CN103736408B - A kind of polysulfone porous membrane to temperature, acidity response and preparation method thereof and application - Google Patents

Abstract

The invention belongs to the technical field of membrane preparation and modification, in particular to a polysulfone porous membrane responsive to temperature and acidity, its preparation method and application. The invention utilizes the principle of "click chemistry" to chemically graft the environment-responsive polymer at the end of the alkynyl group to the surface of the polysulfone membrane through the reaction between the alkynyl group and the azide, thereby obtaining the surface-grafted environment-responsive polymer The chain polysulfone membrane achieves the purpose of modifying the environmental responsiveness of the polysulfone membrane. The membrane pores of the temperature- and acidity-responsive polysulfone porous membrane prepared by the method can change with the change of pH and temperature, and have reversibility, and at the same time, the physical and chemical properties of the membrane substrate basically do not change.

Description

A polysulfone porous membrane responsive to temperature and acidity and its preparation method and application

technical field

The invention belongs to the technical field of membrane preparation and modification, in particular to a polysulfone porous membrane responsive to temperature and acidity, its preparation method and application.

Background technique

Polysulfone is a slightly amber amorphous transparent or translucent polymer with excellent mechanical properties, high rigidity, wear resistance, high strength, high thermal stability, hydrolysis resistance, good dimensional stability, small molding shrinkage, and non-toxic , radiation resistance, flame resistance, extinguishing property, good chemical stability, except for concentrated nitric acid, concentrated sulfuric acid and halogenated hydrocarbons, it can withstand general acids, alkalis and salts, and can swell in ketones and esters. Porous membranes prepared based on polysulfone have the same advantages as polysulfone substrates, and are widely used in electronics, food and daily necessities, automobiles, aviation, medical and general industries.

Due to the hydrophobic nature of polysulfone membrane itself, its application in many fields is limited, and its contact angle is generally greater than 70°. The traditional modification of polysulfone membrane is limited to environmental responsive modification. Hydrophilic modification of polysulfone membrane can effectively reduce the adsorption of environmental responsive substances in the filtrate on the surface of polysulfone membrane, but with the use of the membrane, the membrane flux will decrease. This is because: (1) Difficulty Fine particles soluble in water are adsorbed on the surface of the membrane and block the membrane pore channels; (2) Repeated use under a certain pressure causes the deformation of the membrane pores and the damage of the membrane structure.

To solve the problem (1), the usual method is to backwash the membrane, that is, through reverse pressure, the particles that were originally embedded in the membrane pores can be separated out from the original path. However, compared with constant direction pressure, variable direction pressure is more cumbersome to operate. To meet the requirements of question (2), it is necessary not to add other functional polymers as much as possible to ensure that the physical and chemical properties of the polysulfone substrate do not change.

The main purpose of this patent is how to prepare a membrane that can remove the particulate adsorbate on the surface of the polysulfone membrane by applying constant pressure while maintaining the physical and chemical properties of the polysulfone substrate.

If the size of membrane pores can be increased controllably under changing external conditions, and can be restored, then problem (1) can be solved by applying constant pressure. When particles are trapped in the pores of the polysulfone membrane, by changing the external conditions, the size of the pores of the polysulfone membrane increases, and the particles can be washed through the pores of the polysulfone membrane by water pressure to be removed. Then change the external conditions to restore the polysulfone membrane pores to their original size and reuse them. And temperature and pH are the easiest to achieve and can change the means. To achieve this purpose, it is very meaningful to design and synthesize polysulfone membranes whose pores have temperature or pH response.

The commonly used blending modification method modifies polysulfone membrane, that is, the additive containing specific hydrophilic or hydrophobic units and polysulfone are blended in a certain proportion to form a membrane. The patent similar to the present invention is CN101721023A. The base membrane of this invention is polysulfone Vinylidene fluoride, by grafting stimuli-responsive polymer side chains to achieve the desired effect in question (1). However, this method will affect the physical and chemical properties of the membrane substrate, resulting in poor film formation, non-uniform membrane pores, and unstable membrane structure, which is not conducive to solving the problem (2). The patent CN1962040A adopts the composite method, that is, the temperature-sensitive polymer is covered on the surface of the base film to achieve the effect of problem (1), but the limitation of this method is that the film-forming performance of the temperature-sensitive polymer is extremely poor, and the substrate The combination of the membrane is only a physical combination, and the stability of the membrane prepared by this method needs to be improved.

