KR20110034842A - Polymer desalination membrane comprising sulfonated poly(arylene ether) copolymers having crosslinkable moiety combined in the chain of polymers - Google Patents

Abstract

PURPOSE: A polymer desalination membrane produced with a sulfonated poly(arylene ether) copolymer forming a cross-linking structure is provided to secure the high salt removal rate and the excellent dimensional stability for the moisture of the membrane. CONSTITUTION: A polymer desalination membrane contains a cross-linking compound of a sulfonated poly(arylene ether) copolymer marked with chemical formula 1. In the chemical formula 1, SAr1 is a sulfonated aromatic group, and Ar is an un-sulfonated aromatic group. CM is a cross-linkable moiety, and n is a polymerization degree of sulfonated poly(arylene ether) with the value of 10~500.

Description

Polymer desalination membrane comprising sulfonated poly (arylene ether) copolymers having crosslinkable moiety combined in the chain of polymers}

The present invention relates to a salt removal membrane, and more particularly to a polymer salt removal membrane comprising a crosslinking compound of sulfonated poly (arylene ether) copolymer.

 In order to obtain fresh water from seawater, components dissolved or suspended in seawater must be removed to meet the water and drinking water standards. Currently, commercially available seawater desalination methods include reverse osmosis and evaporation. The reverse osmosis method is widely used because it has relatively superior energy efficiency in terms of energy efficiency by using osmosis as a reverse method to almost eliminate ionic substances in seawater and pass pure water through a membrane for removing salt. .

However, the most widely used polyamide composite reverse osmosis membrane is manufactured through interfacial polymerization, so the surface is coarse to obtain a high fouling effect (a small amount of foreign matter slowly accumulates on the surface to reduce water permeation and salt removal rate). In addition, chlorine treatment (NaOCl solution treatment) is required to improve the performance degradation caused by bio fouling (generated by adsorption of bacteria or microorganisms on the membrane surface). Even in the main chain bond easily broken there is a problem that the salt removal rate is significantly reduced.

Thus, in the US Patent No. 4,419,486, a reverse osmosis membrane having high chlorine stability was developed using a sulfonated poly (arylene ether ketone) copolymer, but in this case, there is a problem of low salt removal rate (about 70%).

Therefore, there is a need for the development of a salt removal membrane having a high chemical stability, particularly a chlorine stability and a high salt removal rate while having mechanical stability against high pressure above the osmotic pressure applied to separate the ionic material and pure water. to be.

The technical problem to be solved by the present invention is to provide a polymer salt removal membrane having a high salt removal rate, excellent chemical and mechanical stability.

One aspect of the present invention to achieve the above technical problem provides a polymer salt removal film comprising a crosslinking compound of sulfonated poly (arylene ether) copolymer represented by the following formula (1).

 [Formula 1]

Wherein SAr1 represents sulfonated aromatic, Ar represents non sulfonated aromatic, CM represents crosslinkable moiety,

b and k each have a value of 0.001 to 1.000, d has a value of 1-b, s has a value of 1-k,

n has a value of 10 to 500 as the degree of polymerization of sulfonated poly (arylene ether).

SAr1 is

,

,

,

,

,

또는

일 수 있고,

,

,

,

,

,

or

Can be,

,

또는

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

,

or

Can be,

M ⁺ is a counterion with a cationic charge, which may be potassium ions (K ⁺ ), sodium ions (Na ⁺ ) or alkylammonium ions ( ⁺ NR ₄ ).

Ar is

,

,

또는

일 수 있다.

,

,

or

Can be.

The CM is

,

또는

일 수 있고,

,

or

Can be,

(m은 0 또는 1)일 수 있으며,J is

(m can be 0 or 1),

), R1이 치환되어 있는 에틸렌 함유기(R =

) 또는

의 가교성 관능기일 수 있고,R is an ethynyl group in which R 1 is substituted (R =

), The ethylene-containing group in which R 1 is substituted (R =

) or

It may be a crosslinkable functional group of,

일 수 있으며,R1 is a C1 to C5 alkyl group substituted with H, F, H or F, or

Can be,

,

또는

일 수 있고,G is a single bond where carbon and carbon are directly connected,

,

or

Can be,

R2 may be H, X (halogen atom), or a C1 to C5 alkyl group substituted with H or F.

Y in SAr1, Ar and CM is

,

,

,

,

,

,

,

,

,

,

또는

일 수 있고,A single bond where carbon and carbon are directly connected,

,

,

,

,

,

,

,

,

,

,

or

Can be,

,

,

,

,

,

,

또는

일 수 있으며,A is a single bond in which carbon and carbon are directly connected,

,

,

,

,

,

,

or

Can be,

일 수 있고,E is a C1 to C5 alkyl group substituted with H, CH ₃ , F, CF ₃ , H or F, or

Can be,

L may be H, F, or a C1 to C5 alkyl group substituted with H or F.

As described above, according to the present invention, the polymer salt removing film formed by the crosslinking reaction of the sulfonated poly (arylene ether) copolymer has a high salt removing rate, and is in terms of chemical stability, mechanical stability, and dimensional stability against moisture. Shows excellent effect.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Therefore, it is to be understood that all changes, equivalents, and substitutes included in the spirit and scope of the present invention are included.

Sulfonated Poly ( Arylene Ether ) Of the copolymer Crosslinking  Polymer salt removal membrane containing a compound

Polymer salt removing membrane according to an embodiment of the present invention includes a crosslinking compound of sulfonated poly (arylene ether) copolymer represented by the following formula (1).

[Formula 1]

In Formula 1, SAr1 represents a sulfonated aromatic, for example,

,

,

,

,

,

또는

일 수 있다.

,

,

,

,

,

or

Can be.

,

또는

일 수 있다. 여기서, 일 예로

는 연결부분이 오르소(ortho), 메타(meta), 파라(para) 위치에 올 수 있는 벤젠구조를 의미한다. 본 발명의 명세서서 전체에 있어서 이러한 형태의 분자 표현은 동일한 의미로 해석된다.Wherein Z is carbon and -SO ₃ of ^benzene are combined with M ⁺ is connected directly,

,

or

Can be. Here, as an example

Refers to a benzene structure in which the linking portion may be at ortho, meta, and para positions. Throughout the specification of the present invention, the molecular expression of this form is interpreted with the same meaning.

M ⁺ is a counterion having a cationic charge, and may be, for example, potassium ions (K ⁺ ), sodium ions (Na ⁺ ) or alkylammonium ions ( ⁺ NR ₄ ), preferably potassium ions or Sodium ions.

In Formula 1, Ar represents non-sulfonated aromatic, for example,

,

,

또는

일 수 있다.

,

,

or

Can be.

,

,

,

,

,

,

,

,

,

,

또는

일 수 있고,In SAr1 and Ar, Y is a single bond in which carbon and carbon are directly connected,

,

,

,

,

,

,

,

,

,

,

or

Can be,

,

,

,

,

,

,

또는

일 수 있으며,A is a single bond in which carbon and carbon are directly connected,

,

,

,

,

,

,

or

Can be,

일 수 있고,E is a C1 to C5 alkyl group substituted with H, CH ₃ , F, CF ₃ , H or F, or

Can be,

L may be H, F, or a C1 to C5 alkyl group substituted with H or F.

