KR20100095725A - Desalination membrane based on sulfonated poly(arylene ether) containing crosslinking at end group - Google Patents

Abstract

PURPOSE: A desalination membrane based on sulfonated poly(arylene ether) containing crosslinking at end group is provided to improve the efficiency of removing poly(amide) salt, and secure high stability even when being exposed to moisture for long time. CONSTITUTION: A salt removing layer is formed with arylene ether copolymers of a cross bridge structure. SAr1 and SAr2 indicates sulfonated aromatic. Ar indicates the aromatic family which is not sulfonated. CM indicates the part of cross-linking. K is between 0.001 - 1.000. The equation of s = 1 - k is satisfied. N indicates a repeating unit of polymer and is integer which is between 10-500.

Description

Desalination membrane based on sulfonated Poly (Arylene Ether) containing crosslinking at end group}

The present invention relates to a technique for desalination of seawater, and more particularly, to a salt removal membrane for desalination of seawater.

The shortage of water resources is a global phenomenon and various efforts are being made to overcome them. The amount of water available on the planet is limited, and Science (313, 1088-1090, 2006) reports that by 2025, about 45% of the world's population will suffer from water shortages.

Moreover, in developing countries, 25,000 people die every day from drinking contaminated water. One alternative to meet the scarcity of water is to desalination seawater. However, since there are various kinds of salts in seawater (raw water), a method of removing the salts by applying an osmotic pressure or more and passing the salt removal membrane to obtain fresh water is a reverse osmosis membrane method.

In the case of Film Tech, the polyamide composite reverse osmosis membrane produced by Dow Chemical, which is currently widely used, and RE8040-SHN produced by Woongjin Chemical, high water permeability and high salt removal rate (over 99.7%) Indicates. However, since it is manufactured through interfacial polymerization, the surface is rough, which may cause a high fouling effect (a small amount of foreign matter slowly accumulates on the surface to reduce the water permeation rate and the salt removal rate), and also occurs by surface adsorption of bacteria or microorganisms in raw water. Degradation occurs due to the bio fouling.

In order to solve this problem, chlorine treatment (NaOCl solution treatment) must be performed to suppress bacteria, microorganisms and bacteria in raw water. In the case of polyamide reverse osmosis membranes, the bonds of main chains are easily broken even at low concentrations (less than 100 ppm). Significantly reduces the removal rate. Therefore, after chlorination, there must be a chlorine removal step process for the polyamide composite reverse osmosis membrane. However, currently used reverse osmosis membranes have the disadvantage of being very vulnerable to chlorine.

US Pat. No. 4,992,485 discloses a poly (therther ketone) membrane in which microsized pores exist as a material having excellent chlorine stability. However, the sulfonic acid group does not exist and is not used as a filtration membrane and a reverse osmosis membrane due to the micro-sized holes, and is used as a support for the filtration membrane or the reverse osmosis membrane.

In addition, in US Pat. No. 4,419,486, a sulfonated poly (arylene ether ketone) copolymer was developed for the reverse osmosis membrane having high chlorine stability, but the salt removal rate (about 70%) was low.

Therefore, there is an urgent need for research on the development of materials having high chemical stability, particularly chlorine stability, and requiring high salt removal rate.

A first object of the present invention for solving the above problems is to provide a salt removal film made of a sulfonated poly (arylene ether) copolymer having a crosslinked structure at the terminal.

 The present invention provides a salt removing film having a high dimensional resistance (swelling rate) while increasing the salt removal rate by introducing a crosslinked structure at the end of the sulfonated poly (arylene ether) copolymer represented by the following formula.

In the formula, SAr1 represents a sulfonated aromatic, Ar represents a non sulfonated aromatic, and CM represents a crosslinkable moiety.

In addition, in the above formula, k has a range of 0.001-1.000, has a value of s = 1-k, n represents a repeating unit of the polymer, and n represents 10 to 500 as an integer.

In addition, the present invention provides a salt removing film having a high dimensional resistance (swelling rate) while increasing the salt removal rate by introducing a crosslinked structure at the end of the sulfonated poly (arylene ether) copolymer represented by the following chemical formula. .

In the above formula, SAr2 represents a sulfonated aromatic, Ar represents a non sulfonated aromatic, and CM represents a crosslinkable moiety.

In addition, in the above formula, k has a range of 0.001-1.000, has a value of s = 1-k, n represents a repeating unit of the polymer, and n represents 10 to 500 as an integer.

The present invention provides a sulfonated poly (arylene ether) having a crosslinked structure at a terminal by forming a polymer polymer using a dihydroxy monomer and a dihalide monomer and using a substitution reaction by condensation polymerization at the terminal of the polymer polymer. It provides a salt removal film having a high salt removal rate and a high dimensional stability made of a copolymer.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First embodiment

The sulfonated poly (arylene ether) copolymer according to the first embodiment of the present invention is a salt removing film having a crosslinked structure at its terminal. The sulfonated poly (arylene ether) copolymer is according to the following formula (1).

[Formula 1]

In Formula 1, SAr1 represents sulfonated aromatic. SAr1 in Formula 1 is

또는

이다.

or

to be.

또는

이다. In addition, Ar represents none sulfonated aromatic,

or

to be.

,

,

또는

이며, A는 탄소와 탄소가 직접 연결되어 있는 단일결합,

또는

이며, E는 H, F, C1 ~ C5 또는

이다. 또한, Y에서

는 연결부분이 오르소, 메타, 파라 위치에 올 수 있는 벤젠구조를 나타내며,

는 불소(F)가 완전히 치환되어 있으며 연결부분이 오르소, 메타, 파라 위치에 올수 있는 벤젠구조를 의미한다. 즉

라 함은 연결부분이 오르소 (

), 메타 (

), 파라 (

) 위치에 올 수 있는 불소가 완전히 치환된 벤젠구조들을 의미한다. 또한 E에서 H는 수소를, F는 불소를, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조를

는 L이 벤젠에 치환되어 있는 벤젠구조를 의미한다. 상기 구조식에서 L은 H, F, C1 ~ C5 를 나타내며, H는 수소를, F는 불소를, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조를 의미한다.Y is a single bond where carbon and carbon are directly connected,

,

,

or

A is a single bond in which carbon is directly connected to carbon,

or

E is H, F, C1 to C5 or

to be. Also, in Y

Represents a benzene structure in which the linking moiety can be in the ortho, meta, or para position,

Refers to a benzene structure in which fluorine (F) is completely substituted and the linking portion can be at ortho, meta and para positions. In other words

Means the connection is ortho (

), Meta (

), Para (

Benzene structure which is completely substituted with fluorine which may be at position). In E, H represents hydrogen, F represents fluorine, and C1 to C5 represent an alkyl structure having hydrogen or fluorine substituted with 1 to 5 carbon atoms.

Means a benzene structure in which L is substituted for benzene. In the above structural formula, L represents H, F, C1 ~ C5, H means hydrogen, F is fluorine, C1 ~ C5 means an alkyl structure substituted with hydrogen or fluorine having 1 to 5 carbon atoms.

,

또는

이며 오르소, 메타, 파라 구조의 위치에 올 수 있 다. Z에서 Y는 앞서 설명한 Y와 의미가 같다.In addition, Z is a bond in which carbon of benzene and -SO ₃ ^- M ⁺ are directly connected,

,

or

And may come in positions of ortho, meta, and para structures. Y in Z has the same meaning as Y described above.

M ⁺ is a counterion having a cationic charge and represents potassium ions (K ⁺ ), sodium ions (Na ⁺ ), alkyl amines ( ⁺ NR ₄ ), and the like, preferably potassium ions or sodium ions.

