KR101446955B1 - Manufacturing method of hydrogen ion conduction film - Google Patents

Abstract

The present invention relates to a method for producing a hydrogen ion conductive film and a hydrogen ion conductive film produced by the method. The method for producing a hydrogen ion conductive film according to the present invention is characterized in that it is easy to control the graft rate and has a high degree of sulfonation and a high hydrogen ion conductivity In addition, there is no formation of homopolymers of monomers by radiation, which makes it possible to irradiate on a large scale.

Description

[0001] The present invention relates to a method of manufacturing a hydrogen ion conductive film,

The present invention relates to a method for producing a hydrogen ion conductive film, and more particularly, to a method for producing a hydrogen ion conductive film using a radiation precursor method and a hydrogen ion conductive film produced thereby.

There are gamma rays, X rays, electron beams, etc. in the kind of ionizing radiation having high energy level. Gamma ray emitted from Co ⁶⁰ is excellent in ability to permeate substance, and is widely used for sterilization of foods and medical products, In the case of electron beams accelerated, the penetration power is smaller than that of the gamma rays, but it is widely used for manufacturing tires and cables because it can generate high energy in a short time.

Radiation-based grafting has been studied for a long time, and since the grafting technique using radiation can be grafted evenly into the inside of the material, it can be usefully used to impart new functionality to commercialized films For example, Korean Patent Registration No. 10-1088404.

Such a graft method using radiation can combine two or more different materials appropriately to produce a functional hybrid material capable of manifesting the properties possessed by the respective materials. For example, it is possible to use tetrafluoroethylene-hexafluoropropylene (FEP), perfluoroalkyl vinyl ether (PFA), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF) (PE), polypropylene (PP), polyetheretherketone (PEEK), polysulfone (PEEK), and polyetheretherketone (PTFE), which are relatively inexpensive compared to fluoropolymer films and fluoropolymer films having high thermal stability and mechanical strength such as fluoroethylene Based polymer film such as polyvinylidene fluoride (PSU), polyether sulfone (PES), polyimide (PI), and polybenzylimidazole (PBI) and then, if necessary, And an ion conductive membrane having mechanical strength can be produced.

The most typical example of the ion conductive polymer film produced by using the radiation graft is a radiation grafting of a styrene monomer to a fluorine polymer film, sulfonation with chlorosulfonic acid, followed by the addition of a poly (styrene sulfonic acid ) Is a grafted ion conductive polymer film.

The ion conductive polymer membrane prepared as described above can produce a membrane in which sulfonic acid functional groups are evenly distributed to the inside of the membrane through the radiation grafting and sulfonation process, and when used as a fuel cell membrane, exhibits high ion conductivity and electric power density, The manufacturing cost of the film is increased and the ion conductive graft polymer chains are gradually broken due to the hydroxyl radicals generated in the fuel cell driving environment of the grafted polystyrene.

On the other hand, in the grafting method using radiation, the simultaneous irradiation method is advantageous in that gamma ray is mainly used and convenient and quick grafted polymer can be produced at a low temperature, while an excessive amount of a homopolymer is formed in the irradiation process, There is a disadvantage that it is difficult to apply in mass production.

Therefore, there is a need for research on a method for producing a hydrogen ion conductive film having high ion conductivity and stability while being capable of mass production.

Korean Patent Registration No. 10-1088404 (Nov. 24, 2011)

The present invention is intended to provide a method for producing a hydrogen ion-conducting film capable of mass production in a simple manner.

In addition, the present invention provides a hydrogen ion conductive membrane, an ion exchange membrane, and a fuel cell membrane, which are produced according to the present invention.

The present invention relates to a method for producing a hydrogen ion conductive film having high hydrogen ion conductivity and mechanical properties, and a method for producing a hydrogen ion conductive film,

a) preparing a polymer film by irradiating the polymer film with radiation;

b) preparing a solution of a vinyl chloride benzyl monomer or a vinyl chloride benzyl monomer;

c) adding the radiation-irradiated polymer membrane to the vinyl chloride benzyl monomer or vinyl chloride benzyl monomer solution and reacting them to prepare a polyvinyl chloride-grafted polymer membrane; And

and d) subjecting the polyvinyl chloride-grafted polymer membrane to a sulfonation reaction to produce a polyvinylbenzyl sulfonic acid-grafted polymer membrane.