In recent years, there have been many similar literature and patent reports on the preparation of temperature- or pH-responsive polysulfone membranes by surface initiation. Patents CN102875195A and CN103123958A, Journal of Membrane Science 352 (2010) 22-31 and Journal of Membrane Science 442 (2013) 206-215 all report the external environment responsive membrane prepared by this method. The advantage of this method is that the polymer modification is only carried out on the surface of the membrane and has no effect on the physical and chemical properties of the membrane substrate. can meet the requirements of question (2). However, the limitations of this method are also obvious. The surface-initiated grafted polymer requires special treatment of the substrate membrane to provide usable initiated surface functional groups. For example, plasma radiation, ultraviolet irradiation, acid-base treatment, etc. Some of these methods are expensive to operate and cannot be mass-produced, and some of them are relatively harsh, which will have adverse effects on the basement membrane itself. High, it needs to be strictly anaerobic, otherwise the polymerization efficiency and polymerization controllability will be greatly reduced. Therefore, for modified polysulfone membranes, more gentle and simple means are needed.

Click chemistry, as a method that has been widely concerned and used in the field of polymers in recent years, has the outstanding characteristics of simple and easy to operate reaction conditions, mild and not harsh conditions.

This patent combines the advantages of click chemistry and improves the preparation method to solve the problems mentioned above. Firstly, azide polysulfone and polysulfone substrate are blended. The azide functional group available for reaction is introduced into the polysulfone substrate. Since the physical and chemical properties of polysulfone azide are very similar to the polysulfone substrate, the blending has little effect on the performance of the polysulfone substrate, avoiding the problem described in (2) Defects. Secondly, the pre-prepared thermosensitive polymer containing alkyne groups at the end was gently grafted to the surface of the polysulfone/polysulfone azide blend membrane and the inner wall surface of the membrane pores through a click chemical reaction to solve the problem (1 ) desired target.

Contents of the invention

In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a polysulfone porous membrane responsive to temperature and acidity.

Another object of the present invention is to provide a method for preparing the above-mentioned polysulfone porous membrane responsive to temperature and acidity.

Another object of the present invention is to provide the application of the above-mentioned polysulfone porous membrane responsive to temperature and acidity.

The object of the present invention is achieved through the following technical solutions:

A method for preparing a polysulfone porous membrane responsive to temperature and acidity, comprising the steps of:

(1) Blending of polysulfone industrial products and polysulfone azide: Add 1-14 parts by mass of industrial-grade polysulfone raw materials, 1-14 parts by mass of polysulfone azide, and 1 part by mass of porogen In 40 parts by mass of organic solvent A, stir at room temperature until transparent and clear to obtain a casting solution of polysulfone industrial products and polysulfone azide blended membranes;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting solution of the polysulfone industrial product and polysulfone azide blend membrane prepared in step (1) onto the substrate of the wiper , adjust the height of the scraper, scrape to form a film, and immerse the substrate in the coagulation bath solvent at 25-50°C; after the film is separated from the substrate, take out the film and dry it to prepare a polysulfone/polysulfone azide porous film ;

(3) Modify the surface of the polysulfone/polysulfone azide porous membrane: immerse the polysulfone/polysulfone azide porous membrane prepared in step (2) into 400 parts by mass of solvent B; then add 10 to 50 parts by mass of environmentally responsive polymer C, 1 part by mass of copper sulfate, and 1 part by mass of sodium ascorbate, seal the reactor, then feed inert gas and bubble for 20 to 50 minutes to remove most of the Oxygen; place the reactor in a constant temperature water bath, and react for 12 to 72 hours at a temperature of 15 to 50°C and a pH of 6.0 to 9.0; after the reaction, take out the membrane and wash it with water for 1 to 5 times to remove the Dry the unreacted environment-responsive polymer C and other impurities; obtain a polysulfone porous membrane responsive to temperature and acidity;

The industrial-grade polysulfone raw material described in step (1) is polysulfone S3010 (BASF, Germany), and its structural formula is shown in formula 1:

The structural formula of polysulfone azide described in step (1) is shown in formula 2:

References for the synthesis of polysulfone azide: H.Toiserkani, G.Yilmaz, Y.Yagci, L.Torun, Macromol.Chem.Phys.211(2010);

The porogen described in step (1) is polyethylene glycol with a molecular weight of 2000Da;

The organic solvent A described in the step (1) is methylpyrrolidone, dimethylacetamide, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, dichloromethane, chloroform, carbon tetrachloride A sort of;

The scraper height of the scraper described in step (2) is 150um;

The coagulation bath solvent described in step (2) is one or more mixtures of water, ethanol, methanol, and isopropanol;

The polysulfone/polysulfone azide porous membrane described in step (2) has a pore diameter of 5-10um and a porosity of 63%;

The solvent B described in step (3) is one or more mixtures of water, ethanol, methanol, and isopropanol;

The environmentally responsive polymer C described in step (3) is an environmentally responsive polymer with an alkyne group at the end; -C≡CH), a copolymer of alkyne-terminated polyisopropylacrylamide and acrylic acid (P(NIPAAm-co-AA)-C≡CH), or a copolymer of alkyne-terminated polyisopropylacrylamide and methacrylic acid Any polymer in the substance (P(NIPAAm-co-MAA)-C≡CH);

The synthesis method of the alkynyl-terminated polyacrylic acid (PAA-C≡CH) comprises the following steps: take 1 mass part of propynyl bromoisobutyrate initiator, 150 mass parts of acrylic acid (AA), 100 mass parts Methanol, 1 mass part of CuCl and 1 mass part of 2,2'-bipyridine were subjected to atom transfer radical polymerization (ATRP) reaction at 50°C under the protection of nitrogen to obtain PAA-C with a degree of polymerization (DP) of 85 ≡CH;

The synthesis method of the alkynyl-terminated polymethacrylic acid (PMAA-C≡CH) comprises the following steps: taking 1 mass part of propynyl bromoisobutyrate initiator, 150 mass parts of methacrylic acid (MAA) , 100 parts by mass of methanol, 1 part by mass of CuCl and 1 part by mass of 2,2'-bipyridine, and carry out atom transfer radical polymerization (ATRP) reaction at 50°C under the protection of nitrogen, and the degree of polymerization (DP) is 85 PMAA-C≡CH;

The synthesis method of the alkynyl-terminated polyisopropylacrylamide and acrylic acid copolymer (P(NIPAAm-co-AA)-C≡CH) comprises the following steps: take 1 mass part of propyne bromoisobutyrate Ester initiator, 100 parts by mass of isopropylacrylamide (NIPAAm), 50 parts by mass of acrylic acid (AA), 100 parts by mass of methanol, 1 part by mass of CuCl, and 1 part by mass of pentamethyldivinyltriamine , Atom transfer radical polymerization (ATRP) was carried out at 40°C under the protection of nitrogen to obtain P(NIPAAm-co-AA)-C≡CH with a degree of polymerization (DP) of 108;

The synthesis method of the copolymer of alkynyl-terminated polyisopropylacrylamide and methacrylic acid (P(NIPAAm-co-MAA)-C≡CH) comprises the following steps: take 1 mass part of bromoisobutyric acid propargyl ester initiator, 100 parts by mass of isopropylacrylamide (NIPAAm), 50 parts by mass of methacrylic acid (MAA), 100 parts by mass of methanol, 1 part by mass of CuCl and 1 part by mass of pentamethyldi Vinyltriamine was subjected to atom transfer radical polymerization (ATRP) at 40°C under the protection of nitrogen to obtain P(NIPAAm-co-MAA)-C≡CH with a degree of polymerization (DP) of 109.

Among them, the reference for the synthesis of propynyl bromoisobutyrate: Ternary Graft Copolymers and Their Use in Nanocapsule Preparation. Macromolecules (2013) 46; 2646-2657;

The membrane pores of the polysulfone porous membrane prepared in the present invention responding to temperature and acidity can change with the change of pH and temperature, and have reversibility, and at the same time, the physical and chemical properties of the membrane substrate basically do not change, and can be widely used in membrane preparation and modification technology field.