또는

이다. CM에서 R은 R1이 치환되어있는 삼중결합(ethynyl part)(R=

), 이중결합(vinyl part)(R=

) 또는

이며 오르소, 메타, 파라 구조의 위치에 올 수 있다. 상기 R에서 G는 탄소와 탄소가 직접 연결되어 있는 단일 결합,

또는

를 의미한다. 또한 R1은 H, F, C1 ~ C5 또는

이다. 상기 R1에서 H는 수소를, F는 불소를, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조, R2가 오르소, 메타, 파라 위치에 치환되어 있을 수 있는 벤젠구조(

)들을 갖는 치환체임을 나타낸다. R2는 H, X 또는 C1~C5이다. 상기 R2에서 H는 수소, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조, X는 할로겐 원자(F, Cl, Br)에 해당되며, X의 경우는 다른 고분자 사슬의 하이드록시 그룹과의 중합을 이룰 수 있는 기능성 그룹이기도 하다. 또한 상기 화학식 1에서 k는 0.001 - 1.000 의 범위를 지니며, s = 1 - k 값을 가지며, n은 고분자 중합체의 반복단위(repeating unit)를 나타내며, n은 정수로서 10~500을 나타낸다.CM represents a crosslinkable moiety,

or

to be. In CM, R is an ethynyl part where R1 is substituted (R =

), The double part (R =

) or

And can come in positions of ortho, meta, and para structures. G in R is a single bond in which carbon and carbon are directly connected,

or

Means. R1 is also H, F, C1 to C5 or

to be. In R1, H is hydrogen, F is fluorine, and C1 to C5 are hydrogen or fluorine-substituted alkyl structures having 1 to 5 carbon atoms, R2 may be substituted at ortho, meta and para positions. Benzene Structure

It is a substituent having a). R2 is H, X or C1-C5. In R2, H is hydrogen, C1 to C5 is an alkyl structure substituted with hydrogen or fluorine having 1 to 5 carbon atoms, X is a halogen atom (F, Cl, Br), and in case of X another polymer It is also a functional group capable of polymerizing with the hydroxy group of the chain. In addition, in Chemical Formula 1, k has a range of 0.001-1.000, has a value of s = 1-k, n represents a repeating unit of the polymer, and n represents 10 to 500 as an integer.

The polycondensation reaction and the crosslinkable group introduction reaction for the synthesis of sulfonated poly (arylene ether) copolymers containing a crosslinked structure at the terminal of the invention are selected from hydroxides, carbonates and sulfates of alkali or alkaline earth metals as bases. An inorganic base may be used, or an organic base selected from conventional amines including ammonia may be used.

As the reaction solvent, aprotic polar solvents or methylene chlorides such as N -methylpyrrolidone (NMP), dimethylformamide (DMF), N, N -dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO) Protic polar solvents such as (CH ₂ Cl ₂ ), chloroform (CH ₃ Cl) and tetrahydrofuran (THF) may be used, and benzene, toluene, xylene or the like may be used as a non-solvent.

The present invention is a salt removal film made of a sulfonated poly (arylene ether) copolymer containing a crosslinked structure at the terminal having the above structure has a salt removal currently commercialized in the film forming ability, mechanical stability, physical properties, salt removal rate, etc. It has high chemical resistance (particularly chlorine stability) while maintaining similar salt removal rate as poly (amide) membrane used as membrane, and has high dimensional stability (low expansion rate) against water due to the crosslinked structure of molecular chain. The results were shown.

Such the present invention will be described in more detail based on the following production examples, but the present invention is not limited thereto.

Preparation Example 1: Preparation of salt removal membrane with sulfonated poly (arylene ether) copolymer (SPAE-HQ)

Scheme 1

Hydroquinonesulfonic acid potassium salt (3 g) in a 100 ml two-necked round flask equipped with agitator, nitrogen inlet tube, magnetic stub, Dean-Stark (azeotropic distillation) , 13.1423 mmol) and K ₂ CO ₃ (2.15 g), and N, N -dimethylacetamide (DMAc) (50 ml) and benzene (25 ml) were added.

The activation step was carried out for 6 to 8 hours after raising the temperature up to 6 hours in the range of 135 ^o C to 140 ^o C. Water produced as a by-product during the reaction was subjected to azeotropic distillation with benzene, one of the reaction solvents. Was removed, and benzene was removed from the reactor after the end of the activation step.

Thereafter, decafluorobiphenyl (4.4 g, 13.1693 mmol) was added to the reactor, and the reaction temperature was maintained at 140 ^° C. for at least 12 hours. After the reaction was completed, precipitated in 500 mL of ethanol, washed several times with water and ethanol, and vacuum dried at 60 ℃ for 3 days. The final product was obtained as a pale brown solid, yielding at least 90%.

The structure of the SPAE-HQ polymer synthesized by the above method was analyzed by ¹ H-NMR and ¹⁹ F-NMR.

As a result of ¹ H-NMR analysis of FIG. 1, it can be seen that there is no hydroxy group peak of the monomer. In addition, the peak of the polymer was found to be 7.51, 7.32, 7.28 ppm, and ¹⁹ F-NMR analysis of FIG. 2 showed that only two peaks appeared in the para position of the decafluorobiphenyl group. I was able to confirm that I had fallen off.

Sulfonated poly (arylene ether) (SPAE-HQ) was dissolved in a solvent to prepare a salt removal membrane, filtered using a 0.45 μm PTFE membrane filter, and cast a polymer solvent onto a clean glass plate support. After pouring on the glass plate by the method, it is left in a 40 ^° C oven for 24 hours, and then left in a 70 ^° C vacuum oven for more than 24 hours to completely remove the solvent. At this time, the solvent that can be used is a dipolar solvent, specifically N, N' -dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO) or N-methylpyrroly You can use money (NMP).

Preparation Example 2 Preparation of Salt-Removing Membrane with Sulfonated Poly (Arylene Ether) Copolymer (E-SPAE-HQ)

Scheme 2

E-SPAE-HQ was prepared by introducing 3-ethynylphenol group into the terminal of the polymer SPAE-HQ synthesized in Preparation Example 1.

That is, 3-ethynylphenol, benzene (20 ml) and K ₂ CO ₃ (0.7 g) were added to the polymer solution synthesized in Preparation Example 1 in an amount corresponding to a molar ratio of 0.2-0.5 times the decafluorobiphenyl monomer. After addition and further reaction at 140 ^° C. for at least 6 hours, benzene was completely removed. In addition, water was removed by azeotropic distillation with benzene in order to remove the by-product water during the reaction.

After the reaction was completed, precipitated in 500 mL of ethanol, washed several times with water and ethanol, and vacuum dried at 60 ℃ for 3 days. The final product was obtained as a pale brown solid, yielding at least 90%.

The structure of the E-SPAE-HQ polymer synthesized by the above method was analyzed by ¹ H-NMR, ¹⁹ F-NMR, and IR.

As a result of ¹ H-NMR analysis of FIG. 1, it can be seen that there is no hydroxy group peak of the monomer. In addition, the peaks of the polymer were found to be 7.51, 7.32, and 7.28 ppm, and the hydrogen peak of ethynyl at the terminal was shown at 3.16. As shown in ¹ H-NMR of the ethynyl phenol monomer of FIG. It can be seen that this is substituted.

As a result of ¹⁹ F-NMR analysis of FIG. 2, it was confirmed that only two peaks appeared and F dropped in the para position of the decafluorobiphenyl group by participating in the polymerization reaction.