는 연결부분을 제외하고서는 벤젠고리가 F(불소)로 완전히 치환되어 있는 벤젠구조를 의미한다. 본 발명의 명세서서 전체에 있어서 이러한 형태의 분자 표현은 동일한 의미로 해석된다. 즉,

라 함은 연결부분이 오르소 (

), 메타 (

), 파라 (

) 위치에 올 수 있는 F로 완전히 치환된 벤젠구조들을 의미한다.Here, as an example

Denotes a benzene structure in which the benzene ring is completely substituted with F (fluorine) except for the connecting portion. Throughout the specification of the present invention, the molecular expression of this form is interpreted with the same meaning. In other words,

Means the connection is ortho (

), Meta (

), Para (

Benzene structures completely substituted with F which may be at

In Chemical Formula 1, CM represents a crosslinkable moiety, for example,

,

또는

일 수 있다.

,

or

Can be.

(m은 0 또는 1)일 수 있으며,J is

(m can be 0 or 1),

), R1이 치환되어 있는 에틸렌 함유기(R =

) 또는

등의 가교성 관능기일 수 있고,R is an ethynyl group in which R 1 is substituted (R =

), The ethylene-containing group in which R 1 is substituted (R =

) or

Crosslinkable functional groups such as

일 수 있으며,R1 is a C1 to C5 alkyl group substituted with H, F, H or F, or

Can be,

,

또는

일 수 있고,G is a single bond where carbon and carbon are directly connected,

,

or

Can be,

R2 may be H, X (halogen atom), or a C1 to C5 alkyl group substituted with H or F.

Y in the CM is the same as Y described above.

In Formula 1, b and k each have a value of 0.001 to 1.000, d has a 1-b value, and s has a 1-k value. K, s, b and d correspond to the molar ratios of each monomer participating in the reaction.

In Chemical Formula 1, n has a value of 10 to 500 as a degree of polymerization of sulfonated poly (arylene ether) copolymer.

Sulfonated Poly ( Arylene Ether ) Of the copolymer Crosslinking  Preparation of Polymer Salt-Removing Membrane Containing Compound

First, sulfonated poly (arylene ether) copolymer can be prepared by the following Scheme 1.

Scheme 1

[Formula 1]

Scheme 1 illustrates a reaction process for preparing a polymer of formula 1 (sulfonated poly (arylene ether) copolymer). The method of preparing the polymer according to Chemical Formula 1 is a condensation polymerization method, and specific monomers participating in the reaction may vary depending on the desired salt removing membrane.

In Reaction Scheme 1, k has a value of 0.001 to 1.000, has a value of s = 1-k, b has a value of 0.001 to 1.000, and has a value of d = 1-b. K, s, b and d correspond to the molar ratios of each monomer participating in the reaction.

In the preparation of Scheme 1, first, the sulfonated hydroxy monomer (HO-SAr1-OH) and the unsulfonated hydroxy monomer (HO-Ar-OH) are activated. The activation process is a process of activating the hydroxy monomer to facilitate the polycondensation reaction with the following halide monomer.

The crosslinkable halide monomer (X-CM-X) and the unsulfonated halide monomer (X-Ar-X) are then introduced into the polycondensation reaction. However, the crosslinkable halide monomer (X-CM-X) and the unsulfonated halide monomer (X-Ar-X) may be added to the manufacturing process in the same step as the hydroxy monomer.

In the above process, a base, a non-solvent and a polar solvent are appropriately used, and a polycondensation reaction is carried out for 1 to 100 hours in a temperature range of 0 ° C to 300 ° C to prepare a copolymer represented by Chemical Formula 1.

As the base, an inorganic base selected from hydroxides of alkali metals or alkaline earth metals, carbonates and sulfates, or organic bases selected from common amines including ammonia may be used.

Among the polar solvents, aprotic polar solvents include N-methylpyrrolidone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc) or dies. Methyl sulfoxide (DMSO) may be used, and methylene chloride (CH ₂ Cl ₂ ), chloroform (CH ₃ Cl) or tetrahydrofuran (THF) may be used as a protic polar solvent. . In addition, as the non-solvent, benzene, toluene or xylene may be used.

Next, the copolymer prepared by the above reaction is precipitated and dried to obtain a solid product. The solid copolymer is again dissolved in a suitable polar solvent and then applied to a support. Subsequently, a solvent is removed through heat treatment, and a polymer salt removing film including a crosslinking compound of a sulfonated poly (arylene ether) copolymer is prepared by inducing a crosslinking reaction of a crosslinkable functional group present in the copolymer. do.

The coating method may be spin coating, dip coating, ink-jet printing, spray coating, screen printing, casting or doctor blade. blade) can be carried out by an appropriately selected method.

The heat treatment step may be performed at a temperature at which a complete crosslinking reaction of the crosslinkable functional group may occur, and this temperature may be measured by differential calorimetry (DSC).

The salt removal mechanism by the polymer salt removal film of the present invention has not been clearly identified, but the principle thereof is briefly described as follows.

1 is a schematic diagram showing a salt removing mechanism by the polymer salt removing film of the present invention.

2 is a schematic diagram showing a network structure formed by internal crosslinking of sulfonated poly (arylene ether) copolymer.

As shown in FIG. 1, the salt removal membrane of the present invention is composed of hydrophobic domains occupied by the main chain of sulfonated poly (arylene ether) copolymer and hydrophilic domains occupied by sulfonic acid group. Can be. In this case, since the sulfonated hydrophilic group is present as a copolymer, hydrophilic nanochannels may be formed in the salt removing layer (these nanochannels have been confirmed by various literatures. Journal of Membrnae Science, 243). See pp. 317).

In particular, in an environment where water is present, SO ₃ ⁻ ions and paired ions such as Na ⁺ or K ⁺ are dissociated in the hydrophilic domain (the pair is omitted on the drawing).

For example, the NaCl aqueous solution is filtered by the salt removing membrane, and Na ⁺ and Cl ⁻ ions present in the NaCl aqueous solution are prevented from electrostatic repulsion by a large amount of dissociated + and − ions present in the salt removing membrane. It will be difficult to pass through the salt removal membrane. In addition, since the hydrophilic channel formed in the salt removing membrane is controlled to a nano size, hydrated Na ⁺ ions or Cl ⁻ ions are relatively more difficult to pass through the salt removing membrane and the water selectivity can be increased.

In addition, as shown in FIG. 2, the network structure due to internal crosslinking of the copolymer forming the salt removing film forms a network having nano-sized pores in the salt removing film, thereby allowing small water molecules to pass therethrough and water molecules. Larger hydrated Na ⁺ ions and hydrated Cl ⁻ ions do not pass through.

