KR102082997B1 - Thermosensitive copolymers and forward osmosis water treatment devices and methods using the same - Google Patents

Abstract

화학식 2에서, R₄은 C2 내지 C5 알킬렌기임.A first repeating unit grafted with a temperature sensitive oligomer; And a second repeating unit comprising an ionic moiety and a counter ion of the ionic moiety, wherein the temperature sensitive oligomer comprises an oligomer comprising a repeating unit derived from an unsaturated monomer having a moiety represented by Formula 1 or Formula 2. There is provided a temperature sensitive copolymer which is or is an oligomer comprising repeating units derived from heterocyclic compounds containing C, N and O in the ring and having C = N bonds:
[Formula 1]
* -C (= O) N (R ₂ ) (R ₃ )
In formula (1), R ₂ and R ₃ are each independently hydrogen or a straight or branched C 1 to C 6 alkyl group, C 3 to C 7 cycloalkyl group, or C 6 to C 10 aryl group, R ₂ and R All _three may not be hydrogen, and R ₂ and R ₃ may combine with each other to form a nitrogen-containing hetero ring;
[Formula 2]

In formula (2), R ₄ is a C2 to C5 alkylene group.

Description

Temperature-sensitive copolymer, forward osmosis water treatment apparatus and forward osmosis water treatment method using the same {THERMOSENSITIVE COPOLYMERS AND FORWARD OSMOSIS WATER TREATMENT DEVICES AND METHODS USING THE SAME}

The present invention relates to a temperature sensitive copolymer, a forward osmosis water treatment apparatus and a forward osmosis water treatment method using the same.

Osmosis (or forward osmosis) refers to the phenomenon in which water moves from a solution having a lower solute concentration to a solution of a higher solute concentration by osmotic pressure. Reverse osmosis is a method of moving water in the opposite direction by artificially applying pressure.

Desalination methods through reverse osmosis are known techniques in the field of water treatment. Typically, reverse osmosis processes require very high pressures, which results in very high energy consumption. In order to improve energy efficiency, a forward osmosis process using the principle of osmotic pressure has been proposed, and the solutes used in the osmotic induction solution are ammonium bicarbonate, sulfur dioxide, and aliphatic alcohols. ), Aluminum sulfate, glucose, fructose, potassium nitrate, and the like. Among them, ammonium bicarbonate derived solution is most widely known. Ammonium bicarbonate, a solute included in the derived solution, can be separated into ammonia and carbon dioxide at a temperature of about 60 ° C. after the forward osmosis process. . In addition, newly proposed inducing solutes include nanomagnetic particles (separated by magnetic fields) to which hydrophilic polymers such as peptides and low molecular materials are attached, and polymer electrolytes such as dendrimers (UF and NF membrane separation).

In the case of ammonium bicarbonate, it is necessary to heat more than 60 ℃ to vaporize high energy consumption is required, because the complete removal of ammonia is practically difficult to use as drinking water due to the ammonia smell. In the case of nano magnetic particles, it is difficult to redistribute the magnetic particles separated and aggregated by the magnetic field, and it is impossible to completely remove the nano particles. Magnetic nanoparticles coated with a thermally sensitive dendrimer or a hydrophilic polymer or a hydrophilic low molecular material also require a filter such as a nanofiltration membrane or an ultrafiltration membrane with a polymer size of several to several tens of nm.

In one embodiment, the present invention is directed to a temperature sensitive copolymer that can provide high osmotic pressure, very low level of reverse diffusion of solutes, and can provide an induction solution that is easy to recover and regenerate solutes.

In another embodiment, the present invention is directed to a method of preparing the copolymer.

In another embodiment, the present invention is directed to an apparatus and a forward osmosis water treatment method for performing an forward osmosis process using an induction solution comprising the temperature sensitive copolymer and water.

In one embodiment, the present invention includes a first repeating unit (grafted), the temperature sensitive oligomer is grafted; And a second repeating unit including an ionic moiety and a counter ion of the ionic moiety, wherein the temperature sensitive oligomer is represented by Formula 1 or Formula 2 Temperature sensitivity which is an oligomer comprising a repeating unit derived from an unsaturated monomer having an or a repeating unit derived from a heterocyclic compound containing C, N and O in a ring and having a C═N bond Copolymers are provided:

[Formula 1]

* -C (= O) N (R ₂ ) (R ₃ )

In formula 1, R ₂ and R ₃ are each independently hydrogen or a straight or branched C 1 to C 6 alkyl group, C 3 to C 7 cycloalkyl group, or C 6 to C 10 aryl group, R ² and R All ^three may not be hydrogen, and R ² and R ³ may combine with each other to form a nitrogen-containing hetero ring;

[Formula 2]

In formula (2), R ₄ is a C2 to C5 alkylene group.

The temperature sensitive copolymer may be a polyamino acid derivative.

The heterocyclic compound may be an oxazoline compound represented by Formula 3:

[Formula 3]

In formula (3), Ak is a linear or branched alkyl group having 1 to 10 carbon atoms, and R is independently hydrogen or an alkyl group having 1 to 3 carbon atoms.

The temperature sensitive oligomer may include repeating units derived from N-alkyl (meth) acrylamide represented by the following formula (4), repeating units derived from N-vinyl lactam represented by the following formula (5), or a combination thereof And optionally, further includes repeating units derived from (meth) acrylamide.

[Formula 4]

In formula (4), R ₁ is hydrogen or methyl, R ₂ and R ₃ are each independently hydrogen or a linear or branched C 1 -C 6 alkyl group, C 3 -C 7 cycloalkyl group, or C 6 -C 10 aryl group, R ₂ And R ₃ may not all be hydrogen, and R ₂ and R ₃ may be linked to each other to form a nitrogen-containing hetero ring;

[Formula 5]

In formula (5), R ₄ is alkylene having 2 to 5 carbon atoms.

The temperature sensitive oligomer may have a degree of polymerization of 2 to 30.

The ionic moiety of the second repeating _{^{units, -COO -, -SO 3 -,}} -PO 3 2 - and can be anionic date sex glass selected from a combination of the two.

The second repeating unit may include the same ionic moiety or may independently include different ionic moieties.

The counter ion may be selected from cations of alkali metals, cations of alkaline earth metals, and combinations thereof.

The molar ratio between the first repeating unit and the second repeating unit may be 1:99 to 60:40.

The temperature sensitive copolymer including the first repeating unit and the second repeating unit may be represented by the following Chemical Formula 6:

[Formula 6]

In formula (6), A ⁻ is a group containing an ionic moiety, M ⁺ is a counter ion of the ionic moiety, and Q is —NR— (where R is hydrogen or an alkyl group having 1 to 5 carbon atoms) or- S-, L is a direct bond, substituted or unsubstituted C1 to C20 alkylene, or substituted or unsubstituted C1 to C20 thioalkylene, Og is an oligomer comprising a repeating unit of formula (7), An oligomer comprising a repeating unit of Formula 8, or an oligomer comprising a repeating unit of Formula 9;

[Formula 7]

In formula (7), R ₁ is hydrogen or methyl, R ₂ and R ₃ are each independently hydrogen or a straight or branched C 1 to C 6 alkyl group, C 3 to C 7 cycloalkyl group, or C 6 to C 10 aryl Wherein both R ₂ and R ₃ may not be hydrogen, and R ₂ and R ₃ may combine with each other to form a nitrogen-containing hetero ring;

[Formula 8]

In formula (8), R ₄ is a C2 to C5 alkylene group;

[Formula 9]

In formula (9), Ak is a linear or branched alkyl group having 1 to 10 carbon atoms, and R is independently hydrogen or alkyl having 1 to 3 carbon atoms.

In the formula 6, A ^- are the same or ^{different, -COO -, -CONR-Z-} SO 3 -, -CONR-ZO-PO 3 -2, -CO-SZ-SO 3 -, and -CO- SZO-PO ₃ ^-2 , wherein R is hydrogen or an alkyl group of C1 to C5, Z is a substituted or unsubstituted C1-20 alkylene group, and M ⁺ is Na ⁺ , K ⁺ , Li ⁺ , it may be selected from ^{Ca 2 +, Mg 2 +,} Ba 2 +, and combinations thereof.

The temperature sensitive copolymer may have a number average molecular weight of 5,000 to 250,000.