As a result of IR analysis of FIG. 3, it was confirmed that the ethynyl group was substituted at the polymer terminal as a peak near 2900 cm ⁻¹ .

To prepare a salt removal membrane, sulfonated poly (arylene ether) (E-SPAE-HQ) containing a crosslinked structure at the end was dissolved in a solvent, filtered using a 0.45 μm PTFE membrane filter, and then cleaned. After pouring the polymer solvent onto the glass plate by casting method, it is allowed to stand in a 40 ^o C oven for 24 hours and then left in a 70 ^o C vacuum oven for 24 hours to place the membrane plated glass support near 200 ^o C. After the heat treatment was performed for 20 minutes or more, heat treatment was performed at 250 ^° C. to 260 ^° C. for 2 hours or more to crosslink the polymer at the polymer terminal. At this time, the solvent that can be used is a dipolar solvent, specifically N, N ' -dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO) or N-methylpyrroli You can use money (NMP).

Differential scanning calorimetry (DSC) was measured under nitrogen atmosphere at 10 ° C./min to confirm crosslinking of the terminal. As a result of DSC analysis of FIG. 4, when crosslinked at 250 ° C. for 20 minutes, an endothermic peak at 250 ° C. exists. This indicates that there is still a terminal, uncrosslinked ethynyl group. As time passes by 100 minutes, the endothermic peak disappears at 250 ° C. This indicates that the terminal ethynyl group is fully crosslinked.

The salt removal membrane (SPAE-HQ) prepared in Preparation Example 1 and the salt removal membrane (E-SPAE-HQ) having a crosslinked structure at the end thereof were evaluated for the basic performance of the salt removal membrane.

As shown in FIG. 5, the experiment was performed by adjusting the pressure using a gas control regulator (gas regulator) by connecting nitrogen gas to dead-end filtration (Sterlitech ™ HP4750 stirred cell, Sterlitech Corp WA) equipment. A certain amount of 250 ml of 2000 ppm NaCl solution was selected as an injection solution in a stirred cell (selection of this concentration was used in various papers (Polymer Paper, 49, 2243, Angew. Chem. Int. Ed, Paper 47, 6019). Concentration) The pressure was raised to 1000 psi (about 68 Mpa) with nitrogen gas. To maintain a constant concentration in the stirred cell, the mixture was mixed using a magnetic stirrer inside the stirred cell.

The nitrogen gas may be used in a variety of pressure from 10psi to 1000psi, the pressure is not limited to 1000psi. In addition, a stable argon gas which is commonly used may be used instead of the nitrogen gas.

In addition, a salt removal apparatus was manufactured as shown in FIG. 6.

After passing through the salt removing membrane to inject a constant concentration of 2000 ppm NaCl solution, separate the solution (permeated solution) and the concentrated NaCl concentrated water excluded by the salt removing membrane, and then mix the injected solution with an appropriate amount of distilled water again. The concentration is kept constant (2000 ppm NaCl) to continue circulation. At this time, the power to inject the solution was pumped and each line was maintained at a constant pressure of 400psi by the valve (regulator). The area of the above cell is 19cm2.

NaCl rejection was calculated from the following equation by comparing the concentration of the solution that passed through the salt film with the concentration of NaCl solution to be injected first.

% Removal = (1-C _p / C _f ) × 100

C _p (injection concentration): NaCl 2000ppm, C _f: permeation concentration, pressure: 1000psi, temperature: 25 ℃ (concentration was measured by a digital conductivity meter (Oakton con110, Cole Parmer).

The injected solution used is not limited to NaCl solution, the solution that can be used may be a solution in which salts such as MgSO4 solution, MgCl2 solution, KCl solution dissolved.

The time of permeation was also measured from the permeated amount of water, and the water permeation amount was calculated from the following equation.

Water Permeation Rate = {(V.l) / (A.t. △ p)}

V is the volume of water permeated, l is the thickness of the membrane, A is the area of the membrane, t is the time during permeation, and Δp is the pressure difference.

In addition, the dimensional stability of water as a salt removal membrane was expressed as the area swelling ratio (%) of the membrane to water.

For 24 hours, the salt removal membrane was impregnated with water, and the area of the membrane after drying was compared with that of the membrane after the impregnation, and the expansion ratio was calculated as in the following equation.

% Expansion = (A wet-A dry) x 100 / A dry,

 A wet is the wetted membrane area, A dry is the dry membrane area

The performances of the salt removal membrane are shown in Table 1 for the salt removal rate, water permeation rate, expansion rate, and ion exchange capacity.

In the case of cross-linking salt removal film (SPAE-HQ) and cross-linked salt removal film (E-SPAE-HQ), the NaCl removal rate was increased from 75.2% to 89.0%.

Referring to the salt removal process of the salt removal membrane made of the sulfonated poly (arylene ether) copolymer of the present invention, the salt removal membrane of the NaCl solution is permeated, as shown in the schematic diagram of FIG. The removal membrane is composed of a hydrophilic group and a hydrophobic group. As shown in the formula (1), the hydrophilic group is sulfonated, and in the environment in which water is present, SOO- and Na + or K + are dissociated. Since the +-charges of the dissociated ions present in the salt removing film are present in a large amount, Na + Cl-ions present in the NaCl solution do not pass through the salt removing film due to the charge repulsive force and pass only water. In addition, the sulfonated hydrophilic groups are present as copolymers to form nanochannels. These nanochannels have been identified so far in the literature (Journal of Membrnae Science, p. 243, p. 317). Because the sulfonated hydrophilic channels are nanoscale controlled, more and more Na + ions or Cl- ions pass through the salt removal membrane. It doesn't work.

The reason why the NaCl removal rate is increased by the crosslinking effect is that as shown in the schematic diagram of FIG. 7, ethyl groups (ethyl) at both ends are converted into a benzene structure by heat (250 ° C., 2 hours) to form a chemical crosslink. Chemical crosslinking has been known from several published publications (Chem. Mater, 8, 4519, Macromolecules, 34, 7817). Due to the chemical cross-linking of the end groups, the nanostructures are connected to each other like a net, and small water passes through it. Hydrated Na + ions or Cl- ions do not pass through the salt removal membrane because they are larger than water. This crosslinking effect increases the NaCl removal rate.

In addition, the expansion ratio for water was lowered from 31.5% to 29.3% due to the crosslinking effect, thereby increasing the performance as a salt removing membrane. The reason why the expansion ratio with respect to water is important as the salt removal film is that the salt removal film is operated in an environment in which water is present, so that if the area of the salt removal film is increased, the dimensional stability is lowered and the salt removal performance may be deteriorated. On the other hand, the water permeation rate is slightly reduced due to the crosslinking effect of the terminal structure.

However, as shown in the table below, SW30HR-380 manufactured by Dow Chemical, the best performing salt remover among the commercialized poly (amides) to date (see http://www.dow.com/liquidseps/) Compared to the salt removal membrane, the salt removal membrane according to the present invention shows a high performance as the salt removal membrane because the water permeation amount is about 5 times larger than the salt removal rate, although the salt removal rate is lowered.

In addition, the pressure of the commercially available poly (amide) salt removal film is usually used at 225 psi, because the salt removal film is damaged under high pressure, thereby reducing efficiency. However, the salt removal membrane of the present invention does not damage the salt removal membrane even when raised to a high pressure (1000psi), and appears to have excellent stability even at a high pressure.

