KR101817301B1 - Cross-linked cationic conductive polymer and uses thereof - Google Patents

Abstract

The present invention relates to a process for preparing a halogenated polymer by halogenating a polystyrene-based polymer and a polyphenylene oxide-based polymer, respectively; A step of preparing a crosslinked polymer by mixing a halogenated polystyrene type polymer and a halogenated polyphenylene oxide type polymer and then adding a crosslinking agent having an electron withdrawing group to form a crosslinking type polymer by halogenation between the halogenated polymer at the halogen functional site of the halogenated polymer ; And a cation-exchangeable functional group-imparting step of functionalizing the crosslinking type polymer with a cation-exchangeable functional group, a cation exchange membrane for a reverse electrodialysis (RED) device manufactured through the method And a reverse electrodialyser including the same. The crosslinkable cation exchange membrane according to the present invention has excellent mechanical properties and chemical resistance and can inhibit the rapid crosslinking reaction during the production of the membrane to prevent the change of the membrane shape, By using phenol oxide, it has superiority in price competitiveness compared to conventional materials, but it has superior performance compared to conventional commercial cation exchange membranes.

Description

Cross-linked cationic conductive polymers and uses thereof < RTI ID = 0.0 >

The present invention relates to a process for preparing a halogenated polymer by halogenating a polystyrene-based polymer and a polyphenylene oxide-based polymer, respectively; A step of preparing a crosslinked polymer by mixing a halogenated polystyrene type polymer and a halogenated polyphenylene oxide type polymer and then adding a crosslinking agent having an electron withdrawing group to form a crosslinking type polymer by halogenation between the halogenated polymer at the halogen functional site of the halogenated polymer ; And a cation-exchangeable functional group-imparting step of functionalizing the crosslinking type polymer with a cation-exchangeable functional group, a cation exchange membrane for a reverse electrodialysis (RED) device manufactured through the method And a reverse electrodialyser including the same.

Worldwide, the value of water resources is increasing due to the deepening of drought phenomena caused by global warming, depletion of groundwater, progress of desertification, population increase, increase of living and industrial water use by industrialization, and the desalination of seawater, And recycling are emerging as new issues. In addition, there is a growing interest in the production of ultra pure water for industrial use, and as the demand for clean water for eating and washing increases in living, studies on the development of highly efficient ion removal apparatus have been actively conducted.

Currently, ion removal technology is mainly used in evaporation, reverse osmosis, and ion exchange membrane. Evaporation and reverse osmosis membranes have high operating costs and operation problems due to high energy consumption. The most widely used ion exchange membranes It has disadvantages of making secondary pollutants because it uses excess acid or salt (NaCl) during regeneration.

Concentrated water as such by-product can be used as a good raw material in the reverse electrodialysis process. Reverse electrodialysis is a renewable energy system that produces electricity through the reverse operation of electrodialysis. In other words, when the cation exchange membrane and the anion exchange membrane alternate with each other to create a compartment and alternately flow salt water and agricultural water to each compartment, ion flow is generated through each ion exchange membrane and the current generated through the ion exchange membrane is utilized. The ion exchange membrane, which is the core material of the ion exchange membrane, is the most important material that determines the performance of the system. However, since the ion exchange membrane used is very expensive and the durability is not satisfactory due to the ion selectivity, new materials and technologies Is required.

Electrodialysis using an ion exchange membrane is a process for separating ionic materials dissolved in water by using an electric field formed by a direct current power supplied through an electrode and an electrolyte solution. The ion exchange membrane used here indicates the selective permeability of the corresponding ions by the ionic bonding of the fixed ions in the membrane in the electrolyte solution. In general, ion exchange membranes are required to have high permeability selectivity, low electrical resistance, excellent mechanical strength, and high chemical stability.

A method for producing an ion exchangeable and / or ionically conductive crosslinked polymer by using an existing amine-based crosslinking agent is a method in which a tertiary amine is used as a crosslinking agent and the tertiary amine crosslinking agent is converted into an ammonium ion, . However, this affects the functionality of the ion exchange membrane, such as water uptake and conductivity.

As a conventional technique for such a crosslinked ion-exchange polymer, Korean Patent Laid-Open No. 10-2010-0076902 discloses a method of using an amine compound for nucleophilic substitution chemical crosslinking by using crosslinked sulfonated polystyrene, In order to overcome the disadvantage of using the polystyrene having low chemical resistance and mechanical properties as a main material of the ion-exchange membrane, it is formed in the form of a composite membrane, and the outer and inner surfaces of the commercialized porous base membrane are coated with polystyrene and then cross- The complicated manufacturing process can be a major obstacle to commercialization, and a large disadvantage is recognized in that the film to be produced is a multi-layered structure, which may cause deformation of the composite membrane of the membrane or interlayer separation of the cross-linked ion membrane with the basement membrane.