In another embodiment, the present invention provides a kit comprising: a first repeating unit grafted with a temperature sensitive oligomer; And a second repeating unit comprising an ionic moiety and a counter ion of the ionic moiety, the method comprising the steps of:

Preparing polysuccinimide;

A temperature sensitive oligomer comprising a repeating unit derived from a monomer represented by the following formula (3) having an amine group or a thiol group at one end, or a repeating unit derived from a monomer represented by the following formula (4) having an amine group or a thiol group at one terminal; Preparing a temperature sensitive oligomer comprising a repeating unit derived from a monomer represented by Formula 5 or a combination thereof;

[Formula 3]

In formula (3), Ak is a straight-chain or branched alkyl group having 1 to 10 carbon atoms, and R is each independently hydrogen or alkyl having 1 to 3 carbon atoms;

[Formula 4]

In formula (4), R ₁ is hydrogen or methyl, R ₂ and R ₃ are each independently hydrogen or a linear or branched C 1 -C 6 alkyl group, C 3 -C 7 cycloalkyl group, or C 6 -C 10 aryl group, R ₂ And R ₃ may not all be hydrogen, and R ₂ and R ₃ may be linked to each other to form a nitrogen-containing hetero ring;

[Formula 5]

In formula (5), R ₄ is alkylene having 2 to 5 carbon atoms;

Reacting the polysuccinimide with the temperature sensitive oligomer to open a portion of the succinimide rings of the polysuccinimide to graf the temperature sensitive oligomer; And

The product of the reaction is reacted with an amine compound containing an ionic moiety, a thiol compound containing an ionic moiety, an inorganic base, or a combination thereof to open the succinimide rings remaining in the polysuccinimide and to ion Introducing a sex moiety and a counter ion.

The polysuccinimide may have a number average molecular weight of 5,000 or less.

The amine compound having an ionic residue may be an ester compound of phosphoric acid and an alkanolamine of C2 to C20, a sulfoalkylamine of C2 to C20, or a combination thereof, and the inorganic base may be an alkali metal hydroxide or an alkaline earth metal. Hydroxides or combinations thereof.

In another embodiment, the present invention provides an aqueous medium; And an osmotic pressure induced polymer chain dissolved in the aqueous medium and comprising an ionic moiety and a counter ion of the ionic moiety and a temperature sensitive oligomer in the form of graft. An inducing solute containing a covalently bound temperature sensitive copolymer, wherein the inducing solute provides an osmotic induction solution that can be recovered by phase separation above a low critical solution temperature.

The temperature sensitive copolymer may have a low critical solution temperature (LCST) in a range of 10 to 50 ° C. at a concentration of 0.01 g / ml.

The temperature sensitive copolymer may have a solubility in water of less than or equal to 100 g / L at or below the low critical solution temperature (LCST), and solubility in water may be less than or equal to 1 g / L at or above the low critical solution temperature (LCST). .

When raising the temperature of the osmotic induction solution above the low critical solution temperature (LCST) below the low critical solution temperature, at least 50% by weight of the total inducing solute may exhibit a 10-fold increase in particle size.

The temperature sensitive oligomer comprises an amide and an aliphatic moiety covalently bonded to the nitrogen atom of the amide and hydrophobic relative to the amide, wherein the aliphatic moiety is covalently or bonded to a carbon atom of the amide Oligomers that are not present, or may include repeating units derived from heterocyclic compounds containing C, N and O in the ring and having C═N bonds.

In another embodiment, the present invention, the feed solution containing water and the substance to be dissolved in the water (feed solution); The osmotic induction solution described above; A semipermeable membrane positioned at one side in contact with the inflow liquid and at the other side in contact with the osmotic induction solution; A recovery system for removing said temperature sensitive copolymer from a treatment solution comprising water moved by said osmotic pressure from said influent to said osmotic induction solution through said semipermeable membrane; And a connection for feeding the temperature sensitive copolymer removed from the recovery system back into the osmotic induction solution.

The forward osmosis water treatment apparatus may further include a discharge unit for discharging the treated water produced by removing the temperature sensitive copolymer from the treatment solution in the recovery system.

The recovery system may include a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane or a centrifuge.

The recovery system may include a temperature controller that heats the removed temperature sensitive copolymer above its low critical solution temperature (LCST).

The recovery system may include a temperature controller to cool the removed temperature sensitive copolymer below the low critical solution temperature (LCST).

In another embodiment, the present invention is in contact with the inlet liquid containing water and the substance to be dissolved in the water, the osmotic induction solution and the semi-permeable membrane interposed therebetween, through the semi-permeable membrane by osmotic pressure from the influent Obtaining a treatment solution comprising water transferred to the osmotic induction solution; Heating at least a portion of the treatment solution to a temperature above the low critical solution temperature (LCST) of the temperature sensitive copolymer to agglomerate the temperature sensitive copolymer in the treatment solution; And removing the agglomerated temperature sensitive copolymer from the treatment solution to obtain treated water.

The forward osmosis water treatment method may further include cooling the removed temperature sensitive copolymer below its low critical solution temperature (LCST) and feeding it back into the osmotic induction solution in contact with the semipermeable membrane.

The temperature sensitive copolymer can provide an induction solution that generates a high osmotic pressure, and can be easily separated from the solution by a temperature change, so the apparatus and method for forward osmosis water treatment using the same have high energy or water treatment efficiency and reduced cost. Can be driven.

Figure 1 is a schematic diagram of the forward osmosis water treatment apparatus according to an embodiment of the present invention.
2 is a ¹ H-NMR spectrum of the copolymer synthesized in Example 1. FIG.
3 is a graph showing the change in the osmotic pressure according to the concentration in the solution containing the copolymers of Examples 1 and 2 and Reference Example 1, respectively.
Figure 4 is a graph showing the absorbance at 500nm wavelength according to the temperature of the osmotic induction solution containing the copolymer of Example 1.
FIG. 5 is a graph of absorbance at 500 nm wavelength according to the temperature of the osmotic induction solution including the copolymer of Example 2. FIG.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments make the disclosure of the present invention complete, and those of ordinary skill in the art to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Thus, in some implementations, well known techniques are not described in detail in order to avoid obscuring the present invention. Unless otherwise defined, all terms used in the present specification (including technical and scientific terms) may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly. When any part of the specification is to "include" any component, which means that it may further include other components, except to exclude other components unless specifically stated otherwise.

In addition, the singular also includes the plural unless specifically stated otherwise in the text.

Embodiments described herein will be described with reference to schematic diagrams, which are ideal illustrations of the invention. Accordingly, the regions illustrated in the figures have schematic attributes and are not intended to limit the scope of the invention. Like reference numerals refer to like elements throughout.

As used herein, "substituted" means that at least one hydrogen in the residue is a hydroxy group, nitro group, cyano group, amino group, carboxyl group, straight or branched C1 to C30 alkyl group; C1 to C10 alkylsilyl group; C3 to C30 cycloalkyl group; C6 to C30 aryl group; C2 to C30 heteroaryl group; C1 to C10 alkoxy group; Halogen group; Or a substituted with a C1 to C10 fluoroalkyl group.

In one embodiment, the temperature sensitive copolymer comprises: a first repeating unit grafted with a temperature sensitive oligomer; And a second repeating unit comprising an ionic moiety and a counter ion of the ionic moiety. The temperature sensitive copolymer may be a polyamino acid derivative. The copolymer may comprise two or more different first repeating units and / or two or more different second repeating units.

The temperature sensitive oligomers grafted to the first repeating unit of the copolymer may exhibit water solubility in water at significantly lower values in response to small temperature changes. The temperature sensitive oligomer is an oligomer comprising a repeating unit derived from an unsaturated monomer having a residue represented by the formula (1) or (2), or from a heterocyclic compound containing C, N and O in a ring and having a C═N bond Oligomers containing derived repeat units:

[Formula 1]

* -C (= O) N (R ₂ ) (R ₃ )

In formula (1), R ₂ and R ₃ are each independently hydrogen or a straight or branched C 1 to C 6 alkyl group, C 3 to C 7 cycloalkyl group, or C 6 to C 10 aryl group, R ₂ and R All _three may not be hydrogen, and R ₂ and R ₃ may combine with each other to form a nitrogen-containing hetero ring.

[Formula 2]

In formula (2), R ₄ is a C2 to C5 alkylene group.

The backbone of the temperature sensitive oligomer may be derived from unsaturated monomers such as vinyl monomers, acrylic monomers, or may include repeating units such as polyethers, polyethylene glycols, polyesters, and the like.