Desalination film Ion exchange capacity
(meq / g) NaCl removal rate
(%) ^c Water permeation
(L · μm / m ² · h · bar) ^d Area expansion rate
(%) ^e Calculated ^a Experimental value ^b SPAE-HQ
(Crossing) 2.065 2.279 75.2 3.5 31.5 E-SPAE-HQ (After School) 2.065 2.123 89.0 2.8 29.3 Poly (amide) Salt Removal Film - - 99.7 0.61 ^f - a: Calculated as monomer mole ratio {IEC = (1000 / repeat unit molecular weight) x sulfonated ratio x number of sulfonic acid groups}
b: Soaked in 0.01 N NaCl solution for 24 hours, titrated with 0.01 N NaOH and measured (indicative of phenolphthalein).
c: removal rate (%) = (1-C _p / C _f ) × 100, C _p (injection concentration): NaCl 2000ppm,
C _f: permeation concentration, pressure: 1000psi, temperature: 25 ℃ (concentration is measured by digital conductivity meter (Oakton con110, Cole Parmer)
d: Water permeation was measured by dead-end filtration (Sterlitech TM HP4750 stirred cell, Sterlitech Corp WA)
Water permeability = {(Vl) / (AtΔp)} V is the volume of water permeated, l is the thickness of the membrane, A is the membrane area, t is the time of permeation, and Δp is the pressure difference
e: Expansion rate (%) is {expansion rate (%) = (A wet-A dry) x 100 / A dry, A wet is the area of the membrane in the wet state, A dry is the area of the membrane in the dry state}
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

Preparation Example 3: Preparation of salt removal membrane with sulfonated poly (arylene ether) copolymer (SFQK-BP-10)

Scheme 3

SFQK-BP-10 was synthesized in the same manner as in Preparation Example 1, except that 90% hydroquinonesulfonic acid potassium salt and 10% biphenol were used. The yield of the final product was at least 90%. Preparation of the salt removal film was also prepared in the same manner as in Preparation Example 1.

Preparation Example 4: Reverse osmosis membrane prepared from sulfonated poly (arylene ether) copolymer (E-SFQK-BP-10) containing a crosslinked structure at the end

Scheme 4

E-SFQK-BP-10 was synthesized in the same manner as in Preparation Example 2, except that 90% hydroquinonesulfonic acid potassium salt and 10% biphenol were used. The yield of the final product was at least 90%. Preparation of the salt removal film was also prepared in the same manner as in Preparation Example 2.

Salt removal membrane performance evaluation was also performed in the same manner as in Preparation Example 2.

In the case of the cross-linking salt removing film (SFQK-BP-10) and the cross-linked salt removing film (E-SFQK-BP-10), the NaCl removal rate was increased from 83.1% to 93.2% as shown in Table 2. As described in Preparation Example 2, the reverse osmosis membrane performance was increased because the expansion ratio for water was also lowered from 26.3% to 15.3% due to the crosslinking effect of the terminal structure and the nanostructure between molecules.

On the other hand, due to the crosslinking effect, water is hard to permeate the membrane, so the water permeation amount is further reduced from 2.4 (L · μm / m ² · h · bar) to 1.9 (L · μm / m ² · h · bar). However, as shown in the table below, the water permeation rate is about 3 to 4 times larger than that of the poly (amide) salt removal membrane, and although the salt removal rate is slightly lower, the water permeation rate shows a great performance. Excellent performance as a removal film.

Desalination film Ion exchange capacity
(meq / g) NaCl removal rate
(%) ^c Water permeation
(L · μm / m ² · h · bar) ^d Expansion rate
(%) ^e Calculated ^a Experimental value ^b SFQK-BP-110)
(Crossing) 1.963 1.969 83.1 2.4 26.3 E-SFQK-BP-10
(After school) 1.963 1.936 93.2 1.9 15.3 Poly (amide) Salt Removal Film - - 99.7 0.61 ^f - a: Calculated as monomer mole ratio {IEC = (1000 / repeat unit molecular weight) x sulfonated ratio x number of sulfonic acid groups}
b: Soaked in 0.01 N NaCl solution for 24 hours, titrated with 0.01 N NaOH and measured (indicative of phenolphthalein).
c: removal rate (%) = (1-C _p / C _f ) × 100, C _p (injection concentration): NaCl 2000ppm,
C _f: permeation concentration, pressure: 1000psi, temperature: 25 ℃ (concentration is measured by digital conductivity meter (Oakton con110, Cole Parmer)
d: Water permeability was measured with a dead-end filttration (Sterlitech ™ HP4750 stirred cell, Sterlitech Corp WA) instrument
Water permeability = {(Vl) / (AtΔp)} V is the volume of water permeated, l is the thickness of the membrane, A is the membrane area, t is the time of permeation, and Δp is the pressure difference
e: The expansion rate (%) is {expansion rate (%) = (A wet-A dry) x 100 / A dry, A wet is the wetted membrane area, Wdry is the dry membrane area}
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

Preparation Example 5 Preparation of Salt-Removing Membrane with Sulfonated Poly (Arylene Ether) Copolymer (SFQK-BP-20)

Scheme 5

SFQK-BP-10 was synthesized in the same manner as in Preparation Example 1, except that 80% hydroquinonesulfonic acid potassium salt and 20% biphenol were used. The yield of the final product was at least 90%. Preparation of the salt removal film was also prepared in the same manner as in Preparation Example 1.

Preparation Example 6 Reverse Osmosis Membrane Preparation with Sulfonated Poly (arylene Ether) Copolymer (E-SFQK-BP-20)

Scheme 6

E-SFQK-BP-20 was synthesized in the same manner as in Preparation Example 2, except that 80% hydroquinonesulfonic acid potassium salt and 20% biphenol were used. The yield of the final product was at least 90%. Preparation of the salt removal film was also prepared in the same manner as in Preparation Example 2.

The salt removal membrane performance evaluation was also conducted in the same manner as in Preparation Example 2. In the case of the salt-removing membrane (SFQK-BP-20) and the cross-linked salt-removing membrane (E-SFQK-BP-20) before crosslinking, as described in Preparation Example 2, the cross-linking effect of the terminal structure was used as a nanostructure between molecules and molecules. Compared with NaCl removal rate, it was increased from 87.3% to 96.4%, and the structure of nano-structure was formed due to the cross-linking effect of the terminal structure. Increased.

On the other hand, due to the crosslinking effect of the terminal structure, water is difficult to permeate the membrane, so the water permeation amount is slightly reduced from 1.9 (L · μm / m ² · h · bar) to 1.2 (L · μm / m ² · h · bar).

 However, as shown in the table below, the water permeation amount is about two times larger than that of the poly (amide) salt removing film, which shows excellent performance as the salt removing film. Compared to the commercially available poly (amide) salt removing membrane showing 99.7%, the salt removal rate was almost similar to 96.4% of the cross-linked salt removing membrane (E-SFQK-BP-20). In addition, the water permeation rate is also about 2 times higher, which is excellent as a salt removal membrane.

