CN108610494B - Preparation method of polyethersulfone/functional sugar-containing polymer hybrid membrane - Google Patents

Abstract

The invention discloses a preparation method of a polyethersulfone/functional sugar-containing polymer hybrid membrane. The method uses polyethersulfone membrane as base membrane, adopts "click chemistry" technology, uses cuprous bromide as catalytic system, and bipyridine as initiator to rapidly complete functional sugar-containing polymers under anhydrous and oxygen-free conditions. Surface Grafting of Polyethersulfone. The "living"/controllable free radical polymerization method is adopted to synthesize functional sugar-containing polymers, maintaining the activity of acetylenic bonds, and the synthesis rate is high. The invention combines the functional sugar-containing polymer with the polyethersulfone membrane, has stable structure, can change the hydrophobicity of the membrane surface, endow the membrane material with excellent hydrophilicity, anti-fouling property, adsorption capacity and service life, and significantly improve the polyether sulfone membrane. Hydrophilization and reuse of sulfone membranes.

Description

Preparation method of polyethersulfone/functional sugar-containing polymer hybrid membrane

technical field

The invention belongs to the technical field of polymer materials, relates to a preparation method of a polyethersulfone/functional sugar-containing polymer hybrid membrane, and in particular relates to a functional sugar-containing polymer mannose (Mannose) prepared by a controllable free radical polymerization method. ), glucose (Glucose) and galactose (Galactose) and the preparation method of polymer membrane materials formed by grafting them to the surface of polyethersulfone membrane by "click chemistry" technology respectively.

Background technique

Polyethersulfone membrane has low surface energy and strong hydrophobicity, which is an ideal membrane for separation and purification of non-aqueous systems. However, for the separation, purification and concentration of proteins and biological solutions, the hydrophobicity of polyethersulfone membranes can easily cause the adsorption of organic substances and colloids (proteins) on the membrane surface and in the pores, resulting in reduced permeation flux and membrane fouling problems. Therefore, in order to improve the separation efficiency of polyethersulfone membrane, reduce membrane fouling, improve membrane flux and prolong the service life of membrane, it is necessary to carry out hydrophilic modification on polyethersulfone membrane. There are many modification methods of polyethersulfone membrane, mainly including physical modification and chemical modification. The former mainly includes surface coating and material blending, while the latter is mainly realized by bulk modification of membrane material and grafting of membrane surface. The physical modification method is relatively simple and easy to operate, but it has the problems that the surface-coated or blended polymers are easy to fall off and cannot achieve permanent modification. Existing chemical modification methods are mainly bulk modification of membrane materials, such as the introduction of functional groups and graft modification on the membrane surface, to generate reactive sites on the membrane surface, and use the active sites to trigger the reactive monomers with double bonds in the membrane. The surface of the membrane is grafted and polymerized to form a functional graft layer. Existing chemical modification methods are cumbersome, uncontrollable, and not efficient enough.

Sugar-containing polymer refers to a polymer formed by introducing sugar molecules into the polymer chain as its pendant groups or chain end groups. Such polymers possess high functionality, biocompatibility, pharmacological activity, low toxicity, optical activity, and biodegradability. It has broad application prospects in glycomics, pharmacy, biotechnology, sensors and separation science. In order to prepare an excellent sugar-containing polymer with the above functions, it must have a predetermined molecular weight and molecular weight distribution range, a controllable structure, a definite sugar group position and a sugar group density. The advent of "living"/controlled free radical polymerization, due to the high compatibility of homofunctional groups, has enabled the synthesis of many structurally well-defined sugar-containing polymers with predetermined molecular weights and narrow molecular weight distributions, enabling The application fields of sugar-containing polymers are more extensive.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of a polyethersulfone/functional sugar-containing polymer hybrid membrane. The method uses "click chemistry" technology to graft sugar-containing polymers on the surface of polyethersulfone membrane materials, which endow the membrane materials with special wettability, excellent antifouling properties and improved separation properties.