Specifically, the temperature sensitive oligomer may be an oligomer including a repeating unit derived from an oxazoline compound represented by the following Chemical Formula 3, or a repeating unit derived from an N-alkyl (meth) acrylamide represented by the following Chemical Formula 4, It may be an oligomer comprising repeating units derived from N-vinyl lactam represented by the following formula (5), or a combination thereof:

[Formula 3]

In formula (3), Ak is a linear or branched alkyl group having 1 to 10 carbon atoms, specifically 1 to 5 carbon atoms, for example, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, an isopentyl group, Each R is independently hydrogen or alkyl having 1 to 3 carbon atoms;

[Formula 4]

In formula (4), R ₁ is hydrogen or methyl, and R ₂ and R ₃ are as defined in formula (1);

[Formula 5]

In formula (5), R ₄ is as defined in formula (2).

If the temperature sensitive oligomer is an oligomer comprising repeating units derived from N-alkyl (meth) acrylamide, repeating units derived from N-vinyllactam, or a combination thereof, optionally repeating derived from (meth) acrylamide It may further include a unit.

More specifically, the oxazoline compound is 2-methyl-oxazoline, 2-ethyl-2-oxazoline, 2-propyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-butyl-2 Oxazoline, 2-isobutyl-2-oxazoline, 2-pentyl-2-oxazoline, 2-isopentyl-2-oxazoline, or a combination thereof, but is not limited thereto. Polymerization (eg, cationic polymerization) of the oxazoline compound yields oligomers of desired molecular weight comprising repeating units of formula (9), and specific polymerization conditions and methods are known:

[Formula 9]

In formula (9), Ak and R are as defined in formula (3).

The said N-alkyl (meth) acrylamide is N-isopropyl (meth) acrylamide (NIPAAM), N-isobutyl (meth) acrylamide, N-isopentyl (meth) acrylamide, N, N-dimethyl ( One or more selected from meth) acrylamide, N, N-ethylmethyl (meth) acrylamide, and N, N-diethyl (meth) acrylamide (DEAAM), wherein the N-vinyllactam is N-vinyl capro At least one selected from lactam (VCL), N-vinyl-2-pyrrolidone and N-vinyl-piperidone.

When the oligomer is a co-oligomer of one or more of N-alkyl (meth) acrylamide and N-vinyllactam and (meth) acrylamide, the molar ratio of (meth) acrylimide in all monomers is 40 mol% or less. , Specifically 30 mol% or less, more specifically 15 mol% or less, and most specifically 10 mol% or less.

When the N-alkyl (meth) acrylamide represented by the formula (4) or the N-vinyllactam represented by the formula (5) is polymerized (for example, radical polymerization), each of the repeating units represented by the following formula (7) Oligomers having a degree of polymerization or oligomers having a desired degree of polymerization comprising a repeating unit represented by the following formula (8) can be obtained, and specific polymerization methods / conditions are known:

[Formula 7]

In Formula 7, R ₁ , R ₂ , and R ₃ are as defined in Formula 4.

[Formula 8]

In formula (8), R ₄ is as defined in formula (5).

In the second repeating unit of the temperature-sensitive copolymer, and specific examples of the ionic moieties _{^{-COO -, -SO 3 -, -PO}} 3 2 -, or a combination thereof. The counter ions included in the second repeating unit have a charge opposite to the ionic residue, and may be a cation of an alkali metal, a cation of an alkaline earth metal, or a combination thereof. The ionic moiety and the counterion may be present in an ionic bond.

In the temperature sensitive copolymer, the second repeating units may comprise the same ionic moiety, or may each independently comprise different ionic moieties. In other words, the copolymer may comprise one ionic moiety or may comprise two or more ionic moieties. As a non-limiting example, all second repeating units present in the temperature sensitive copolymer may include -COO ^- as the ionic moiety. As another non-limiting example, some of the second repeat unit is present in the thermosensitive copolymer is -COO ^- include an ionic moiety, and the other is -SO ₃ ^- include ^- and / or -PO ₃ ² can do.

Specifically, a temperature sensitive copolymer comprising a first repeating unit grafted with a temperature sensitive oligomer and a second repeating unit having an ionic moiety and a counter ion may be represented by the following Chemical Formula 6:

[Formula 6]

In formula (6), A ⁻ is a group containing an ionic moiety, M ⁺ is a counter ion of the ionic moiety, and Q is —NR— (where R is hydrogen or an alkyl group having 1 to 5 carbon atoms) or- S-, L is a direct bond, substituted or unsubstituted C1 to C20 alkylene, or substituted or unsubstituted C1 to C20 thioalkylene, and Og is an oligomer comprising a repeating unit of Formula 7 , An oligomer comprising a repeating unit of Formula 8, or an oligomer comprising a repeating unit of Formula 9.

Specifically, A ^- are the same or ^{different, -COO -, -CONR-Z-} SO 3 -, -CONR-ZO-PO 3 -2, -CO-SZ-SO 3 -, and -CO-SZO- Selected from PO ₃ ^-2 , wherein R is hydrogen or an alkyl group of C1 to C5, Z is a substituted or unsubstituted C1-10 alkylene group, and M ⁺ is Na ⁺ , K ⁺ , Li ⁺ , Rb ⁺ , Ca ^{2 +,} Mg ^{2 +,} may be selected from Ba ^{+ 2,} and combinations thereof.

The temperature sensitive copolymer has a low critical solution temperature (LCST) and can significantly reduce its solubility in water in response to small temperature changes and can precipitate. As used herein, " temperature sensitive " means that the solubility of a given copolymer (or corresponding oligomer) in a particular solvent (e.g., water) is significantly reduced above a critical temperature, thereby reversibly agglomerating based on the critical temperature or Or physical properties of the polymer (or oligomer) to be dissolved. Here, the low critical solution temperature refers to a critical temperature above which a solution (eg, an aqueous solution) of the temperature sensitive copolymer can exhibit phase separation. That is, below the low critical solution temperature, the temperature sensitive copolymer is miscible with water. The low critical solution temperature of the temperature sensitive copolymer may be present in the range of about 10 to about 50 ° C., at a solution concentration of 0.01 g / ml, for example about 25 to about 50 ° C., specifically about 30 to about 45 It may be present in the range of ℃.

Below the low critical solution temperature (LCST), the temperature sensitive oligomer grafted to the copolymer may form a hydrogen bond with water, so that the copolymer may be present in a dissolved state in water. Above the low critical solution temperature (LCST), the hydrophilicity of the copolymer is significantly lowered such that hydrophobic interactions between the grafted oligomers dominate. Accordingly, the copolymer has low solubility in water and may precipitate out of solution by forming self-aggregated particles by intramolecular or intermolecular hydrophobic interaction. Self-aggregated copolymer particles at temperatures above the low critical temperature have increased size and can be easily separated from solutions (eg, osmotic induction solutions).

According to one embodiment, the temperature sensitive copolymer at a temperature higher than the low critical solution temperature (LCST) is characterized in that its main chain forms a shell, and the grafted temperature sensitive oligomer forms a core. Primary aggregated particles in the form of core-shells can be formed. Here, by adjusting the grafted temperature-sensitive oligomer component or increasing the copolymer concentration in the solution, the intermolecular interaction (intermolecular interaction) is likely to occur to form secondary aggregated particles. In a non-limiting example, control of the grafted oligomer component includes increasing the degree of polymerization of the oligomer or increasing the content of the first repeating unit (ie, the content of temperature sensitive oligomers) in the copolymer. By this secondary agglomeration, the copolymer particles have an increased size and therefore can be easily separated from the solution. Therefore, particle separation can be easily achieved without using energy-consuming means (eg, centrifugation, reverse osmosis (RO) membrane, nanofiltration, etc.) (eg, by fine filtration (MF), etc.). Therefore, when the temperature sensitive copolymer is used as the inducing solute, separation of the solute from the osmotic induction solution is facilitated.

In addition, the temperature sensitive copolymer may include a second repeating unit including an ionic moiety and a counter ion, and the ionic moiety and the counter ion may impart ionicity to the copolymer. This ionicity allows the temperature sensitive copolymer to have a high level of solubility in water at temperatures below LCST and to exhibit increased hydraulic capacity. Accordingly, the aqueous solution of the copolymer may exhibit a higher level of osmotic pressure. This effect can be more pronounced the smaller the ionic radius of the counter ion of the ionic moiety. Since the ionic moiety is contained in the polymer chain and the counterion is bound to the ionic moiety (by interaction with an ionic bond or the like), when it is used as an osmotic inducing solute, it is possible to despread the solute through the semipermeable membrane. High osmotic pressure can be provided while suppressing to a minimum level. In addition, by introducing the appropriate ionic moiety and counter ions thereof into the second repeating unit of the copolymer, the final copolymer can be biocompatible and biodegradable. Therefore, such copolymers are useful as inducing solutes for water treatment.