Desalination film Ion exchange capacity
(meq / g) NaCl removal rate
(%) ^c Water permeation
(L · μm / m ² · h · bar) ^d Expansion rate
(%) ^e Calculated ^a Experimental value ^b SFQK-BP-20
(Crossing) 1.860 1.893 87.3 1.9 20.6 E-SFQK-BP-20
(After school) 1.869 1.879 96.4 1.2 7.6 Poly (amide) Salt Removal Film - - 99.7 0.61 ^f - a: Calculated as monomer mole ratio {IEC = (1000 / repeat unit molecular weight) x sulfonated ratio x number of sulfonic acid groups}
b: Soaked in 0.01 N NaCl solution for 24 hours, titrated with 0.01 N NaOH and measured (indicative of phenolphthalein).
c: removal rate (%) = (1-C _p / C _f ) × 100, C _p (injection concentration): NaCl 2000ppm,
C _f: permeation concentration, pressure: 1000psi, temperature: 25 ℃ (concentration is measured by digital conductivity meter (Oakton con110, Cole Parmer)
d: Water permeation was measured with a dead-end filttration (Sterlitech ™ HP4750 stirred cell, Sterlitech Corp WA) instrument
Water permeability = {(Vl) / (AtΔp)} V is the volume of water permeated, l is the thickness of the membrane, A is the membrane area, t is the time of permeation, and Δp is the pressure difference
e: The expansion rate (%) is {expansion rate (%) = (A wet-A dry) x 100 / A dry, A wet is the wetted membrane area, Wdry is the dry membrane area}
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

Preparation Example 7 Preparation of Salt-Removing Membrane with Sulfonated Poly (Arylene Ether) Copolymer (SFQK-BP-30)

 Scheme 7

SFQK-BP-30 was synthesized in the same manner as in Preparation Example 1, except that 70% of hydroquinonesulfonic acid potassium salt and 30% of biphenol were used. The yield of the final product was at least 90%. Preparation of the salt removal film was also prepared in the same manner as in Preparation Example 1.

Preparation Example 8: Reverse osmosis membrane prepared from sulfonated poly (arylene ether) copolymer (E-SFQK-BP-30) containing a crosslinked structure at the end

Scheme 8

E-SFQK-BP-30 was synthesized in the same manner as in Preparation Example 2, except that 70% hydroquinonesulfonic acid potassium salt and 30% biphenol were used. The yield of the final product was at least 90%. Preparation of the salt removal film was also prepared in the same manner as in Preparation Example 2.

The salt removal membrane performance evaluation was also conducted in the same manner as in Preparation Example 2. In the case of the salt-removing membrane (SFQK-BP-20) and the cross-linked salt-removing membrane (E-SFQK-BP-20) before cross-linking, as described in Preparation Example 2, the cross-linking effect of the terminal structure is linked to the nano-molecular structure between molecules. In comparison, NaCl removal rate increased from 90.3% to 98.4% .By forming the nanostructured net structure due to the cross-linking effect of the terminal structure, the molecular-molecule linkage was formed, and the expansion ratio was lowered from 20.6% to 7.6%. Membrane performance increased.

On the other hand, due to the crosslinking effect of the terminal structure, the water permeation was difficult to permeate the membrane, so the water permeation amount was slightly decreased from 0.8 (L · μm / m ² · h · bar) to 0.7 (L · μm / m ² · h · bar).

 However, as shown in the table below, the water permeation amount is maintained higher than that of the poly (amide) salt removal membrane, showing excellent performance as a salt removal membrane. Compared to commercially available poly (amide) salt removal membranes showing 99.7%, the salt removal rate is almost close to 98.4% of the cross-linked salt removal membranes (E-SFQK-BP-20). In addition, the water permeation amount also shows a higher value, which is excellent as a salt removal membrane.

So far, the graph of comparing the salt removal membrane made from Preparation Example 1 to Preparation Example 8 according to the change of the sulfonic acid group, that is, the NaCl removal rate according to the ion exchange capacity, with the salt removal membrane before crosslinking and the salt removal membrane after crosslinking is shown in FIG. 8. .

As can be seen in FIG. 8, the sulfonic acid group gradually decreases, that is, the NaCl removal rate increases as the ion exchange capacity decreases. This is due to the fact that the size of the sulfonated hydrophilic group is gradually reduced, and the size of the hydrophobic group is gradually increased, as shown in the schematic diagram of FIG. That is, as the sulfonic acid group gradually decreases, the hydrophilic group becomes smaller in size, and the hydrated Na + ions and Cl- ions cannot penetrate. By this principle, as the sulfonic acid group decreases gradually, the NaCl salt removal rate increases gradually.

 In addition, in the case of the salt removal film crosslinked according to the present invention, the NaCl removal rate is higher in all cases than the salt removal film not crosslinked.

In addition, a graph comparing the change in water permeation (L · μm / m ² · h · bar) according to the change of the sulfonic acid group, that is, the ion exchange capacity, with the salt removal membrane before crosslinking and the salt removal membrane after crosslinking is shown in FIG. 9.

As can be seen in FIG. 9, as the sulfonic acid group decreases gradually, that is, the ion exchange capacity (IEC) decreases, the water permeation rate decreases, which decreases the water permeation rate because the ratio of the hydrophilic group -SOOH decreases in the molecular structure.

In addition, in the case of the crosslinked salt removing membrane, the water permeation amount is lower in all cases than the uncrosslinked salt removing membrane. As shown in the schematic diagram of FIG. 7, due to the network structure connected to each other between the molecular molecules through the terminal cross-linking structure, it seems that the density of molecules is higher and the water permeation amount is lowered. As a comparative example, the water permeation rate of the poly (amide) salt removal membrane was 0.71 (L / m ² · h · bar) compared to 0.61 (L / m ² · h · bar) in the case of the terminal crosslinked salt removal membrane (E-SFQK-BP-30). Μm / m ² h) is slightly higher, and the chlorine stability is also very good, showing a suitable performance as a salt removing film.

In addition, the graph of comparing the swelling ratio (%) change in water according to the composition of the sulfonic acid group, that is, the ion exchange capacity (IEC), with the salt removal membrane before crosslinking and the salt removal membrane after crosslinking is shown in FIG. 10. As can be seen in FIG. 10, the sulfonic acid group gradually decreases, that is, the ion exchange capacity (IEC) gradually decreases, and the swelling rate gradually decreases, which decreases the ratio of the hydrophilic group sulfonic acid group (SOOH) in the molecular structure and thus the ability to contain water. This is because the expansion rate decreases.

 In addition, in the case of the crosslinked salt removing film, the expansion ratio is lower in all cases than the uncrosslinked salt removing film. This is due to the net structure connected between the molecular chains through the terminal crosslinking structure, the expansion rate for water seems to be lowered.

Desalination film Ion exchange capacity
(meq / g) NaCl removal rate
(%) ^c Water permeation
(L · μm / m ² · h · bar) ^d Expansion rate
(%) ^e Calculated ^a Experimental value ^b SFQK-BP-30
(After school) 1.757 1.800 90.3 0.8 15.6 E-SFQK-BP-30
(After school) 1.757 1.796 98.4 0.7 7.0 Poly (amide) Salt Removal Film - - 99.7 0.61 ^f - a: Calculated as monomer mole ratio {IEC = (1000 / repeat unit molecular weight) x sulfonated ratio x number of sulfonic acid groups}
b: Soaked in 0.01 N NaCl solution for 24 hours, titrated with 0.01 N NaOH and measured (indicative of phenolphthalein).
c: removal rate (%) = (1-C _p / C _f ) × 100, C _p (injection concentration): NaCl 2000ppm,
C _f: permeation concentration, pressure: 1000psi, temperature: 25 ℃ (concentration is measured by digital conductivity meter (Oakton con110, Cole Parmer)
d: Water permeation was measured with a dead-end filttration (Sterlitech ™ HP4750 stirred cell, Sterlitech Corp WA) instrument
Water permeability = {(Vl) / (AtΔp)} V is the volume of water permeated, l is the thickness of the membrane, A is the membrane area, t is the time of permeation, and Δp is the pressure difference
e: The expansion rate (%) is {expansion rate (%) = (A wet-A dry) x 100 / A dry, A wet is the wetted membrane area, Wdry is the dry membrane area}
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

The salt-removing membrane (E-SFQK-BP-30) having a crosslinked structure at the end of the salt-removing membrane (SFQK-BP-30) prepared in Preparation Example 7 was impregnated with 3000 ppm NaOCl solution at pH 4 for 10 days. After the change of ATR-IR spectrum was confirmed.