Principle of the present invention:

Azide polysulfone and polysulfone are blended to form a membrane, so as to introduce azide functional groups on the surface of the polysulfone membrane and the inner surface of the membrane pores, and then use the principle of "click chemistry" to make the environment-responsive polymer at the end of the alkyne group, through The reaction chemistry between the alkyne group and the azide is grafted onto the surface of the polysulfone membrane, thereby obtaining a polysulfone membrane grafted with an environment-responsive polymer chain on the surface, so that the performance of the preparation base is basically similar to that of polysulfone, and the membrane pore size has a Environmentally responsive polysulfone membrane (shown in Figure 1).

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

(1) Azide polysulfone is easy to prepare, low in cost, and easy to industrialize;

(2) After azide polysulfone and polysulfone are blended, azide functional groups available for reaction are provided on the surface of the membrane, and at the same time, the physical and chemical properties of polysulfone are basically not affected. Moreover, the operation is simple, the cost is low, and the purpose is easy to achieve;

(3) The structure of the environment-responsive polymerization grafted onto the membrane surface is strictly controllable, and its ratio and degree of polymerization can be adjusted arbitrarily according to the pore size of the polysulfone basement membrane.

Description of drawings

Figure 1 is a schematic diagram of the principle of the polysulfone porous membrane in response to temperature and acidity.

Figure 2 shows the flux of the polysulfone porous membrane in response to temperature and acidity at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0.

Detailed ways

The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings. However, the embodiments of the present invention are not limited thereto.

The raw material used in the embodiment is as follows:

Among them, the reference for the synthesis of propynyl bromoisobutyrate: Ternary Graft Copolymers and Their Use in Nanocapsule Preparation. Macromolecules (2013) 46; 2646-2657;

References for the synthesis of polysulfone azide: H.Toiserkani, G.Yilmaz, Y.Yagci, L.Torun, Macromol.Chem.Phys.211(2010);

The parts involved in the following examples are all parts by mass.

Example 1

(1) Blending of polysulfone industrial products and polysulfone azide: Add 1 part of polysulfone S3010, 14 parts of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) to 40 parts of methylpyrrolidone , stirred at 25°C until transparent and clear to obtain the casting solution of polysulfone industrial products and polysulfone azide blend membrane;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting liquid of the polysulfone industrial product and polysulfone azide blend membrane prepared in step (1) onto the substrate of the film applicator , adjust the height of the scraper to 150um, squeegee to form a film, and immerse the substrate in water at 25°C; after the film is separated from the substrate, take out the film and dry it to prepare a polysulfone/polysulfone azide porous membrane. 5 ~ 10um, porosity 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 150 parts of methacrylic acid, 100 parts of methanol, 1 part of CuCl and 1 part of 2,2'-bipyridine, and conduct the Atom transfer radical polymerization (ATRP) reaction to obtain PMAA-C≡CH with a degree of polymerization (DP) of 85;

Submerge the polysulfone/polysulfone azide porous membrane prepared in step (2) into 400 parts of water; then add 10 parts of environmentally responsive polymer PMAA-C≡CH, 1 part of copper sulfate, and 1 part of sodium ascorbate. The reactor was sealed; then an inert gas was bubbled for 20 minutes to remove most of the oxygen in the reactor; the reactor was placed in a constant temperature water bath, and the temperature was 15°C and the pH was 7.0, and the reaction was for 12 hours; after the reaction, the membrane Take it out and wash it once with water to remove the unreacted environment-responsive polymer PMAA-C≡CH and other impurities on the porous membrane and then dry it; obtain a polysulfone porous membrane responsive to temperature and acidity;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 16.85×10 ^-3 MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in the figure 2.