In the temperature sensitive copolymer, the oligomer grafted to the first repeating unit may have a degree of polymerization in the range of 2 to 30, specifically, 2 to 25, more specifically 4 to 25. Further, the temperature sensitive copolymer including the first repeating unit grafted with the temperature sensitive oligomer and the second repeating unit including the ionic moiety / counter ion may be in the range of 5000 to 250,000, specifically, in the range of 5000 to 100,000, more specifically. It may have a number average molecular weight in the range of 5,000 to about 50,000. The temperature sensitive copolymer having the oligomer polymerization degree in the above range and the number average molecular weight in the above range has a high solubility in water below the low critical solution temperature (LCST) to provide a high concentration of the aqueous solution, and the prepared aqueous solution has a high level. The osmotic pressure of can be generated to induce higher water flux.

By adjusting the molar ratio between the first repeating unit and the second repeating unit of the temperature sensitive copolymer, the level of temperature sensitivity and osmotic pressure of the final copolymer can be adjusted. While not wishing to be bound by any theory, the higher the relative molar ratio of the first repeating unit, the more prominent the temperature sensitivity is, and an increase in the relative molar ratio of the second repeating unit can lead to higher levels of osmotic pressure. According to one embodiment, the molar ratio (first repeating unit: second repeating unit) between the first repeating unit and the second repeating unit in the temperature sensitive copolymer is 1:99 to 60:40, specifically, 1: 99 to 40:60, more specifically 2:98 to 20:80, even more specifically, 2:98 to 10:90. In this range of molar ratios the copolymer can express high levels of osmotic pressure while having significant temperature sensitivity.

The temperature sensitive copolymer may be, but is not limited to, a block copolymer, a random copolymer, or a graft copolymer of the first and second repeating units.

The temperature sensitive copolymer aggregates (self) in a solution above the low critical solution temperature (LCST), resulting in a sharp increase in particle size. The temperature sensitive copolymer has a particle size of at least about 10%, in particular from about 10 to about 10,000 times, of at least about 50% by weight of the total copolymer present in the solution at or above LCST, relative to a temperature below LCST. Specifically, it may increase from about 100 times to about 10,000 times, and most specifically, about 1,000 times to about 10,000 times. This change in particle size can be confirmed by measuring hydrodynamic diameter through the Dynamic Light Scattering method. The hydraulic diameter of the copolymer particles at a temperature above LCST may be, for example, in the range of about 100 nm to about 10,000 nm, specifically 300 nm about 50 μm, more specifically about 300 nm to about 5 μm.

The temperature sensitive copolymer may have a solubility in water of less than about 100 g / L below the low critical solution temperature (LCST), and a solubility in water of less than about 10 g / L above the low critical solution temperature (LCST). Can be. Specifically, the temperature sensitive copolymer may have a solubility in water of less than the low critical solution temperature (LCST) of about 200 g / L to about 800 g / L, and above the low critical solution temperature (LCST) of water. Solubility may be from about 0.1 g / L to about 10 g / L. More specifically, the copolymer compound has a solubility in water of about 500 g / L to about 800 g / L below the low critical solution temperature (LCST), and a solubility in water above the low critical solution temperature (LCST). About 0.1 g / L to about 1 g / L.

When the temperature sensitive copolymer is prepared as an aqueous solution, the aqueous solution may have an osmotic pressure of 20 atm or more at a temperature of less than the low critical solution temperature (LCST) of the copolymer and a concentration of 0.4 g / ml. The osmotic pressure can be measured by a freezing point lowering method or by using a membrane osmometer. The temperature sensitive copolymer can provide this level of osmotic pressure, and as will be described later, it may find utility as a solute of the osmotic induction solution. In addition, since it has a temperature sensitivity, it can be found useful in various fields that can utilize temperature sensitivity in addition to the use of induction solutes. For example, the temperature sensitive copolymer may be used for a drug delivery system (DDS) or the like.

In another embodiment, the present invention provides a kit comprising: a first repeating unit grafted with a temperature sensitive oligomer; And a second repeating unit comprising an ionic moiety and a counter ion of the ionic moiety, the method comprising the steps of:

Preparing polysuccinimide;

A temperature sensitive oligomer comprising a repeating unit derived from a monomer represented by the following formula (3) having an amine group or a thiol group at one end, or a repeating unit derived from a monomer represented by the following formula (4) having an amine group or a thiol group at one terminal; Preparing a temperature sensitive oligomer comprising a repeating unit derived from a monomer represented by Formula 5 or a combination thereof;

[Formula 3]

In formula (3), Ak is a straight-chain or branched alkyl group having 1 to 10 carbon atoms, and R is each independently hydrogen or alkyl having 1 to 3 carbon atoms;

[Formula 4]

In formula (4), R ₁ is hydrogen or methyl, R ₂ and R ₃ are each independently hydrogen or a linear or branched C 1 -C 6 alkyl group, C 3 -C 7 cycloalkyl group, or C 6 -C 10 aryl group, R ₂ And R ₃ may not all be hydrogen, and R ₂ and R ₃ may be linked to each other to form a nitrogen-containing hetero ring;

[Formula 5]

In formula (5), R ₄ is alkylene having 2 to 5 carbon atoms;

Reacting the polysuccinimide with the temperature sensitive oligomer to open a portion of the succinimide ring of the polysuccinimide and to graft the temperature sensitive oligomer; And

The product of the reaction is reacted with an amine compound containing an ionic moiety, a thiol compound containing an ionic moiety, an inorganic base, or a combination thereof to open the remaining succinimide ring of the polysuccinimide and ion Introducing a sex moiety and a counter ion.

The number average molecular weight of the poly succinic acid imide may be 1000 to 25,000, but is not limited thereto. In one embodiment, the polysuccinic acid imide may have a number average molecular weight of 5,000 or less. Polysuccinic acid imides in this molecular weight range can be prepared according to known methods.

An oligomer having an amine group or a thiol group at one end and including a repeating unit derived from the formula (3), and a repeating unit derived from the formula (4) having a amine group or a thiol group at one end, and a repeat derived from the formula (5) The details for oligomers comprising units, or combinations thereof, are substantially the same as described above for temperature sensitive oligomers. The oligomer is an N-alkyl (meth) acrylamide oligomer, a co-oligomer of N-alkyl (meth) acrylamide and (meth) acrylamide, an oligomer of N-vinyl lactam, 2- (alkyl) Oligomers of 2-oxazoline, or combinations thereof. Specific examples of the oligomer include N-isopropyl acrylamide oligomer, co-oligomer of N-isopropyl acrylamide- (meth) acrylamide N, N-diethylacrylamide oligomer, N-vinylcaprolactam oligomer, and 2- Isopropyl-2-oxazoline oligomers, but is not limited thereto. The oligomer contains an amine group or a thiol group at one end. The ring-opening reaction of the succinimide ring may be triggered by the amine group or thiol group. The amine group or thiol group may be derived from a chain transfer agent used in preparing the oligomer. Alternatively, the amine group or thiol group can be introduced by appropriately reacting the oligomer prepared.

The reaction of opening the ring of polysuccinic acid imide with the oligomer (opening reaction) may be performed in a solution in which a predetermined amount of polysuccinic acid imide and a predetermined amount of temperature sensitive oligomer are dissolved in a solvent. By adjusting the ratio of the amount between the polysuccinic acid imide and the temperature sensitive oligomer, the molar ratio between the first repeating unit and the second repeating unit can be adjusted in the temperature sensitive copolymer. The solvent is not particularly limited as long as it can dissolve the polysuccinic acid imide and the temperature sensitive oligomer and does not cause side reaction with an amine or thiol group. Specific examples of the solvent include, but are not limited to, N, N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and sulfolane. The temperature and time of the ring-opening reaction are also not particularly limited and can be appropriately selected. For example, the ring opening reaction may be performed at a temperature of 50 to 100 degrees, specifically 60 to 90 degrees, and more specifically 70 to 80 degrees, for example, 3 hours to 72 hours. The ring-opening reaction may optionally be carried out in the presence of triethylamine, triethanolamine, pyridine or a combination thereof. Through the ring-opening reaction, the temperature sensitive oligomer is grafted to the polymer backbone, and the graft ratio may be controlled by adjusting the amounts of the polysuccinic acid imide and the temperature sensitive oligomer.