The radiation according to an embodiment of the present invention may be an electron beam, an ion beam or a gamma ray, and the irradiation dose of the radiation may be 1 to 300 kGy.

The polymer film according to an embodiment of the present invention is a polymer film obtained by copolymerizing tetrafluoroethylene-hexafluoropropylene (FEP), perfluoroalkyl vinyl ether (PFA), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), polyetheretherketone (PEEK), polysulfone (PSU), polyethersulfone (PES) ) Or polybenzimidazole (PBI).

In the vinylbenzyl chloride monomer solution according to an embodiment of the present invention, the vinylbenzyl chloride monomer may be contained in an amount of 20 to 90% by volume, preferably 30 to 70% by volume, based on the solvent, and the vinylbenzyl chloride monomer In addition to the vinylbenzyl chloride monomer, the solution may further contain 0.01 to 0.5% by volume of acrylamide relative to the vinylbenzyl chloride monomer solution.

The solvent according to an embodiment of the present invention may be any one or more selected from methanol, carbon tetrachloride, chloroform, tetrahydrofuran), dichloromethane, 1,2-dichloroethane, toluene, 1,4-dioxane, hexane, heptane and isopropanol .

The reaction of step c) according to an embodiment of the present invention may be performed at 50 to 70 ° C for 1 to 48 hours.

The method for producing a proton conductive membrane according to an embodiment of the present invention may further include a step of drying the polyvinyl chloride-grafted polymer membrane after step c).

The sulfonation reaction of step d) according to an embodiment of the present invention may be carried out,

1) reacting the polyvinyl chloride-grafted polymer membrane of step c) with a thiourea solution to introduce a thiouronium salt;

2) adding the thiouronium salt-introduced polymer membrane to a basic solution to hydrolyze the polymer membrane to prepare a polymer membrane including a thiol group; And

3) oxidizing the polymer membrane containing the thiol group.

The present invention also provides a hydrogen-ion conducting membrane produced according to the present invention and an ion exchange membrane or fuel cell membrane using the same.

The method for producing a hydrogen ion conductive film of the present invention can control the grafting rate of polyvinyl chloride benzylide in comparison with the conventional simultaneous irradiation method by preparing a hydrogen ion conductive film by a method of preliminary irradiation, and has a high degree of sulfonation even at the same graft rate The hydrogen ion conductivity is remarkably high.

In addition, the method of producing a hydrogen-ion conducting film according to the present invention can produce masses more easily than conventional simultaneous irradiation methods, and the formation of a homopolymer by radiation is not directly irradiated to the vinyl chloride benzyl monomer solution The consumption of raw materials is reduced and the cost is reduced.

In addition, the hydrogen-ion conductive membrane manufactured according to the method of manufacturing a hydrogen-ion conductive membrane according to the present invention has a high hydrogen ion conductivity and grafted polyvinyl chloride is stable, and the ion-exchange membrane or the fuel cell including the hydrogen- The membrane has high efficiency.

1 is a schematic view showing a method for producing a proton conductive film according to an embodiment of the present invention,
2 is a graph showing the results of analysis of the graft rate of vinylbenzyl chloride with respect to various solvents,
3 is a graph showing the tensile strength and the tensile strength of the polyvinyl chloride-grafted polymer membrane prepared according to an embodiment of the present invention.

The present invention provides a method for producing a hydrogen ion conductive film which is excellent in ionic conductivity and mechanical properties, and can be mass-produced, and a method for producing a hydrogen ion conductive film of the present invention

a) preparing a polymer film by irradiating the polymer film with radiation;

b) preparing a solution of a vinyl chloride benzyl monomer or a vinyl chloride benzyl monomer;

c) adding the radiation-irradiated polymer membrane to the vinyl chloride benzyl monomer or vinyl chloride benzyl monomer solution and reacting them to prepare a polyvinyl chloride-grafted polymer membrane; And

and d) subjecting the polyvinyl chloride-grafted polymer membrane to a sulfonation reaction to produce a polyvinylbenzyl sulfonic acid-grafted polymer membrane.