Example 2

(1) Blending polysulfone industrial products with polysulfone azide: Add 3 parts of polysulfone S3010, 12 parts of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) to 40 parts of dimethyl ethylene glycol In amide, stir until transparent and clear at 25°C to obtain a casting solution for a blend film of polysulfone industrial products and polysulfone azide;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting liquid of the polysulfone industrial product and polysulfone azide blend membrane prepared in step (1) onto the substrate of the film applicator , adjust the height of the scraper to 150um, squeegee to form a film, and immerse the substrate in ethanol at 25°C; after the film is separated from the substrate, take out the film and dry it to prepare a polysulfone/polysulfone azide porous membrane. 5 ~ 10um, porosity 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 150 parts of acrylic acid (AA), 100 parts of methanol, 1 part of CuCl and 1 part of 2,2'-bipyridyl, under nitrogen protection at 50°C Atom transfer radical polymerization (ATRP) reaction was carried out to obtain PAA-C≡CH with a degree of polymerization (DP) of 85;

Submerge the polysulfone/polysulfone azide blend membrane prepared in step (2) into 400 parts of methanol; then add 15 parts of environmentally responsive polymer PAA-C≡CH, 1 part of copper sulfate, and 1 part of sodium ascorbate , the reactor is sealed; then feed inert gas bubbles for 25min to remove most of the oxygen in the reactor; place the reactor in a water bath, and react for 18h at a temperature of 25°C and a pH of 6.0; The membrane is taken out and washed with water for 3 times, and the unreacted environment-responsive polymer and other impurities on the porous membrane are removed, and then dried; a polysulfone porous membrane responsive to temperature and acidity is obtained;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 17.25×10 ^-3 MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in the figure 2.

Example 3

(1) Blending polysulfone industrial products with polysulfone azide: Add 5 parts of polysulfone S3010, 10 parts of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) to 40 parts of dimethylformaldehyde In amide, stir until transparent and clear at 25°C to obtain a casting solution for a blend film of polysulfone industrial products and polysulfone azide;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting liquid of the polysulfone industrial product and polysulfone azide blend membrane prepared in step (1) onto the substrate of the film applicator , adjust the height of the scraper to 150um, scrape to form a film, and immerse the substrate in methanol at 25°C; after the film is separated from the substrate, take the film out and dry it to prepare a polysulfone/polysulfone azide porous membrane. 5 ~ 10um, porosity 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 150 parts of methacrylic acid, 100 parts of methanol, 1 part of CuCl and 1 part of 2,2'-bipyridine, and conduct the Atom transfer radical polymerization (ATRP) reaction to obtain PMAA-C≡CH with a degree of polymerization (DP) of 85;

Submerge the polysulfone/polysulfone azide blend membrane prepared in step (2) into 400 parts of ethanol; then add 20 parts of environmentally responsive polymer PMAA-C≡CH, 1 part of copper sulfate, and 1 part of sodium ascorbate , seal the reactor; then pass inert gas bubbling for 30 minutes to remove most of the oxygen in the reactor; place the reactor in a constant temperature water bath, and react for 24 hours at a temperature of 35°C and a pH of 7.0; after the reaction Take out the membrane and wash it with water for 3 times, remove the unreacted environment-responsive polymer and other impurities on the porous membrane, and then dry it to obtain a polysulfone porous membrane responsive to temperature and acidity;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 17.54×10 ^-3 MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in the figure 2.

Example 4

(1) Blending polysulfone industrial products with polysulfone azide: Add 7 parts of polysulfone S3010, 8 parts of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) to 40 parts of dimethyl sulfide In sulfone, stir until transparent and clear at 25°C to obtain a casting solution for a blended membrane of polysulfone industrial products and polysulfone azide;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting solution of the polysulfone industrial product and polysulfone azide blend membrane prepared above onto the substrate of the film applicator, adjust the scraper Plate height to 150um, scrape coating to form a film, immerse the substrate in isopropanol at 25°C; after the membrane is separated from the substrate, take out the membrane and dry it to prepare a polysulfone/polysulfone azide porous membrane with a pore size of 5 ～10um, porosity 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 100 parts of isopropylacrylamide (NIPAAm), 50 parts of methacrylic acid (MAA), 100 parts of methanol, 1 part of CuCl and 1 part of Pentamethyldivinyltriamine was subjected to atom transfer radical polymerization (ATRP) reaction at 40°C under the protection of nitrogen to obtain P(NIPAAm-co-MAA)-C≡CH with a degree of polymerization (DP) of 109;

Submerge the polysulfone/polysulfone azide blend membrane prepared in step (2) into 400 parts of isopropanol; then add 30 parts of the environment-responsive polymer P(NIPAAm-co-MAA)-C≡CH, 1 part of copper sulfate, 1 part of sodium ascorbate, seal the reactor; then pass through an inert gas bubble for 35 minutes to remove most of the oxygen in the reactor; place the reactor in a constant temperature water bath at a temperature of 45 °C and a pH of Under 9.0, react for 30 hours; after the reaction, take out the membrane and wash it with water for 3 times, remove the unreacted environment-responsive polymer and other impurities on the porous membrane, and then dry it to obtain a polysulfone porous membrane responsive to temperature and acidity. membrane;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 18.21×10 ^-3 MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in the figure 2.

