KR20050056288A - Acrylamides monomer and thermoresponsive acrylamides polymer prepared by using same - Google Patents

Abstract

The present invention relates to an acrylamide-based monomer and a temperature-sensitive acrylamide-based polymer prepared by using the same, by using an acrylamide-based monomer having an amide group, a benzene group, and a hydrophobic long-chain alkyl group that cause intermolecular hydrogen bonds. Acrylamide polymers prepared by simple radical polymerization without crosslinking agents or surfactants exhibit sol-gel phase transitions in aromatic organic solvents with temperature, selectively separating toxic solvents such as benzene and toluene from rivers, seas or wastewater. There is an effect that can be removed.

Description

Acrylamide monomers and thermosensitive acrylamide polymers prepared using the same {Acrylamides Monomer and Thermoresponsive Acrylamides Polymer Prepared by Using Same}

The present invention relates to an acrylamide monomer and a temperature sensitive acrylamide polymer prepared using the same. More specifically, the acrylamide monomer according to the present invention has an amide group, a benzene group and a hydrophobic long-chain alkyl group which cause intermolecular hydrogen bonds, so that the acrylamide-based polymer prepared by using the acrylamide monomer according to the temperature in the aromatic organic solvent is sol-based. Acrylamide-based monomers capable of selectively separating and removing toxic solvents such as benzene and toluene from rivers, seas, or wastewaters as they exhibit sol-gel phase transitions, and temperature-sensitivity prepared using the same. It relates to an acrylamide polymer.

A stimulus responsive polymer refers to a polymer that is sensitive to external signal stimuli and changes the substrate itself. External stimulus sources include physical stimuli such as electric fields, magnetic fields, currents, temperatures and light, and chemical stimuli such as pH, ions and species. Responses to external stimuli include phase transitions in aqueous polymer solutions, changes in volume, or optical properties in hydrogels, which are swollen polymer gels in water. These irritant polymers are widely used in biomaterials such as drug delivery systems (DDS), sensors, isolation materials, and artificial muscles (K. Dusek, Advances in Polymers Science: Responsive Gels, Vol. 109 & 110, Springer, Berlin (1993); Langer et al., Science, 249, 1527-1533 (1990); Jeong et al., Nature, 388, 860-862 (1997); Siegel et al., Macromolecules, 21, 3253 (1998); Rollason et al, Biomaterials, 14, 153 (1993)).

On the other hand, a temperature sensitive polymer having a temperature as a stimulus source shows high solubility (sol state) below a certain temperature, but shows low solubility (gel state) above a certain temperature. In other words, the temperature at which such sol-gel phase separation occurs is referred to as low critical solution temperature (LCST). On the other hand, a temperature that shows low solubility below a certain temperature and high solubility above a certain temperature is called an upper critical solution temperature (UCST). (H. Fail, YH Bae, Y. Feijen, and SW Kim, Macromolecules, 25, 5528 (1992)).

Polymers exhibiting the former LCST include N-isopropyl acrylamide (NIPAM) homo and copolymers (Chen et al., Nature, 373, 49-52 (1995)), hydrophobic poly (propylene oxide) Block copolymer (Almgren et al., Colloid Polym. Sci., 273, 2-15 (1995)), a biodegradable poly (ethylene oxide) block and a poly (ethylene oxide) block Block copolymers composed of (L-lactic acid) blocks (Jeong et al., Macromolecules, 32, 7064-7069 (1999); Korean Laid-Open Patent Publication 2001-0022707) and the like are well known. These LCST type temperature sensitive polymers exhibit a very large difference in solubility according to temperature change in an aqueous solution, thus reversibly showing a sharp phase transition in a narrow temperature range. This forms an intermolecular hydrogen bond between the amide bond contained in the NIPAM homo or copolymer chain and water, resulting in a sol with a very high solubility in water below a certain temperature, and as the temperature rises, these intermolecular hydrogen bonds gradually break up. The solubility is lowered and the hydrogen bond is completely broken above a certain temperature, so that the water molecules dissolved in the polymer chain are completely out of the polymer chain and become gel.

In general, temperature-sensitive polymers exhibiting LCST behavior vary in phase transition temperature depending on the composition ratio of hydrophilic and hydrophobic groups. In other words, if the composition of the hydrophilic group is increased, the phase transition temperature is increased. If the composition of the hydrophobic group is increased, the phase transition temperature is lowered. In addition, the temperature of LSCT can be controlled in various ways by adding co-solvent, salt, surfactant, and acidic comonomer mixed with methanol or ethanol mixed with water (Aoki et al., Polymer J. 28, 8987-9). , 1996; Otake et al., Macromolecules, 23, 283-289 (1990); Shi et al, Colloids & Surfaces A: Physicochem. Eng. Aspects, 175, 41-49 (2000); Ringsdorf et al., Macromolecules, 24, 1678 (1991).

On the other hand, an example of a temperature-sensitive polymer exhibiting UCST having high solubility in water at high temperature is an interpenetrating polymer network of a copolymer of poly (acrylic acid) and N, N-dimethylacrylamide and butyl methacrylate. ) Has been reported, but there are very few examples.

On the other hand, the temperature-sensitive polymers mentioned so far are not dissolved in hydrophobic organic solvents such as benzene or toluene, but only dissolved in an aqueous solution, resulting in low or high critical temperature. Therefore, these temperature-sensitive polymers are limited to their use as biomaterials such as drug carriers, sensors, or artificial muscles using sol-gel phase transitions in aqueous solutions.