For example, when the sulfonated poly (arylene ether) copolymer having an ethynyl group as a crosslinkable functional group in the polymer chain is heat-treated at an appropriate temperature, the ethynyl group in the polymer chain is converted into a benzene structure by heat. Change and form a crosslink. Crosslinking formation by the binding of three ethynyl groups has been known from several previously published documents (Chem. Mater Paper 8, page 4519, Macromolecules Paper 34, page 7817).

The formation of such a crosslink can make nano-sized pores in the salt removing membrane to act as a filtration membrane of the aqueous salt solution. In addition, as the degree of polymerization of the crosslinkable functional group increases in the copolymer, a denser network structure is formed, thereby improving the salt removal rate of the salt removing film.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are merely to aid the understanding of the present invention, and the present invention is not limited thereto.

Preparation Example 1 Preparation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-100) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAEDF-mSXb-100)

Sulfonated Poly ( Arylene Ether ) Copolymer ( SPAEDF - mSXb -100)

Scheme 2

Hydroquinonesulfonic acid potassium salt (20 mmol) in a 250 ml two-necked round flask equipped with agitator, nitrogen introduction tube, magnetic stub and Dean-Stark (azeotropic distillation) , k = 1) and K ₂ CO ₃ (1.15 equiv) and N, N-dimethylacetamide (DMAc) (60 ml) and benzene (20 ml) were added.

Activation step was carried out for 6 to 8 hours after raising the temperature to 105 ℃ to 110 ℃ range over 6 hours. Water produced as a by-product during the reaction was removed by azeotropic distillation with benzene, one of the reaction solvents, and benzene was removed from the reactor after completion of the activation step. Thereafter, the molar ratio of 1-ethynyl-3,5-difluorobenzene and decafluorobiphenyl was 1 mmol: 19 mmol (b: d = 0.05: 0.95), and the reaction temperature was maintained at 110 ° C and reacted for at least 12 hours. After the reaction was completed, precipitated in 500 ml of ethanol, washed several times with water and ethanol, and then vacuum dried at 60 ℃ 3 days. The final product was obtained as a light brown solid, yielding at least 90%.

The final product is named SPAEDF-mSX5-100. 5 followed by SX indicates that the molar ratio of b is 0.05, which is converted into a percentage.

In addition, the molar ratio of starting material 1-ethynyl-3,5-difluorobenzene and decafluorobiphenyl was 2 mmol: 18 mmol (b: d = 0.1: 0.9), 3 mmol: 17 mmol (b: d = 0.15: 0.85), 4 mmol: 16 mmol (b: d = 0.2: 0.8), 5 mmol: 15 mmol (b: d = 0.25: 0.75) , 6 mmol: 14 mmol (b: d = 0.3: 0.7), 7 mmol: 13 mmol (b: d = 0.35: 0.65), 8 mmol: 12 mmol (b: d = 0.4: 0.6), 9 mmol: 11 Sulfonated poly (arylene ether) copolymer (SPAEDF-) having a crosslinkable functional group inside the polymer chain with mmol (b: d = 0.45: 0.55) and 10 mmol: 10 mmol (b: d = 0.5: 0.5) mSXb-100) was prepared. Copolymers formed according to the difference in the molar ratio of the starting material are SPAEDF-mSX10-100, SPAEDF-mSX15-100, SPAEDF-mSX20-100, SPAEDF-mSX25-100, SPAEDF-mSX30-100, SPAEDF-mSX35-100, Named SPAEDF-mSX40-100, SPAEDF-mSX45-100, SPAEDF-mSX50-100. Each yield was over 90%.

3 shows the ¹ H-NMR spectrum of a sulfonated poly (arylene ether) copolymer (SPAEDF-mSXb-100). Referring to Figure 3, it can be seen that there is no peak of the hydroxyl group (hydroxyl group) of the monomer, which means that the hydrogen of the hydroxyl group by the condensation polymerization reaction. Peaks of sulfonated benzene hydrogens were found at 7.51, 7.32, 7.18 ppm, peaks of benzene hydrogen with ethynyl group and peaks of ethynyl hydrogen were found at 6.81, 6.3 and 4.3 ppm, respectively. In addition, it can be seen that as the ratio of 1-ethynyl-3,5-difluorobenzene is increased to 10%, 15%, and 25%, each corresponding peak increases slightly, which is a sulfonated poly (arylene). Ether) means that the degree of polymerization of the crosslinkable functional groups in the copolymer is increased.

Sulfonated Poly ( Arylene Ether ) Copolymer ( SPAEDF - mSXb Polymer salt removal membrane using -100 SPAEDF-mSXb-100)  Produce

The sulfonated poly (arylene ether) copolymer (SPAEDF-mSXb-100) prepared above was dissolved in a solvent and then filtered using a PTFE membrane filter of 0.45 μm to 1 μm. At this time, as a solvent which can be used, it is a dipolar solvent specifically N, N- dimethylformamide (DMF), N, N- dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO) Or N-methylpyrrolidone (NMP) can be used. Thereafter, the polymer solution was poured into a clean glass plate support by a casting method, and then left in a 40 ° C. oven for 24 hours. The solvent was then completely removed by standing in a 70 ° C. vacuum oven for at least 24 hours.

Subsequently, heat treatment was performed for at least 30 minutes at a temperature of 80 ° C to 350 ° C, preferably at 240 ° C to 260 ° C, for at least 2 hours for crosslinking in the polymer chain. However, the heat treatment temperature may be selected in an appropriate range depending on the type of the crosslinkable functional group.

Here, when the polymer salt-base film is prepared using a sulfonated poly (arylene ether) copolymer (SPAEDF-mSXb-100), the polymer salt-removal film is named C-SPAEDF-mSXb-100.

Preparation Example 2 Preparation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-6FK) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAEDF-mSXb-6FK)

Sulfonated Poly ( Arylene Ether ) Copolymer ( SPAEDF - mSXb -6 FK Manufacturing

Scheme 3

In a 250 ml two-necked round flask equipped with agitator, nitrogen introduction tube, magnetic stub and Dean-Stark (azeotropic distillation), hydroquinonesulfonic acid potassium salt and 4, The molar ratio of 4 '-(hexafluoroisopropylidene) diphenol (4,4'-(hexafluoroisopropylidene) diphenol) was added as 14 mmol: 6 mmol (k: s = 0.70: 0.30), followed by K ₂ CO ₃ (1.15 equiv. Ratio) and N, N-dimethylacetamide (DMAc) (60 ml) and benzene (20 ml) were added.

Activation step was carried out for 6 to 8 hours after raising the temperature to 105 ℃ to 110 ℃ range over 6 hours. Water produced as a by-product during the reaction was removed by azeotropic distillation with benzene, one of the reaction solvents, and benzene was removed from the reactor after completion of the activation step. Thereafter, the molar ratio of 1-ethynyl-3,5-difluorobenzene and decafluorobiphenyl is 1 mmol: 19 mmol (b: d = 0.05 : 0.95), and added to the reactor, the reaction temperature was maintained at 110 ℃ and reacted for more than 12 hours. After the reaction was completed, precipitated in 500 ml of ethanol, washed several times with water and ethanol, and then vacuum dried at 60 ℃ 3 days. The final product was obtained as a light brown solid, yielding at least 90%.

