at only one ultraviolet light wavelength.

[0021] The present invention also provides a carboxylated polyethersulfone material prepared by the above preparation method.

[0022] The present invention also provides an application of the above carboxylated polyethersulfone material in the preparation of ultrafiltration membranes.

[0023] Preferably, the ultrafiltration membrane is prepared by the following method

[0024] Adding the carboxylated polyethersulfone material and a pore-forming agent into an organic solvent, stirring and dissolving to obtain a casting solution; then uniformly coating the casting solution on a glass plate, controlling the film-forming thickness to be 100 to 200 μm; then immediately immersing it in deionized water and changing the water 3 times within 24 h to obtain the ultrafiltration membrane.

[0025] The dosage ratio of the carboxylated polyethersulfone material, the pore-forming agent and the organic solvent is 15 to 25 g: 5 to 10 g: 80 to 100 mL;

[0026] Most preferably, the dosage ratio of the carboxylated polyethersulfone material, the pore-forming agent and the organic solvent is 20 g: 8 g: 90 mL.

[0027] The pore-forming agent is polyethylene glycol.

[0028] Beneficial effects: The present invention provides a novel method for preparing a carboxylated polyethersulfone material. By carboxylating the polyethersulfone resin, the hydrophilic property of the prepared carboxylated polyethersulfone material is enhanced, thereby improving the hydrophilic property of the polyethersulfone ultrafiltration membrane prepared from the carboxylated polyethersulfone material. In particular, the hydrophilic property of the carboxylated polyethersulfone material prepared by using both 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid as carboxyl-containing compounds is significantly improved compared to the carboxylated polyethersulfone materials prepared by using 16-mercaptohexadecanoic acid or p-mercaptobenzoic acid alone as carboxyl-containing compounds; it has excellent hydrophilic properties. Detailed implementation manners

[0029] The following specific examples are used to further explain the present invention, but the examples do not limit the protection scope of the present invention.

[0030] In the following examples, the polyethersulfone resin selected is the polyethersulfone with the brand name PESE6020 from BASF Corporation, Germany; other raw materials not specified in terms of source are conventional raw materials that can be purchased by those skilled in the art.

[0031] Example 1 Preparation of carboxylated polyethersulfone material

[0032] (1) Take the polyethersulfone resin and dissolve it in the organic solvent N,N-dimethylformamide, then add the carboxyl-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; wherein, the dosage ratio of the polyethersulfone resin, the carboxyl-containing compound, the photoinitiator to the organic solvent is 8 g: 1.5 g: 0.8 g: 80 mL;

[0033] (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light having a wavelength of 360 nm at 100 mW / cm 2 for 2.5 h to obtain the carboxylated polyethersulfone material;

[0034] The carboxyl-containing compound described in step (1) is 16-mercaptohexadecanoic acid;

[0035] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 1:1.

[0036] Example 2 Preparation of carboxylated polyethersulfone material

[0037] (1) Take the polyethersulfone resin and dissolve it in the organic solvent N,N-dimethylformamide, then add the carboxyl-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; wherein, the dosage ratio of the polyethersulfone resin, the carboxyl-containing compound, the photoinitiator to the organic solvent is 5 g: 1 g: 0.5 g: 100 mL;

[0038] (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light at 80 mW / cm2 React for 3 h under ultraviolet light with a wavelength of 350 nm to obtain a carboxylated polyethersulfone material;

[0039] The carboxyl-containing compound described in step (1) is 16-mercaptohexadecanoic acid;

[0040] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 3:1.

[0041] Preparation of carboxylated polyethersulfone material in Example 3

[0042] (1) Take polyethersulfone resin and dissolve it in the organic solvent N,N-dimethylformamide, then add the carboxyl-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; among them, the dosage ratio of polyethersulfone resin, carboxyl-containing compound, photoinitiator to the organic solvent is 10 g:2 g:1 g:50 mL;

[0043] (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light with a wavelength of 370 nm at 120 mW / cm 2 React for 2 h to obtain a carboxylated polyethersulfone material;

[0044] The carboxyl-containing compound described in step (1) is 16-mercaptohexadecanoic acid;

[0045] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 1:3.

[0046] Preparation of carboxylated polyethersulfone material in Example 4

[0047] (1) Take polyethersulfone resin and dissolve it in the organic solvent N,N-dimethylformamide, then add the carboxyl-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; among them, the dosage ratio of polyethersulfone resin, carboxyl-containing compound, photoinitiator to the organic solvent is 8 g:1.5 g:0.8 g:80 mL;

[0048] (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light with a wavelength of 360 nm at 100 mW / cm 2 React for 2.5 h to obtain a carboxylated polyethersulfone material;

[0049] The carboxyl-containing compound described in step (1) is p-mercaptobenzoic acid;

[0050] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 1:1.

