CN108610494B

CN108610494B - Preparation method of polyether sulfone/functional sugar-containing polymer hybrid membrane

Info

Publication number: CN108610494B
Application number: CN201810231373.8A
Authority: CN
Inventors: 林芳; 张强; 仇志强; 刘世洋
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2018-03-20
Filing date: 2018-03-20
Publication date: 2020-11-06
Anticipated expiration: 2038-03-20
Also published as: CN108610494A

Abstract

The invention discloses a preparation method of a polyether sulfone/functional sugar-containing polymer hybrid membrane. The method takes a polyether sulfone membrane as a substrate membrane, adopts a click chemistry technology, takes cuprous bromide as a catalytic system and bipyridine as an initiator, and quickly finishes surface grafting of the functional sugar-containing polymer to the polyether sulfone under the anhydrous and oxygen-free conditions. The method adopts an active/controllable free radical polymerization method to synthesize the functional sugar-containing polymer, maintains the activity of acetylene bonds and has high synthesis rate. The functional sugar-containing polymer is combined with the polyether sulfone membrane, so that the structure is stable, the hydrophobicity of the surface of the membrane can be changed, the membrane material is endowed with excellent hydrophilicity, stain resistance, adsorption capacity and service life, and the hydrophilization and recycling rate of the polyether sulfone membrane are obviously improved.

Description

Preparation method of polyether sulfone/functional sugar-containing polymer hybrid membrane

Technical Field

The invention belongs to the technical field of high polymer materials, relates to a preparation method of a polyether sulfone/functional sugar-containing polymer hybrid membrane, and particularly relates to a preparation method of a functional sugar-containing polymer Mannose (Mannose), Glucose (Glucose) and Galactose (Galactose) prepared by a controllable free radical polymerization method and a high polymer membrane material formed by respectively grafting the functional sugar-containing polymer Mannose (Mannose), Glucose (Glucose) and Galactose (Galactose) to the surface of a polyether sulfone membrane by using a click chemistry technology.

Background

The polyether sulfone membrane has low surface energy and strong hydrophobicity, and is an ideal membrane for the separation and purification process of a non-aqueous system. However, for the separation, purification and concentration of protein and biological solution, the hydrophobic property of the polyethersulfone membrane easily causes the adsorption of organic substances and colloids (protein) on the surface and in the pores of the membrane, thereby causing the problems of reduced permeation flux and membrane pollution. Therefore, in order to improve the separation efficiency of the polyethersulfone membrane, reduce membrane fouling, improve membrane flux and prolong the service life of the membrane, the polyethersulfone membrane needs to be subjected to hydrophilic modification. The modification method of the polyether sulfone membrane is various, and mainly comprises physical modification and chemical modification. The former is mainly surface coating and material blending, and the latter is mainly realized by bulk modification of membrane materials and surface grafting of the membrane. The physical modification method is simple and easy to operate, but has the problems that the surface coated or blended polymer is easy to fall off and cannot achieve permanent modification and the like. The existing chemical modification method mainly comprises the steps of modifying a membrane material body, such as introducing a functional group and grafting modification on the surface of the membrane, generating a reaction active point on the surface of the membrane, and initiating active monomers with double bonds to graft and polymerize on the surface of the membrane by utilizing the active point to form a functional grafting layer. The existing chemical modification method is complex to operate, uncontrollable and not efficient enough.

The sugar-containing polymer refers to a polymer formed by introducing a sugar molecule into a polymer chain as a pendant group or a chain end group thereof. Such polymers have high functionality, biocompatibility, pharmaceutical activity, low toxicity, optical activity, and biodegradable properties. Has wide application prospect in glycomics, pharmacy, biotechnology, sensors and separation science. To produce an excellent sugar-containing polymer having the above-mentioned functions, it is necessary to have a predetermined molecular weight and molecular weight distribution range, a controllable structure, a definite sugar group position and a density of sugar groups. The advent of "living"/controlled radical polymerization has enabled the synthesis of many structurally distinct saccharide-containing polymers due to the high degree of compatibility with functional groups, and such polymers have a predetermined molecular weight and narrow molecular weight distribution, making the application fields of saccharide-containing polymers more widespread.