The final product is named SPAEDF-mSX5-6F70. 5 following SX indicates that the molar ratio of b is 0.05, and 70 following 6F indicates that the molar ratio of k is 0.70. That is, b and k in the name of the product are the molar ratios of 1-ethynyl-3,5-difluorobenzene and hydroquinonesulfonic acid potassium salt in terms of percentage, respectively.

In addition, starting materials hydroquinonesulfonic acid potassium salt (hydroquinonesulfonic acid potassium salt), 4,4'- (hexafluoroisopropylidene) diphenol (4,4'-hexafluoroisopropylidene) diphenol, 1- ethynyl- Crosslinking within the polymer chain with varying molar ratios (k: s: b: d) of 1, ethynyl-3,5-difluorobenzene and decafluorobiphenyl Sulfonated poly (arylene ether) copolymers (SPAEDF-mSXb-6Fk) with functional groups were prepared.

4 shows the ¹ H-NMR spectrum of a sulfonated poly (arylene ether) copolymer (SPAEDF-mSX10-6F80).

Referring to Figure 4, it can be seen that there is no peak of the hydroxyl group (hydroxyl group) of the monomer, which means that the hydrogen of the hydroxyl group is substituted by the polycondensation reaction. In addition, it can be seen that the peak appears in the chemical shift (chemical shift) corresponding to each of benzene hydrogen and ethynyl hydrogen.

Sulfonated Poly ( Arylene Ether ) Copolymer ( SPAEDF - mSXb -6 Fk Polymer salt removal membrane (C-) SPAEDF-mSXb-6Fk)  Produce

A polymer salt removing film (C-SPAEDF-mSXb-6Fk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAEDF-mSXb-6Fk).

Preparation Example 3: Preparation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-BPk) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAEDF-mSXb-BPk)

Sulfonated Poly ( Arylene Ether ) Copolymer ( SPAEDF - mSX - BPk Manufacturing

Scheme 4

Except for using 4,4'-biphenol instead of 4,4 '-(hexafluoroisopropylidene) diphenol as starting material Then, the same method as described in Preparation Example 2 was performed, and sulfonated poly having a crosslinkable functional group in the polymer chain while varying the molar ratio (k: s: b: d) of the starting materials in various ways ( Arylene ether) copolymer (SPAEDF-mSX-BPk) was prepared. Each yield was at least 90%.

A polymer salt removing film (C-SPAEDF-mSX-BPk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAEDF-mSX-BPk).

5 shows the ¹ H-NMR spectrum of a sulfonated poly (arylene ether) copolymer (SPAEDF-mSX10-BP80).

Referring to Figure 5, it can be seen that there is no peak of the hydroxyl group (hydroxyl group) of the monomer, which means that the hydrogen of the hydroxyl group is substituted by the polycondensation reaction. In addition, it can be seen that the peak appears in the chemical shift (chemical shift) corresponding to each of benzene hydrogen and ethynyl hydrogen.

Sulfonated Poly ( Arylene Ether ) Copolymer ( SPAEDF - mSXb - BPk Polymer salt removal membrane using C-SPAEDF-mSXb-BPk)  Produce

A polymer salt removing film (C-SPAEDF-mSXb-BPk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAEDF-mSXb-BPk).

Preparation Example 4 Preparation of Polymer Salt-Removing Membrane (C-SPAES-mSXb-100) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAES-mSXb-100)

 Scheme 5

Except for using 4,4'-difluorodiphenyl sulfone (4,4'-difluorodiphenyl sulfone) instead of decafluorobiphenyl as the starting material, the same method as in Preparation Example 1 The process was carried out, starting materials 1-ethynyl-3,5-difluorobenzene and 4,4'-difluorodiphenylsulfone (4,4'- A sulfonated poly (arylene ether) copolymer (SPAES-mSXb-100) having a crosslinkable functional group in the polymer chain was prepared while varying the molar ratio (b: d) of difluorodiphenyl sulfone). Each yield was at least 90%.

A polymer salt removing film (C-SPAES-mSXb-100) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAES-mSXb-100).

Preparation Example 5 Preparation of Polymer Salt-Removing Membrane (C-SPAES-mSXb-6Fk) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAES-mSXb-6Fk)

 Scheme 6

4,4'-difluorodiphenyl sulfone was used instead of decafluorobiphenyl as a starting material, except that 4,4'-difluorodiphenyl sulfone was used. The method was carried out, and sulfonated poly (arylene ether) copolymers having crosslinkable functional groups inside the polymer chain while varying the molar ratio (k: s: b: d) of the starting materials (SPAES-mSXb-6Fk) Was prepared. Each yield was at least 90%.

A polymer salt removing film (C-SPAES-mSXb-6Fk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAES-mSXb-6Fk).

Preparation Example 6 Preparation of Polymer Salt-Removing Membrane (C-SPAES-mSXb-BPk) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAES-mSXb-BPk)

 Scheme 7

4,4'-difluorodiphenyl sulfone was used instead of decafluorobiphenyl as a starting material, and 4,4 '-(hexafluoroisopropylidene) was used. Except for using 4,4'-biphenol (4,4'-biphenol) instead of diphenol ((4,4'-hexafluoroisopropylidene) diphenol), the same method as in Preparation Example 2 was carried out In addition, sulfonated poly (arylene ether) copolymer (SPAES-mSXb-BPk) having a crosslinkable functional group in the polymer chain was prepared while varying the molar ratio (k: s: b: d) of the starting materials. . Each yield was at least 90%.

A polymer salt removing film (C-SPAES-mSXb-BPk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAES-mSXb-BPk).

Preparation Example 7 Preparation of Polymer Salt-Removing Membrane (C-SPAES-mSXb-HQk) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAES-mSXb-HQk)

 Scheme 8

4,4'-difluorodiphenyl sulfone was used instead of decafluorobiphenyl as a starting material, and 4,4 '-(hexafluoroisopropylidene) was used. Except for using hydroquinone (hydroquinone) instead of diphenol ((4,4'-hexafluoroisopropylidene) diphenol), the same method as described in Preparation Example 2 was carried out, the molar ratio of the starting materials (k: s A sulfonated poly (arylene ether) copolymer (SPAES-mSXb-HQk) was prepared having various crosslinking functional groups inside the polymer chain with various changes of: b: d). Each yield was at least 90%.

A polymer salt removing film (C-SPAES-mSXb-HQk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAES-mSXb-HQk).

Preparation Example 8 Preparation of Polymer Salt-Removing Membrane (C-SPAEK-mSXb-6Fk) Using Sulfonated Poly (arylene Ether) Copolymer (SPAEK-mSXb-6Fk)

 Scheme 9

The same method as in Preparation Example 2 was performed except that 4,4'-difluorobenzophenone was used instead of decafluorobiphenyl as a starting material. A sulfonated poly (arylene ether) copolymer (SPAEK-mSXb-6Fk) having a crosslinkable functional group inside the polymer chain was prepared while varying the molar ratio (k: s: b: d) of the starting materials. It was. Each yield was at least 90%.