[0051] Preparation of carboxylated polyethersulfone material in Example 5

[0052] (1) Dissolve polyethersulfone resin in the organic solvent N,N-dimethylformamide, then add the carboxyl group-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; wherein, the dosage ratio of polyethersulfone resin, carboxyl group-containing compound, photoinitiator to the organic solvent is 8 g: 1.5 g: 0.8 g: 80 mL;

[0053] (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light having a wavelength of 360 nm at 100 mW / cm 2 for 2.5 h to obtain a carboxylated polyethersulfone material;

[0054] The carboxyl group-containing compound described in step (1) is composed of 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid with a weight ratio of 3:1;

[0055] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 1:1.

[0056] Preparation of carboxylated polyethersulfone material in Example 6

[0057] (1) Dissolve polyethersulfone resin in the organic solvent N,N-dimethylformamide, then add the carboxyl group-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; wherein, the dosage ratio of polyethersulfone resin, carboxyl group-containing compound, photoinitiator to the organic solvent is 8 g: 1.5 g: 0.8 g: 80 mL;

[0058] (2) Under a nitrogen atmosphere, first irradiate the reaction solution with ultraviolet light having a wavelength of 360 nm at 100 mW / cm 2 for 1.5 h; then irradiate with ultraviolet light having a wavelength of 240 nm at 100 mW / cm 2 for 1 h to obtain a carboxylated polyethersulfone material;

[0059] The carboxyl group-containing compound described in step (1) is composed of 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid with a weight ratio of 3:1;

[0060] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 1:1.

[0061] Preparation of carboxylated polyethersulfone material in Comparative Example 1

[0062] (1) Dissolve polyethersulfone resin in the organic solvent N,N-dimethylformamide, then add the carboxyl group-containing compound and the photoinitiator, and stir evenly to obtain a reaction solution; wherein, the dosage ratio of polyethersulfone resin, carboxyl group-containing compound, photoinitiator to the organic solvent is 8 g: 1.5 g: 0.8 g: 80 mL;

[0063] (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light having a wavelength of 240 nm at 100 mW / cm 2 for 1 h; then irradiate it with ultraviolet light having a wavelength of 360 nm at 100 mW / cm 2 for 1.5 h; to obtain the carboxylated polyethersulfone material;

[0064] The carboxyl-containing compound described in step (1) is composed of 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid with a weight ratio of 3:1;

[0065] The photoinitiator described in step (1) is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate with a weight ratio of 1:1.

[0066] Experimental Example

[0067] Respectively use the carboxylated polyethersulfone materials prepared in Examples 1 to 6 and Comparative Example 1 as raw materials to prepare carboxylated polyethersulfone ultrafiltration membranes; at the same time, test the contact angles of each carboxylated polyethersulfone ultrafiltration membrane (the smaller the contact angle, the better the hydrophilicity), and the test results are shown in Table 1.

[0068] The preparation method is as follows:

[0069] Add the carboxylated polyethersulfone material and the pore-forming agent polyethylene glycol to the organic solvent N,N-dimethylformamide, stir and dissolve to obtain a casting solution; then evenly coat the casting solution on a glass plate, control the film-forming thickness to be 200 μm; then immediately immerse it in deionized water and change the water 3 times within 24 h to obtain the ultrafiltration membrane.

[0070] Among them, the dosage ratio of the carboxylated polyethersulfone material, the pore-forming agent and the organic solvent is 20 g:8 g:90 mL.

[0071] Table 1.

[0072] Raw materials for preparing ultrafiltration membrane Contact angle Carboxylated polyethersulfone material prepared in Example 1 50.7° Carboxylated polyethersulfone material prepared in Example 2 54.6° Carboxylated polyethersulfone material prepared in Example 3 52.1° Carboxylated polyethersulfone material prepared in Example 4 52.9° Carboxylated polyethersulfone material prepared in Example 5 35.4° Carboxylated polyethersulfone material prepared in Example 6 21.7° Carboxylated polyethersulfone material prepared in Comparative Example 1 32.3°

[0073] It can be seen from the experimental results in Table 1 that the contact angles of the ultrafiltration membranes prepared from the carboxylated polyethersulfone materials described in Example 1 are all less than 60 °C; this shows that the carboxylated polyethersulfone materials prepared by the method of the present invention have hydrophilic properties.