The method for producing a hydrogen-ion conductive film of the present invention is a method for producing a hydrogen-ion conductive film, which comprises irradiating a polymer film with a radiation to irradiate a polymer film with a radiation, and reacting the prepared polymer film with a vinyl chloride- The ion conductive film can be mass-produced and the vinylbenzyl chloride monomer is not irradiated with radiation, so that the homopolymer of the monomer is less formed and the cost is also reduced.

In addition, it is easy to control the graft ratio in the production of a polyvinyl chloride-grafted polymer membrane. In the simultaneous irradiation method, since excessive monomers and solvents are consumed and the penetration depth of electron beams is limited, it is difficult to irradiate the electron beams. The electron beam is more preferable in view of all the irradiation of the radiation, the mass production, the operation of the reaction is not difficult, and the direct irradiation of the polymer film is possible.

Further, in the method for producing a proton conductive film of the present invention, by using a vinyl chloride benzyl monomer, that is, the chlorinated vinyl benzyl is not a structure in which the chlorine group is directly connected to the benzene ring as compared with the styrene chloride, And thus the polymer is grafted with the irradiated polymer membrane, so that when the polyvinyl chloride-grafted polymer membrane is sulphonated, it is not decomposed at the? -Position of the polymer main chain.

Hereinafter, a method of manufacturing the hydrogen ion conductive film according to the present invention will be described in more detail.

First, step a) according to the present invention is a step of irradiating a polymer film with radiation.

The radiation in step a) may be an electron beam, an ion beam, or a gamma ray, and more preferably, an electron beam capable of irradiating the radiation within a short period of time.

The total irradiation dose of the radiation according to an embodiment of the present invention may be 1 to 300 kGy and the total irradiation dose is 10 to 200 in order to increase the graft rate of the vinylbenzyl chloride to the polymer film without decomposing the polymer film desirable.

The irradiation with the electron beam is preferably performed under an inert gas atmosphere in the irradiation of the radiation according to an embodiment of the present invention in order to prevent the polymer film and the vinyl chloride monomer from being irradiated with electron beams to prevent grafting.

The inert gas may be nitrogen, helium or the like, and more preferably nitrogen.

The polymer film of step a) may be at least one selected from the group consisting of tetrafluoroethylene-hexafluoropropylene (FEP), perfluoroalkyl vinyl ether (PFA), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride ) And polytetrafluoroethylene (PTFE), polyethylene (PE), polypropylene (PP), polyetheretherketone (PEEK), polysulfone (PSU), polyether sulfone (PES), polyimide Benzylimidazole (PBI).

Next, in step b), the vinylbenzyl chloride monomer or the vinylbenzyl chloride monomer is dissolved in a solvent to prepare a solution of a salt and a vinylbenzyl monomer. The solvent is selected from the group consisting of methanol, carbon tetrachloride, chloroform, Dichloromethane, 1,2-dichloroethane, toluene, 1,4-dioxane, hexane, 1,2-dichloroethane, Heptane and isopropanol may be used, and it is more preferable to use heptane as a solvent in order to exhibit mechanical properties and a high grafting ratio.

The monomer of the vinyl chloride monomer solution of the present invention may be contained in an amount of 20 to 90% by volume based on the solvent, and preferably 30 to 70% by volume of the vinyl chloride monomer is contained in order to increase the reaction efficiency and obtain a high graft rate .

The vinyl chloride benzyl monomer solution of the present invention may further contain 0.01 to 0.5% by volume of acrylamide relative to 100% by volume of the vinylbenzyl chloride monomer solution in addition to vinyl chloride benzyl monomer, and may further contain hydrogen ion conduction The effect of increasing the wettability of the film can be obtained.

Next, the irradiated polymer membrane prepared above is added to the vinyl chloride benzyl monomer or vinyl chloride benzyl monomer solution and reacted to prepare a polyvinyl chloride-grafted polymer membrane.