A polymer salt removing film (C-SPAEK-mSXb-6Fk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAEK-mSXb-6Fk).

Preparation Example 9 Preparation of Polymer Salt-Removing Membrane (C-SPAEK-mSXb-BPk) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAEK-mSXb-BPk)

 Scheme 10

4,4'-difluorobenzophenone was used instead of decafluorobiphenyl as a starting material, and 4,4 '-(hexafluoroisopropylidene) diphenol was used. Except that 4,4'-biphenol (4,4'-biphenol) was used instead of ((4,4'-hexafluoroisopropylidene) diphenol), the same method as in Preparation Example 2 was carried out. A sulfonated poly (arylene ether) copolymer (SPAEK-mSXb-BPk) having a crosslinkable functional group inside the polymer chain was prepared while varying the molar ratio (k: s: b: d) of the starting materials. Each yield was at least 90%.

A polymer salt removing film (C-SPAEK-mSXb-BPk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAEK-mSXb-BPk).

Preparation Example 10 Preparation of Polymer Salt-Removing Membrane (C-SPAEK-mSXb-HQk) Using Sulfonated Poly (Arylene Ether) Copolymer (SPAEK-mSXb-HQk)

 Scheme 11

4,4'-difluorobenzophenone was used instead of decafluorobiphenyl as a starting material, and 4,4 '-(hexafluoroisopropylidene) diphenol was used. Except for using hydroquinone (hydroquinone) instead of ((4,4'-hexafluoroisopropylidene) diphenol), the same method as described in Preparation Example 2 was carried out, the molar ratio of the starting materials (k: s: b A sulfonated poly (arylene ether) copolymer (SPAEK-mSXb-HQk) having a crosslinkable functional group inside the polymer chain was prepared with various changes of: d). Each yield was at least 90%.

A polymer salt removing film (C-SPAEK-mSXb-HQk) was prepared by the same method as described in Preparation Example 1 with the copolymer (SPAEK-mSXb-HQk).

Experimental Example 1 Performance Evaluation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-100)

Basic performance of the polymer salt removing membrane (C-SPAEDF-mSXb-100) prepared in Preparation Example 1 was evaluated.

6 is a schematic diagram of a cross-flow cell (Osmonics) device for the performance evaluation of the polymer salt removal membrane.

Since the performance of the salt removing membrane is affected by the concentration of the injection solution, it is necessary to keep the concentration of the injection solution constant using the apparatus for accurate performance evaluation.

Referring to FIG. 6, the concentration of 2000 ppm in the salt removing membrane cell (the selection of this concentration is used in various papers (Polymer Paper, 49, 2243, Angew. Chem. Int. Ed, Paper 47, 6019), etc.). In order to inject NaCl solution at a constant concentration, the solution after passing through the salt removing membrane (permeated solution) and the concentrated NaCl concentrated water excluded by the salt removing membrane are separated. Next, after measuring the concentration of the permeate solution, the permeate solution and NaCl concentrated water is sent back to the injection solution, mixed with an appropriate amount of distilled water to maintain a constant concentration (2000ppm NaCl) (2000ppm NaCl) and the circulation cycle is repeated . At this time, the power to inject the solution was a pump, and each line was maintained at a constant pressure of 400psi by the valve (regulator). The area of the cell is 19 cm 2.

NaCl  Removal rate measurement

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

% Removal = (1-Cp / Cf) × 100

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

At this time, the injection solution used is not limited to NaCl solution, any solution in which salt is dissolved, such as MgSO ₄ solution, MgCl ₂ solution, KCl solution can be used.

Water permeation measurement

The amount of water permeated through the polymer salt removal membrane and the time taken to permeate were measured, and water permeability was calculated from the following equation.

Water Permeation Rate = (V × l) / (A × t × △ p)

(V: volume of water permeated, l: membrane thickness, A: area of membrane, t: time taken to permeate, Δp: pressure difference)

Expansion rate  Measure

The dimensional stability of the polymer salt removal membrane in water is expressed by the area swelling ratio of the membrane in water.

The salt removal membrane was impregnated with water for 24 hours, and the expansion ratio was calculated from the following equation by comparing the area of the membrane after drying with the area of the membrane after impregnation.

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

(A wet: the area of the membrane in the wet state, A dry: the area of the membrane in the dry state)

FIG. 7 is a graph showing NaCl rejection and water permeability according to the ratio of the crosslinkable functional group (SX) of the polymer salt removing membrane (C-SPAEDF-mSXb-100).

Referring to FIG. 7, it can be seen that when the ratio of 1-ethynyl-3,5-difluorobenzene, which is a crosslinkable functional group, is increased from 5% to 40%, NaCl removal rate is increased while water permeation amount is decreased. have.

FIG. 8 is a graph showing the gel fraction and the swelling ratio according to the ratio of the crosslinkable functional group (SX) of the polymer salt removing membrane (C-SPAEDF-mSXb-100).

Referring to FIG. 8, when using 1-ethynyl-3,5-difluorobenzene as the crosslinkable functional group and increasing the ratio from 5% to 40%, the degree of crosslinking was increased while the expansion rate was decreased. Can be.

Table 1 summarizes the degree of crosslinking, NaCl removal rate, water permeation rate and expansion rate and NaCl removal rate and water permeation rate of the polyamide salt removing membrane (C-SPAEDF-mSXb-100).

TABLE 1

Desalination film Degree of crosslinking
(%) ^a NaCl removal rate
(%) ^b Water flux
(L · μm / m ² · h · bar) ^c Expansion rate
(%) ^d C-SPAEDF-mSX5-100 65.2 70.2 2.8 32.3 C-SPAEDF-mSX10-100 72.3 72.3 2.1 25.3 C-SPAEDF-mSX20-100 83.0 78.6 1.9 21.1 C-SPAEDF-mSX30-100 92.2 85.3 1.76 15.5 C-SPAEDF-mSX40-100 98.3 89.0 1.41 9.2 Polyamide
Desalination film ^e - 99.7 0.61 ^f - a: The crosslinking degree was tested for 24 hours using DMSO (dimethyl suloxide) as a solvent extraction method and a Soxhlet extractor, and the crosslinking degree was calculated from the following equation after removing the solvent.
% Crosslinking = W ₂ / W ₁ × 100
(W ₁ : weight before extraction, W ₂ : weight after extraction)
b:% removal = (1-C _p / C _f ) × 100
(C _p (injection concentration): NaCl 2000ppm, C _f : Permeation concentration, pressure: 1000 psi, temperature: 25 ° C (concentration measured by digital conductivity meter (Oakton con110, Cole Parmer))
c: water permeation amount = (V × l) / (A × t × Δp)
(V: volume of water permeated, l: thickness of membrane, A: area of membrane, t: permeation time, Δp: pressure difference)
d:% expansion = (A wet-A dry) × 100 / A dry
(A wet: area of membrane in wet state A dry: area of membrane in dry state)
e: SW30HR-380 (Dow Chemical)
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

Referring to Table 1, in the case of the polymer salt removal membrane (C-SPAEDF-mSXb-100) prepared according to Preparation Example 1, the ratio of 1-ethynyl-3,5-difluorobenzene as a starting material was As it increases, the degree of crosslinking and NaCl removal increases, and the expansion rate to water decreases. The reason why the expansion ratio of the salt removal membrane with respect to water is important is that since the salt removal membrane is operated in an environment in which water is present, the larger the expansion ratio of the salt removal membrane with water, the lower the dimensional stability is, resulting in a lower salt removal rate. On the other hand, the amount of water permeation decreased slightly as the degree of crosslinking increased. Nevertheless, it was found that the water permeation rate was significantly improved compared to the commercialized polyamid salt removing membrane.