The product of the ring-opening reaction is reacted with an amine compound containing an ionic moiety, a thiol compound containing an ionic moiety, an inorganic base, or a combination thereof to open the succinimide ring remaining in the polysuccinimide. Introduce ionic moieties and counter ions into the polymer. Specific examples of the amine compound including an ionic moiety include an ester compound of phosphoric acid such as orthophosphoethanolamine and the like and a C1 to C20 sulfoalkylamine such as aminoethanesulfonic acid and the like. However, the present invention is not limited thereto. Specific examples of the inorganic base include, but are not limited to, alkali metal hydroxides such as NaOH, KOH, LiOH, and alkaline earth metal hydroxides such as CaOH, MgOH, BaOH, and the like.

The temperature sensitive copolymer may be used as an osmotic inducing solute in the forward osmosis water treatment process. Details of the temperature sensitive copolymer are as described above. The forward osmosis water treatment process uses a osmotic induction solution having a higher concentration than the influent to transfer water molecules from the influent to the osmotic induction solution, and separates the solutes from the final osmotic induction solution to produce fresh water. The separated derived solute can be reused. Forward osmosis water treatment can be operated at a lower cost than reverse osmosis water treatment, which is a pressure-driven process, but its development is delayed due to the absence of suitable induction solutions. Temperature sensitive copolymers having the structures described above can cause high levels of osmotic pressure in aqueous solutions. That is, the temperature sensitive copolymer includes a first repeating unit grafted with a temperature sensitive oligomer and a second repeating unit having an ionic moiety / counter ion, so that the temperature sensitive copolymer may Solubility is high, it is possible to prepare a high concentration of osmotic induction solution and cause high osmotic pressure. Moreover, since the said temperature sensitive copolymer shows a remarkable difference in solubility before and after LCST temperature, a polymer can be easily collect | recovered by temperature control and the energy consumption required for polymer (solute) removal is low. In addition, since it has a relatively high molecular weight compared to other derived solutes, reverse draw solute diffusion is minimized. In addition, since the copolymer self-aggregates and precipitates at or above the low critical solution temperature (LCST), the solute may be easily separated and recovered from the induction solution. When the separated copolymer is cooled back below the low critical solution temperature (LCST), the agglomerates dissolve and the solubility in water increases rapidly and can be reused as an inducing solute. It also has a polyamino acid backbone and contains ionic moieties / counter ions, so it is biodegradable and biocompatible (ie, low biotoxicity), and thus can be used for the provision of drinking water or domestic water and the like. For example, even in the case of relatively high molecular weight temperature sensitive copolymers, there is no biotoxicity, for example up to 3000 ppm.

Another embodiment of the present invention is an aqueous medium; And an osmotic pressure induced polymer chain dissolved in the aqueous medium and comprising an ionic moiety and a counter ion of the ionic moiety and a temperature sensitive oligomer in the form of graft. An inducing solute containing a covalently bound temperature sensitive copolymer, wherein the inducing solute provides an osmotic induction solution that can be recovered by phase separation above a low critical solution temperature.

The aqueous medium may be water. Details of the temperature sensitive copolymer are as described above. For example, the temperature sensitive copolymer may have a low critical solution temperature (LCST) of 10 to 50 ° C. at a concentration of 0.01 g / ml. The temperature sensitive copolymer may have a solubility in water of less than or equal to 100 g / L at or below the low critical solution temperature (LCST), and solubility in water may be less than or equal to 1 g / L at or above the low critical solution temperature (LCST). . When raising the temperature of the osmotic induction solution above the low critical solution temperature (LCST) below the low critical solution temperature, at least 50% by weight of the total inducing solute may exhibit a 10-fold increase in particle size.

The temperature sensitive oligomer comprises an amide and an aliphatic moiety that is covalently bonded to the nitrogen atom of the amide and is hydrophobic relative to the amide, and the aliphatic moiety is covalently or unbound to the carbon atom of the amide. Oligomers, or repeating units derived from heterocyclic compounds containing C, N and O in the ring and having C═N bonds. The aliphatic moiety may be, for example, an alkyl group in linear, branched, or cyclic form.

In another embodiment, there is provided a forward osmosis water treatment apparatus comprising an induction solution comprising the temperature sensitive copolymer. The forward osmosis water treatment apparatus, a feed solution containing water and the substance to be separated dissolved in the water (feed solution); The osmotic induction solution described above; A semipermeable membrane positioned at one side in contact with the inflow liquid and at the other side in contact with the osmotic induction solution; A recovery system for removing said temperature sensitive polymer from a treatment solution comprising water moved from said inlet liquid through said semipermeable membrane to said osmotic induction solution by osmotic pressure; And a connection for introducing the temperature sensitive copolymer removed from the recovery system back into the osmotic induction solution. Figure 1 is a schematic diagram of the forward osmosis water treatment apparatus according to an embodiment that can be operated according to the forward osmosis water treatment method to be described later.

The semi-permeable membrane is water-permeable to water and non-permeable to the material to be separated. The type of the influent is not particularly limited as long as forward osmosis water treatment is possible. The material to be separated may be impurities. Specific examples of the influent include, but are not limited to, sea water, brackish water, ground water, waste water. In a non-limiting example, drinking water can be obtained by treating seawater with the forward osmosis water treatment device.

Details of the temperature sensitive copolymer are as described above. The osmotic induction solution is adjusted at a concentration so as to cause an osmotic pressure higher than the influent. For example, some temperature sensitive copolymers may cause an osmotic pressure above about 40 atmospheres for a given treatment liquid when dissolved at a concentration of about 10 wt% (even at 0.01 g / ml or 0.02 g / ml). . In addition, other temperature sensitive copolymers can cause an osmotic pressure of at least about 80 atmospheres for a given treatment liquid when dissolved at as high as about 20 wt%. The concentration of the osmotic induction solution and the osmotic pressure induced therefrom may vary depending on the structure of the polymer and the type of influent. For example, for seawater desalination osmotic pressures as low as 26 atm, or about 50 atm or higher may be required. As another example, for wastewater purification, a relatively low osmotic pressure of about 10 to about 20 atmospheres may be required, for example an osmotic induction solution of concentration up to about 2 wt% may be used. In some embodiments, the temperature sensitive copolyis exhibits high levels of osmotic pressure (eg, at least 50 atm at 0.02 g / ml) even at very low concentrations, and can exhibit low phase transition temperatures even at such concentrations, leading to ideal induction. Solution may be provided.

Removal of the temperature sensitive copolymer in the recovery system can utilize the temperature sensitivity of the copolymer. The recovery system includes a temperature controller to heat the treatment liquid above the low critical solution temperature (LCST). By heating, the copolymer in the treatment liquid self-aggregates to form particles of increased size, and the particles formed are easily filtered and separated. Specific examples of such a temperature controller may include a heating unit such as a heating jacket, but are not limited thereto. In a non-limiting example, the temperature controller utilizes waste heat from an industrial water heat source, such as a waste water treatment plant, a power plant, a distillation plant, and the like. It may be a device. The recovery system may comprise a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane or a centrifuge for filtration or separation of the aggregated copolymer. In a non-limiting example, the copolymer forms particles having a micro-sized micelle network by the heating, and these particles can be separated into a microfiltration membrane, so that the recovery energy can be significantly lowered. The removed copolymer can be introduced back into the induction solution through the connection. The recovery system may include a temperature controller that cools the removed copolymer below the low critical solution temperature (LCST). Specific examples of such temperature controllers include, but are not limited to, cooling units such as cooling jackets. Copolymers cooled below the low critical solution temperature (LCST) may exhibit high solubility in water and are therefore reusable as solutes.

The forward osmosis water treatment apparatus may further include a discharge unit for discharging the treated water produced by removing the temperature sensitive copolymer from the treatment solution in the recovery system. The type of the discharge portion is not particularly limited.