The technical solution that realizes the object of the present invention is as follows:

The preparation method of polyethersulfone/functional sugar-containing polymer hybrid membrane, the specific steps are as follows:

Step 1, mix polyethersulfone, chloroform, zinc chloride and chloromethyl methyl ether, pass nitrogen, react in a water bath at 40-50°C, cool down after the reaction is complete, add the mixed solution dropwise to methanol, filter with suction, Dissolving the precipitate in dimethylacetamide (DMAC), repeating the steps of precipitation and suction filtration, washing the precipitate with water and suction filtration, and drying to obtain chloromethylated polyethersulfone;

Step 2, mix the chloromethylated polyethersulfone and sodium azide, dissolve in dimethyl sulfoxide (DMSO), pass nitrogen, and react in a water bath at 65-75°C. After the reaction, cool to room temperature , the mixed solution was added dropwise to methanol, filtered with suction, the precipitate was dissolved in DMAC, the above steps of precipitation and suction filtration were repeated, and the precipitate was washed with water and suction filtered, and dried to obtain azide polyethersulfone;

Step 3, after dropping concentrated sulfuric acid into the mixed solution of anhydrous ether and silica gel, rotary evaporation and drying to obtain silicon-containing sulfuric acid, mixing propynyl alcohol, monosaccharide and silicon-containing sulfuric acid, and reacting in a water bath at 60 to 70 ° C, the reaction After the end, the product is purified and vacuumized to obtain the acetylenically bonded monosaccharide;

Step 4: Dissolve the azide polyethersulfone, acetylenic monosaccharide and bipyridine in N,N dimethylformamide (DMF) to obtain a mixed solution A, remove the water and air in the mixed solution A , the mixed solution A after dewatering and degassing is introduced into the degassed cuprous bromide, and the reaction is carried out in a water bath at 50-60 °C to obtain a polyethersulfone grafted with a functional sugar-containing polymer;

Step 5, dissolving the polyethersulfone and polyethersulfone grafted with the functional sugar-containing polymer in N-methylpyrrolidone (NMP), adding polyvinylpyrrolidone (PVP) as a pore-forming agent, at 70-75° C. After the reaction is completed, filter the filtrate, remove the bubbles in the liquid by vacuuming, and finally spread it evenly on the non-woven fabric and soak it in water until it forms a film to obtain a polyethersulfone/functional sugar-containing polymer hybrid. Film material.

Preferably, in step 1, the molecular weight of the polyethersulfone is 60000, the molar ratio of polyethersulfone and chloromethyl methyl ether is 1:490, and the reaction time is 6 hours.

Preferably, in step 2, the molar ratio of the chloromethylated polyethersulfone and sodium azide is 1:780, and the reaction time is 48 hours.

Preferably, in step 3, the monosaccharide is selected from mannose, glucose or galactose, the molar ratio of the propargyl alcohol and the monosaccharide is 1:2, and the reaction time is 8 hours.

Preferably, in step 4, the mass ratio of the azide polyethersulfone, the acetylenic monosaccharide and the bipyridine is 11.45:11.45:1, and the reaction time is 24 hours.

Preferably, in step 5, the mass ratio of the polyethersulfone, polyethersulfone and PVP grafted with the functional sugar-containing polymer is 1.5:1:0.875, the reaction time is 48 hours, and the soaking time is 24 hours.

Based on the "click reaction" grafting technology, the present invention starts from the untreated pure polyethersulfone membrane material, selects the sugar-containing polymer with hydrophilicity, anti-fouling and anti-adsorption, and realizes the The surface grafting modification of the polyethersulfone membrane material endows the polyethersulfone membrane material with special wettability, excellent antifouling and improved separation.

Compared with the prior art, the present invention has the following advantages:

(1) Using "click chemistry" (Click reaction) technology, using cuprous bromide as the catalytic system and bipyridine as the initiator, under anhydrous and oxygen-free conditions, the reaction of functional sugar-containing polymers to polyethersulfone was rapidly completed. Surface grafting; using the "living"/controlled free radical polymerization method, the functional sugar-containing polymer can be rapidly synthesized, and the activity of the acetylene bond can also be maintained, and the synthesis rate is high.

(2) The functional sugar-containing polymer is combined with the polyethersulfone membrane, which has a stable structure and can change the hydrophobicity of the membrane surface, endow the membrane material with excellent hydrophilicity, anti-fouling, adsorption capacity and service life, and significantly improve the polyether sulfone. Hydrophilization of the sulfone membrane to improve its reusability.

Description of drawings

FIG. 1 is a schematic flow chart of the present invention.

Figure 2 is a synthetic route diagram of the grafting of sugar-containing polymers to the membrane surface.

Figure 3 is a gel chromatogram of a sugar-containing polymer.