The reason why the pH4 condition was chosen was that the ATR-IR spectrum before and after impregnation of NaOCl solution, as shown in FIG. 11 (see Journal of Membrane Science Paper, No. 300, p. 165) for poly (amide) salt removal membranes and pH10. Almost the same, for pH4, the change in the spectrum was confirmed. The reason for this is that the concentration of ClO- is high at pH 10, while the concentration of HClO is high at pH 4, and HClO acts on the chlorination reaction.

In the case of SFQK-BP-30 (pre-crosslinking) salt removal film of FIG. 12, the spectral change of ATR-IR could not be confirmed. There is no change in the spectrum of the aromatic C = C bonds at wave numbers 1650 cm-1 and 1405 cm-1, the position of the sulfonated (SO3) group at 1233 cm-1 and 1023 cm-1, and the change in this spectrum is also 10 days Is not visible while. Spectra of CH bonds at 890 cm-1 and 815 cm-1 also showed no change for 10 days. As the spectra showing the major chain bonds of the salt-removal membrane of E-SFQK-BP-30 were shown as it is, it showed no change in molecular structure, and the chlorine stability of the main chain was excellent for 10 days under 3000 ppm NaOCl solution pH4. It can be seen that it shows excellent performance as an excellent salt removal film.

In the case of the E-SFQK-BP-30 (post-crosslinked) salt removal membrane shown in Fig. 13, no change in the spectrum of ATR-IR could be confirmed. There is no change in the spectrum of the aromatic C = C bonds at wave numbers 1650 cm-1 and 1405 cm-1, the position of the sulfonated (SO3) group at 1233 cm-1 and 1023 cm-1, and the change in this spectrum is also 10 days Is not visible while. Spectra of C-H bonds at 890 cm-1 and 815 cm-1 also showed no change for 10 days. The spectra showing the major chain bonds of the salt-removing membrane of E-SFQK-BP-30 were shown intact, which shows no change in molecular structure and excellent chlorine stability of the main chain for 10 days under 3000 ppm NaOCl solution pH4. Excellent performance as a removal film.

As a comparative example, the poly (amide) salt removal film shown in Fig. 14 started to disappear from the hydrogen bonding spectrum of C = O and NH at 1610 cm-1 after 1 hour under the same conditions, and the C = O stretching spectrum at 1542 cm-1. It started to disappear, and after 24 hours, the two spectra completely disappeared. This shows that the amide bond of the poly (amide) salt removal membrane is degraded. In the case of the poly (amide) salt removal film, due to decomposition of the main chain, the salt removal rate is lowered, resulting in poor performance.

As described above, in the case of the salt removing film according to the embodiments of the present invention, it can be seen that it has a high chemical stability, in particular chlorine stability, compared to the commercialized poly (amide) salt removing film. In addition, in the case of the terminal crosslinked salt removal film (E-SFQK-BP-30), the salt removal rate (NaCl removal rate), which is the most important property as the salt removal film, shows the highest 98.4% property. Among the commercialized poly (amides), the best salt removal membrane to date is SW30HR-380 manufactured by Dow Chemical (http://www.dow.com/liquidseps/) and NaCl removal rate is up to 99.7%. In the case of the terminal crosslinked salt removal membrane (E-SFQK-BP-30), the performance of the salt removal rate of 98.4% is comparable.

In addition, the water permeation rate (L · μm / m ² · h · bar), which is an important performance as the salt removal membrane, is in the case of all salt removal membranes, the poly (amide) salt removal membrane (0.61 L / m ² · h · bar). The water permeation amount is higher than the case, showing excellent performance as the salt removing membrane.

In addition, the injection concentration of the 2000 ppm NaCl solution and 3000 ppm NaOCl pH4 solution was selected for 24 hours, using a device shown in Preparation Example 2, the NaCl removal rate and water permeation rate of the cross-linked salt removal membrane (E-SFQK- BP-30) was compared with the poly (amide) salt removal membrane. As shown in FIG. 15, the poly (amide) salt removal film showed the first 99.7% NaCl removal rate but decreased to about 20% after 6 hours as the NaCl removal rate was reduced to 50% in one hour (60 minutes). This is because, as shown in the ATR-IR spectrum of FIG. 14, the hydrogen bonding spectrum of C = O and N-H disappears at 1610 cm-1, and the C = O stretching spectrum disappears at 1542 cm-1. It is thought that the NaCl removal rate was reduced because the hydrated Na + ions or Cl-ions easily passed through the salt removal membrane as the structure of the molecule began to degrade.

In contrast, in the case of the crosslinked salt removing film (E-SFQK-BP-30), as shown in ATR-IR under the same conditions, there is no degradation of the molecular structure, and there is no change in NaCl removal rate for 24 hours.

In addition, when the water permeation amount was compared for 24 hours under the conditions as shown in FIG. 16, in the case of the poly (amide) salt removing membrane, the initial 0.61 (L / m ² · h · bar) was twice or more in about 1 hour. After 6 hours, it increased more than 4 times. As described above, water is permeable easily as C = O and NH bonds of the poly (amide) salt removal membrane start to decompose, and the water permeation amount seems to increase.

However, in the case of the cross-linked salt removing membrane (E-SFQK-BP-30), under the same conditions, there is almost no decomposition of the molecular structure as described above, so that there is no change in water permeation for 24 hours.

As a result of FIGS. 15 and 16, the cross-linked salt removing film (E-SFQK-BP-30) shows superior chemical stability under NaOCl conditions compared to the poly (amide) salt removing film.

Second embodiment

The sulfonated poly (arylene ether) copolymer according to the second embodiment of the present invention has a crosslinked structure at the end and is represented by the following Chemical Formula 4.

[Formula 2]

In Formula 4, SAr2 represents a sulfonated aromatic.

,

In addition, in Formula 4, SAr2 is

,

이다.or

to be.

또는

이다.In addition, in Formula 4, Ar represents non-sulfonated aromatic,

or

to be.

,

또는

이며, A는 탄소와 탄소가 직접 연결되어 있는 단일결합

,

또는

이며, E는 H, F, C1 ~ C5 또는

이다. 또한, Y에서

는 연결부분이 오르소, 메타, 파라 위치에 올 수 있는 벤젠구조를 나타내며,

는 불소(F)가 완전히 치환되어 있으며 연결부분이 오르소, 메타, 파라 위치에 올수 있는 벤젠구조를 의미한다. 즉

라 함은 연결부분이 오르소 (

), 메타 (

), 파라 (

) 위치에 올수 있는 불소가 완전히 치환된 벤젠구조들을 의미한다. 또한 E에서 H는 수소를, F는 불소를, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조를

는 L이 벤젠에 치환되어 있는 벤젠구조를 의미한다. 상기 구조식에서 L은 H, F, C1 ~ C5 를 나타내며, H는 수소를, F는 불소를, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조를 의미한다.In the molecular formula disclosed as an example of SAr 2 and Ar, Y is a single bond in which carbon is directly connected to carbon.

,

or

A is a single bond in which carbon is directly connected to carbon.