In the apparatus, the forward osmosis process is performed at a temperature below the low critical solution temperature (LCST) of the temperature sensitive copolymer, and the treatment solution from the forward osmosis process is above the low critical solution temperature (LCST) in the recovery system. By heating, the temperature sensitive copolymer (ie, inducing solute) can be easily separated and recovered. In particular, since the low critical solution temperature (LCST) of the copolymer ranges from about 10 to about 50 ° C., high temperature conditions are not required for recovery of the induced solute, thereby reducing operating energy. In addition, the temperature sensitive copolymer separated from the recovery system can be cooled to a temperature below LCST and reused as an inducing solute.

In another embodiment of the present invention, there is provided a forward osmosis water treatment method, which is in contact with an inflow liquid containing water and a substance to be dissolved in the water and the osmotic induction solution described above with a semipermeable membrane interposed therebetween, Obtaining a treatment solution comprising water transferred from the influent to the osmotic induction solution through the semipermeable membrane; Heating at least a portion of the treatment solution to a temperature above the low critical solution temperature (LCST) of the temperature sensitive copolymer to agglomerate the temperature sensitive copolymer in the treatment solution; And removing the aggregated temperature sensitive copolymer from the treatment solution to obtain treated water. The treated water can be properly discharged.

When the inflow liquid and the osmotic induction solution are in contact with the semipermeable membrane therebetween, the water contained in the inflow liquid may move to the osmotic induction solution through the semipermeable membrane by osmotic pressure.

Details of the temperature sensitive copolymer, semipermeable membrane, forward osmosis process, heating / cooling and aggregation of the copolymer are as described above.

The forward osmosis water treatment method may further include cooling the recovered temperature sensitive copolymer to a low critical solution temperature (LCST) or lower and feeding it back into the osmotic induction solution. The low critical solution temperature (LCST) of the temperature sensitive copolymer may be about 10 to about 50 ° C.

[ Example ]

Example  One

According to Scheme 1, a copolymer of Formula 11 is synthesized.

Scheme 1

One) NIPAAm Oligomer  synthesis

Through free radical polymerization, (N-isopropylacrylamide oligomer ( oligo -NIPAAm) represented by Formula 10 is synthesized 5.8 g (51.2 mmol) of NIPAAm monomer, aminoethanethiol hydrochloride, as a chain transfer agent. 0.175 g (1.53 mmol) of AET-HCl) and 0.084 g (0.51 mmol) of azobisisobutyronitile (AIBN) as an initiator were dissolved in 30 ml dimethylformamide (DMF) at 72 ° C. in nitrogen. The reaction is carried out in an atmosphere for 15 hours The polymerized NIPAAm oligomer is precipitated in diethyl ether, centrifuged and dried in a vacuum oven for one day.

[Formula 10]

In the above formula, z is the degree of polymerization, and is 18 to 25 when calculated through terminal analysis through ¹ H-NMR.

2) temperature Irritability Copolymer  synthesis

0.97 g of Polysuccinimide (PSI) (10 mmol as calculated for the succinimide ring) [Condensation polymerization from L-aspartic acid under phosphoric acid catalyst (hereinafter referred to as compound), number average molecular weight : 18,000] and 2.5 g (1 mmol) of the NIPAAm oligomer represented by Formula 10 are reacted for 48 hours at 70 ° C. in a DMF solvent in the presence of 0.28 mL (2 mmol) of triethylamine. The reaction product is added to 1M NaOH solution and stirred to open all the imide rings remaining in the reaction product. The reaction solution is continuously dialyzed against methanol and water for 48 hours each to obtain a liquid product which is lyophilized to obtain a powdery product. The product confirms that the copolymer represented by the following formula (11) through its NMR. 2 is a H ¹ -NMR analysis spectrum of the copolymer synthesized in Example 1. FIG.

[Formula 11]

In Formula 11, R is -ONa, x is the degree of polymerization of the second repeating unit comprising an ionic moiety, y is the degree of polymerization of the first repeating unit grafted NIPAAm oligomer, z is the degree of polymerization of the NIPAAM oligomer , 18-25.

The temperature sensitive copolymer has a content of 10 mol% (the content of the second repeating unit is 90 mol%) of the first repeating unit. The number average molecular weight of the synthesized copolymer, as determined by GPC and ¹ H-NMR, is 26,400 g / mol.

Example  2

The content of the first repeating unit in the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (composite, number average molecular weight: 18,000) and 10 g (4 mmol) of NIPAAm oligomer represented by Formula 10 were used. This 40 mol% (the content of the second repeating unit is 60 mol%) is synthesized a temperature sensitive copolymer. As determined by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound is 127,800 g / mol.

Example  3

In the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (Bayer, number average molecular weight: 2000 to 3000) and 0.5 g (0.2 mmol) of the NIPAAm oligomer represented by Formula 10 were used. A copolymer having a content of 1 repeating unit of 2 mol% (content of a second repeating unit of 98 mol%) is synthesized. As determined by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound was 6,527 g / mol.

Example  4

First repeating unit in the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (Bayer, molecular weight: 2000 to 3000) and 1 g (0.4 mmol) of NIPAAm oligomer represented by Chemical Formula 10 were used. A copolymer copolymer having a content of 4 mol% (the content of the second repeating unit is 96 mol%) is synthesized. As determined by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound is 8,123 g / mol.

Example  5

In the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (composite, number average molecular weight: 18,000) and 0.5 g (0.2 mmol) of the NIPAAm oligomer represented by Formula 10 were used. A copolymer having a content of 2 mol% (the content of the second repeating unit is 98 mol%) is synthesized. As confirmed by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound is 20,678 g / mol.

Example  6

Content of the first repeating unit in the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (composite, number average molecular weight: 18,000) and 1 g (0.4 mmol) of NIPAAm oligomer represented by Formula 10 were used. This 4 mol% (content of the second repeating unit is 96 mol%) is synthesized. As confirmed by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound is 23,625 g / mol.

Example  7

In the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (composite, number average molecular weight: 18,000) and 1.5 g (0.6 mmol) of NIPAAm oligomer represented by Formula 10 were used. A copolymer having a content of 6 mol% (the content of the second repeating unit is 94 mol%) is synthesized. As determined by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound is 25591 g / mol.

Example  8

The content of the first repeating unit in the same manner as in Example 1, except that 0.97 g (10 mmol) of PSI (composite, number average molecular weight: 18,000) and 2 g (0.8 mmol) of NIPAAm oligomer represented by Formula 10 were used. This 8 mol% (content of the second repeating unit is 92 mol%) is synthesized. As determined by GPC and ¹ H-NMR, the number average molecular weight of the synthesized copolymer compound is 29,029 g / mol.

Example  9

According to Scheme 2, a copolymer of Formula 12 or Formula 13 is synthesized:

Scheme 2

One) NIPAAm Oligomer  synthesis

In the same manner as in Example 1 to synthesize the NIPAAm oligomer represented by the formula (10).

2) Copolymer  synthesis

0.97 g (10 mmol) of PSI (Bayer, number average molecular weight: 2000-3000) and 2.5 g (0.1 mmol) of the NIPAAm oligomer represented by the formula (10) were added over a DMF solvent in the presence of 0.28 mL (2 mmol) of triethylamine. The reaction is carried out at 70 ° C. for 48 hours. The reaction product was dissolved in 4.85 ml of DMF and an aqueous solution of orthophosphoethanolamine (0.14 g, 0.1 equiv. For the remaining succinimide ring) was added and then reacted for 24 hours under stirring. The obtained product is added to 1M NaOH solution (1.2 equiv. For the remaining succinimide rings) and vigorously stirred at room temperature for 3 hours to open all the imide rings remaining in the reaction product. The reaction solution is continuously dialyzed against methanol and water for 48 hours each to obtain a powdery product. The powdery product obtained is freeze dried. The product confirms that the copolymer represented by the following formula (12) through its NMR.

[Formula 12]

The copolymer has a first proportion of the repeating units is 2 mol%, the content of the second repeating units is 98 mol%, provided that, COO ^- molar ratio between _{^{(COO - -: PO 3 2}} -) and PO ₃ ² 9 : 1.

Example  10

The copolymer represented by the formula (12) in the same manner as in Example 9 except that an aqueous solution of 0.41 g of orthophosphoethanolamine (0.3 equiv. For the remaining succinimide ring) was used, wherein the repeating unit is 2 mol%, the content of the second repeating units is 98 mol%, provided that, COO ^- and PO ₃ ^{2 -} mole between the ratio _{^{(COO -: PO 3 2 -}} ) is 7: synthesis of 3-Im) .