The polyvinyl chloride-grafted polymer membrane of the present invention can be prepared by reacting the irradiated polymer membrane with a vinyl chloride benzyl monomer or by reacting with a vinyl chloride benzyl monomer solution, and preferably reacting with a vinyl chloride benzyl monomer solution .

The reaction of step c) according to an embodiment of the present invention can be performed at 50 to 70 ° C for 1 to 48 hours. When the temperature is less than 50 ° C, the reaction time of the graft takes a long time and the graft rate is low If it exceeds 70 ° C, there is a problem that the graft rate is lowered due to polymer radical chain transfer.

The method for producing a proton conductive membrane according to an embodiment of the present invention may further include drying a polyvinyl chloride-grafted polymer membrane after step c) in order to obtain a high graft rate and a mechanical strength, Can be carried out at 30 to 80 ° C for 1 to 24 hours.

In the next step d), the polyvinyl chloride-grafted polymer membrane prepared in the step c) is subjected to a sulfonation reaction to produce a hydrogen-ion conductive membrane.

The sulfonation reaction of step d) according to an embodiment of the present invention may be carried out,

1) reacting the polyvinyl chloride-grafted polymer membrane of step c) with a thiourea solution to introduce a thiouronium salt;

2) adding the thiouronium salt-introduced polymer membrane to a basic solution to hydrolyze the polymer membrane to prepare a polymer membrane including a thiol group; And

3) oxidizing the polymer membrane containing the thiol group.

Hereinafter, the sulfonation reaction according to the present invention will be described step by step.

First, in step 1, the polyvinyl chloride-grafted polymer membrane in step c) is added to a thiourea solution and reacted to introduce a thiouronium salt.

The thiourea solution is preferably prepared by adding thiourea to an ethanol solution. The membrane prepared by the above method is washed with ethanol and dried in a vacuum oven.

Next, step 2 according to the present invention is a step of adding the thiouronium salt-introduced polymer membrane prepared in step 1 to a basic solution to hydrolyze the polymer membrane. The basic solution is preferably a sodium hydroxide solution or the like. The membrane prepared by the above method is washed with dilute hydrochloric acid and distilled water to neutralize the pH of the washing solution, and dried in a vacuum oven.

Next, step 3 according to the present invention is a step of oxidizing the polymer membrane containing a thiol group by the hydrolysis of step 2 above. The polyvinylbenzylthiol-grafted polymer membrane of step 2 is added to a mixed solution of hydrogen peroxide / acetic acid and reacted. The membrane prepared by the above method is washed with distilled water and dried in a vacuum oven.

The grafting rate can be controlled through the reaction time by irradiating the polymer film with the irradiation of the polymer film by the above-mentioned production method, heating the polymer film by immersing it in a mixed solution containing vinyl chloride benzyl, It is possible to provide a hydrogen-ion conductive film in which benzylsulfonic acid is grafted.

The present invention also provides a hydrogen-ion conducting membrane produced according to the present invention.

The hydrogen ion conductive membrane has high sulfonation degree and hydrogen ion conductivity at the same graft rate as the hydrogen ion conductive membrane using the radiation simultaneous irradiation method, and the formation of the homopolymer of the monomer by radiation is small. The hydrogen ion exchange membrane manufactured by the above production method can be applied to a variety of functional membranes such as an ion exchange membrane, a separator for a battery, a sorbent for a toxic substance, etc., as well as a fuel cell membrane. Can be usefully used.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are intended to illustrate the present invention, but the present invention is not limited by the following Examples.

[Example 1] Production of polyvinylbenzylgrafted ETFE film 1

a) Step: irradiating the polymer film with radiation

The ETFE film was cut into 5 cm x 10 cm size, placed in a glass container, covered with a rubber mask, and then nitrogen was blown through the needle for 15 minutes. The ETFE film was irradiated with an electron beam accelerator at a dose of 100 kGy.

b) a step of dissolving the vinyl chloride monomer in a solvent to prepare a vinyl chloride monomer solution

The vinylbenzyl chloride (VBC) to be grafted was added in toluene solvent at a volume ratio of 50:50 by volume in a glass vessel to prepare a mixed solution. The mixed solution was blocked with a rubber stopper and nitrogen was injected through the needle for 15 minutes to remove dissolved oxygen do.