,

or

E is H, F, C1 to C5 or

to be. Also, in Y

Represents a benzene structure in which the linking moiety can be in the ortho, meta, or para position,

Refers to a benzene structure in which fluorine (F) is completely substituted and the linking portion can be at ortho, meta and para positions. In other words

Means the connection is ortho (

), Meta (

), Para (

Benzene structure that is completely substituted with fluorine which may be at position). In E, H represents hydrogen, F represents fluorine, and C1 to C5 represent an alkyl structure having hydrogen or fluorine substituted with 1 to 5 carbon atoms.

Means a benzene structure in which L is substituted for benzene. In the above structural formula, L represents H, F, C1 ~ C5, H means hydrogen, F is fluorine, C1 ~ C5 means an alkyl structure substituted with hydrogen or fluorine having 1 to 5 carbon atoms.

,

또는

이며 오르소, 메타, 파라 구조의 위치에 올 수 있다. Z에서 Y는 앞서 설명한 Y와 의미가 같다.In addition, Z is a bond in which carbon of benzene and -SO ₃ ^- M ⁺ are directly connected,

,

or

And can come in positions of ortho, meta, and para structures. Y in Z has the same meaning as Y described above.

M ⁺ is a counterion having a cationic charge and represents potassium ions (K ⁺ ), sodium ions (Na ⁺ ), alkyl amines ( ⁺ NR ₄ ), and the like, preferably potassium ions or sodium ions.

또는

이다. CM에서 R은 R1이 치환되어있는 삼중결합(ethynyl part)(R=

), 이중결합(vinyl part)(R=

) 또는

이며 오르소, 메타, 파라 구조의 위치에 올 수 있다. 상기 R에서 G는 탄소와 탄소가 직접 연결되어 있는 단일 결합,

또는

를 의미한다. 또한 R1은 H, F, C1 ~ C5 또는

이다. 상기 R1에서 H는 수소를, F는 불소를, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조, R2가 오르소, 메타, 파라 위치에 치환되어 있을 수 있는 벤젠구조(

)들을 갖는 치환체임을 나타낸다. R2는 H, X 또는 C1~C5이다. 상기 R2에서 H는 수소, C1 ~ C5는 탄소수가 1에서 5를 의미하는 수소 또는 플루오린이 치환되어 있는 알킬구조, X는 할로겐 원자(F, Cl, Br)에 해당되며, X의 경우는 다른 고분자 사슬의 하이드록시 그룹과의 중합을 이룰 수 있는 기능성 그룹이기도 하다. 또한 상기 화학식 1에서 k는 0.001 - 1.000 의 범위를 지니며, s = 1 - k 값을 가지며, n은 고분자 중합체의 반복단위(repeating unit)를 나타내며, n은 정수로서 10~500을 나타낸다.CM represents a crosslinkable moiety,

or

to be. In CM, R is an ethynyl part where R1 is substituted (R =

), The double part (R =

) or

And can come in positions of ortho, meta, and para structures. G in R is a single bond in which carbon and carbon are directly connected,

or

Means. R1 is also H, F, C1 to C5 or

to be. In R1, H is hydrogen, F is fluorine, and C1 to C5 are hydrogen or fluorine-substituted alkyl structures having 1 to 5 carbon atoms, R2 may be substituted at ortho, meta and para positions. Benzene Structure

It is a substituent having a). R2 is H, X or C1-C5. In R2, H is hydrogen, C1 to C5 is an alkyl structure substituted with hydrogen or fluorine having 1 to 5 carbon atoms, X is a halogen atom (F, Cl, Br), and in case of X another polymer It is also a functional group capable of polymerizing with the hydroxy group of the chain. In addition, in Chemical Formula 1, k has a range of 0.001-1.000, has a value of s = 1-k, n represents a repeating unit of the polymer, and n represents 10 to 500 as an integer.

 The polycondensation reaction and the crosslinkable group introduction reaction for the synthesis of sulfonated poly (arylene ether) copolymers containing a crosslinked structure at the terminal of the invention are selected from hydroxides, carbonates and sulfates of alkali or alkaline earth metals as bases. An inorganic base may be used, or an organic base selected from conventional amines including ammonia may be used.

As the reaction solvent, aprotic polar solvents or methylene chlorides such as N -methylpyrrolidone (NMP), dimethylformamide (DMF), N, N -dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO) Protic polar solvents such as (CH ₂ Cl ₂ ), chloroform (CH ₃ Cl) and tetrahydrofuran (THF) may be used, and benzene, toluene, xylene or the like may be used as a non-solvent.

The present invention is a salt removal or separation membrane made of sulfonated poly (arylene ether) copolymer containing a crosslinked structure at the terminal having the above structure is currently commercialized in the film forming ability, mechanical stability, physical properties, salt removal rate, etc. It has high chemical resistance (especially chlorine stability) while maintaining similar salt removal rate as poly (amide) membrane used as salt removal membrane, and high dimensional stability (water swelling) due to crosslinked structure of molecular chain Rate).

Such the present invention will be described in more detail based on the following production examples, but the present invention is not limited thereto.

Preparation Example 9 Preparation of Sulfonated Poly (Arylene Ether Sulfon) -FBA50 Copolymer (SPAESO-FBA50)

SPAESO-FBA50 was synthesized in the same manner as in Preparation Example 1 except that 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone (3,3'-disulfonated-4, 0.5 mole ratio dihalide monomer of 4'-dichlorodiphenyl sulfone) and unsulfonated monomer and 0.5 mole ratio dihalide monomer of 4,4'-dichlorodiphenyl sulfone and 4,4'-dichlorodiphenyl sulfone A dihydroxy monomer in a 1 mole ratio of 4 '-(hexafluoroisopropylidene) diphenol ((4,4'-hexafluoroisopropylidene) diphenol) was used. In addition, the polymerization was carried out by changing the temperature to 150-180 ^° C than in Preparation Example 1. The yield of the final product was at least 87%.

Preparation Example 10 Preparation of sulfonated poly (arylene ether sulfone) -FBA50 copolymer (E-SPAESO-FBA50) containing a crosslinked structure at the end

E-SPAESO-FBA50 was synthesized in the same manner as in Preparation Example 3, except that SPAESO-FBA50 was used as the sulfonated polymer, and the reaction temperature was different from that carried out in the range of 150 to 180 ^° C.

Preparation Example 11 Preparation of Sulfonated Poly (Arylene Ether Ketone) -FBA50 Copolymer (SPAEK-FBA50)

SPAEK-FBA50 was synthesized in the same manner as in Preparation Example 1 except that 3,3'-disulfonated-4,4'-difluorobenzophenone (3,3'-disulfonated-4) was used as a sulfonated monomer. 0.5 mole ratio of 4,4'-difluorobenzophenone (4,4'-difluorobenzophenone) and 0.5 mole ratio of dihalide monomer and 4,4'-difluorobenzophenone A dihydroxy monomer in 1 mole ratio of 4 '-(hexafluoroisopropylidene) diphenol ((4,4'-hexafluoroisopropylidene) diphenol) was used. In addition, the polymerization was carried out by changing the temperature to 150-180 ^° C than in Preparation Example 1. The yield of the final product was at least 93%.

Preparation Example 12 Preparation of Sulfonated Poly (Arylene Ether Ketone) -FBA50 Copolymer (E-SPAEK-FBA50) Containing a Crosslinked Structure at the Terminal

E-SPAEK-FBA50 was synthesized in the same manner as in Preparation Example 3, except that SPAEK-FBA50 was used as the sulfonated polymer, and the reaction temperature was different from that performed in the range of 150 to 180 ^° C.