Experimental Example 2: Performance Evaluation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-6Fk)

By performing the same method as in Experimental Example 1, the basic performance of the polymer salt removing membrane (C-SPAEDF-mSXb-6Fk) prepared according to Preparation Example 2 was evaluated.

Table 2 summarizes the crosslinking degree, NaCl removal rate, water permeation rate and expansion rate, and NaCl removal rate and water permeation rate of the polyamide salt removing membrane (C-SPAEDF-mSXb-6Fk).

TABLE 2

Desalination film Degree of crosslinking
(%) ^a NaCl removal rate
(%) ^b Water flux
(L · μm / m ² · h · bar) ^c Expansion rate
(%) ^d C-SPAEDF-mSX5-6F70 74.3 86.3 2.4 30.3 C-SPAEDF-mSX10-6F70 79.6 88.3 1.9 23.3 C-SPAEDF-mSX20-6F70 85.6 92.7 1.75 20.1 C-SPAEDF-mSX30-6F70 94.1 96.8 1.6 13.5 C-SPAEDF-mSX40-6F70 98.6 98.6 1.3 7.2 Polyamide
Desalination film ^e - 99.7 0.61 ^f - a: The crosslinking degree was tested for 24 hours using DMSO (dimethyl suloxide) as a solvent extraction method and a Soxhlet extractor, and the crosslinking degree was calculated from the following equation after removing the solvent.
% Crosslinking = W ₂ / W ₁ × 100
(W ₁ : weight before extraction, W ₂ : weight after extraction)
b:% removal = (1-C _p / C _f ) × 100
(C _p (injection concentration): NaCl 2000ppm, C _f : Permeation concentration, pressure: 1000 psi, temperature: 25 ° C (concentration measured by digital conductivity meter (Oakton con110, Cole Parmer))
c: water permeation amount = (V × l) / (A × t × Δp)
(V: volume of water permeated, l: thickness of membrane, A: area of membrane, t: permeation time, Δp: pressure difference)
d:% expansion = (A wet-A dry) × 100 / A dry
(A wet: area of membrane in wet state A dry: area of membrane in dry state)
e: SW30HR-380 (Dow Chemical)
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

Referring to Table 2, the polymer salt removing membrane (C-SPAEDF-mSXb-6Fk) prepared according to Preparation Example 2, when k is 70%, the starting material 1-ethynyl-3,5-difluoro As the ratio of robenzene increases, the degree of crosslinking and NaCl removal increases, and the expansion ratio to water decreases, so that the performance as a salt removing membrane increases. On the other hand, the amount of water permeation decreased slightly as the degree of crosslinking increased. Nevertheless, it was found that the water permeation rate was significantly improved compared to the commercialized polyamid salt removing membrane.

Experimental Example 3: Performance Evaluation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-BPk)

By performing the same method as in Experimental Example 1, the basic performance of the polymer salt removing membrane (C-SPAEDF-mSXb-BPk) prepared according to Preparation Example 3 was evaluated.

Table 3 summarizes the crosslinking degree, NaCl removal rate, water permeation rate and expansion rate, and NaCl removal rate and water permeation rate of the polyamide salt removing membrane (C-SPAEDF-mSXb-BPk).

[Table 3]

Desalination film Degree of crosslinking
(%) ^a NaCl removal rate
(%) ^b Water flux
(L · μm / m ² · h · bar) ^c Expansion rate
(%) ^d C-SPAEDF-mSX5-BP70 75.6 87.2 2.2 29.1 C-SPAEDF-mSX10-BP70 81.5 89.4 1.75 21.3 C-SPAEDF-mSX20-BP70 86.7 94.1 1.61 18.6 C-SPAEDF-mSX30-BP70 95.6 97.6 1.52 12.7 C-SPAEDF-mSX40-BP70 99.0 99.2 1.13 6.9 Polyamide
Desalination film ^e - 99.7 0.61 ^f - a: The crosslinking degree was tested for 24 hours using DMSO (dimethyl suloxide) as a solvent extraction method and a Soxhlet extractor, and the crosslinking degree was calculated from the following equation after removing the solvent.
% Crosslinking = W ₂ / W ₁ × 100
(W ₁ : weight before extraction, W ₂ : weight after extraction)
b:% removal = (1-C _p / C _f ) × 100
(C _p (injection concentration): NaCl 2000ppm, C _f : Permeation concentration, pressure: 1000 psi, temperature: 25 ° C (concentration measured by digital conductivity meter (Oakton con110, Cole Parmer))
c: water permeation amount = (V × l) / (A × t × Δp)
(V: volume of water permeated, l: thickness of membrane, A: area of membrane, t: permeation time, Δp: pressure difference)
d:% expansion = (A wet-A dry) × 100 / A dry
(A wet: area of membrane in wet state A dry: area of membrane in dry state)
e: SW30HR-380 (Dow Chemical)
f: the water permeability per unit thickness ^{(L / m 2 · h ·} bar)

Referring to Table 3, the polymer salt removal membrane (C-SPAEDF-mSXb-BPk) prepared according to Preparation Example 3, when k is 70%, 1-ethynyl-3,5-difluoro as a starting material As the ratio of robenzene increases, the degree of crosslinking and NaCl removal increases, and the expansion ratio to water decreases, so that the performance as a salt removing membrane increases. On the other hand, the amount of water permeation decreased slightly as the degree of crosslinking increased. Nevertheless, it was found that the water permeation rate was significantly improved compared to the commercialized polyamid salt removing membrane.

Experimental Example 4: Performance Evaluation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-BPk) According to Composition Ratio of Sulfonated Aromatic Compounds>

To evaluate the basic performance of the polymer salt removal membrane (C-SPAEDF-mSXb-BPk) prepared according to Preparation Example 3 by performing the same method as in Experimental Example 1, the crosslinkable functional group (1-ethynyl The composition ratio of -3,5-difluorobenzene) was fixed at 40%, and the composition ratio of the sulfonated aromatic compound (hydroquinone sulfonic acid potassium salt) was changed.