On the other hand, currently used water treatment and energy ion exchange membranes can be roughly classified into perfluorocarbon materials and non-fluorocarbon materials based on hydrocarbons. Among them, perfluorocompounds are very complicated to manufacture and expensive, It is difficult to use the membrane in an area where an electrolyte membrane of the electrolyte membrane should be used. On the other hand, non-fluorine-based materials are suitable for use in renewable energy and water treatment fields, which are highly dependent on manufacturing cost, because of their excellent price competitiveness. However, most of them are crosslinked polystyrene-based materials. However, it is difficult to commercialize it because of the disadvantage that it is not superior in price competitiveness or inferior durability compared with crosslinked polystyrenic materials, and it is difficult to commercialize it. Even if a crosslinking process is introduced to improve durability, Is becoming a reality. Therefore, the development of ion conductive materials with high efficiency at low production costs using simple crosslinking processes and low cost materials such as polystyrene and polyphenylene oxide is indispensable for developing ion conductive materials for water treatment and renewable energy.

Korean Patent Publication No. 10-2010-0076902

The present invention has been developed to solve the above problems and provides a process for producing a crosslinkable cationic conductive polymer having excellent mechanical properties and chemical resistance and capable of inhibiting a rapid crosslinking reaction in the production of a membrane to prevent a change in the shape of the membrane .

The present invention also provides a crosslinking agent capable of crosslinking only without formation of an ion exchangeable functional group and having an electron withdrawing group capable of inhibiting a sudden crosslinking reaction in the production of a film to prevent a change in the shape of the film, Type cationic conductive polymer.

Also, in the present invention, reverse electrodialysis (RED), electrodialysis (ED), or capacitive deionization (CDI), which is manufactured using a cross-linkable cationic conductive polymer crosslinked with an electron withdrawing group, And a reverse electrodialyser including the cation exchange membrane.

In order to solve the above-described problems, the present invention provides a method for preparing a halogenated polymer, comprising the steps of: halogenating a polyphenylene oxide polymer; A cross-linking agent represented by the following Chemical Formula 1 is added after mixing a halogenated polystyrene-based polymer and a halogenated polyphenylene oxide-based polymer to form a crosslinked polymer by a cross-linking reaction between the halogenated polymer at the halogen functional site of the halogenated polymer Manufacturing steps; And a cation-exchangeable functional group-imparting step of functionalizing the cross-linkable polymer with a cation-exchangeable functional group.

≪ Formula 1 >

In Formula 1,

A is a single bond, - (C = O) - , - (P = O) -, - (SO 2) -, -CF 2 - or _{- (C (CF 3) 2} ) - and, R ₁ to R ₈ Each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkyl group substituted with a halogen, an allyl group, a cyano group, an aryl group, a nitro group, a perfluoroalkyl group, A perfluoroalkyl group, a perfluoroalkyl group, a perfluoroalkyl group, a perfluoroalkyl group, a perfluoroalkyl group, a perfluoroalkyl group, a perfluoroalkyl group, a perfluoroaryl group or a perfluoroaryl group containing a sulfur atom, the number of the repeating units a and b are each independently 0 or an integer of 1 to 100, and D and D 'is NH _2, or -NHR where R is each independently a C ₁ to C ₁₂ alkyl group.

In the method for producing a crosslinkable cationic electroconductive polymer according to an embodiment of the present invention, the halogenated polystyrene-based polymer may be represented by the following formula (2).

(2)

Z is 0 or an integer of 1 or more and 20 or less, X ₁ is a halogen atom which is one of chlorine (Cl), bromine (Br) or iodine (I), x / Or more.

The polymer of Formula 2 is prepared by halogenated alkylation of commercial polystyrene, and the raw material polystyrene has a molecular weight of 1000 to 1,000,000, more preferably 1000 to 100,000.

In the process for preparing a crosslinkable cationic electroconductive polymer according to an embodiment of the present invention, the halogenated polyphenylene oxide-based polymer may be represented by the following Chemical Formula 3

(3)

X ₂ is a halogen atom which is one of chlorine (Cl), bromine (Br) or iodine (I), and a / (a + b) is 0.01 or more and 1 or less.

The polymer of Formula 3 is prepared by halogenation of a polyphenylene oxide. The raw material polyphenylene oxide has a molecular weight of 1,000 to 1,000,000, more preferably 1,000 to 100,000. .