Example  11

Instead of an aqueous solution of orthophosphoethanolamine, an aqueous solution of 0.12 g of aminoethane sulfonic acid (0.1 equiv. For the remaining succinimide ring) was used, except that the reaction was carried out at 25 ° C. for 24 hours. example 9 and in the same manner, to a copolymer represented by the general formula (13) [wherein, a first proportion of the repeating units is 2 mol%, the second content of the repeating unit is 98 mol%, provided that, COO ^- and SO ₃ ^- between Molar ratio (COO ⁻ : SO ₃ ⁻ ) is 9: 1.

[Formula 13]

Example  12

The reaction was carried out at 25 ° C. for 24 hours, using an aqueous solution of aminoethane sulfonic acid (0.37 g, 0.3 equiv. For the remaining succinimide ring) instead of an aqueous solution of orthophosphoethanolamine. example 7 by the same method as, the copolymer represented by the general formula (13) [wherein, a first proportion of the repeating units is 2 mol%, the second content of the repeating unit is 98 mol%, provided that, ONa ^- and SO ₃ ^- between the molar ratio (ONa ^-: SO ₃ ^-) is 7: 3 being synthesized.

Reference Example  One

0.97 g of polysuccinimide (PSI) (10 mmol, molecular weight: 2000-3000, purchased from Bayer) is added to a 1N NaOH aqueous solution and stirred for 3 hours. The reaction is precipitated in excess methanol, centrifuged and vacuum dried to yield a polyamino acid with y = 0 in formula (11).

Reference Example  2

A polyamino acid having y = 0 in Formula 11 was obtained in the same manner as in Reference Example 1, except that 0.97 g (molecular weight: 18,000, compound) of polysuccinimide (PSI) was used.

Experimental Example  1: Preparation of Osmotic Induction Solution and Osmotic Pressure Analysis

Using the copolymer synthesized in Examples 1 to 12 and the polymer synthesized in Reference Examples 1 and 2, an osmotic induction solution was prepared at various concentrations as shown in the following tables, and an osmotic pressure measuring device using a membrane measurement method (Osmomat090). , Gonotek) to analyze the osmotic pressure (average value) for each solution, the results are summarized in Table 1 to Table 4 below.

Reference Example 1 Example 1 Example 2 Concentration [g / ml] Osmotic pressure [atm] Concentration [g / ml] Osmotic pressure [atm] Concentration [g / ml] Osmotic pressure [atm] 0.025 0.58 0.05 1.06 0.1 1.2 0.05 1.24 0.1 1.74 0.3 4.2 0.1 2.87 0.2 3.76 0.5 7.4

Figure 3 shows the results of Table 1 graphically. From the results of Table 1 it can be seen that Example 1 and Example 2 shows an increased osmotic pressure with increasing concentration.

matter Reference Example 1
OAspNa matter Example 3
OAspNa-ON2% Example 4
OAspNa-ON 4% Concentration [g / ml] medium Standard Deviation Concentration [g / ml] medium Standard Deviation medium Standard Deviation 0.4 41.574 1.68 0.25 24.631 0.979 29.1 0.831 0.375 37.0205 1.4 0.125 9.66 0.593 11.6 0.45 0.25 19.8502 0.73 0.0625 4.57 0.37 5.489 0.21 0.205 14.7349 0.66 0.164 11.1835 0.45 0.125 9.359 0.37 0.1 7.567 0.342 0.05 3.9342 0.14

matter Example 9 Example 10 Example 11 Example 12 Molarity
[M] medium Standard Deviation medium Standard Deviation medium Standard Deviation medium Standard Deviation 5.00E-04 21.026 0.197 27.026 0.253 14.718 0.138 18.918 0.177 2.50E-04 8.419 0.180 10.822 0.232 5.894 0.126 7.575 0.162 1.25E-04 3.515 0.044 4.518 0.056 2.460 0.031 3.162 0.039 6.25E-05 1.467 0.008 1.886 0.011 1.027 0.006 1.320 0.007 3.13E-05 0.822 0.075 1.056 0.097 0.575 0.053 0.739 0.068

From the results of Tables 1 to 4, the copolymers synthesized from Examples 1 to 12, when prepared in an aqueous solution, contain a specific composition of the copolymer (e.g., molecular weight of polysuccinimide used, graft ratio of oligonifam, etc.) and It is confirmed that depending on the concentration in the aqueous solution, it can cause an osmotic pressure as high as 50 atm or more.

Experimental Example  2: Low threshold  Solution temperature ( LCST ) Measurement

An osmotic induction solution comprising the copolymers prepared in Examples 1 and 2 is prepared. (Concentration: 0.01 g / ml) The solubility change of the solution according to the temperature is observed by measuring the absorbance at a fixed visible wavelength of 500 nm while gradually increasing the temperature of the solution from room temperature and then decreasing back to room temperature. 4 shows the results for the copolymer of Example 1. FIG. 5 shows the results for the copolymer of Example 2. FIG. With increasing temperature, the temperature up to 90% of the saturated value of absorbance is determined as "Low Critical Solution Temperature (LCST)" and summarized in Table 5.

Example 1 Example 2 LCST (℃) 32-35 ℃ 32-35 ℃ 0.45㎛ filter separation able to seperate able to seperate Reversibility (at 25 ° C) ○ ○

The copolymers of Examples 1 and 2 exhibit phase transition temperatures at 32 ° C., similar to oligo (NIPAAm), and show hysteresis in both heating and cooling cycles. This is thought to be due to the structural limitations of the analytical instrument. In other words, the measuring solution cannot be uniformly stirred in the measuring equipment, so that the temperature distribution inside the cell is not uniform. The copolymer of Example 2 shows a higher level of absorbance than Example 1. This is because the graft rate of the oligo NIPAAm of Example 2 is higher than that of Example 1, indicating a higher degree of hydrophobicity with increasing temperature. Higher hydrophobicity can increase the size of the resulting self-aggregated aggregates or increase the number of aggregates.

Experimental Example  3: Forward osmosis  Performance evaluation

For the induction solution in which the copolymers of Examples 3 and 4 were dissolved as induction solutes, osmotic flow analysis was performed as follows. A U-shaped semi dynamic forward osmosis device is built directly to evaluate the osmotic pressure flow. To evaluate the performance of the inducing solutes, a commercially available semipermeable FO membrane (cellulose trifluoroacetate) (Hydration Technology Innovation (HTI), USA) is placed in the middle of the device. Both sides of the membrane are filled with distilled water, which is a feed solution, respectively, and an induction solution with a predetermined concentration. The selective layer faces towards the inlet solution, and the water flux from the inlet solution to the induction solution is calculated from the volume change of each solution for one hour after 30 minutes. Reverse Solute Flux (RSF) through the membrane from the induction solution to the inlet solution is characterized by conductivity, inductively coupled plasma optical emission spectroscopy (ICP-OES) and total organic carbon (TOC). TOC).

The results are shown in Table 6 and Table 7 below.

Water Flux [LMH] DS Reference Example 1 Example 3 Example 4 Conc.
[g / ml] Aver. STD Aver. STD Aver. STD 0.25 5.163 0.055 5.447 0.095 4.151 0.091 0.5 6.198 0.072 6.46 0.107 4.897 0.095 One 7.464 0.08 7.35 0.432 6.245 0.27

RSF [GMH] DS Reference Example 1 Example 3 Example 4 Conc.
[g / ml] Aver. STD Aver. STD Aver. STD 0.25 4.140 0.250 0.250 0.098 0.160 0.067 0.5 4.968 0.120 0.320 0.050 0.192 0.050 One 5.960 0.250 0.429 0.064 0.230 0.060

From the results in the table, it can be seen that the induction solution containing the copolymers of Examples 1 and 2 exhibited high water flux values and low levels of reverse salt flux with respect to the influent. have.

Experimental Example  4: recovery test

As a result of a recovery test using a microfiltration membrane at 40 ° C. and atmospheric pressure, the inducing solution containing the copolymers of Examples 1 to 6 was able to separate / recover the inducing solute with an efficiency of 94.1% or more. Check. On the other hand, it is confirmed that the polymer of Reference Example 1 could not be separated under the same conditions.