[0074] As can be seen from the experimental results in Table 1, the contact angle of the ultrafiltration membrane prepared from the carboxylated polyethersulfone material described in Example 5 is significantly smaller than that of Examples 1 to 4; this shows that: in the preparation method of the present invention, the carboxylated polyethersulfone materials prepared using different carboxyl-containing compounds have relatively large differences in hydrophilicity; when the carboxylated polyethersulfone material is prepared using both 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid as the carboxyl-containing compounds, its hydrophilicity is much higher than that of the carboxylated polyethersulfone material prepared using only 16-mercaptohexadecanoic acid or p-mercaptobenzoic acid as the carboxyl-containing compound; using both 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid as the carboxyl-containing compounds can synergistically improve the hydrophilicity of the prepared carboxylated polyethersulfone material.

[0075] As can be seen from the experimental results in Table 1, the contact angle of the ultrafiltration membrane prepared from the carboxylated polyethersulfone material described in Example 6 is further significantly smaller than that of Example 5; this shows that: in the present invention, the carboxylated polyethersulfone material prepared by irradiating and reacting with a photoinitiator composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate at two different ultraviolet light wavelengths in the present invention can further significantly improve the hydrophilicity of the prepared carboxylated polyethersulfone material; its hydrophilicity is much higher than that of the carboxylated polyethersulfone material prepared by irradiating and reacting at only one ultraviolet light wavelength.

[0076] As can be seen from the experimental results in Table 1, the reduction in the contact angle of the ultrafiltration membrane prepared from the carboxylated polyethersulfone material described in Example 7 is not significant compared to Example 5, and the reduction is much smaller than that of Example 6; this shows that: not any random selection of two different wavelengths of ultraviolet light for irradiation reaction can further significantly improve the hydrophilicity of the prepared carboxylated polyethersulfone material; only by irradiating and reacting at the two different ultraviolet light wavelengths described in the present invention (i.e., first reacting for 1 to 2 h under irradiation with ultraviolet light having a wavelength of 350 to 380 nm at 80 to 120 mW / cm 2 and then reacting for 0.5 to 1 h under irradiation with ultraviolet light having a wavelength of 235 to 250 nm at 80 to 120 mW / cm 2 ) can the hydrophilicity of the prepared carboxylated polyethersulfone material be further significantly improved.

Claims

1. A preparation method of a carboxylated polyethersulfone material, characterized in that, It includes the following steps: (1) Dissolve the polyethersulfone resin in an organic solvent, then add a carboxyl group-containing compound and a photoinitiator, and stir evenly to obtain a reaction solution; (2) Under a nitrogen atmosphere, irradiate the reaction solution with ultraviolet light having a wavelength of 350 - 380 nm at 80 - 120 mW / cm 2 for 1 - 2 h; then irradiate it with ultraviolet light having a wavelength of 235 - 250 nm at 80 - 120 mW / cm 2 for 0.5 - 1 h to obtain a carboxylated polyethersulfone material; The carboxyl group-containing compound is composed of 16-mercaptohexadecanoic acid and p-mercaptobenzoic acid.

2. The preparation method of the carboxylated polyethersulfone material according to claim 1, wherein In step (1), the dosage ratio of the polyethersulfone resin, the carboxyl group-containing compound, the photoinitiator to the organic solvent is 5-10 g: 1-2 g: 0.5-1 g: 50-100 mL.

3. The preparation method of the carboxylated polyethersulfone material according to claim 1, wherein, In step (1), the dosage ratio of the polyethersulfone resin, the carboxyl group-containing compound, the photoinitiator to the organic solvent is 8 g: 1.5 g: 0.8 g: 80 mL.

4. The preparation method of the carboxylated polyethersulfone material according to claim 1, characterized in that, The weight ratio of 16-mercaptohexadecanoic acid to p-mercaptobenzoic acid is 3-4:

1.

5. The preparation method of the carboxylated polyethersulfone material according to claim 1, characterized in that, The photoinitiator is composed of 1-hydroxycyclohexyl phenyl ketone and methyl benzoylformate.

6. The preparation method of the carboxylated polyethersulfone material according to claim 5, characterized in that, The weight ratio of 1-hydroxycyclohexyl phenyl ketone to methyl benzoylformate is 1-3:1-3.

7. The carboxylated polyethersulfone material prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the carboxylated polyethersulfone material according to claim 7 in the preparation of an ultrafiltration membrane.