In the present invention, the polymer of Formula 2 and Formula 3 is crosslinked using the crosslinking agent of Formula 1, and the crosslinked polymer may be represented by Chemical Formula 4 below.

≪ Formula 4 >

In Formula 4,

A is a single bond, - (C = O) - , - (P = O) -, - (SO 2) -, -CF 2 - or _{- (C (CF 3) 2} ) - and, R ₁ to R ₈ Each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkyl group substituted with a halogen, an allyl group, a cyano group, an aryl group, a nitro group, a perfluoroalkyl group, A perfluoroaryl group or a -O-perfluoroaryl group, and a and b, which are the numbers of repeating units, are independently 0 or an integer of 1 or more and 100 or less, and D '' and D '''are each independently selected from NH-, or -NR- where R is a C ₁ to C ₁₂ alkyl group, x / (x + y) is less than 0.01 1, r / (r + s ) Is not less than 0.01 and not more than 1.

In the method for producing a crosslinkable cationic electroconductive polymer according to an embodiment of the present invention, the cation-exchangeable functional group-imparting step may include a step of reacting the crosslinkable polymer with a compound containing a sulfonic acid group, a phosphoric acid group and an acetic acid group, Or cationic exchange functional groups in their salt state.

According to one embodiment of the present invention, the crosslinking polymer of Formula 4 may be prepared from a crosslinking type cationic conductive polymer represented by Formula 5 through the step of imparting a cation-exchangeable functional group.

≪ Formula 5 >

In Formula 5,

A is a single bond, - (C = O) - , - (P = O) -, - (SO 2) -, -CF 2 - or _{- (C (CF 3) 2} ) - and, R ₁ to R ₈ Each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkyl group substituted with a halogen, an allyl group, a cyano group, an aryl group, a nitro group, a perfluoroalkyl group, A perfluoroaryl group or a -O-perfluoroaryl group, and a and b, which are the numbers of repeating units, are independently 0 or an integer of 1 or more and 100 or less, and D 'And D''' are each independently NH- or -NR-, wherein R is a C ₁ to C ₁₂ alkyl group, y 'and y "are in the range of 0.001? Y' / (y '+ y' (S '+ s') is in the range of 0.01 to 1, and s' and s "are in the range of 0.001 s' / (s' + s (S '+ s'') / (r + s' + s '') is 0.01 or more and 1 or less, z is 0 or an integer of 1 or more and 20 or less, E is Ion exchange function A cation exchange functional group through reaction with a compound containing a sulfonic acid group, a phosphoric acid group or an acetic acid group, or a cation exchange functional group in the salt state thereof.

Specific examples of the desired cation exchange functional groups according to one embodiment of the present invention include sulfonic acid, phosphoric acid, trifluoroacetic acid and the like, and one or more of the ion exchange functional groups may be selected.

In addition, the membrane according to one embodiment of the present invention may be a cation exchange membrane for reverse electrodialysis (RED), electrodialysis (ED) or capacitive deionization (CDI) devices.

Reverse Electrodialysis is a blue energy technology that generates power using the difference in salinity between seawater and fresh water, such as PRO (pressure-retarded osmosis). It is a general energy that generates electricity by supplying electricity. In contrast to the dialysis process, electrodialysis is a technique for obtaining energy while reversing the process of desalination using electrodialysis. Electrodialysis is an electrodialysis technique using an electric field formed by a direct current power supplied through an electrode and an electrolyte solution, And the capacitive deionization (CDI) is adsorbed on the surface of the charged electrode by electrostatic attraction, ions adsorbed on the surface of the electrode short-circuit the two electrodes ) Or by application of a reverse potential.

In addition, according to one embodiment of the present invention, the cation exchange membrane may be formed directly in the form of a membrane, or the cation-conductive polymer may be impregnated into a support to form a membrane. At this time, the support may be any one of a porous film made of a fluorine-containing resin such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF), a porous film made of a polyolefin resin, a nonwoven fabric or a mesh.

Also, using the membrane according to one embodiment of the present invention, an anode; A cathode; And at least one unit cell spaced apart from the anode and the cathode so as to form a flow path for the fresh water, wherein the unit cell includes an anion exchange membrane spaced apart from the anode to form a flow path through which seawater flows, A reversed electrodialyser comprising a cation exchange membrane comprising a crosslinkable cationic conductive polymer can be produced.

As described above, the cross-linked cation exchange membrane according to the present invention has excellent mechanical properties and chemical resistance, and has an advantage of preventing a change in shape of the membrane by suppressing a rapid cross-linking reaction during the production of the membrane.