c) Step: The step of producing a polyvinyl chloride-grafted ETFE film (ETFE-g-PVBC)

After the ETFE film contained in the glass filled with nitrogen was irradiated with electron beam, the oxygen free VBC monomer solution was transferred by using a needle under a nitrogen atmosphere, and then grafted in a 60 ° C thermostat for 24 hours. After completion of the graft reaction, the grafted film was washed with dichloromethane (CH ₂ Cl ₂ ) and dried in a vacuum oven at 60 ° C for 12 hours to remove the homopolymer formed during the reaction and the excess monomer not participating in the reaction Respectively.

[Example 2] Production of polyvinylbenzylgrafted ETFE film 2

A polyvinylbenzyl grafted ETFE membrane was prepared in the same manner as in Example 1 except that the solvent was heptane in the step b) of Example 1 according to the present invention.

[Example 3] Production of polyvinyl benzyl grafted ETFE film 3

A polyvinyl benzyl grafted ETFE membrane was prepared in the same manner as in Example 1 except that the solvent was isopropanol in the step b) of Example 1 according to the present invention.

[Example 4] Production of polyvinylbenzylgrafted ETFE film [

The procedure of Example 2 was repeated except that the graft reaction time was changed to 5 hours and the graft rate was about 60% in the step c) of Example 2 according to the present invention. Thus, polyvinylbenzylgraft ETFE Membranes were prepared.

[Example 5] Production of polyvinyl benzyl grafted ETFE film [

The procedure of Example 3 was repeated except that the graft reaction time was changed to 3 hours and the graft rate was about 60% in the step c) of Example 3 according to the present invention. Thus, polyvinylbenzyl-grafted ETFE Membranes were prepared.

[Example 6] Production of polyvinylbenzylsulfonic acid grafted ETFE film 1

a) Step: irradiating the polymer film with radiation

The ETFE film was cut into 5 cm x 10 cm size, placed in a glass container, covered with a rubber mask, and then nitrogen was blown through the needle for 15 minutes. The ETFE film was irradiated with an electron beam accelerator at a dose of 100 kGy.

b) a step of dissolving the vinyl chloride monomer in a solvent to prepare a vinyl chloride monomer solution

The vinylbenzyl chloride (VBC) to be grafted was added in a volume ratio of 50:50 by volume of a hapten solvent in a glass container to prepare a mixed solution. The mixed solution was blocked with a rubber stopper and nitrogen was injected through the needle for 15 minutes to remove dissolved oxygen do.

c) Step: The monomer solution of step b) is irradiated with electron beams ETFE  The film was added and heat was applied Polyvinyl Chloride Grafted ETFE  The step of producing the membrane ETFE -g-PVBC)

After the ETFE film contained in the glass filled with nitrogen was irradiated with electron beam, the deoxygenated VBC monomer solution was transferred using a needle under a nitrogen atmosphere, and the reaction was carried out in a 60 ° C thermostat for 8 hours. After completion of the graft reaction, the grafted film was washed with dichloromethane (CH ₂ Cl ₂ ) and dried in a vacuum oven at 60 ° C for 12 hours to remove the homopolymer formed during the reaction and the excess monomer not participating in the reaction Respectively.

d) Step: Polyvinyl Chloride Grafted ETFE  Stop Sulfonation  Reacted Polyvinylbenzylsulfonic acid Grafted ETFE  Steps to make the membrane

Step 1. Preparation step of ETFE film (PVBTS) grafted with polyvinylbenzylthiouronium salt (ETFE-g-PVBTS)

The ETFE membrane obtained by grafting polyvinyl chloride (PVBC) was immersed in 20 ml of an ethanol solution containing 200 mg of thiourea, and the reaction was carried out at 40 ° C for 6 hours in order to convert the grafted polyvinyl chloride to a thiouronium salt . The thiouronium salt grafted membrane was washed several times with ethanol and dried in a vacuum oven at 60 < 0 > C.