Figure 4 is the ¹ H nuclear magnetic spectrum of chloromethylated polyethersulfone and azide polyethersulfone.

Figure 5 is an infrared image of pure polyethersulfone, chloromethylated polyethersulfone, azide polyethersulfone, and mannose-grafted polyethersulfone.

Fig. 6 is the SEM membrane edge image of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane (a ₁ -d ₁ ), SEM) film surface image (a ₂ -d ₂ ).

FIG. 7 is the infrared images of pure polyethersulfone membrane, functional galactose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional mannose-containing polymer hybrid membrane.

8 is an X-ray photoelectron spectroscopy analysis diagram of azide polyethersulfone, mannose-grafted polyethersulfone, glucose-grafted polyethersulfone, and galactose-grafted polyethersulfone.

Figure 9 shows the X of azide polyethersulfone (a), mannose-grafted polyethersulfone (b), glucose-grafted polyethersulfone (c), and galactose-grafted polyethersulfone (d) Ray photoelectron spectroscopy analysis of peaks.

FIG. 10 is a water contact angle diagram of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane.

Figure 11 is the pore size distribution diagram of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane.

Figure 12 is a pure water flux diagram of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane.

Fig. 13 is (A) of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane for the retention of bovine serum albumin solution (A) UV image, (B) Rejection graph.

Figure 14 shows (A) of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane in water-bovine serum albumin solution (A ) flux plot, (B) recovery rate plot.

15 is a water contact angle diagram of the functional mannose-containing polymer hybrid membrane, the functional glucose-containing polymer hybrid membrane, and the functional galactose-containing polymer hybrid membrane soaked in the concanavalin solution.

Detailed ways

The present invention will be described in further detail below in conjunction with the embodiments and the accompanying drawings.

Example 1

Step 1, add polyethersulfone and chloroform into a three-necked flask (connected to a condenser), then add zinc chloride and chloromethyl methyl ether to mix, pass nitrogen for 15 minutes, and react under a water bath at 40-50°C. After the reaction is completed, the cooled mixed solution product is added dropwise to methanol to form a white precipitate, which is filtered with suction, and then the precipitate is dissolved in DMAC, and the above steps of precipitation and suction filtration are repeated. Put in an oven to dry to obtain chloromethylated polyethersulfone.

Step 2, mix the chloromethylated polyethersulfone and sodium azide, dissolve in DMSO, pass nitrogen for 15 minutes, and react in a water bath at 65-75°C. After the reaction is completed, after the product is cooled to room temperature, It was added dropwise to methanol to form a white precipitate, which was filtered with suction, and then the precipitate was dissolved in DMAC. The above steps of precipitation and suction filtration were repeated, and the precipitate was washed with water and suction filtered. Nitrided polyethersulfone.

Step 3, add propynyl alcohol and monosaccharide (mannose, glucose or galactose) to the round-bottomed flask, then add and mix with silicon-containing sulfuric acid. After the reaction is completed, the product is subjected to silica gel column purification, and finally vacuumized to obtain three acetylenic monosaccharides (mannose, glucose or galactose). ).

Step 4, take two reaction flasks (marked as A/B), add azide polyethersulfone, acetylenic monosaccharide (mannose, glucose or galactose) and bipyridine into flask A, dissolve A mixed solution A was obtained in DMF to form a reactant system. Cuprous bromide was added to bottle B to form a catalyst system. Freeze the liquid in bottle A with liquid nitrogen, then pump out the air and water in the bottle, put the bottle A into hot water to thaw, then freeze with liquid nitrogen, pump air, repeat 5-6 times, and repeat the pumping of bottle B , the process of nitrogen filling. After degassing and dewatering, the liquid in bottle A was introduced into bottle B with a long needle tube, and bottle B was put into a 50-60° C. water bath for reaction to obtain a polyethersulfone grafted with a functional sugar-containing polymer.

5 mg of pure polyethersulfone and the prepared chloromethylated polyethersulfone, azide polyethersulfone, and polyethersulfone grafted with mannose were dissolved in N-N dimethylformamide reagent and subjected to gel chromatography. The GPC of each polymer was measured (Figure 3), and their molecular weight gradually increased, indicating that the polymer was successfully prepared.

1,2-Chloromethyl methyl ether and polyethersulfone were reacted to obtain chloromethylated polyethersulfone. After 24 hours of reaction at 40 °C, an NMR sample was taken to obtain a ¹ H NMR spectral resonance characteristic map (Fig. 4a). The final product was at 4.5 ppm, which clearly demonstrated the presence of chloromethyl linkages, other peaks have been indicated in Figure 4a.