Disclosure of Invention

The invention aims to provide a preparation method of a polyether sulfone/functional sugar-containing polymer hybrid membrane. The method grafts the sugar-containing polymer on the surface of the polyether sulfone membrane material by a 'click chemistry' technology, and endows the membrane material with special wettability, excellent stain resistance and improved separability.

The technical solution for realizing the purpose of the invention is as follows:

the preparation method of the polyether sulfone/functional sugar-containing polymer hybrid membrane comprises the following specific steps:

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 Dimethylacetamide (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 dimethyl sulfoxide (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 azidated 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 a product after the reaction is finished, and vacuumizing to obtain alkyne-bonded monosaccharide;

step 4, dissolving azide polyether sulfone, acetylene bond monosaccharide and bipyridine in N, N Dimethylformamide (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 N-methyl pyrrolidone (NMP), adding polyvinylpyrrolidone (PVP) 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, thus obtaining the polyether sulfone/functional sugar-containing polymer hybrid film material.

Preferably, 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.

Preferably, in step 2, the mole ratio of the chloromethylated polyethersulfone to the 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 propiolic alcohol to the monosaccharide is 1:2, and the reaction time is 8 hours.

Preferably, in the step 4, the mass ratio of the nitrified polyether sulfone to the acetylenized monosaccharide to the bipyridine is 11.45:11.45:1, and the reaction time is 24 hours.

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

The method is based on a click chemistry (click reaction) grafting technology, selects a sugar-containing polymer with hydrophilicity, stain resistance and adsorption resistance from a non-treated pure polyether sulfone membrane material, realizes surface grafting modification of the polyether sulfone membrane material, and endows the polyether sulfone membrane material with special wettability, excellent stain resistance and improved separability.

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

(1) by adopting a Click chemistry (Click reaction) technology, cuprous bromide is used as a catalytic system, bipyridyl is used as an initiator, and the surface grafting of the functional sugar-containing polymer to the polyether sulfone is quickly completed under the anhydrous and anaerobic conditions; the 'activity'/controllable free radical polymerization method is adopted to quickly synthesize the functional sugar-containing polymer, and the activity of acetylene bonds can be maintained, so that the synthesis rate is high.

(2) The functional sugar-containing polymer is combined with the polyether sulfone membrane, has a stable structure, can change the hydrophobicity of the surface of the membrane, endows the membrane material with excellent hydrophilicity, dirt resistance and adsorption capacity and service life, obviously improves the hydrophilization of the polyether sulfone membrane, and improves the reutilization rate of the polyether sulfone membrane.

Drawings

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

FIG. 2 is a synthetic scheme showing the grafting of sugar-containing polymers to the membrane surface.

FIG. 3 is a gel chromatogram of a saccharide-containing polymer.

FIG. 4 shows chloromethylated and azido polyethersulfonesIs/are as follows¹H nuclear magnetic spectrum.

FIG. 5 is an infrared image of pure polyethersulfone, chloromethylated polyethersulfone, azidated polyethersulfone, and mannose-grafted polyethersulfone.

FIG. 6 is an edge view of a scanning electron microscope membrane 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-d₁) Scanning electron microscope) film surface map (a)₂-d₂)。

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

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

FIG. 9 is an X-ray photoelectron spectroscopy analysis peak chart of azide polyethersulfone (a), mannose-grafted polyethersulfone (b), glucose-grafted polyethersulfone (c) and galactose-grafted polyethersulfone (d).

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.

FIG. 11 is a 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.

FIG. 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 shows the ultraviolet image (A) and the retention rate image (B) of the bovine serum albumin solution retained by the pure polyethersulfone membrane, the functional mannose-containing polymer hybrid membrane, the functional glucose-containing polymer hybrid membrane and the functional galactose-containing polymer hybrid membrane.

FIG. 14 is (A) flux diagram and (B) recovery diagram of water-bovine serum albumin solution of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane and functional galactose-containing polymer hybrid membrane.

FIG. 15 is a graph of water contact angles of a functional mannose-containing polymer hybrid membrane, a functional glucose-containing polymer hybrid membrane, and a functional galactose-containing polymer hybrid membrane after soaking in a solution of concanavalin.

Detailed Description

The present invention will be described in more detail with reference to the following examples and the accompanying drawings.