However, as the use of organic solvents and petroleum rapidly increases due to the recent industrial development, the pollution of rivers and the oceans as well as the destruction of environmental ecosystems are seriously caused by the marine accidents of oil tankers transporting oils along with the spillage of organic solvents. Therefore, there is an urgent need to develop an oil-absorbing material capable of selectively absorbing and separating the organic solvent, oil, such as crude oil, etc., from the water for water quality improvement and environmental protection. Therefore, the study of the original technology for the new oil-absorbing polymer new material that can selectively absorb and separate only the organic solvent or oil from the water in order to remove the organic solvent or oil widely spilled, US Patent No. 3,668, 118, US Patent Nos. 3,812,973, Japanese Patent Laid-Open No. 50-15882, Japanese Patent Laid-Open No. 50-59486 and Japanese Patent Laid-Open No. 50-94092, respectively.

In addition, Korean Patent Application No. 2001-79360 has a high oil absorption ratio for organic solvents such as benzene, toluene, chloroform and n-octane, high oil absorption rate, high oil absorption rate, and excellent pressure-retaining force against external pressure. A new oil absorbent polymer with a uniform and porous structure is described. However, such oil-absorbing polymers are acrylamide polymers prepared by emulsion polymerization or suspension polymerization in the presence of a crosslinking agent and a surfactant, rather than a simple radical polymerization reaction.

Accordingly, the present inventors found that the copolymer obtained by the radical copolymerization reaction with a homopolymer prepared using an acrylamide monomer having a specific structure and a vinyl monomer such as styrene and NIPAM is a high critical solution in an aromatic organic solvent such as benzene and toluene. It has been found that the phenomenon of temperature is exhibited to complete the present invention.

In order to solve the above problems, the present invention exhibits a sol-gel phase transition phenomenon in accordance with the temperature in the aromatic organic solvent, toxic solvents such as benzene, toluene from river, sea or wastewater An object of the present invention is to provide an acrylamide-based monomer having a structure that can be selectively separated and removed, and a temperature-sensitive acrylamide-based polymer prepared by a simple radical polymerization reaction using no crosslinking agent or surfactant.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides an acrylamide monomer of the formula (1) having an amide group, a benzene group and a hydrophobic long-chain alkyl group to cause intermolecular hydrogen bonds.

[Formula 1]

Where

R is H or CH ₃ ,

R 'is Z, , , or Where Z is ortho-, meta-, or Wherein R ″ is a hydrophobic long-chain alkyl group Where m is an integer between 10 and 20, and Y is Is,

Where n is an integer from 1 to 10, X is an aromatic group, ortho-phenylene, m-phenylene, p-phenylene, o-naphthalene ( ortho-naphthalene, m-naphthalene or anthracene group.

The acrylamide-based monomer of Formula 1 is N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide (N- [4- (3- (4-dodecyl-phenylcarbamoyl) ) -propyl) phenyl] acrylamide, NDPA); (N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide (N- [5- (4-dodecyl-phenylcarbamoyl) -pentyl] acrylamide, DPPA); N- [3-{( 4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide (N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide, DMCPA); or N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide (N- [3-{(4-dodecyl -phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide, DPMCPA);

The present invention also provides an acrylamide-based polymer, characterized in that it is prepared from the acrylamide monomer alone or a mixture of acrylamide monomer and vinyl monomer as described above.

The acrylamide monomers include N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide; (N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide;

N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide; Or N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide; Can be.

The vinyl monomers are styrene, N-isopropyl acrylamide (NIPAM), N, N-dimethylacrylamide, N, N-ethylmethylacrylamide (N, N- ethylmethylacrylamide) or methylmethacrylate.

In addition, the present invention comprises the steps of: (A) dissolving the acrylamide monomer of Formula 1 alone or a mixture of acrylamide monomer and vinyl monomer in an organic solvent; (B) injecting the dissolved monomer and radical initiator into an ampoule; (C) completely removing the oxygen present in the solution in the ampoule with a vacuum pump by a freeze-thawing method; (D) sealing the ampoules from which the oxygen has been completely removed; And (e) radical polymerization by heating the sealed ampoule; It provides a method for producing an acrylamide-based polymer comprising a.

In the step (A), the monomer is the acrylamide monomer of Formula 1 alone or a mixture of acrylamide monomer and vinyl monomer of Formula 1, when the content of acrylamide is 10% by weight or more in the mixture, THF, benzene, An organic solvent selected from the group consisting of toluene and xylene may be used at 20 to 80% by weight based on the entire monomer.

The radical initiator in step (b) is azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), or 2,2'-azobis- (2,4-dimethylvaleronitrile). 2,2'-azobis- (2,4-dimethylvaleronitrile).

In the step (b), the radical initiator may be used in an amount of 0.001 to 2.0% by weight based on the entire monomer.

In the step (e), the radical polymerization may be performed at 60 to 100 ° C. for 8 to 48 hours.

The number average molecular weight of the acrylamide polymer may be 3,000 to 150,000.

The acrylamide-based polymer exhibits a sol-gel phase transition phenomenon in an aromatic organic solvent of any one of benzene and toluene.

Hereinafter, the present invention will be described in detail.

The present invention is a monomer for preparing a temperature-sensitive polymer capable of selectively separating aromatic organic solvents, such as benzene and toluene, which are highly toxic by exhibiting a sol-gel phase transition phenomenon according to temperature change. It is characterized by having an amide group, a benzene group and a hydrophobic long-chain alkyl group in the structure, which cause intermolecular hydrogen bonds.