Experimental Example  5: Low threshold  Measurement of the solution temperature

For the copolymers of Examples 3 to 8, the low critical solution temperature was measured at different concentrations in the same manner as described in Experimental Example 2, and the results are summarized in the table below.

matter Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Molarity [M] Low critical solution temperature ( ^o C) 1.00E-03 40.47 40.22 40.87 40.72 40.37 40.87 5.00E-04 44.08 43.67 44.58 44.07 43.72 44.07 2.50E-04 52.42 50.67 52.82 51.17 49.4 49.4 1.25E-04 60.48 58.34 60.98 60.34 60.34 57.07 6.25E-05 61.93 61.72 62.33 62.22 62.22 57.62 3.13E-05 63.74 62.74 64.24 63.24 63 58.62

From Table 8, it can be seen that the copolymer of Examples 3 to 8 has a relatively low critical solution temperature (LCST) at a concentration capable of exhibiting high osmotic pressure, and thus can be removed at a relatively low temperature.

Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

Claims (30)

A first repeating unit represented by Chemical Formula 6-1; And an osmotic inducing solute comprising a temperature sensitive copolymer comprising a second repeating unit represented by Chemical Formula 6-2:
[Formula 6-1]

In Chemical Formula 6-1,
Q is -NR- (where R is hydrogen or an alkyl group having 1 to 5 carbon atoms) or -S-,
L is a direct bond, substituted or unsubstituted C1 to C20 alkylene, or substituted or unsubstituted C1 to C20 thioalkylene,
Og includes a first oligomer comprising a repeating unit of Formula 7, a second oligomer comprising a repeating unit of Formula 8, a third oligomer comprising a repeating unit of Formula 9, or a combination thereof;
[Formula 7]

In formula 7, R ₁ is hydrogen or methyl, R ₂ and R ₃ are each independently hydrogen or a straight or branched C 1 to C 6 alkyl group, C 3 to C 7 cycloalkyl group, or C 6 to C 10 aryl group R ₂ and R ₃ may not all be hydrogen, and R ₂ and R ₃ may combine with each other to form a nitrogen-containing hetero ring;
[Formula 8]

In formula (8), R ₄ is a C2 to C5 alkylene group;
[Formula 9]

In formula (9), Ak is a straight chain or branched alkyl group having 1 to 10 carbon atoms, and R is independently hydrogen or an alkyl group having 1 to 3 carbon atoms;
[Formula 6-2]

In Chemical Formula 6-2,
A ⁻ is a group comprising an ionic moiety and M ⁺ is a counter ion of the ionic moiety. delete delete delete delete delete The method of claim 1,
Wherein said Og further comprises a fourth oligomer comprising repeating units derived from (meth) acrylamide. The method of claim 1,
The Og may include a first oligomer including 2 to 30 repeating units of Formula 7, a second oligomer including 2 to 30 repeating units of Formula 8, and 2 to 30 repeating units of Formula 9 An osmotic inducing solute comprising a third oligomer comprising, or a combination thereof. The method of claim 1,
Wherein the ions of the second repeating unit moiety _{^{is, -COO -, -SO 3 -,}} -PO 3 2-, and anion moieties of inducing osmotic solute is selected from a combination of the two. The method of claim 1,
The second repeating unit includes the same ionic moiety or each osmotic inducing solute comprises a different ionic moiety independently. The method of claim 1,
The counter ion is an osmotic inducing solute selected from a cation of an alkali metal, a cation of an alkaline earth metal, and a combination thereof. The method of claim 1,
Wherein said temperature sensitive copolymer comprises said first repeating unit and said second repeating unit in a molar ratio of 1:99 to 60:40. delete The method of claim 1,
Of Formula 6-2 A ^- is the same or ^{different, -COO -, -CONR-Z-} SO 3 -, -CONR-ZO-PO 3 -2, -CO-SZ-SO 3 -, and -CO -SZO-PO ₃ ^-2 , wherein R is hydrogen or an alkyl group of C1 to C5, Z is a substituted or unsubstituted C1-20 alkylene group, and M ⁺ is Na ⁺ , K ⁺ , Li ⁺ , An osmotic inducing solute selected from Ca ²⁺ , Mg ²⁺ , Ba ²⁺ , and combinations thereof. The method of claim 1,
Wherein said temperature sensitive copolymer has a number average molecular weight of 5,000 to 250,000. The method of claim 1,
Wherein said temperature sensitive copolymer is prepared by a process comprising the following steps (A) to (D):
(A) preparing a polysuccinic acid imide;
(B) a third oligomer comprising a repeating unit derived from a monomer represented by the following formula (3) having an amine group or a thiol group at one terminal, and derived from a monomer represented by the following formula (4) having an amine group or a thiol group at one terminal; Preparing a temperature-sensitive oligomer comprising a first oligomer comprising a repeating unit, a second oligomer comprising a repeating unit derived from a monomer represented by Formula 5, or a combination thereof:
[Formula 3]

In formula (3), Ak is a linear or branched alkyl group having 1 to 10 carbon atoms, and R is each independently hydrogen or alkyl having 1 to 3 carbon atoms;
[Formula 4]

In formula (4), R ₁ is hydrogen or methyl, R ₂ and R ₃ are each independently hydrogen or a linear or branched C 1 -C 6 alkyl group, C 3 -C 7 cycloalkyl group, or C 6 -C 10 aryl group, R ₂ And R ₃ may not all be hydrogen, and R ₂ and R ₃ may be linked to each other to form a nitrogen-containing hetero ring;
[Formula 5]

In formula (5), R ₄ is an alkylene group having 2 to 5 carbon atoms;
(C) reacting the polysuccinic acid imide with the temperature sensitive oligomer to open a portion of the succinimide rings and to graft the temperature sensitive oligomer; And
(D) reacting the product of the reaction with an amine compound comprising an ionic moiety, a thiol compound comprising an ionic moiety, an inorganic base, or a combination thereof to open the remaining succinimide rings and Introducing counter ions. The method of claim 16,
The polysuccinic acid imide is an osmotic inducing solute having a number average molecular weight of 5,000 or less. The method of claim 16,
The amine compound having an ionic moiety is an ester compound of phosphoric acid and an alkanolamine of C2 to C20, a sulfoalkylamine of C2 to C20, or a combination thereof, and the inorganic base is an alkali metal hydroxide or alkaline earth metal hydroxide. Osmotic inducing solutes, which are roxides or combinations thereof. Aqueous medium; And
An osmotic induction solution comprising an osmotic inducing solute according to any one of claims 1, 7-12, and 14-18. The method of claim 19,
The osmotic inducing solution is an osmotic induction solution having a low critical solution temperature (LCST) in the range of 10 to 50 ℃ can be recovered by phase separation at a concentration of 0.01 g / ml. The method of claim 20,
The osmotic inducing solution has an solubility in water of 100 g / L or more below the low critical solution temperature (LCST), and an solubility in water of 1 g / L or less above the low critical solution temperature (LCST). The method of claim 20,
Osmotic induction solution when raising the temperature of said osmotic induction solution above said low critical solution temperature (LCST) above said low critical solution temperature, at least 50% by weight of the total osmotic induction solute exhibits a 10-fold increase in particle size. delete Influent containing the material to be separated and water; Osmotic induction solution of claim 19; A semipermeable membrane positioned at one side in contact with the inflow liquid and at the other side in contact with the osmotic induction solution; A recovery system for removing the osmotic inducing solute from the treatment solution comprising water moved by osmotic pressure from the influent to the osmotic inducing solution through the semipermeable membrane; And a connection unit for introducing the osmotic inducing solution removed from the recovery system back into the osmotic inducing solution. The method of claim 24,
And an outlet for discharging the treated water produced by removing the osmotic inducing solute from the treatment solution in the recovery system. The method of claim 24,
The recovery system includes a forward filtration membrane, an ultrafiltration membrane, a nanofiltration membrane or a centrifugal separator. The method of claim 24,
And the recovery system comprises a temperature controller for heating the removed osmotic inducing solute above its low critical solution temperature (LCST). The method of claim 24,
And the recovery system includes a temperature controller for cooling the removed osmotic inducing solute below a low critical solution temperature (LCST). The inflow liquid containing water and the substance to be dissolved in the water and the osmotic induction solution of claim 19 are contacted with a semipermeable membrane interposed therebetween. Obtaining a treating solution comprising; Heating at least a portion of the treatment solution to a temperature above the low critical solution temperature (LCST) of the osmotic induced solute to agglomerate the osmotic induced solute in the treatment solution; And removing the aggregated osmotic inducing solute from the treatment solution to obtain treated water. The method of claim 29,
And cooling the removed osmosis inducing solute to below a low critical solution temperature (LCST) and introducing the osmosis solution into the osmotic inducing solution in contact with the semipermeable membrane.

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