9A, 9B, and 9C are graphs illustrating water permeation rate, NaCl removal rate, and expansion ratio with respect to water of the polymer salt removing membrane (C-SPAEDF-mSX40-BPk) according to the composition ratio of the hydroquinone sulfonic acid potassium salt.

Referring to FIG. 9A, it can be seen that the water permeation rate decreases as the degree of sulfonation decreases, because the ratio of the sulfonic acid group (-SO 3 ⁻ ), which is a hydrophilic group, decreases in the molecular structure of the copolymer forming the salt removing membrane.

On the other hand, referring to Figure 9b, it can be seen that the NaCl removal rate increases from 86.1% to 98.6% as the degree of sulfonation decreases. This shows that the polymer salt removing film of the present invention has comparable salt removing performance as compared to the commercially available polyamide salt removing film (NaCl removal rate of 99.7%).

Referring to Figure 9c, it can be seen that the expansion rate decreases as the degree of sulfonation decreases. This is a sulfonic acid group (-SO ₃ ^-) a hydrophilic group in the molecular structure of the copolymer forms a film removing salt is because the ability to also reduce in accordance with this reduced ratio, remove salt film containing water.

Table 4 summarizes the sulfonation degree, NaCl removal rate, water permeation rate, and water expansion rate and NaCl removal rate and water permeation rate of the polyamide salt removal membrane of the polymer salt removal membrane (C-SPAEDF-mSXb-BPk).

[Table 4]

Desalination film Sulfonated
(%) NaCl removal rate
(%) ^a Water flux
(L · μm / m ² · h · bar) ^b Expansion rate
(%) ^c C-SPAEDF-mSX40-BP90 90 86.1 2.39 37.2 C-SPAEDF-mSX40-BP80 80 88.4 1.79 24.3 C-SPAEDF-mSX40-BP70 70 97.1 1.52 20.6 C-SPAEDF-mSX40-BP60 60 98.6 1.40 9.7 Polyamide
Desalination film ^d - 99.7 0.61 ^e - a:% removal rate = (1-C _p / C _f ) × 100
(C _p (injection concentration): NaCl 2000ppm, C _f : Permeation concentration, pressure: 1000 psi, temperature: 25 ° C (concentration measured by digital conductivity meter (Oakton con110, Cole Parmer))
b: water permeation amount = (V × l) / (A × t × Δp)
(V: volume of water permeated, l: thickness of membrane, A: area of membrane, t: permeation time, Δp: pressure difference)
c: Expansion rate (%) = (A wet-A dry) × 100 / A dry
(A wet: area of membrane in wet state A dry: area of membrane in dry state)
d: SW30HR-380 (Dow Chemical)
e: Water permeation rate per unit thickness (L / m ² · h · bar)

Experimental Example 5: Chemical Stability Evaluation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-BPk) _1>

Using the sulfonated poly (arylene ether) copolymer prepared in Preparation Example 3 (SPAEDF-mSX40-BP70) to make a salt removal film, the salt removal film (NC-SPAEDF that does not occur cross-linking reaction by varying the heat treatment temperature -mSX40-BP70, hereinafter referred to as 'pre-crosslinking desalination membrane' and a cross-linking salt-removing membrane (C-SPAEDF-mSX40-BP70, hereinafter referred to as 'crosslinking desalination membrane') were prepared, respectively.

After the cross-linking salt removing film and the cross-linking salt removing film was impregnated in 5000 ppm NaOCl solution (pH 4 conditions) for 10 days, the ATR-IR spectrum change was measured.

Here, the reason why the pH 4 condition is selected is to give a condition under which the chlorination reaction can occur by increasing the HClO concentration of the reaction solution.

FIG. 10 is a graph measuring the change in ATR-IR spectrum by impregnating a salt removal film (NC-SPAEDF-mSX40-BP70) before crosslinking in a 5000 ppm NaOCl solution (pH 4 condition).

FIG. 11 is a graph measuring the change in ATR-IR spectrum by impregnating a salt removal film (C-SPAEDF-mSX40-BP70) after crosslinking in a 5000 ppm NaOCl solution (pH 4 condition).

Referring to FIG. 10, in the case of the salt-removing membrane before crosslinking (NC-SPAEDF-mSX40-BP70), there is no change in spectrum at wave numbers 1650 cm ^-1 and 1405 cm ^-1 , which is the aromatic of the polymer main chain. ) It means no change in C = C bond structure. In addition, the spectrum represents a CH bond at 890cm ^-1 and 815cm ^-1 also did not show any changes for 10 days. However, at 1233cm ^-1 and 1023cm ^-1 , the intensity of the two peaks begins to decrease after 2 days, and after 6 days, the peak almost disappears. This is a sulfonic acid group (-SO ₃ ^-) means that the bond is gradually start to break, and if as a result of cross-linking before salt removal film (NC-SPAEDF-mSX40-BP70 ) 5000ppm NaOCl solution (pH4 criteria) sulfonic acid group (-SO in ^₃₎ can check decomposed.

Referring to Figure 11, in the case of removal after cross-linking salt film (C-SPAEDF-mSX40-BP70 ), aromatic (aromatic) C = C bond 1650cm ^-1 and 1405cm ^-1 and 890cm ^-1 and 815cm CH bond representing representing spectra no change from ^-1 course, a sulfonic acid group (-SO ₃ ^-) at 1233cm ^-1 and 1023cm ^-1 indicating it can be seen that not show a change in the spectrum. This is because, in the case of the salt removing film (C-SPAEDF-mSX40-BP70) after crosslinking, the polymer chain inside the film can be protected from attack by chlorine by crosslinking formation of the copolymer constituting the salt removing film. Therefore, the polymer salt removing film of the present invention can improve the chlorine stability of the main chain due to the cross-linking effect of the copolymer can exhibit excellent performance as a salt removing film.

12 is a graph measuring the change in ATR-IR spectrum by impregnating a polyamide salt removing film (SW30HR-380, Dow Chemical) in a 5000 ppm NaOCl solution (pH 4 condition).

12, after impregnation 1 time starts, it eliminates the hydrogen bond spectrum of C = O and NH at 1610cm ^-1, and also begins to C = O stretching spectrum is not at 1540cm ^-1, and after 24 hours, We can see that both spectra disappear completely. This means that decomposition occurs at the amide bond of the polyamide salt removing film. Therefore, in the case of the polyamide salt removal membrane, it can be seen that the degradation of the membrane occurs due to decomposition of the main chain during chlorine treatment.

Experimental Example 6: Chemical Stability Evaluation of Polymer Salt-Removing Membrane (C-SPAEDF-mSXb-BPk) _2>

A solution containing 2000 ppm NaCl solution and 5000 ppm NaOCl (pH 4 condition) was selected as an injection solution, and the salt removal membrane (C-SPAEDF-mSX30-BP70) and poly-crosslinked polylinked solution was prepared using the apparatus shown in FIG. 6 of Experimental Example 1 above. The removal rate of NaCl and the water permeation rate of the amide salt removing membrane were compared.

Figure 13a is a graph showing the NaCl removal rate change with time of the salt-removing membrane (C-SPAEDF-mSX30-BP70) and the polyamide salt-removing membrane after crosslinking measured by Experimental Example 6.