The azide polyethersulfone was prepared by reacting sodium azide and chloromethylated polyethersulfone. After reacting at 70 °C for 48 h, a nuclear magnetic sample was taken to obtain a ¹ H NMR spectral resonance characteristic map (Figure 4b) showing the final product. At 2.5 ppm, it clearly demonstrated the presence of azide bonds, other peaks have been indicated in Fig. 4b.

In addition, the ¹ H NMR spectral resonance characteristics of chloromethylated polyether sulfone and azide polyether sulfone (Fig. 4) clearly indicate the location of the bond.

Take 5 mg of pure polyethersulfone and the prepared chloromethylated polyethersulfone, azide polyethersulfone, and polyethersulfone grafted with mannose to obtain 5 mg by infrared measurement. The azide polyethersulfone has azide at about 2100. The characteristic peaks of functional groups and the polyethersulfone grafted with mannose have characteristic peaks of hydroxyl groups around 3500, indicating that the polymer was successfully prepared.

Example 2

Add polyethersulfone and pure polyethersulfone grafted with functional sugar-containing polymer into the vial, add NMP, dissolve at 70 °C, add PVP as a pore-forming agent, and react in a water bath at 70-75 °C . Use a Buchner funnel to filter the product after the reaction, collect the filtrate, and remove air bubbles in the liquid by vacuuming. Finally, it is evenly spread on the non-woven fabric, soaked in water with deionization, and soaked until a film is formed to obtain a polyethersulfone/functional sugar-containing polymer hybrid membrane material.

Figure 6 is the scanning electron microscope images of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane. The polymer hybrid membrane, the functional glucose-containing polymer hybrid membrane, and the functional galactose-containing polymer hybrid membrane had sugar monomers, indicating that the grafting was successful.

The azide polyethersulfone, grafted mannose polyethersulfone, grafted glucose polyethersulfone, and grafted galactose polyethersulfone were tested by X-ray photoelectron spectroscopy (XPS), as shown in Figure 8, all broad spectrum There is the same distribution of peaks, including O1s at 532 eV, C1s at 285 eV, N 1s at 399 eV, and S 2p at 168 eV. The chemical composition of the membrane surface is listed in the table (Fig. 9). The N content in the azide membrane is higher, and the N content decreases after grafting the sugar monomer, indicating that the sugar monomer is successfully grafted. The C 1s energy level spectrum can be divided into three peaks, which are C-C/C-H at 284.7 eV, C-S at 286.1 eV, and O-C-O at 286.4 eV, as shown in Figure 9a, Figure 9b, Figure 9c, and Figure 9d.

Example 3

The water contact angle of each film was measured. Water was dropped on the film, and the water contact angle at 30 seconds was measured as shown in Figure 10. The water contact angle of the hybridized membrane is smaller than that of the pure polyethersulfone membrane, indicating that the hydrophilicity of the hybridized polyethersulfone membrane is improved.

The pore size of each membrane was measured, as shown in FIG. 11 . The pore size distribution of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane is 20-150 nm, indicating that the prepared Membranes are between ultrafiltration membranes and microfiltration membranes.

Measure the pure water flux of each membrane, pre-press at 0.20MPa, and measure the pure water flux at 0.05MPa, 0.10MPa, 0.15MPa, 0.20MPa, 0.25MPa, 0.30MPa, 0.35MPa, 0.40MPa for 30min respectively, The results are shown in Figure 11. The pure water flux of the hybrid membrane is much higher than that of the pure polyethersulfone membrane, indicating that the performance of the hybrid membrane is improved.

The retention of the bovine serum albumin solution of each membrane was measured, and the results are shown in FIG. 13 . Pre-press at 0.20MPa, then use bovine serum albumin solution for interception at 0.10MPa, measure the flux every 10min, until the flux does not change, collect the solution passing through the membrane to measure the ultraviolet light absorption, the result is shown in Figure 13A As shown, the rejection rate of bovine serum albumin solution was calculated according to the peak height, and the result is shown in Figure 13B, in which the rejection rate of the membrane after hybridization was significantly improved, indicating that the performance of the membrane after hybridization was improved.