Step 2. Preparation of polyvinylbenzylthiol (PVBSH) -grafted ETFE membrane (ETFE-g-PVBSH)

The ETFE membrane in which the polyvinylbenzylthiouronium salt (ETFE-g-PVBTS) was grafted was immersed in 50 ml of an aqueous solution containing 4 g of sodium hydroxide for 8 hours at room temperature. The membrane thus prepared was washed with dilute hydrochloric acid and distilled water until the pH of the washing solution became neutral, and dried in a 60 ° C vacuum oven.

Step 3. Preparation of polyvinylbenzylsulfonic acid (PVBSA) -grafted ETFE membrane (ETFE-g-PVBSA)

The ETFE membrane grafted with polyvinylbenzylthiol (ETFE-g-PVBSH) was immersed in a solution containing hydrogen peroxide / acetic acid in a volume ratio of 40:60, and reacted at room temperature for 8 hours. The prepared membrane was washed several times with distilled water and dried in a vacuum oven at 60 캜.

The ETFE film (ETFE-g-PVBSA) obtained by grafting the polyvinylbenzylsulfonic acid according to the present invention was prepared from the ETFE-g-PVBC obtained by polyvinyl chloride-grafting through the above-described sulfonation process .

[Example 7] Production of polyvinylbenzylsulfonic acid grafted ETFE film 2

Example 6 was repeated in the same manner as in Example 6 except that the vinylbenzyl chloride monomer solution having a volume ratio of 50: 50 by volume of vinylbenzyl chloride monomer and solvent heptane further contained 0.1% by volume of acrylamide, To prepare an ETFE film in which benzylsulfonic acid was grafted.

[Comparative Example 1] Production of polyvinylbenzylsulfonic acid grafted ETFE film

a) a step of dissolving a vinylbenzyl chloride monomer in a solvent to prepare a vinylbenzyl chloride monomer solution

Vinylbenzyl chloride (VBC) and a chloroform solvent were added at a volume ratio of 40:60 to prepare a mixed solution.

b) Step: The polymer membrane is added to the monomer solution of step a) Polyvinyl Chloride Grafted ETFE  The step of producing the membrane ETFE -g-PVBC)

ETFE was added to the acetone solution, washed, and then dried. The mixed solution containing the ETFE film was washed with nitrogen for 10 minutes and irradiated with gamma rays at a dose rate of 2 kGy / h such that the total irradiation dose was 20 kGy. The irradiated membrane was washed with dichloromethane (CH ₂ Cl ₂ ) and dried in a vacuum oven at 60 ° C for 12 hours.

c) Step: Polyvinyl Chloride Grafted ETFE  Stop Sulfonation  Reacted Polyvinylbenzylsulfonic acid Grafted ETFE  Steps to make the membrane

Step 1. Preparation step of ETFE film (PVBTS) grafted with polyvinylbenzylthiouronium salt (ETFE-g-PVBTS)

The ETFE membrane in which polyvinyl chloride (PBVC) was grafted was immersed in 20 ml of an ethanol solution containing 200 mg of thiourea, and the reaction was carried out at 40 ° C for 6 hours to convert the grafted polyvinyl chloride to a thiouronium salt . The thiouronium salt grafted membrane was washed several times with ethanol and dried in a vacuum oven at 60 < 0 > C.

Step 2. Preparation of polyvinylbenzylthiol (PVBSH) -grafted ETFE membrane (ETFE-g-PVBSH)

The ETFE membrane in which the polyvinylbenzylthiouronium salt (ETFE-g-PVBTS) was grafted was immersed in 50 ml of an aqueous solution containing 4 g of sodium hydroxide for 8 hours at room temperature. The membrane thus prepared was washed with dilute hydrochloric acid and distilled water until the pH of the washing solution became neutral, and dried in a 60 ° C vacuum oven.

Step 3. Preparation of polyvinylbenzylsulfonic acid (PVBSA) -grafted ETFE membrane (ETFE-g-PVBSA)

The ETFE membrane grafted with polyvinylbenzylthiol (ETFE-g-PVBSH) was immersed in a solution containing hydrogen peroxide / acetic acid in a volume ratio of 40:60, and reacted at room temperature for 8 hours. The prepared membrane was washed several times with distilled water and dried in a vacuum oven at 60 캜.