FIG. 13B is a graph showing changes in water permeation rate of the salt removing membrane (C-SPAEDF-mSX30-BP70) and the polyamide salt removing membrane after crosslinking measured in Experimental Example 6.

Referring to FIGS. 13A and 13B, in the case of the polyamide salt removal membrane, NaCl removal rate of 99.7% was initially shown, but NaCl removal rate decreased to about 50% after 1 hour and to about 20% after 6 hours. At first, the water permeation amount was 0.61 (L / m ² · h · bar), but the water permeation amount increased more than 2 times in about 1 hour and more than 4 times after 6 hours. This is because, as shown in the ATR-IR spectrum of FIG. 12, the decomposition of the amide bond occurs by the 5000 ppm NaOCl solution (pH 4 condition), thereby damaging the polyamide salt removing membrane. Therefore, the hydrated Na ⁺ ions or Cl ^- ions easily pass through the salt removal membrane, thus reducing the NaCl removal rate and increasing the water permeation rate.

On the other hand, in the case of the salt removal membrane (C-SPAEDF-mSX30-BP70) after crosslinking, since the decomposition of the molecular structure does not occur (see FIG. 11 above), the salt removal membrane is not damaged, and the decrease of NaCl removal rate and the increase of water permeation rate are increased. It can be seen that it does not occur.

In other words, the cross-linked salt removing film (C-SPAEDF-mSX30-BP70) exhibits superior chemical stability under NaOCl conditions compared to the polyamide salt removing film.

As described above, the polymer salt removing membrane of the present invention is composed of a crosslinked compound of a sulfonated poly (arylene ether) copolymer and thus has a high salt removal rate and high chemical stability, in particular, chlorine stability. Able to know. In addition, there is an advantage of having excellent performance in terms of water permeation amount and dimensional stability, which are important performances as the salt removing membrane.

In addition, although not shown in the experimental example of the present invention, in the case of commercialized polyamide salt removing film is usually used at a pressure of 225 psi to prevent damage of the salt removing film in a high pressure state, in the case of the polymer salt removing film of the present invention 1000 psi) has excellent mechanical stability without damaging the salt removal membrane.

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications and changes by those skilled in the art within the spirit and scope of the present invention. You can change it.

1 is a schematic diagram showing a salt removal mechanism by the polymer salt removal membrane of the present invention.

2 is a schematic diagram showing a network structure formed by internal crosslinking of sulfonated poly (arylene ether) copolymer.

3 shows the ¹ H-NMR spectrum of a sulfonated poly (arylene ether) copolymer (SPAEDF-mSXb-100).

4 shows the ¹ H-NMR spectrum of a sulfonated poly (arylene ether) copolymer (SPAEDF-mSX10-6F80).

5 shows the ¹ H-NMR spectrum of a sulfonated poly (arylene ether) copolymer (SPAEDF-mSX10-BP80).

6 is a schematic diagram of a cross-flow cell (Osmonics) device for the performance evaluation of the polymer salt removal membrane.

FIG. 7 is a graph showing NaCl rejection and water permeability according to the ratio of the crosslinkable functional group (SX) of the polymer salt removing membrane (C-SPAEDF-mSXb-100).

FIG. 8 is a graph showing the gel fraction and the swelling ratio according to the ratio of the crosslinkable functional group (SX) of the polymer salt removing membrane (C-SPAEDF-mSXb-100).

9A, 9B, and 9C are graphs illustrating water permeation rate, NaCl removal rate, and expansion ratio with respect to water of the polymer salt removing membrane (C-SPAEDF-mSX40-BPk) according to the composition ratio of the hydroquinone sulfonic acid potassium salt.

FIG. 10 is a graph measuring the change in ATR-IR spectrum by impregnating a salt removal film (NC-SPAEDF-mSX40-BP70) before crosslinking in a 5000 ppm NaOCl solution (pH 4 condition).

FIG. 11 is a graph measuring the change in ATR-IR spectrum by impregnating a salt removal film (C-SPAEDF-mSX40-BP70) after crosslinking in a 5000 ppm NaOCl solution (pH 4 condition).

12 is a graph measuring the change in ATR-IR spectrum by impregnating a polyamide salt removing film (SW30HR-380, Dow Chemical) in a 5000 ppm NaOCl solution (pH 4 condition).

Figure 13a is a graph showing the change in NaCl removal rate with time of the salt-removing membrane (C-SPAEDF-mSX30-BP70) and the polyamide salt-removing membrane after crosslinking measured by Experimental Example 6.

Figure 13b is a graph showing the water permeation change with time of the salt removal membrane (C-SPAEDF-mSX30-BP70) and the polyamide salt removal membrane after crosslinking measured by Experimental Example 6.

Claims (5)

A polymer salt removing film comprising a crosslinking compound of a sulfonated poly (arylene ether) copolymer represented by Formula 1 below: [Formula 1]

Wherein SAr1 represents sulfonated aromatic, Ar represents non sulfonated aromatic, CM represents crosslinkable moiety, b and k each have a value of 0.001 to 1.000, d has a value of 1-b, s has a value of 1-k, n has a value of 10 to 500 as the degree of polymerization of sulfonated poly (arylene ether). The method of claim 1, wherein SAr1 is

,

,

,

,

,

or

ego, 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

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

,

,

,

,

,

,

or

, E is a C1 to C5 alkyl group substituted with H, CH ₃ , F, CF ₃ , H or F, or

ego, L is H, F, or C1 to C5 alkyl substituted with H or F, M ⁺ is a polymer salt removal membrane that is a counterion (counterion) having a cation charge. The counterion of claim 2, wherein the counterion having a cationic charge is Polymer salt removal membrane which is potassium ion, sodium ion, or alkylammonium ion. The method of claim 1, wherein Ar is

,

,

or

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

,

,

,

,

,

,

,

,

,

,

or

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

,

,

,

,

,

,

or

ego, E is a C1 to C5 alkyl group substituted with H, CH ₃ , F, CF ₃ , H or F, or

, L is H, F, or a polymer salt removal membrane that is a C1 to C5 alkyl group substituted with H or F. The method of claim 1, wherein the CM

,

or

ego, J is

(m is 0 or 1), R is an ethynyl group in which R 1 is substituted (R =

), The ethylene-containing group in which R 1 is substituted (R =

) or

ego, R1 is a C1 to C5 alkyl group substituted with H, F, H or F, or

And G is a single bond where carbon and carbon are directly connected,

,

or

ego, R2 is an alkyl group of C1 to C5 substituted with H, X (halogen atom), or H or F, Y is a single bond where carbon and carbon are directly connected,

,

,

,

,

,

,

,

,

,

,

or

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

,

,

,

,

,

,

or

, E is a C1 to C5 alkyl group substituted with H, CH ₃ , F, CF ₃ , H or F, or

ego, L is H, F, or a polymer salt removal membrane that is a C1 to C5 alkyl group substituted with H or F.

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