That is, the present invention provides an acrylamide monomer of formula (1) having an amide group, a benzene group, and a hydrophobic long-chain alkyl group causing intermolecular hydrogen bonds.

[Formula 1]

Where

R is H or CH ₃ ,

R 'is Z, , , or Where Z is ortho-, meta- or Wherein R ″ is a hydrophobic long-chain alkyl group Where m is an integer between 10 and 20, and Y is Where n is an integer from 1 to 10 and X is an aromatic group, o-phenylene, m-phenylene, p-phenylene, o-naphthalene, m-naphthalene, or anthracene group.

In the present invention, the reason for adopting the acrylamide-based compound having the same structure as the formula (1) as the monomer of the acrylamide-based polymer is briefly described.

The acrylamide polymer prepared by using the acrylamide compound of formula (1) as a monomer simultaneously contains an amide group, a benzene group, and a nonpolar aliphatic alkyl group in its structure, and at high temperatures, the intermolecular hydrogen bonds of the amide group are weakened. Π-interaction between the benzene group present and the benzene group present in the aromatic solvent structure increases the solubility in the aromatic solvent, resulting in a sol state, and at low temperatures an intermolecular hydrogen bond of the amide group is formed, As the interaction between the benzene group present and the benzene group present in the aromatic solvent structure is weakened, the solubility in the aromatic solvent is reduced to gel. As such, by using an acrylamide-based polymer exhibiting a sol-gel transition phenomenon according to a specific temperature, it is possible to selectively separate and remove aromatic organic solvents such as benzene and toluene mixed in water.

Specific examples of the acrylamide monomer having a structure of Formula 1 include N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide; (N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide; N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4 N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide; etc. are mentioned.

Each of these acrylamide monomers may be synthesized by a variety of methods, and the preferred synthesis method may be N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide. Example 1, Example 2 for (N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene Example 3, N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] for -carbamoyl} propyl-4-phenyl] acrylamide In the case of acrylamide, the method according to Example 4 is mentioned, among which N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4 according to Example 4 is mentioned. -Phenyl] acrylamide is synthesized by the first amidation step, the second decarboxylation step, and the third amidation step, as can be seen in the scheme below.

[Scheme]

In the present invention, the acrylamide monomer having the structure of Formula 1 is used alone or in admixture with a vinyl monomer to prepare a temperature sensitive acrylamide polymer.

Examples of the acrylamide monomers include N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide and N- [5- (4-dodecyl- Phenylcarbamoyl) -phenyl] acrylamide, N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide, N- [3- { (4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide, etc. are mentioned.

In addition, the vinyl monomer is not particularly limited as long as it can be used to prepare a polymer, styrene, N-isopropyl acrylamide (NIPAM), N, N-dimethyl acrylamide (N, N -dimethylacrylamide), N, N-ethylmethylacrylamide, methyl methacrylate, and the like are preferable.

The temperature sensitive acrylamide polymer of the present invention may be a homopolymer prepared from the acrylamide monomer alone or a copolymer prepared from a mixture of two or more kinds. It may also be a copolymer prepared from at least one selected from the acrylamide monomers and at least one selected from the vinyl monomers. Preference is given to acrylamide copolymers prepared from mixtures of acrylamide monomers with styrene or N-isopropylacrylamide.

The temperature-sensitive acrylamide polymer of the present invention is dissolved in an organic solvent alone or a mixture of acrylamide monomer of Formula 1 or a mixture of acrylamide monomer and vinyl monomer of Formula 1 in an organic solvent and then added to an ampoule with a radical initiator and present in a solution. After the oxygen is completely removed by a vacuum pump by a freeze-thawing method, the ampoule is sealed and heated for a predetermined time to prepare a radical polymerization reaction. The polymerization process is carried out without crosslinking agents or surfactants.

The prepared temperature sensitive acrylamide-based polymer can be filtered, dried and purified by conventional post-treatment. For example, the prepared temperature sensitive acrylamide polymer is precipitated, filtered, and dried in methanol solvent, dissolved in the solvent, and reprecipitated in methanol to obtain a pure polymer.

In the preparation of the temperature-sensitive acrylamide polymer, when the monomer is acrylamide monomer alone or a mixture of acrylamide monomer and vinyl monomer, the content of acrylamide is 10% by weight or more in the whole mixture. It is preferable to dissolve and use in organic solvents, such as tetrahydrofuran (THF), benzene, toluene, and xylene. In this case, it is preferable to use an organic solvent selected from the group consisting of THF, benzene, toluene and xylene adjusted to 20 to 80% by weight based on the entire monomer. More preferably, it is 20-50 weight%.

In the production of the temperature sensitive acrylamide polymer, it is based on simple radical polymerization without using a crosslinking agent or a surfactant. As the initiator for radical polymerization, all conventional radical polymerization initiators can be used, and those known to those skilled in the art can be easily purchased and used. Preferably, azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), 2,2'-azobis- (2,4-dimethylvaleronitrile) 2,2'-azobis- (2,4-dimethylvaleronitrile) and the like. The radical initiator is preferably used in 0.001 to 2.0% by weight based on the entire monomer.

Preparation of the temperature sensitive acrylamide-based polymer is preferably polymerized for 8 to 48 hours at a polymerization temperature of 60 to 100 ℃.