The ETFE film (ETFE-g-PVBSA) obtained by grafting the polyvinylbenzylsulfonic acid according to the present invention was prepared from the ETFE-g-PVBC obtained by polyvinyl chloride-grafting through the above-described sulfonation process .

<Experimental Example 1> Analysis of graft rate for various solvents

The grafting rates of the polyvinyl chloride-grafted ETFE membranes prepared in Examples 1 to 3 were calculated by the following Equation 1 and shown in Fig.

[Equation 1]

DOG (%) = [(W _g - W _o ) / W _o ] x 100

(W _o : initial sample weight, W _g : sample weight after grafting)

It can be observed that the increase of the graft rate according to the solvent gradually increases in the order of toluene (Example 1) <heptane (Example 2) <isopropanol (Example 3). Especially in isopropanol (Example 3), which is predicted to be due to the longer life of radicals in the isopropanol solvent than in the other solvents, relative to the other solvents.

Experimental Example 2 Mechanical Property Analysis of ETFE-g-PBVC Membrane Prepared with Various Solvents

The following experiment was conducted to analyze the mechanical properties of the ETFE-g-PVBC film having a graft rate of about 60% prepared in Examples 1 to 3.

The ETFE-g-PVBC membrane, which was prepared from each solvent and had a graft rate of about 60%, was prepared in a ratio (5.3 mm × 31 mm) according to ASTM standard and was measured using INSTRON series IX (Universal Testing System Model 4400) Mechanical properties were measured.

Fig. 3 shows the results of strain rate of the film against tensile stress of ETFE-g-PVBC film prepared from toluene (Example 1), heptane (Example 4) and isopropanol (Example 5) and having a graft rate of about 60%. It can be observed that the mechanical properties of the produced ETFE-g-PVBC film are greatly influenced by the type of solvent used. In particular, it can be seen that the membrane prepared using isopropanol as a solvent (Example 5), which takes a short time to reach a grafting rate of 60%, is destructed immediately after having a yield stress at 50.1 MPa. It can be seen that when the heptane is used (Example 4), the chain breakage occurs at about 210% after the orientation of the chains occurs at a yield stress point of 41.4 MPa and a tensile rate of about 150%. The membrane prepared in toluene (Example 1) was found to have a slightly higher yield stress of 45.2 MPa but a lower tensile ratio of 175% than the membrane prepared in Example 4 (Example 4). From these results, it can be seen that when a VBC grafted film is prepared by using isopropanol, a high graft rate can be obtained, but the mechanical strength is remarkably decreased, so that it is not suitable for producing a material requiring high mechanical properties such as a fuel cell membrane. As a result, it was confirmed that the membrane prepared in heptane (Example 4) had the best mechanical strength.

Experimental Example 3 Measurement of ion exchange capacity, sulfonation degree and hydrogen ion conductivity of polyvinylbenzyl sulfonic acid grafted ETFE membrane (ETFE-g-PVBSA)

In order to measure the ion exchange capacity of Example 6 and Comparative Example 1, the following experiment was conducted.

The ETFE membrane obtained by grafting the polyvinylbenzylsulfonic acid prepared in Example 6 and Comparative Example 1 was immersed in an excess amount of an aqueous solution of sodium chloride (NaCl, 3M) for 24 hours, and the hydrogen chloride produced in the aqueous solution was titrated with sodium hydroxide, The ion exchange capacity (IEC _EXP ) was calculated by equations (2), (3) and (4).

&Quot; (2) &quot;

IEC _EXP (meq / g) = N (meq / ml) x Y (ml) / weight of sample (g)

(N: molar concentration of an appropriate NaOH (meq / ml), Y: amount (ml) of the titrated NaOH)

The ion exchange capacity theoretical value (IEC _Theory ) was calculated by the following equation (3).

&Quot; (3) &quot;

IEC _Theory (meq / g) = 1000 DOG / (100 M _VBC (eq) + DOG x M _PVBC (eq))

(DOG: graft rate, M _VBC : molecular weight of vinyl chloride benzyl monomer, M _PVBC : molecular weight of polyvinyl benzyl sulfonic acid)

Based on the above two values, the degree of sulfonation (DOS) was calculated using the following equation (3).