As described above, according to embodiments of the present invention, a salt removing film made of a sulfonated poly (arylene ether) copolymer containing a crosslinked structure at its terminal is used as a salt removing film currently commercially available in salt removal rate. It has high chemical resistance (particularly chlorine stability) while maintaining similar salt removal rate as amide) membrane, and has high dimensional stability (water swelling ratio) for water due to the crosslinked structure of molecular chain.

1 shows a ¹ H-NMR spectrum of a sulfonated poly (arylene ether) salt removing film (E-SPAE-HQ) containing a crosslinked structure at the terminal of the present invention.

Figure 2 shows the ¹⁹ F-NMR spectrum of the sulfonated poly (arylene ether) salt removing film (E-SPAE-HQ) containing a crosslinked structure at the end of the present invention.

Figure 3 shows the FT-IR spectrum of the sulfonated poly (arylene ether) salt removing film (E-SPAE-HQ) containing a crosslinked structure at the terminal of the present invention.

Figure 4 is a graph showing the endothermic peak of DSC to confirm the terminal crosslinking of the sulfonated poly (arylene ether) (E-SPAE-HQ) salt removal membrane containing a cross-linked structure at the end of the present invention.

5 is a schematic diagram connected with a dead-end filttration (Sterlitech ™ HP4750 stirred cell, Sterlitech Corp WA), which is a salt removal performance evaluation device, and nitrogen gas.

6 is a schematic diagram of a cross-flow cell (GE Osmonics) as a salt removal performance evaluation device.

Figure 7 is a schematic diagram showing the process of salt removal of the sulfonated poly (arylene ether) salt removing film containing a crosslinked structure at the end of the present invention.

8 is a schematic diagram of the nano-size net structure of the sulfonated poly (arylene ether) salt removal membrane due to crosslinking at the thermally terminated ends of the present invention.

Figure 9 is a graph showing the change in NaCl removal rate according to the ion exchange capacity (IEC) of the sulfonated poly (arylene ether) salt removing membrane containing a crosslinked structure at the end of the present invention.

10 is a graph showing the change in water permeation rate according to the ion exchange capacity (IEC) of the sulfonated poly (arylene ether) salt removing membrane containing a crosslinked structure at the terminal of the present invention.

FIG. 11 is a graph showing the change in area expansion rate (%) of water according to the ion exchange capacity (IEC) of a sulfonated poly (arylene ether) salt removing membrane containing a crosslinked structure at the terminal of the present invention.

12 is a graph showing the ATR-IR spectrum at pH 4, pH 7, pH 10 after impregnating a poly (amide) salt removing membrane in 100 ppm NaOCl solution in the Journal of Membrane Science article, No. 300, page 165.

Figure 13 is a graph showing the ATR-IR spectrum at pH 4 conditions after impregnating a sulfonated poly (arylene ether) salt removing membrane containing no crosslinking structure at the end of the present invention in 3000ppm NaOCl solution.

14 is a graph showing the ATR-IR spectrum at pH 4 conditions after impregnating a sulfonated poly (arylene ether) salt removing membrane including a crosslinked structure at the end of the present invention in 3000 ppm NaOCl solution.

FIG. 15 is a graph showing the ATR-IR spectrum at pH 4 after impregnating a poly (amide) salt removing film in a 3000 ppm NaOCl solution. FIG.

FIG. 16 is a graph showing a change in NaCl removal rate with time for 24 hours by injecting a solution in 3000 ppm NaOCl and 2000 ppm NaCl pH4 conditions of a poly (amide) salt removing film and a terminal crosslinked salt removing film (E-SFQK-BP30) to be.

FIG. 17 is a graph showing a change in water permeation rate over time by injecting a solution under conditions of 3000 ppm NaOCl and 2000 ppm NaCl pH4 of a poly (amide) salt removing membrane and a terminal crosslinked salt removing membrane (E-SFQK-BP30) .

Claims (10)

Salt-removing membrane consisting of a sulfonated poly (arylene ether) copolymer having a crosslinking structure at the terminal represented by the following formula (1). [Formula 1]

In Formula 1, SAr1 represents a sulfonated aromatic, Ar represents a non sulfonated aromatic, and CM represents a crosslinkable moiety. In addition, in Chemical Formula 1, k has a range of 0.001-1.000, has a value of s = 1-k, n represents a repeating unit of the polymer, and n represents 10 to 500 as an integer. The method of claim 1, wherein SAr1 is

,

or

Z is a bond in which benzene carbon and -SO ₃ ^- M ⁺ are directly connected to each other,

,

or

Y is a single bond where carbon and carbon are directly connected

,

,

,

,

or

A is a single bond in which carbon is directly connected to carbon.

or

E is H, F, C1 to C5 or

Wherein L is H, F, C1 to C5, and M ⁺ is a salt-depleted membrane made of a sulfonated poly (arylene ether) copolymer, characterized in that it is a counterion having a cationic charge. 3. The salt removal membrane according to claim 2, wherein the counterion having a cationic charge is potassium ion, sodium ion or alkyl amine. The method of claim 1, wherein Ar is

or

Y is a single bond in which carbon is directly connected to carbon.

,

,

,

or

A is a single bond in which carbon is directly connected to carbon.

,

or

E is H, F, C1 to C5 or

L is H, F, salt removal film consisting of a sulfonated poly (arylene ether) copolymer, characterized in that. The method of claim 1, wherein the CM

or

R is a triple bond in which R1 is substituted (R =

), The double part (R =

) or

G is a single bond in which carbon and carbon are directly connected,

or

R1 is H, F, C1 to C5 or

to be. R2 is H, X or salt removal film consisting of a sulfonated poly (arylene ether) copolymer, characterized in that. The sulfonated membrane of claim 1, wherein the salt removing membrane is made of a reverse osmosis membrane, an UF membrane (Ultra Filteration membrane), an NF membrane (Nano Filteration membrane), or an MF membrane (Micro Filteration membrane). Membrane consisting of poly (arylene ether). Salt-removing membrane consisting of a sulfonated poly (arylene ether) copolymer having a crosslinking structure at the terminal represented by the following formula (2). [Formula 2]

In Formula 4, SAr2 represents a sulfonated aromatic, Ar represents a non sulfonated aromatic, and CM represents a crosslinkable moiety. In addition, in Chemical Formula 4, k has a range of 0.001-1.000, has a value of s = 1-k, n represents a repeating unit of the polymer, and n represents 10 to 500 as an integer. The method of claim 7, wherein SAr2 is

,

or

And Ar is

or

Y is a single bond of carbon and carbon directly connected

,

or

A is a single bond in which carbon is directly connected to carbon.

or

E is H, F, C1 to C5 or

L is H, F, C1 ~ C5, Z is a bond in which carbon of benzene and -SO ₃ ^- M ⁺ is directly connected,

,

or

M ⁺ is a salt removal membrane composed of sulfonated poly (arylene ether) copolymer, characterized in that the potassium ion, sodium ion or alkyl amine as a counter ion having a cationic charge. The method of claim 8, wherein the CM

or

R in CM is an ethynyl part in which R 1 is substituted (R =

), The double part (R =

) or

R in G is a single bond in which carbon and carbon are directly connected,

or

R1 is H, F, C1 to C5 or

R 2 is H, X or C 1 to C 5, and X is a halogenated poly (arylene ether) copolymer, characterized in that a halogen atom. The sulfonated membrane of claim 8, wherein the salt removal membrane is made of a reverse osmosis membrane, an UF membrane (Ultra Filteration membrane), an NF membrane (Nano Filteration membrane), or an MF membrane (Micro Filteration membrane). Membrane consisting of poly (arylene ether).

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