The number average molecular weight (M _n ) of the temperature sensitive acrylamide polymer prepared by the method described above is 3,000 to 150,000. More preferably 3,000 to 120,000. The number average molecular weight of the temperature sensitive acrylamide-based polymer for showing distinct sol-gel phase transition behavior in aromatic solvents such as benzene and toluene should be at least 8,000.

The molecular weight and molecular weight distribution of the polymer as described above may be controlled by the molar ratio of the radical initiator and the monomer used during the polymerization, the concentration of the monomer to the solvent, the polymerization temperature, the polymerization time, and the like. Is easier.

Further, the thermosensitive acrylamide-based polymer prepared according to the invention is a sol in an aromatic organic solvent, such as benzene, toluene - to gel phase transition phenomenon is that occurs in a temperature range of 70 to -20 ^o C-to cause the gel-phase transition, the sol Preference is given to selectively separating aromatic solvents.

The phase transition temperature of the polymer may be controlled by the molecular structure of the crystalline acrylamide, the composition ratio of the copolymer, the concentration of the polymer solution, the molecular weight of the polymer, the molecular weight distribution, and the like. It is easier to adjust to the concentration of.

The acrylamide-based polymer prepared by using the acrylamide-based monomer according to the present invention is a temperature-sensitive polymer having a structure suitable for selectively separating aromatic organic solvents, such as benzene and toluene, spilled into rivers or seas from water. In order to use the acrylamide polymer of the present invention more preferably as a temperature sensitive polymer, the sol-gel phase transition phenomenon should occur in a solution having a low concentration of the acrylamide polymer. If a benzene solution of 5% polymer has a sol-gel phase transition at room temperature, it means that 20 g of benzene per gram of polymer can be selectively separated from water.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples.

Examples 1 to 4: Synthesis of Acrylamide-Based Monomers Having the Structure of Formula 1

Example 1

N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide (N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide, NDPA ) Synthesis

1 g of 4- (4-aminophenyl) butyric acid and 15 mL of solvent methylenen chloride (MC) are added to a 50 mL three-necked round flask, and placed under a nitrogen atmosphere. 0.96 mL of chlorotrimethylsilane was added and reacted under reflux for 2 hours. After the reaction, the temperature was lowered to 1.18 mL of tetraethylamine (TEA) was added dropwise at 0 ° C. for 10 minutes, and a solution of 0.46 mL of acryloyl chloride (AC) in 5 mL of MC was added through a dropping funnel. After dropping for minutes, the mixture was reacted at 0 ° C. for 30 minutes, and again at room temperature for 2 hours. After the reaction, the solvent MC was removed, 50 mL of 2M NaOH solution was added thereto, stirred for 3 hours, and acidified with 2M HCl solution. The acidified solution was added to the separatory funnel with 30 mL of ethyl acetate (EA), shaken, the EA layer was separated, the solvent was removed by an evaporator, and dried to form 4- (4-acryloylaminophenyl) butyric acid ( 4- (4-acryloylaminophenyl) butyric acid (APB) was obtained in the solid phase. The yield was 80% and m.p. was 107 ° C.

After dissolving 1 g of solid APB in 30 mL of THF, the mixture was poured into a 100 mL three-necked flask under a nitrogen atmosphere. The reaction was carried out at 0 ° C. for 10 minutes after being added in equivalent weight. After the reaction, 0.90 g of 1-ethyl-3- (3'-dimethyl aminopropyl) -carbodiimide (1-ethyl-3- (3'-dimethyl aminopropyl) -carbodiimide, EDC) was added, followed by 1 at 0 ° C. After reacting for an hour, the reaction was carried out at room temperature for 18 hours. The reaction solution was added dropwise to 150 mL of distilled water and filtered to remove unreacted EDC, DMAP, EDC urea salt, and DMF. 100 mL of 5% NaHCO ₃ was added to the obtained material, stirred for 1 hour, and filtered. Removal gave a solid. 80 mL of n-hexane was added to the obtained solid, which was stirred for 1 hour and filtered to remove unreacted 4-dodecyl aniline to obtain a solid. The finally obtained solid was dried in a vacuum oven for 24 hours to obtain a pure solid NDPA monomer. The yield was 88% and mp was 177 ° C. The synthesized NDPA was purified by recrystallization twice with chloroform.

The structure of the synthesized NDPA was confirmed by hydrogen nuclear magnetic resonance ( ¹ H-NMR) spectrum, the results are as follows.

¹ H-NMR (DMSO-d ₆ ): d, δ 10.06 (s, 1H); j, δ9.76 (s, 1H); k, δ 7.57 (m, 2H); e, δ 7.45 (d, 2H); f, δ 7.14 (d, 2H); 1, δ 7.04 (d, 2H); c, δ 6.31 (s, 1 H); a, δ6.24 (s, 1H); b, δ 5.74 (s, 1 H); g, δ 2.56 (t, 2H); m, δ 2.25 (t, 2H); h, δ 1.85 (m, 2H); i, δ 1.51 (m, 2H); n, δ 1.09 (m, 20H); o, δ 0.85 (t, 3H).