&Quot; (4) &quot;

DOS (%) = (IEC _EXP / IEC _Theory ) × 100

Experiments were carried out as follows to measure the hydrogen ion conductivity of Example 6 and Comparative Example 1.

Specifically, the electrolyte resistance of the ETFE-g-PVBSA membrane prepared in Example 1 and Comparative Example 1 was measured using an AC impedance analyzer (SI 1260, Solatron Company).

At this time, the impedance measurement was performed in a frequency range of 0.01 to 100 kHz and at room temperature, and the hydrogen ion conductivity was calculated using the following equation (5).

&Quot; (5) &quot;

Hydrogen ion conductivity (?, S / cm) = L / (A.times.R)

Where L is the distance between two electrodes, A is the width in the thickness direction of the polymer electrolyte membrane, and R is the electrical resistance value.

The values calculated in the above Equations 2, 3, 4, and 5 are summarized in Table 1 below.

Sample DOG (%) IEC (meq / g) DOS (%) proton conductivity (S / cm) Comparative Example 1 50 1.35 65 0.06 Example 6 49 1.65 80 0.12 Example 7 51 1.70 82 0.14

The graft ratio of Example 6, Example 7, and Comparative Example 1 is almost equal to 50%, but the measured IEC value is higher than that of Comparative Example 1 in Examples 6 and 7. Sulphonation also showed the same phenomenon. These results indicate that sulfonation is more actively carried out than Comparative Example 1, which was prepared by the simultaneous irradiation of Examples 6 and 7 which were prepared in the sulfonation process. It was also confirmed that the hydrogen ion conductivity value was also higher by this effect.

Claims (11)

(a) at least one of tetrafluoroethylene-hexafluoropropylene (FEP), perfluoroalkyl vinyl ether (PFA), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF) and polytetrafluoro (PEI), polyethersulfone (PSU), polyethersulfone (PES), polyimide (PI) or polybenzylimidazole (PBI) Irradiating the polymer film including the polymeric film to irradiate the polymer film to irradiate the polymer film;
b) preparing a solution of a vinyl chloride benzyl monomer or a vinyl chloride benzyl monomer, wherein the vinyl chloride benzyl monomer solution contains acrylamide in an amount of 0.01 to 0.5% by volume;
c) adding the radiation-irradiated polymer membrane to the vinyl chloride benzyl monomer or vinyl chloride benzyl monomer solution and reacting them to prepare a polyvinyl chloride-grafted polymer membrane; And
and d) preparing a polyvinyl benzyl sulfonic acid-grafted polymer membrane by sulfonating the polyvinyl chloride-grafted polymer membrane to produce a hydrogen ion-conducting membrane. The method according to claim 1,
Wherein the radiation is electron beam, ion beam or gamma ray. 3. The method of claim 2,
Wherein the radiation is a method of producing a hydrogen ion conductive film having a total irradiation dose of 1 to 300 kGy delete The method according to claim 1,
Wherein the vinyl chloride monomer solution contains 20 to 90% by volume of a vinyl chloride monomer as a solvent. delete 6. The method of claim 5,
Wherein the solvent is at least one selected from the group consisting of methanol, carbon tetrachloride, chloroform and tetrahydrofuran), dichloromethane, 1,2-dichloroethane, toluene, 1,4-dioxane, hexane, heptane and isopropanol . The method according to claim 1,
Wherein the reaction of step c) is carried out at 50 to 70 캜 for 1 to 48 hours. The method according to claim 1,
And drying the polyvinyl chloride-grafted polymer membrane after the step c). The method according to claim 1,
The sulfonation reaction in step d)
1) reacting the polyvinyl chloride-grafted polymer membrane of step c) with a thiourea solution to introduce a thiouronium salt;
2) adding the thiouronium salt-introduced polymer membrane to a basic solution to hydrolyze the polymer membrane to prepare a polymer membrane including a thiol group; And
3) oxidizing the polymer membrane containing the thiol group. A hydrogen-ion-conducting membrane produced according to any one of claims 1 to 3, 5 and 7 to 10.

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