In addition, since the present invention uses not only a low-cost crosslinking process but also a polystyrene-based resin as a low-cost base material and polyphenylene oxide as an engineering plastic, it is advantageous in terms of cost competitiveness compared to conventional materials have.

In addition, the present invention is advantageous in that it is easy to manufacture a reinforced membrane impregnated with a polymer by ion exchange through a post-functionalization process.

Further, since the present invention uses a copolymer of a polymer having different physical properties, it is easy to control the physical properties. More specifically, in the case of a low-priced crosslinked polymer ion conductor, a membrane produced by crosslinking using a styrene monomer and divinylbenzene as a crosslinking agent and introducing an ion exchanger is very well broken down. In the present invention, however, a polyphenylene Since the physical properties and the membrane resistance can be controlled effectively by adjusting the ratio of the oxides and the chemical reaction between the crosslinking agent and the known crosslinking agent does not occur unlike known divinylbenzene, the crosslinking agent can be used more efficiently and the degree of crosslinking can be predicted.

In addition, the crosslinking process according to the present invention is very advantageous for the process application for the production of a membrane because crosslinking takes place within a few minutes or does not require a long crosslinking time of several tens of hours, and has a crosslinking delay time of about 2 hours under the drying condition of the electrolyte membrane .

In addition, reverse electrodialysis (RED), electrodialysis (ED), or capacitive deionization (CDI) using a crosslinking type cationic conductive polymer crosslinked with a crosslinking agent having an electron withdrawing group according to the present invention, ) Device has superior performance to conventional commercial cation exchange membranes.

1 is a ¹ H-NMR result showing the halogenation results of polystyrene according to one embodiment of the present invention.
FIG. 2 shows ¹ H-NMR results showing the halogenation results of polyphenylene oxide according to one embodiment of the present invention.
FIG. 3 shows the quality of a polyphenylene oxide / polystyrene crosslinked cation exchange membrane according to an embodiment of the present invention.
FIG. 4 illustrates the effect of reverse electrodialysis of an ion exchange membrane according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The term " degree of halogenation " as used throughout this specification is the number of halogen functional groups produced in the whole polymer by halogenated or halogenated alkylation divided by the total number of repeating units. That is, the number of halogen functional groups per repeating unit. Similarly, for example, "degree of bromination" is a value obtained by dividing the number of bromine functional groups produced in the entire polymer by the number of all repeating units through the bromination reaction, and "degree of chloromethylation " "Is a value obtained by dividing the number of chlorine functional groups produced in the whole polymer by the number of all repeating units through chloromethylation reaction.

In the present invention, the degree of halogenation of the halogenated polymer is 1 to 150% (0.01 to 1.5), such as 10 to 120% (0.1 to 1.2), 10 to 30% (0.1 to 0.3), 30 to 50% (0.3 to 0.5) 80 to 100% (0.8 to 1), and the like.

In the present invention, the halogenated polymer can be used by obtaining a commercially available one, or by directly halogenating the non-halogenated polymer. Also, in the present invention, the halogenated polymer may be prepared by directly obtaining a monomer, polymerizing it directly, and halogenating it to prepare a desired polymer

The reaction temperature, the reaction time, the stirring conditions, and the halogen element used in the halogenation are not particularly limited, but may be appropriately selected depending on the size, performance characteristics, quality and other properties of the resultant ion exchange membrane. The halogen atom is not particularly limited, but includes fluorine, chlorine, bromine and iodine in particular.

The halogenation reaction temperature is selected, for example, preferably in the range of 0 to 300 占 폚, more preferably in the range of 20 to 200 占 폚. The halogenation reaction time can be appropriately selected depending on other conditions, and is preferably 1 to 10 hours. Under stirring conditions at the time of halogenation, a stirring speed in a usual halogenation reaction may be used. The reaction initiator used may be water-soluble or lipophilic, and its peroxide or azo-based initiator may be used in a conventional reaction. For additives, conventional stabilizers and others may be used. Other reaction conditions are not specifically limited.

Hereinafter, embodiments and embodiments of the present invention will be described in detail in order to facilitate those skilled in the art to which the present invention belongs. In particular, the technical idea of the present invention and its core structure and action are not limited by this. In addition, the content of the present invention can be implemented by various other types of equipment, and is not limited to the embodiments and examples described herein.

<Selection of crosslinking agent>

In order to compare the crosslinking rates of aliphatic and aromatic amine compounds as crosslinking agents, the eight amine compounds shown in Table 1 were tested.