Example 2

Synthesis of N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide (N- [5- (4-dodecyl-phenylcarbamoyl) -pentyl] acrylamide, DPPA)

2.62 g of 6-aminohexanoic acid and 0.8 g of NaOH were added to a 100 mL three-necked round flask, and 15 mL of tertiary distilled water was added and dissolved at 0 ° C. After dissolving, a solution of 1.7 mL of AC and 2 mL of MC was dropped in a syringe for 90 minutes, and then the pH of the solution was adjusted. If weakly acidic, the pH of the final solution was adjusted to 7.5 to 7.8 by adjusting the pH with an aqueous NaOH solution. It was. After adjusting the pH, the reaction was stirred at room temperature for 9 hours. 200 mL of EA was added to the reacted solution, placed in a separatory funnel, shaken, and the aqueous layer was separated to remove unreacted 6-aminehexanoic acid and AC. In addition, magnesium sulfate anhydrous was added to remove the trace amount of water dissolved in the EA organic layer, stirred for 30 minutes, filtered, and the EA solvent was evaporated. In addition, 100 mL of ethyl ether was added to the acrylic acid produced during the reaction, stirred for 3 hours, filtered, and then removed to obtain a solid. The obtained solid was dried to obtain pure 6-acryloyl aminohexanoic acid. The yield was 45% and m.p. was 78 ° C.

0.5 g of dried 6-acryloyl aminohexanoic acid was dissolved in 15 mL of DMF, placed in a 100 mL three-necked round flask under nitrogen atmosphere, and 0.71 g of 4-dodecylaniline and 0.2 g of DMAP were added thereto. An ice bath was installed, and 0.75 g of EDC, a water remover, was added to the reaction flask, followed by reaction at 0 ° C. for 2 hours and at room temperature for 24 hours. The reaction solution was added dropwise to 200 mL of distilled water, stirred for 3 hours, filtered, and then stirred for 2 hours by adding 150 mL of 5% aqueous NaHCO₃ solution to the material obtained by removing unreacted DMAP, EDC, EDC urea salt and DMF. Filtration to remove unreacted 6-acryloyl aminohexanoic acid gave a solid. 150 mL of n-hexane was added to the obtained solid, stirred for 1 hour, and filtered to remove an n-hexane solution in which unreacted 4-dodecylaniline was dissolved. The solid obtained after filtration was dried in a vacuum oven for at least 24 hours to obtain pure DPPA. The yield was 85% and m.p. was 140 ° C. The synthesized DPPA was purified by recrystallization twice with methanol.

The structure of the synthesized DPPA was confirmed by the hydrogen nuclear magnetic resonance ( ¹ H-NMR) spectrum, the results are as follows.

¹ H-NMR (CDCl ₃ ): i, δ 7.39 (d, 2H); j, δ 7.09 (d, 2H); b, δ 6.24 (d, 1H); c, δ 6.07 (m, 1H); h, δ5.70 (s, 1H); a, δ 5.82 (d, 1H); e, δ 3.34 (t, 2H); k, δ 2.57 (t, 2H); g, δ 2.35 (t, 2H); e, δ 1.75-1.42 (m, 8H); 1, δ 1.24 (m, 20H); m, δ 0.88 (t, 3H).

Example 3

N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide (N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl } propyl-4-phenyl] acrylamide, DMCPA)

0.2 g (1.142 mmol) of t-butoxycarbonyl-glycine (t-Boc-glycine) and 4-dodecylaniline (0.299 g) were added to a 100 mL three-necked round flask, THF 30 mL After the addition was dissolved under nitrogen atmosphere at 0 ° C., 0.02 g of DMAP as a catalyst was added thereto, stirred for 10 minutes, 0.2 g of EDC as a moisture remover was added thereto, and stirred for 1 hour, followed by reaction at room temperature for 18 hours. The reaction solution was added dropwise to 150 mL of distilled water, stirred for 1 hour, filtered, and 100 mL of 5% NaHCO ₃ aqueous solution was added to the material obtained by removing DMAP, EDC, EDC urea salt, and THF. To remove the unreacted t-Boc-glycine to obtain a solid. N-hexane was added to the obtained solid, stirred for 1 hour, and filtered to remove unreacted 4-dodecylaniline to obtain a solid. The final solid was dried in a vacuum oven for 24 hours to give a pure solid [(4-dodecylphenyl-carbamoyl) -methyl] -carbamic acid t-butyl ester ([(4-dodecylphenyl-carbamoyl) -methyl] -carbamic acid tert-butyl ester, DCMCABE) was obtained. At this time, the yield was 73%.

0.16 g (0.396 mmol) of the synthesized DCMCABE and 5 mL of MC were added to a 1-neck round flask, and dissolved at 40 ° C., cooled to room temperature, and 0.54 mL of trifluoroacetic acid was added thereto, followed by 2 hours at room temperature. Was stirred. After stirring, all solvents were evaporated, 20 mL of ethyl ether was added to the remaining solid, stirred for 30 minutes, and filtered to remove unreacted DCMCABE, thereby obtaining a solid. The solid obtained was dried to give pure [(4-dodecylphenyl-carbamoyl) -methyl] -carbamic acid ([(4-dodecylphenyl-carbamoyl) -methyl] -carbamic acid (DCMCA), yielding 95 It was%.

The synthesized DCMCA 0.15g (0.47mmol), APB 0.11g, 0.47mmol was added to a 100mL 3-necked round flask, THF 30mL was added, 0.1g of EDC, a moisture remover, and stirred for 1 hour, and stirred at room temperature for 18 hours. The reaction was completed by stirring. The reaction solution was added dropwise to 100 mL of distilled water, stirred for 1 hour, filtered, and 100 mL of 5% NaHCO ₃ aqueous solution was added to the material obtained by removing DMAP, EDC, EDC urea salt, and THF. Unreacted APB was removed to give a solid. 20 ml of ethanol was added to the obtained solid, stirred for 1 hour, and filtered to remove unreacted DCMCA to obtain a solid. The obtained solid was dried in a vacuum oven for 24 hours to give pure DMCPA monomer. At this time, the yield was 34%.