The water-bovine serum albumin solution flux was measured for each membrane. Pre-press at 0.20MPa, measure the flux with pure water at 0.10MPa for 30min, measure the flux with bovine serum albumin solution for 90min, then soak in pure water for 1h, repeat the above operation twice, and finally use pure water at 0.10MPa Measure for 30min, as shown in Figure 14A. The recovery rate of the membrane was obtained by calculation ( FIG. 14B ), and the recovery rate of the membrane after hybridization was improved, indicating that the performance of the membrane after hybridization was improved.

The prepared functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane were soaked in 1 g/L concanavalin solution for 30 min. Rinse with clean water, and then measure the water contact angle with clean water after freeze-drying. Drop clear water on the film, and measure the water contact angle at 30 seconds (as shown in Figure 15). It was improved, indicating that the grafted membrane had specific adsorption to concanavalin.

Table 1 Chemical composition of azide polyethersulfone, mannose-grafted polyethersulfone, glucose-grafted polyethersulfone, and galactose-grafted polyethersulfone

Claims (6)

1. The preparation method of the polyether sulfone/functional sugar-containing polymer hybrid membrane is characterized by comprising the following specific steps of:

step 1, mixing polyether sulfone, chloroform, zinc chloride and chloromethyl methyl ether, introducing nitrogen, reacting in a water bath at 40-50 ℃, cooling after the reaction is finished, dropwise adding the mixed solution into methanol, performing suction filtration, dissolving a precipitate in DMAC, repeating the steps of precipitation and suction filtration, washing the precipitate with water, performing suction filtration, and drying to obtain chloromethylated polyether sulfone;

step 2, mixing chloromethylated polyether sulfone and sodium azide, dissolving in DMSO, introducing nitrogen, reacting in a water bath at 65-75 ℃, cooling to room temperature after the reaction is finished, dropwise adding the mixed solution into methanol, performing suction filtration, dissolving the precipitate in DMAC, repeating the steps of precipitation and suction filtration, washing the precipitate with water, performing suction filtration, and drying to obtain azide polyether sulfone;

step 3, dripping concentrated sulfuric acid into a mixed solution of anhydrous ether and silica gel, performing rotary evaporation and drying to obtain siliceous sulfuric acid, mixing propargyl alcohol, monosaccharide and siliceous sulfuric acid, reacting in a water bath at the temperature of 60-70 ℃, purifying and vacuumizing a product after the reaction is finished to obtain alkyne-bonded monosaccharide, wherein the monosaccharide is selected from mannose, glucose or galactose;

step 4, dissolving azide polyether sulfone, acetylene bond monosaccharide and bipyridine in DMF to obtain a mixed solution A, removing water and air in the mixed solution A, introducing the mixed solution A subjected to water removal and degassing into degassed cuprous bromide, and reacting in a water bath at 50-60 ℃ to obtain polyether sulfone grafted with a functional sugar-containing polymer;

and 5, dissolving the polyether sulfone grafted with the functional sugar-containing polymer and the polyether sulfone in NMP, adding PVP (polyvinyl pyrrolidone) as a pore-forming agent, carrying out water bath reaction at 70-75 ℃, filtering after the reaction is finished, collecting filtrate, vacuumizing to remove bubbles in the liquid, uniformly coating the filtrate on a non-woven fabric, and soaking the non-woven fabric in water until a film is formed, thereby obtaining the polyether sulfone/functional sugar-containing polymer hybrid film material.

2. The preparation method according to claim 1, wherein in step 1, the molecular weight of the polyethersulfone is 60000, the molar ratio of the polyethersulfone to chloromethyl methyl ether is 1:490, and the reaction time is 6 hours.

3. The method according to claim 1, wherein in step 2, the molar ratio of the chloromethylated polyethersulfone to the sodium azide is 1:780, and the reaction time is 48 hours.

4. The method according to claim 1, wherein the molar ratio of propiolic alcohol to monosaccharide in step 3 is 1:2, and the reaction time is 8 hours.

5. The preparation method according to claim 1, wherein in the step 4, the mass ratio of the azide polyether sulfone to the alkyne-bonded monosaccharide to the bipyridine is 11.45:11.45:1, and the reaction time is 24 hours.

6. The preparation method according to claim 1, wherein in the step 5, the mass ratio of the polyether sulfone grafted with the functional sugar-containing polymer to the PVP is 1.5:1:0.875, the reaction time is 48 hours, and the soaking time is 24 hours.

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