First, a solution of 1 g of poly (2,6-dimethyl-1,4-phenyleneoxide), 30% brominated as a halogenated polymer, in 10 ml of dimethylacetamide was added to an amine compound And then the gelation time was measured by stirring at 25 캜. When 8 kinds of amine compounds were used, all were gelled. The gelation time of each sample is shown in Table 1 below.

Cross-linking agent weight% The molar amount of the crosslinking agent (mmol) Weight of crosslinking agent (g) Volume (ml) of crosslinking agent Gelation time (sec) 1,3-diaminopropane

35 7.364

0.5458 0.6146 19 1,4-diaminobutane 6.192 0.6223 21 1,7-diaminoheptane 4.191

- 18 1,8-diaminooctane 3.783 32 2,6-diaminopyridine 5.001 - 2,6-diaminotoluene 4.467 30 1,3-cyclohexanediamine 4.780 25 4,4'-diaminobenzophenone 2.571 8340

From Table 1 above, it can be seen that 4,4'-diaminobenzophenone exhibits the longest gelation time. This shows that aromatic amine compounds have a slightly longer gelation time than aliphatic amine compounds and amine compounds having an electron withdrawing group C = O between aromatic groups, such as diaminobenzophenone, have a significantly longer gel time . On the other hand, in the case of 2,6-diaminopyridine, the gelation time could not be compared with other amine compounds because it was not soluble in the tested dimethylacetamide solvent.

In order to compare the crosslinking speeds of the diaminobenzophenone having the longest gelation time with the commercial amine crosslinking agent in the crosslinking experiment, four commercial amine crosslinking agents (Kukdo Chemical Co., Ltd.) shown in the following Table 2 and a diaminobenzophenone crosslinking agent The speed was tested.

The crosslinking speed test was carried out in the same manner as in the crosslinking test described above. When diaminobenzophenone was used, diaminobenzophenone was added, and the mixture was kept at 40 캜 for 30 minutes, at 60 캜 for 30 minutes and then at 80 캜 The gelation time was measured at the temperature elevation condition. That is, the cross-linking test was carried out at room temperature in the same manner as the cross-linking test for the commercial amine cross-linking agent, and the cross-linking test was carried out under the temperature increasing condition at which the cross-linking is further accelerated for the diaminobenzophenone.

All four crosslinking agents were gelated and the respective gelation times are listed in Table 2 below.

Classification Cross-linker name weight(%) Weight of crosslinking agent (g) Gelation rate (sec) Aromatic MDA-220
35
0.5458 911 Modified aromatic TH-452N 1660 Metamorphic aliphatic KH-816 73 KH-818B 37 Aromatic 4,4'-diaminobenzophenone 834 5520 * (temperature rise)

Although the aromatic amine compound has a longer gelation time than the aliphatic amine compound in the above crosslinking experiment, the aromatic amine compound in Table 2 has a longer gelation time than the aliphatic amine compound in the above Table 2. However, even in the case of the aromatic amine compound of the same type, In the case of diaminobenzophenone having a group, the remarkably long gelation time

Respectively. In addition, diaminobenzophenone exhibited significantly longer gelation times than conventional amine crosslinking agents even at elevated temperatures, where the crosslinking rate is faster. As a result, 4,4-diaminobenzophenone was selected as a crosslinking agent capable of prolonging the crosslinking reaction at the time of formation because of the longest retention time.

&Lt; Preparation of Polymer Having Cation Exchanger >

(1) Halogenation of polystyrene

Halogenation of polystyrene was carried out according to Reaction Scheme 1 below.

<Reaction Scheme 1>

Specific reaction conditions are as follows. 10.29 g (0.0988 mol) of polystyrene is put into a two-necked flask connected to an argon gas line. 180 ml of chloroform was added to the flask to sufficiently dissolve the polystyrene to 3.33 wt%, thereby preparing a solution. After completely dissolving at room temperature, the temperature of the thermostat is set at 40 ° C. 1.3466 g (0.00988 mol) of catalyst ZnCl2 was added to the reactor and stirred for 30 minutes. Then, 30 m, 1 of chloromethyl methyl ether (CMME) is added using a syringe. The amount of CMME added is calculated by multiplying the number of moles of CMME reacted per moles of polystyrene repeating units by four times. The mixture was vigorously stirred while being injected with a dry inert gas through a gas inlet attached to the reactor, and reacted for 4 hours. After completion of the reaction, the product was precipitated in an excess of methanol, and the precipitated chloromethylated polystyrene was filtered and washed several times with methanol. The washed chloromethylated polystyrene is dried in a vacuum oven at 40 ° C and stored at room temperature.