The structure of the synthesized DMCPA was confirmed by the hydrogen nuclear magnetic resonance (H-NMR) spectrum, the results are as follows.

¹ H-NMR (DMSO-d ₆ ): d, δ 10.04 (s, 1H); 1, δ9.84 (s, 1H); j, δ 8.13 (t, 1H); e, δ 7.55 (d, 2H); m, δ 7.44 (d, 2H); f, n, δ 7.07 (d, 4H); c, δ 6.40 (m, 1H); a, δ 6.21 (d, 1H); b, δ 5.71 (d, 1H); k, 53.83 (d, 2H); o, δ 2.44 (t, 2H); g, δ 2.17 (t, 2H); I, δ 1.79 (t, 2H); h, δ 1.52 (t, 2H); p, δ 1.23 (m, 20H); q, δ 0.85 (t, 3H).

Example 4

N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide (N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene- carbamoyl} propyl-4-phenyl] acrylamide, DPMCPA)

0.5 g (2.16 mmol) of 6- (butoxycarbonyl-amino) caproic acid, 6- (Boc-amino) caproic acid and 4-dodecylaniline (0.622 g) Was added to a 100mL three-necked round flask, and 50ml of THF was added thereto, dissolved in a nitrogen atmosphere at 0 ° C, and then added with 0.05g of DMAP as a catalyst and stirred for 10 minutes. After stirring, 0.5 g of EDC, which is a moisture remover, was added thereto, stirred for 1 hour, and reacted at room temperature for 18 hours. The reaction solution was added dropwise to 2000 mL of distilled water, and then stirred for 1 hour, filtered, and 150 mL of a 5% aqueous NaHCO ₃ solution was added to the material obtained by removing DMAP, EDC, EDC urea salt, and THF. Unreacted 6- (Boc-amino) caproic acid was removed to obtain a solid. N-hexane was added to the obtained solid, stirred for 1 hour, and filtered to remove unreacted 4-dodecylaniline to obtain a solid. The obtained solid was dried in a vacuum oven for 24 hours to obtain pure [5- (4-dodecylphenyl-carbamoyl) -pentyl] -carbamic acid t-butyl ester ([5- (4-dodecylphenyl-carbamoyl) -pentyl] Carbamic acid t-butyl ester, DCPCABE, was obtained, yielding 75%.

0.747 g (1.373 mmol) of the synthesized DCPCABE was added to 9 mL of MC, and then put into a 1-neck round flask, dissolved at 40 ° C., and the temperature was lowered to room temperature. Then, 1.4 mL of trifluoroacetic acid was added to the reaction flask solution, followed by stirring at room temperature for 2 hours, and then the solvent was evaporated. 30 mL of ethyl ether was added to the remaining solid, stirred for 30 minutes, and filtered to remove DCPCABE. The obtained solid was dried to obtain pure [5- (4-dodecylphenyl-carbamoyl) -pentyl] -carbamic acid (DCPCA). At this time, the yield was 97%.

0.5 g (1.335 mmol) of DCPCA and 0.313 g (1.335 mmol) of APB were added to a 100 mL three-necked round flask, THF 30 mL and 0.3 g of EDC, a water remover, were stirred for 1 hour, and then reacted at room temperature for 18 hours. I was. The reaction solution was added dropwise to 150 mL of distilled water, and then stirred for 1 hour, filtered, and 150 mL of a 5% aqueous NaHCO ₃ solution was added to the material obtained by removing DMAP, EDC, EDC urea salt, and THF, followed by stirring for 1 hour. The unreacted APB was removed to obtain a solid. 20 mL of ethanol was added to the obtained solid, stirred for 1 hour, and filtered to remove unreacted DCPCA to obtain a solid. The obtained solid was dried in a vacuum oven for 24 hours to give pure DPMCPA monomer. The yield was 54% at this time.

The structure of the synthesized DPMCPA was confirmed by hydrogen nuclear magnetic resonance (H-NMR) spectrum, the results are as follows.

¹ H-NMR (DMSO-d ₆ ): d, δ 10.04 (s, 1H); n, δ9.73 (s, 1H); j, 87.74 (t, 1H); e, δ 7.54 (d, 2H); o, δ 7.44 (d, 2H); f, p, δ 7.09 (d, 4H); c, δ 6.40 (m, 1H); a, δ 6.21 (d, 1H); b, δ 5.71 (d, 1H); m, δ 3.02 (t, 2H); g, q, δ 2.48 (t, 4H); k, δ 2.26 (t, 2H); i, δ 2.04 (t, 2H); h, δ 1.65 (m, 2H); 1, δ1.51 (t, 8H); r, δ 1.39 (m, 20H); s, δ 0.85 (t, 3H)

Examples 5 to 9: Preparation of Acrylamide-Based Polymer Using NDPA Acrylamide-Based Monomer of Example 1

Example 5

1.0 g of the acrylamide-based monomer NDPA synthesized in Example 1 and benzoyl peroxide (BPO), a radical initiator, were added to a 20 mL ampoule with 0.5 mL of THF as a solvent in 10 mL of a monomer, and freeze-thawed. After removing the oxygen present in the solution by -thawing), the ampoule was sealed and subjected to radical polymerization for 48 hours in an oven at 80 ℃. After polymerization, the reaction solution was precipitated in 200 mL of methanol as an extraction solvent, and then filtered under reduced pressure and dried to prepare a white NDPA homopolymer. Polymerization conversion rate of the prepared polymer was 70%.