Example 5

(1) Blending of polysulfone industrial products and polysulfone azide: Add 9 parts of polysulfone S3010, 6 parts of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) into 40 parts of tetrahydrofuran at 25°C Stir until transparent and clear to obtain the casting solution of polysulfone industrial products and polysulfone azide blend membrane;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting solution of the polysulfone industrial product and polysulfone azide blend membrane prepared above onto the substrate of the film applicator, adjust the scraper The height of the board is 150um, scrape coating to form a film, and immerse the substrate in water at 25°C; after the membrane is separated from the substrate, take out the membrane and dry it to prepare a polysulfone/polysulfone azide porous membrane with a pore size of 5-10um. The porosity is 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 100 parts of isopropylacrylamide (NIPAAm), 50 parts of acrylic acid (AA), 100 parts by mass of methanol, 1 part of CuCl and 1 part of Penta Methyldivinyltriamine was subjected to atom transfer radical polymerization (ATRP) at 40°C under the protection of nitrogen to obtain P(NIPAAm-co-AA)-C≡CH with a degree of polymerization (DP) of 108;

Submerge the polysulfone/polysulfone azide blend membrane prepared in step (2) into 400 parts of water, then add 35 parts of environmentally responsive polymer P(NIPAAm-co-AA)-C≡CH, 1 part of sulfuric acid Copper, 1 part of sodium ascorbate, the reactor is sealed; then feed inert gas and bubble for 40min to remove most of the oxygen in the reactor; the reactor is placed in a constant temperature water bath, at a temperature of 50°C and a pH of 9, React for 36 hours; after the reaction, take out the membrane and wash it with water for 3 times, remove the unreacted environment-responsive polymer and other impurities on the porous membrane, and then dry it to obtain a polysulfone porous membrane responsive to temperature and acidity;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 18.14×10 ^-3 MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in the figure 2.

Example 6

(1) Blending of polysulfone industrial products and polysulfone azide: Add 11 parts of polysulfone S3010, 4 parts of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) to 40 parts of dichloromethane Stir at 25°C until transparent and clear to obtain the casting solution of polysulfone industrial products and polysulfone azide blend membrane;

(2) Preparation of porous membrane from polysulfone/polysulfone azide blend: Pour the casting solution of the polysulfone industrial product and polysulfone azide blend membrane prepared above onto the substrate of the film applicator, adjust the scraper Plate height to 150um, scrape coating to form a film, immerse the substrate in ethanol at 25°C; after the membrane is separated from the substrate, take out the membrane and dry it to prepare a polysulfone/polysulfone azide porous membrane with a pore size of 5-10um , the porosity is 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 150 parts of acrylic acid (AA), 100 parts of methanol, 1 part of CuCl and 1 part of 2,2'-bipyridyl, under nitrogen protection at 50°C Atom transfer radical polymerization (ATRP) reaction was carried out to obtain PAA-C≡CH with a degree of polymerization (DP) of 85;

Submerge the polysulfone/polysulfone azide blend membrane prepared in step (2) into 400 parts of methanol, then add 40 parts of environmentally responsive polymer PAA-C≡CH, 1 part of copper sulfate, and 1 part of sodium ascorbate , seal the reactor; then pass inert gas bubbling for 45 minutes to remove most of the oxygen in the reactor; place the reactor in a constant temperature water bath, and react for 54 hours at a temperature of 50°C and a pH of 8.0; after the reaction Take out the membrane and wash it with water for 3 times, remove the unreacted environment-responsive polymer and other impurities on the porous membrane, and then dry it to obtain a polysulfone porous membrane responsive to temperature and acidity;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 18.36×10 ^-3 MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in the figure 2.