The chloromethylation degree of chloromethylation (x / n) in the above reaction was 0.164 (16.4%) as measured by ¹ H-NMR spectroscopy as shown in FIG.

(2) Halogenation of polyphenylene oxide

Halogenation of the polyphenylene oxide was carried out according to Reaction Scheme 2 below.

<Reaction Scheme 2>

15 g (0.1248 mol) of poly (2,6-dimethyl-1,4-phenylene oxide) was added to a three-necked flask connected with an argon line and a condenser. 200 ml of chlorobenzene was added to the reactor using a syringe, and the mixture was stirred at room temperature to dissolve the poly (2,6-dimethyl-1,4-phenylene oxide) to prepare a polymer solution. At this time, chlorobenzene corresponds to 6.76 wt% of poly (2,6-dimethyl-1,4-phenylene oxide). To the reactor were added 9.3323 g (0.0524 mol) of NBS (N-bromosuccinimide) and 0.6150 g (0.0037 mol) of AIBN (2,2'-azobis-isobutyronitrile). At this time, the temperature of the thermostat containing the reactor is set at 140 ° C and refluxed for 3 hours to react. After the reaction has ended, the mixture is cooled to room temperature and then precipitated in a 10-fold excess of ethanol. The synthesized poly (2,6-dimethyl-1,4-phenylene oxide) bromide was washed with ethanol several times after filtration and dried in a vacuum oven at 60 ° C for 12 hours.

 The bromination degree of the poly (2,6-dimethyl-1,4-phenylene oxide) in the above reaction was found to be 0.267 (26.8 %).

&Lt; Preparation of Crosslinked Cationic Conducting Polymer Membrane &

(1) Preparation of cross-linked polymer membrane

The process for preparing the crosslinkable cationic electroconductive polymer according to the present invention is summarized in the following Reaction Scheme 3.

<Reaction Scheme 3>

Preparation Example 1:

0.5 g of 25% brominated poly (2,6-dimethyl-1,4-phenylene oxide) (BrPPO25) is dissolved in 7 ml of NMP at room temperature. 0.5 g of 25% chloromethylated polystyrene (chPS25) was dissolved in 7 ml of NMP at room temperature and mixed with the BrPPO20 solution. A crosslinking agent (4,4'-diaminobenzophenone) in an amount corresponding to 5 mol% of the total halogen groups is added to the blending polymer solution and stirred for 20 minutes to sufficiently dissolve the crosslinking agent. The mixed solution is filtered using a microfilter having a pore size of 5.0 mm and then filled into a 11x11 (cm ² ) silicon frame fixed on a glass plate. The solution was heated from 25 ° C to 40 ° C for 1 hour, kept at 40 ° C for 2 hours, raised from 40 ° C to 60 ° C for 1 hour, maintained at 60 ° C for 2 hours, And then dried at 80 DEG C for 12 hours to obtain a film. The quality of the prepared membrane (crosslinked BrPPO25 / chPS25 membrane) is shown in Fig.

(2) Giving ion-exchangeable functional groups of a crosslinked polymer membrane

Example 1:

The crosslinked BrPPO25 / chPS25 membrane is dried in a vacuum oven at 40 占 폚 for 12 hours. 0.25 g of the dried film is dipped in 200 mL of 1,2-dichloromethane (DCE) for 30 minutes to swell. An ice bath was set at 0 ° C and 0.10 ml of chlorosulfonic acid corresponding to 1 equivalent of the polymer reaction site was dissolved in 50 ml of 1,2-dichloromethane to sufficiently dissolve the solution in an amount of 0.27 wt% to prepare a sulfonated solution do. The reactor containing the sulfonated solution is set in an ice bath, set to 0 ° C, and the fully swelled membrane is fully immersed in the sulfonated solution. The membrane that has been sulfonated for 10 minutes is dipped in distilled water at room temperature to remove excess chlorosulfonic acid. The membrane is washed several times with tertiary distilled water and then dried in a vacuum oven at room temperature for 12 hours.

Example 2

The crosslinked BrPPO25 / chPS25 membrane is dried in a vacuum oven at 40 占 폚 for 12 hours. 0.25 g of the dried film is dipped in 200 mL of 1,2-dichloromethane (DCE) for 30 minutes to swell. 0.10 ml of chlorosulfonic acid corresponding to one equivalent of the polymer reaction site is dissolved in 200 mL of 1,2-dichloromethane and dissolved sufficiently to 0.07 wt% to prepare a sulfonated solution. The reactor containing the sulfonated solution is set at 0 ° C, and the fully swelled membrane is fully immersed in the sulfonated solution. The sulfonated membrane is immersed in DCE at room temperature for 1 hour to wash out unreacted chlorosulfonic acid. The membrane is washed several times with tertiary distilled water and then dried in a vacuum oven at room temperature for 12 hours.