[Examples 6 to 9]

NDPA and N-isopropyl acrylamide (NIPAM) synthesized in Example 1 as monomers were used in a reaction molar ratio as shown in Table 1 below, except that n-hexane was used as an extraction solvent. In the same manner as in Example 5, a copolymer of NDPA-NIPAM was prepared.

Examples 10 to 14 Preparation of Acrylamide-Based Polymer Using DPPA Acrylamide-Based Monomer of Example 2

Example 10

0.2 g of acrylamide-based monomer DPPA synthesized in Example 2 and BPO as a radical initiator were added to a 20 mL ampoule with 1.5 mL of solvent benzene at 1.5 wt% based on the monomer to remove oxygen present in the solution by freeze-thawing. The ampoule was sealed and subjected to radical polymerization for 72 hours in an oven at 80 ° C. After polymerization, the reaction solution was precipitated in 200 mL of methanol as an extraction solvent, and then filtered under reduced pressure to obtain a white solid. Methanol 150mL was added to the obtained solid, stirred at 45 ° C for 1 hour, and filtered to remove DPPA monomer of unreacted solid. The white solid obtained was stored in a vacuum oven for at least one day to dry the solvent to prepare a white DPPA homopolymer. Polymerization conversion rate of the prepared polymer was 70%.

Example 11

Prepare a monomer mixture of DPPA and NIPAM synthesized in Example 2, put into an ampoule with 1.0 mL of BPO and benzene 15mL to the monomer to remove the oxygen present in the solution by freeze-thaw method, the ampoule was sealed and 80 The radical copolymerization was carried out for 48 hours in an oven at ℃. After polymerization, the reaction solution was diluted in 200 mL of n-hexane to remove the remaining monomers and initiators, and then filtered and dried to prepare a white DPPA-NIPAM copolymer. Polymerization conversion rate of the prepared polymer was 75%.

[Examples 11 to 14]

A copolymer of DPPA-NDPA was prepared in the same manner as in Example 11 except that DPPA and NIPAM synthesized in Example 2 as the monomer were used in a reaction molar ratio as shown in Table 2 below.

Comparative Examples 1 to 2: preparation of acrylamide polymer using only N-isopropyl acrylamide (NIPAM) monomer

Comparative Example 1

NIPAM homopolymers were prepared in the same manner as in Example 5 except that only NIPAM was used as the acrylamide monomer, 0.5 wt% of the monomer was used as the radical initiator, and benzene was used as the reaction solvent.

Comparative Example 2

NIPAM homopolymers were prepared in the same manner as in Example 5 except that only NIPAM was used as the acrylamide monomer, 1.0 wt% of the monomer was used as the radical initiator, and benzene was used as the reaction solvent.

Determination of Sol-Gel Phase Transition Temperatures for Polymers Prepared by Examples and Comparative Examples

The acrylamide polymers prepared according to Examples 5 to 14 and Comparative Examples 1 and 2 were dissolved in benzene and toluene to prepare polymer solutions of various concentrations as shown in Tables 1 and 2 below. The prepared polymer solution was placed in a vial and adjusted to a temperature range below the boiling temperature of the solvent and above the freezing temperature to measure the sol-gel phase transition temperature for the polymers. The sol-gel phase transition temperature was observed by applying a tilting method (Tilt method: Jeong et al., Nature, 388 (28), 860-862 (1997)) to determine the sol state and gel state. The temperature of 100% gel state which does not flow at all was made into the phase transition temperature of a copolymer. This sol state and gel state can be confirmed through Figures 5a and 5b, Figure 5a is a photograph showing the sol state of the 5% benzene solution of the NDPA homopolymer prepared in Example 5, Figure 5b at 20 ^° C It is a photograph showing that the solution of the polymer does not flow when the gel formed by the phase transition phenomenon is inverted.

Sol-gel phase transition temperatures measured by the method as described above are shown in Tables 1 and 2.

In addition, the sol-gel phase transition temperature according to the concentration in the benzene solvent for the acrylamide polymers of Examples 5 to 9 prepared by varying the monomer composition is shown in Figure 1, Examples 5 to 9 prepared by varying the monomer composition The sol-gel phase transition temperature according to the concentration in the toluene solvent for the acrylamide polymer of is shown in Figure 2, the concentration in the benzene solvent for the acrylamide polymer of Examples 10 to 14 prepared by varying the monomer composition The sol-gel phase transition temperature according to the present invention is illustrated in FIG. 3, and the sol-gel phase transition temperature according to the concentration in the toluene solvent for the acrylamide polymers of Examples 10 to 14 prepared by varying the monomer composition is illustrated in FIG. 4.

As shown in Tables 1 and 2, the acrylamide-based polymers of Examples 5 to 14 prepared by using the acrylamide-based monomer of Formula 1 according to the present invention may have a composition ratio of monomers, It can be seen that it has different sol-gel phase transition temperatures depending on the polymer concentration of. Therefore, by using the acrylamide polymer of the present invention, the concentration of the polymer can be adjusted to selectively separate aromatic compounds such as benzene and toluene.

The acrylamide-based polymers of Comparative Examples 1 and 2 prepared using N-isopropyl acrylamide (NIPAM), which is a monomer of the conventional acrylamide-based polymer, showed no sol-gel phase transition behavior.