Example 7

(1) Blending of polysulfone industrial products and polysulfone azide: add 14 parts of polysulfone S3010, 1 part of polysulfone azide, and 1 part of polyethylene glycol (Mw=2000Da) to 40 parts of chloroform Stir at 25°C until transparent and clear to obtain the casting solution of polysulfone industrial products and polysulfone azide blend membrane;

(2) Preparation of porous membranes from polysulfone/polysulfone azide blends: Pour the casting solution prepared above onto the substrate of the film applicator, adjust the height of the scraper to 150um, scrape to form a film, and place the substrate at 25°C Immerse in methanol; after the membrane is separated from the substrate, the membrane is taken out and dried to prepare a polysulfone/polysulfone azide porous membrane with a pore size of 5-10um and a porosity of 63%;

(3) Modification of the surface of polysulfone/polysulfone azide porous membrane:

Take 1 part of propynyl bromoisobutyrate initiator, 100 parts of isopropylacrylamide (NIPAAm), 50 parts of methacrylic acid (MAA), 100 parts of methanol, 1 part of CuCl and 1 part of Pentamethyldivinyltriamine was subjected to atom transfer radical polymerization (ATRP) reaction at 40°C under the protection of nitrogen to obtain P(NIPAAm-co-MAA)-C≡CH with a degree of polymerization (DP) of 109;

Submerge the polysulfone/polysulfone azide blend membrane prepared in the previous step into 400 parts of ethanol; then add 50 parts of environmentally responsive polymer P(NIPAAm-co-MAA)-C≡CH, 1 part of copper sulfate, 1 part of sodium ascorbate, seal the reactor; then bubble inert gas for 50 minutes to remove most of the oxygen in the reactor; place the reactor in a constant temperature water bath, and react for 72 hours at a temperature of 15°C and a pH of 7.0 After the reaction, the membrane is taken out and washed with water for 5 times, and the unreacted environment-responsive polymer and other impurities on the porous membrane are removed and then dried to obtain a polysulfone porous membrane responsive to temperature and acidity;

The tensile strength of the polysulfone porous membrane in response to temperature and acidity is 18.54×10-3MPa, and the fluxes at high temperature (60°C) and low temperature (5°C), pH=2.2 and pH=9.0 are shown in Figure 2 shown.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (9)

1., to a preparation method for the polysulfone porous membrane of temperature, acidity response, it is characterized in that comprising following steps:

(1) polysulfones industrial goods and Azide polysulfones blended: the technical grade polysulfones raw material of 1 ~ 14 mass parts, the Azide polysulfones of 1 ~ 14 mass parts, the pore-foaming agent of 1 mass parts are joined in the organic solvent A of 40 mass parts, stirring at room temperature, to transparent clarification, obtains the casting solution of polysulfones industrial goods and Azide polysulfones blend film;

(2) polysulfones/Azide polysulfone blends prepares perforated membrane: the polysulfones industrial goods prepare step (1) and the casting solution of Azide polysulfones blend film are poured onto on blade applicator substrate, adjust blade height, blade coating film forming, immerses substrate in coagulating bath solvent at 25 ~ 50 DEG C; After film is separated with substrate, film is taken out and dries, prepare polysulfones/Azide polysulfone porous membrane;

(3) to the modifying surface of polysulfones/Azide polysulfone porous membrane: polysulfones/Azide polysulfone porous membrane step (2) prepared is immersed in the solvent B of 400 mass parts; Add the environment-responsive polymer C of 10 ~ 50 mass parts, the copper sulphate of 1 mass parts, the sodium ascorbate of 1 mass parts again, reactor is sealed, then passes into bubbling inert gas 20 ~ 50min; Reactor is placed in water bath with thermostatic control, is 15 ~ 50 DEG C in temperature, and pH is 6.0 ~ 9.0 times, reaction 12 ~ 72h; After reaction terminates, film is taken out and wash 1 ~ 5 time with water, remove the unreacted environment-responsive polymer C on perforated membrane, and dry again after other impurity; Obtain the polysulfone porous membrane to temperature, acidity response;

The environment-responsive polymer of to be end the be alkynyl of the environment-responsive polymer C described in step (3).