Example 3

The crosslinked BrPPO25 / chPS25 membrane is dried in a vacuum oven at 40 占 폚 for 12 hours. 0.25 g of the dried film is dipped in 200 mL of 1,2-dichloromethane (DCE) for 30 minutes to swell. 0.10 ml of chlorosulfonic acid corresponding to one equivalent of the polymer reaction site is dissolved in 200 mL of 1,2-dichloromethane and dissolved sufficiently to 0.07 wt% to prepare a sulfonated solution. The reactor containing the sulfonated solution is set to 18 ° C, and the fully swelled membrane is fully immersed in the sulfonated solution. The sulfonated membrane for 1 hour is immersed in distilled water at room temperature to remove excess chlorosulfonic acid. The membrane is washed several times with tertiary distilled water and then dried in a vacuum oven at room temperature for 12 hours.

Example 4

The crosslinked BrPPO25 / chPS25 membrane is dried in a vacuum oven at 40 占 폚 for 12 hours. 0.25 g of the dried film is dipped in 200 mL of 1,2-dichloromethane (DCE) for 30 minutes to swell. 0.10 ml of chlorosulfonic acid corresponding to one equivalent of the polymer reaction site is dissolved in 400 mL of 1,2-dichloromethane and dissolved sufficiently to 0.03 wt% to prepare a sulfonated solution. Set the reactor containing the sulfonated solution to 18 ° C, and thoroughly swell the membranes in the sulfonated solution. The sulfonated membrane for 1 hour is immersed in distilled water at room temperature to remove excess chlorosulfonic acid. The membrane is washed several times with tertiary distilled water and then dried in a vacuum oven at room temperature for 12 hours.

The chemical structure of the cross-linked cationic conductive polymer having a sulfonic acid group as the cationic exchange group prepared according to one embodiment of the present invention can be represented by the following Chemical Formula 6.

(6)

(2) Property analysis of cross-linked cationic conductive polymer membrane

The membrane resistance of the cross-linked cationic conductive polymer membrane prepared through Examples 1 to 4 of the present invention was measured and the results are shown below.

The membrane resistance was measured by immersing the ion exchange membrane in a 0.5M NaCl aqueous solution for 24 hours at room temperature. A sample was sandwiched between Pt electrodes having a diameter of 0.5 cm, and resistance was measured with a resistance meter (Hioki 3560) under the electrolyte solution using an aqueous solution of 0.5 MH ₂ SO ₄ as an electrolyte.

 The properties of the membrane were analyzed and summarized in Table 3 below.

Polymer BrPPO25 / chPS25 (g / g) Example 1 Example 2 Example 3 Example 4 Crosslinker content (mol%) 5 Sulfonating agent
Added equivalent 1eq. Sulfonation solution concentration (wt%) 0.27 0.07 0.07 0.03 Temperature (℃) 0 0 18 18 Membrane resistance (Ω · cm ² ) 2.37 0.61 0.49 0.53

Heterogeneous sulfonation reaction was carried out using chlorosulfonic acid as a blending polymer which was cross - linked with an electron - attracting crosslinking agent. The lower membrane resistance and membrane quality were not significantly impaired as the concentration of the sulfonation solution decreased. When the sulfonation temperature was low (0 ° C) and the sulfonation solution concentration was 0.07wt% or less, a suitable membrane of 0.61 Ω · cm 2 It was confirmed that the resistance value and the membrane damage caused by the sulfonating agent were minimized

&Lt; Analysis of reverse electrodialysis using cross-linked cationic conductive polymer membrane >

A cation exchange membrane was prepared using the polymer of Example 2 prepared in accordance with an embodiment of the present invention, and a cation exchange membrane (CMV) of an Asahi glass and an anion exchange membrane (AMV) A reverse electrodialysis cell (RED cell) having a stack, a channel thickness of 0.2 mm, a flow rate of 50 mL / min, and an active area of 5 cm x 5 cm was prepared to compare the performance of the cation exchange membrane of the present invention with that of a commercial cation exchange membrane. 4 (a) is a result of a reverse electrodialysis cell (RED cell) manufactured using commercial cation exchange membrane (CMV) and anion exchange membrane (AMV) of Asahi glass, and FIG. 4 (b) (RED cell) prepared using the cation exchange membrane of Example 2 of the present invention and commercial anion exchange membrane (AMV) of Asahi Glass.