Example 1

Step 1, adding polyether sulfone and chloroform into a three-neck flask (connected with a condenser), then adding zinc chloride and chloromethyl methyl ether, mixing, introducing nitrogen for 15 minutes, and reacting in a water bath at 40-50 ℃. And after the reaction is finished, dropwise adding the cooled mixed solution product into methanol to form white precipitate, 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 in an oven to obtain the chloromethylated polyether sulfone.

And 2, mixing chloromethylated polyether sulfone and sodium azide, dissolving in DMSO, introducing nitrogen for 15 minutes, reacting in a water bath at 65-75 ℃, after the reaction is finished, dropwise adding the product into methanol to form white precipitate after the product is cooled to room temperature, 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 the final product at 40 ℃ to obtain the azido polyether sulfone.

And 3, adding propiolic alcohol and monosaccharide (mannose, glucose or galactose) into a round-bottom flask, adding and mixing with siliceous sulfuric acid, wherein the siliceous sulfuric acid is obtained by dripping concentrated sulfuric acid into a mixed solution of anhydrous ether and silica gel, performing rotary evaporation and drying, reacting in a water bath at 65-70 ℃, purifying a product through a silica gel column after the reaction is finished, and finally vacuumizing to obtain three acetylenic monosaccharide (mannose, glucose or galactose).

And 4, taking two reaction bottles (marked as A/B), adding the nitrine polyethersulfone, the acetylenic monosaccharide (mannose, glucose or galactose) and the bipyridine into the bottle A, and dissolving the mixture in DMF to obtain a mixed solution A to form a reactant system. Cuprous bromide is added into the bottle B to form a catalyst system. Freezing the liquid in bottle A with liquid nitrogen, pumping out air and water from the bottle, thawing bottle A in hot water, freezing with liquid nitrogen, pumping out air, repeating the steps for 5-6 times, and pumping out and charging nitrogen for bottle B. And after degassing and dewatering, introducing the liquid in the bottle A into the bottle B by using a long needle tube, and putting the bottle B into a water bath at 50-60 ℃ for reaction to obtain the polyether sulfone grafted with the functional sugar-containing polymer.

5mg of pure polyethersulfone and prepared chloromethylated polyethersulfone, azido polyethersulfone, and mannose-grafted polyethersulfone were dissolved in N-N dimethylformamide reagent, and GPC (FIG. 3) of each polymer was measured by gel chromatography, and their molecular weights gradually increased, indicating that the polymer was successfully prepared.

Reacting 1, 2-chloromethyl methyl ether with polyether sulfone to prepare chloromethylated polyether sulfone, reacting at 40 ℃ for 24 hours, and taking a nuclear magnetic sample to obtain the product¹The resonance characteristic of the H NMR spectrum (FIG. 4a) shows that the final product is at 4.5ppm, which clearly demonstrates the presence of chloromethyl bonds, and the other peaks are indicated in FIG. 4 a.

Reacting sodium azide with chloromethylated polyether sulfone to prepare polyether sulfone azide, reacting at 70 ℃ for 48 hours, and taking a nuclear magnetic sample to obtain¹The resonance profile of the H NMR spectrum (FIG. 4b) shows that the final product is at 2.5ppm, which clearly demonstrates the presence of the azido bond, and the other peaks are indicated in FIG. 4 b.

In addition, of chloromethylated and azido polyethersulfones¹The resonance characteristic of the H NMR spectrum (FIG. 4) clearly indicates the location of the bond sites.

Pure polyethersulfone, chloromethylated polyethersulfone, azidated polyethersulfone and mannose grafted polyethersulfone are obtained by taking 5mg for infrared measurement, the azidated polyethersulfone has a characteristic peak of an azido functional group about 2100, and the mannose grafted polyethersulfone has a characteristic peak of a hydroxyl group about 3500, which indicates that the polymer is successfully prepared.

Example 2

Adding polyether sulfone grafted with functional sugar-containing polymer and pure polyether sulfone into a small bottle, adding NMP, dissolving at 70 ℃, adding PVP (polyvinyl pyrrolidone) serving as a pore-making agent, and carrying out water bath reaction at 70-75 ℃. And (4) filtering the product after the reaction is finished by using a Buchner funnel, collecting filtrate, and vacuumizing to remove air bubbles in the liquid. And finally, uniformly coating the film on non-woven fabric, soaking the non-woven fabric in water by using deionized water until the film is formed, thus obtaining the polyether sulfone/functional sugar-containing polymer hybrid film material.