As described above, the acrylamide monomer according to the present invention has an amide group, a benzene group, and a hydrophobic long-chain alkyl group which cause intermolecular hydrogen bonds in the structure thereof, and is prepared by simple radical polymerization without crosslinking agents or surfactants. The acrylamide polymer exhibits a sol-gel phase transition phenomenon in an aromatic organic solvent, and it is effective in selectively separating and removing toxic solvents such as benzene and toluene from rivers, seas or wastewater, as well as medical polymers, It is a useful invention that can also be applied to heavy metal ion detection sensor materials and the like.

While the invention has been described in detail above with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the invention, and such modifications and variations fall within the scope of the appended claims. It is also natural.

1 is a graph showing the sol-gel phase transition temperature (sol-gel phase transition temperature) according to the concentration in the benzene solvent of the acrylamide-based polymer prepared according to the embodiment of the present invention.

Figure 2 is a graph showing the sol-gel phase transition temperature according to the concentration in the toluene solvent of the acrylamide-based polymer prepared according to the embodiment of the present invention.

3 is a graph showing the sol-gel phase transition temperature according to the concentration in the benzene solvent of the acrylamide-based polymer prepared according to another embodiment of the present invention.

4 is a graph showing the sol-gel phase transition temperature according to the concentration in the toluene solvent of the acrylamide-based polymer prepared according to another embodiment of the present invention.

Figure 5a is a photograph showing the sol state of the 5% benzene solution of the acrylamide-based homopolymer prepared according to an embodiment of the present invention.

Figure 5b is a photograph showing the gel state of 5% benzene solution of acrylamide-based homopolymer prepared according to an embodiment of the present invention.

Claims (12)

Acrylamide monomer of formula 1 having an amide group, a benzene group and a hydrophobic long-chain alkyl group causing intermolecular hydrogen bonds: [Formula 1] Where R is H or CH3, R 'is Z, , , or Where Z is ortho-, meta-, or Wherein R ″ is a hydrophobic long-chain alkyl group Where m is an integer between 10 and 20, and Y is Where n is an integer from 10 to 10, X is an aromatic group, ortho-phenylene, m-phenylene, p-phenylene, o- Naphthalene, ortho-naphthalene, m-naphthalene, or anthracene group. The method of claim 1, The acrylamide monomer of Formula 1 is N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide (N- [4- (3- (4-dodecyl-phenylcarbamoyl) ) -propyl) phenyl] acrylamide, NDPA); (N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide (N- [5- (4-dodecyl-phenylcarbamoyl) -pentyl] acrylamide, DPPA); N- [3-{( 4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide (N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4-phenyl] acrylamide, DMCPA); or N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide (N- [3-{(4-dodecyl -phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide, DPMCPA). The acrylamide-based polymer of claim 1 prepared from the acrylamide-based monomer alone or a mixture of the acrylamide-based monomer and vinyl-based monomer. The method of claim 3. The acrylamide monomer is N- [4- (3- (4-dodecyl-phenylcarbamoyl) -propyl) phenyl] acrylamide; (N- [5- (4-dodecyl-phenylcarbamoyl) -phenyl] acrylamide; N- [3-{(4-dodecyl-phenylcarbamoyl) -methylene-carbamoyl} propyl-4 -Phenyl] acrylamide or N- [3-{(4-dodecyl-phenylcarbamoyl) -pentamethylene-carbamoyl} propyl-4-phenyl] acrylamide; The method of claim 3, The vinyl monomers are styrene, N-isopropyl acrylamide (NIPAM), N, N-dimethylacrylamide, N, N-ethylmethylacrylamide (N, N- Acrylamide polymer, characterized in that ethylmethylacrylamide) or methyl methacrylate (methylmethacrylate). (A) dissolving the acrylamide monomer of claim 1 alone or a mixture of the acrylamide monomer and vinyl monomer of claim 1 in an organic solvent; (B) injecting the dissolved monomer and radical initiator into an ampoule; (C) completely removing the oxygen present in the solution in the ampoule with a vacuum pump by a freeze-thawing method; (D) sealing the ampoules from which the oxygen has been completely removed; And (E) radical polymerization by heating the sealed ampoule; Method for producing an acrylamide-based polymer, characterized in that comprises a. The method of claim 6, In the step (a), when the monomer is the acrylamide monomer of claim 1 alone, or the mixture of acrylamide monomer and vinyl monomer of claim 1, the content of acrylamide is 10% by weight or more in the mixture, THF, benzene, An organic solvent selected from the group consisting of toluene and xylene is used at 20 to 80% by weight based on the total monomers. The method of claim 6, In step (b), the radical initiator is azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), or 2,2'-azobis- (2,4-dimethylvaleronitrile). 2,2'-azobis- (2,4-dimethylvaleronitrile) method for producing an acrylamide polymer. The method of claim 6, Method of producing an acrylamide polymer, characterized in that in the step (b) using a radical initiator of 0.001 to 2.0% by weight based on the entire monomer. The method of claim 6, In the step (e), the radical polymerization is carried out at 60 to 100 ° C. for 8 to 48 hours. The method of claim 6, The number average molecular weight of the acrylamide-based polymer manufacturing method of the acrylamide-based polymer, characterized in that 3,000 to 150,000. The method of claim 6, The acrylamide-based polymer is a method for producing an acrylamide-based polymer, characterized in that the sol-gel phase transition phenomenon in any one of an aromatic organic solvent of benzene or toluene.