2. the preparation method of a kind of polysulfone porous membrane to temperature, acidity response according to claim 1, is characterized in that:

Technical grade polysulfones raw material described in step (1) is polysulfones S3010, its structural formula as shown in Equation 1:

3. the preparation method of a kind of polysulfone porous membrane to temperature, acidity response according to claim 1, is characterized in that:

The structural formula of the Azide polysulfones described in step (1) is as shown in Equation 2:

4. the preparation method of a kind of polysulfone porous membrane to temperature, acidity response according to claim 1, is characterized in that:

The aperture of the polysulfones described in step (2)/Azide polysulfone porous membrane is 5 ~ 10um, and porosity is 63%.

5. the preparation method of a kind of polysulfone porous membrane to temperature, acidity response according to claim 1, is characterized in that:

Pore-foaming agent described in step (1) is polyethylene glycol, and molecular weight is 2000Da;

Organic solvent A described in step (1) is the one in methyl pyrrolidone, dimethylacetylamide, dimethyl formamide, dimethyl sulfoxide (DMSO), oxolane, carrene, chloroform, carbon tetrachloride;

Blade applicator blade height described in step (2) is 150um;

Coagulating bath solvent described in step (2) is one or more mixtures in water, ethanol, methyl alcohol, isopropyl alcohol;

Solvent B described in step (3) is one or more mixtures in water, ethanol, methyl alcohol, isopropyl alcohol.

6. the preparation method of a kind of polysulfone porous membrane to temperature, acidity response according to claim 1, is characterized in that:

Described end any one polymer that to be the environment-responsive polymer of alkynyl be in PAA-C ≡ CH, PMAA-C ≡ CH, (P (NIPAAm-co-AA)-C ≡ CH) or P (NIPAAm-co-MAA)-C ≡ CH.

7. the preparation method of a kind of polysulfone porous membrane to temperature, acidity response according to claim 6, is characterized in that:

The synthetic method of described PAA-C ≡ CH comprises following steps: get 2 of the bromo acid propynyl ester initator of 1 mass parts, the acrylic acid of 150 mass parts, the methyl alcohol of 100 mass parts, the CuCl of 1 mass parts and 1 mass parts, 2'-bipyridyl, 50 DEG C are carried out atom transition free radical polymerization reaction under nitrogen protection, obtain the PAA-C ≡ CH that the degree of polymerization is 85;

The synthetic method of described PMAA-C ≡ CH comprises following steps: get 2 of the bromo acid propynyl ester initator of 1 mass parts, the methacrylic acid of 150 mass parts, the methyl alcohol of 100 mass parts, the CuCl of 1 mass parts and 1 mass parts, 2'-bipyridyl, 50 DEG C are carried out atom transition free radical polymerization reaction under nitrogen protection, obtain the PMAA-C ≡ CH that the degree of polymerization is 85;

The synthetic method of described P (NIPAAm-co-AA)-C ≡ CH comprises following steps: the PMDETA getting the bromo acid propynyl ester initator of 1 mass parts, the N-isopropylacrylamide of 100 mass parts, the acrylic acid of 50 mass parts, the methyl alcohol of 100 mass parts, the CuCl of 1 mass parts and 1 mass parts, 40 DEG C are carried out atom transition free radical polymerization reaction under nitrogen protection, obtain P (the NIPAAm-co-AA)-C ≡ CH that the degree of polymerization is 108;

The synthetic method of described P (NIPAAm-co-MAA)-C ≡ CH comprises following steps: the PMDETA getting the bromo acid propynyl ester initator of 1 mass parts, the N-isopropylacrylamide of 100 mass parts, the methacrylic acid of 50 mass parts, the methyl alcohol of 100 mass parts, the CuCl of 1 mass parts and 1 mass parts; 40 DEG C are carried out atom transition free radical polymerization reaction reaction under nitrogen protection, obtain P (the NIPAAm-co-MAA)-C ≡ CH that the degree of polymerization is 109.

8. to a polysulfone porous membrane for temperature, acidity response, it is characterized in that: adopt method according to any one of claim 1 ~ 7 to prepare.

9. the application of polysulfone porous membrane in film preparation and technical field of modification to temperature, acidity response according to claim 8.