FIG. 6 is a scanning electron microscope image of pure polyethersulfone membrane, functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane, with sugar monomers on the functional mannose-containing polymer hybrid membrane, functional glucose-containing polymer hybrid membrane, and functional galactose-containing polymer hybrid membrane, illustrating the success of grafting.

The azido polyethersulfone, grafted mannose polyethersulfone, grafted glucose polyethersulfone, grafted galactose polyethersulfone were subjected to X-ray photoelectron spectroscopy (XPS) tests as shown in FIG. 8, and all broad spectra had the same peak distribution including O1S532eV, C1S at 285eV, N1S at 399eV, and S2 p at 168 eV. The chemical composition of the membrane surface is shown in the table (in FIG. 9), where the N content in the azide membrane is higher and decreases after grafting of the sugar monomer, indicating successful grafting of the sugar monomer. The C1S level spectrum can be divided into 3 peaks, C-C/C-H at 284.7eV, C-S at 286.1eV, and O-C-O at 286.4eV, as shown in FIG. 9a, FIG. 9b, FIG. 9C, and FIG. 9 d.

Example 3

The water contact angle of each film was measured. The film was dropped with clean water, and the water contact angle at 30 seconds was measured as shown in FIG. 10. The water contact angle of the hybridized film is smaller than that of the pure polyether sulfone film, which shows that the hydrophilicity of the hybridized polyether sulfone film is improved.

The pore size of each membrane was measured as shown in fig. 11. The pore diameters of the pure polyethersulfone membrane, the functional mannose-containing polymer hybrid membrane, the functional glucose-containing polymer hybrid membrane and the functional galactose-containing polymer hybrid membrane are distributed in the range of 20-150 nm, which indicates that the prepared membrane is between an ultrafiltration membrane and a microfiltration membrane.

The pure water flux of each film was measured, and the pure water flux was measured at 0.20MPa for 30min, pre-pressing, and at 0.05MPa, 0.10MPa, 0.15MPa, 0.20MPa, 0.25MPa, 0.30MPa, 0.35MPa, and 0.40MPa, respectively, and the results are shown in FIG. 11. The pure water flux of the hybridized membrane is greatly improved compared with that of a pure polyether sulfone membrane, which shows that the performance of the hybridized membrane is improved.

The retention of the bovine serum albumin solution in each membrane was measured, and the results are shown in FIG. 13. Prepressing under 0.20MPa, intercepting by using a bovine serum albumin solution under 0.10MPa, measuring flux every 10min, collecting the solution passing through the membrane until the flux is not changed, measuring the ultraviolet absorption quantity, and calculating the bovine serum albumin solution interception rate according to the peak height as shown in figure 13A, wherein the membrane interception rate after hybridization is obviously improved, which indicates that the performance of the membrane after hybridization is improved as shown in figure 13B.

The flux of the water-bovine serum albumin solution was measured for each membrane. Prepressing at 0.20MPa, measuring flux with pure water at 0.10MPa for 30min, measuring flux with bovine serum albumin solution for 90min, soaking in pure water for 1h, repeating the above operation twice, and measuring with pure water at 0.10MPa for 30min, as shown in FIG. 14A. The recovery rate of the membrane is obtained through calculation (fig. 14B), and the recovery rate of the membrane after hybridization is improved, which shows that the performance of the membrane after hybridization is improved.

Soaking the prepared functional mannose-containing polymer hybrid membrane, the functional glucose-containing polymer hybrid membrane and the functional galactose-containing polymer hybrid membrane in a 1g/L solution of sword bean protein for 30min, washing with clear water, freeze-drying, and measuring the water contact angle with clear water. When the clear water is dropped on the membrane, the water contact angle of the membrane after soaking the sword bean protein solution is obviously reduced when the water contact angle of the membrane is measured at 30 seconds (as shown in figure 15), which indicates that the hydrophilicity of the membrane after soaking the sword bean protein solution is improved, and indicates that the grafted membrane has specific adsorption to sword bean protein.

TABLE 1 chemical composition of polyethersulfone azide, polyethersulfone grafted with mannose, polyethersulfone grafted with glucose, polyethersulfone grafted with galactose

Claims

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.