As can be seen from FIG. 4, the cation exchange membrane prepared according to one embodiment of the present invention exhibited a 13.4% improvement in the performance of reverse electrodialysis compared to the commercial cation exchange membrane.

INDUSTRIAL APPLICABILITY As described above, the crosslinkable cation exchange membrane according to the present invention has excellent mechanical properties and chemical resistance, and can inhibit a rapid crosslinking reaction in the production of a membrane to prevent changes in the morphology of the membrane. By using polyphenylene oxide, which is an engineering plastic, it has superiority in price competitiveness compared to conventional materials and superior performance to existing commercial cation exchange membranes.

Claims (10)

A step of preparing a halogenated polymer in which each of the polystyrene-based polymer and the polyphenylene oxide-based polymer is halogenated;
A halogenated polystyrene-based polymer and a halogenated polyphenylene oxide-based polymer are mixed and then an electron withdrawing group is formed between two aromatic rings represented by the following formula (1) to form an anion exchangeable functional group having delayed crosslinking reactivity with a halogen functional group Or a secondary amine cross-linking agent to form a cross-linked polymer by a cross-linking reaction between the halogenated polymer at a halogen functional site of the halogenated polymer; And
A cation-exchangeable functional group-imparting step of functionalizing the crosslinkable polymer with a cation-exchangeable functional group,
&Lt; Formula 1 >

In Formula 1,
A is - (C = O) -, the substituent represented by R ₁ to R ₈ is a hydrogen atom, D and D 'are each independently NH ₂ or -NHR and R is a C ₁ to C ₁₂ alkyl group . The method according to claim 1,
Wherein the halogenated polystyrene-based polymer is represented by the following formula (2): < EMI ID =
(2)

Z is 0 or an integer of 1 or more and 20 or less, X ₁ is a halogen atom which is one of chlorine (Cl), bromine (Br) or iodine (I), x / Or more. The method according to claim 1,
Wherein the halogenated polyphenylene oxide-based polymer is represented by the following formula (3): < EMI ID =
(3)

X ₂ is a halogen atom which is one of chlorine (Cl), bromine (Br) or iodine (I), and a / (a + b) is 0.01 or more and 1 or less. The method according to claim 1,
The cation-exchangeable functional group-imparting step comprises reacting the crosslinkable polymer with a compound containing a sulfonic acid group, a phosphoric acid group and an acetic acid group to give a cation-exchange functional group, or a cation-exchange functional group in a salt thereof, (METHOD FOR PREPARING CONDUCTIVE POLYMER). Wherein the ion-conductive polymer is represented by the following formula (A): < EMI ID =
&Lt; Formula (A)

In the above formula (A)
A is - (C = O) -, and the substituent represented by R ₁ to R ₈ is a hydrogen atom, D '' and D '''are each independently selected from NH-, or -NR- where R is a C ₁ and to C ₁₂ alkyl, y 'and y''it is 0.001≤y' / (y '+ y '') has a range of ≤0.9, (y' + y '') / (x + y '+ y' (S '+ s'') / (r + s'') is in the range of 0.01 to 1, and s' and s '' have a range of 0.001 s '/ (s' + s '') + s '') is 0.01 or more and 1 or less, z is 0 or an integer of 1 or more and 20 or less, E is a cation exchange functional group through reaction with a compound containing a sulfonic acid group, a phosphoric acid group or an acetic acid group as an ion exchange functional group, Lt; / RTI &gt; cation exchange functionality of the salt. A membrane characterized by being molded with a resin comprising the cross-linked cationic electroconductive polymer according to claim 5. A membrane characterized by being impregnated with a crosslinking type cationic electroconductive polymer according to claim 5 in a support. The method of claim 7,
Characterized in that the support is any one of a porous film made of polytetrafluoroethylene (PTFE), a fluorine-containing resin containing polyvinylidene fluoride (PVDF), or a polyolefin resin, a nonwoven fabric or a mesh. The method according to any one of claims 6 to 8,
Wherein the membrane is a cation exchange membrane for reverse electrodialysis (RED), electrodialysis (ED) or capacitive deionization (CDI) devices. An anode;
A cathode; And
And at least one unit cell disposed between the anode and the cathode so as to form a flow path of fresh water,
Wherein the unit cell comprises an anion exchange membrane disposed so as to form a channel through which seawater flows, and a cation exchange membrane composed of the cation conductive polymer according to claim 5.

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