KR101101098B1 - Synthesis of semi fluorinated surfactants for use in supercritical carbon dioxide and their use - Google Patents

Abstract

PURPOSE: A manufacturing method of partially fluorinated surfactant for supercritical carbon dioxide is provided to increase the solubility of carbon dioxide and to remove contaminants between fine gaps. CONSTITUTION: A manufacturing method of partially fluorinated surfactant for supercritical carbon dioxide comprises the step of manufacturing an amphiphilic surfactant in chemical formula 1, as a block copolymer, in which carbon-dioxide-philic components are supplied with a partially fluorinated polymer and carbon dioxide-phobic components are supplied with ethylene oxide. In chemical formula 1, m is 10-455, n is 2-100, and R is CH_2CF_2CF_2CF_3, CH_2CF_2CF_2CF_2CF_3, CH_2CH_2(CF_2)_5CF_3, CH_2(CF_2)_6CF_3 or CH_2CH_2(CF_2)_(3-12)CF_3.

Description

Synthesis of semi fluorinated surfactants for use in supercritical carbon dioxide and their use}

The present invention provides a method for synthesizing a novel partially fluorinated surfactant useful for dry cleaning using supercritical carbon dioxide and a method for improving the removal efficiency of contaminants from various supports such as metals, ceramics, inorganic compounds, polymers, natural fabrics, etc. It is about.

A large amount of organic or halogen solvents are used worldwide every year as process aids, cleaners and dispersants, and in the recent dry cleaning industry, perchlorentylene (PCE), petroleum or stoddard solvents, chlorofluorocarbons, CFC-113) and 1,1,1-trichloroethane are used.

These solvents all present health and safety hazards and are hazardous to the environment. For example, PCE is suspected to be a carcinogen, petroleum-based solvents produce flammability and smog, and CFC-113 destroys ozone, so it is decided not to use it gradually. These solvents have been refrained from being used as the main cause of environmental pollution, and when non-volatile solvents such as aqueous solutions are used instead of these volatile solvents, waste water is generated, There is a big disadvantage of requiring energy.

For this reason, the use of carbon dioxide as a solvent, which is a nontoxic, nonflammable, inexpensive and environmentally friendly substance, has been proposed as an alternative. Carbon dioxide has a low critical temperature (31.1 ℃) and a critical pressure (73.8 bar) to easily reach the supercritical state, and due to the high compressibility in the supercritical state, it is easy to change the density or solvent strength according to the pressure change In addition, since the gas is changed by the reduced pressure, there is an advantage in that the solvent can be easily separated from the solute.

In other words, pollutants can be easily concentrated and separated from carbon dioxide to recover valuable materials or to treat wastes, and carbon dioxide solvents can be obtained in abundance as air or by-products of various chemical processes, and need not be generated separately. The spent carbon dioxide can be recycled and recycled.

However, in the method of removing contaminants from the fabric by simply using carbon dioxide as in US Patent 4012194, contaminants of hydrophilic components such as grape juice, coffee, and kimchi stains are not very soluble in carbon dioxide. It was hard to expect.

Accordingly, researches on surfactants applied to carbon dioxide have been conducted, and in Korean Patent 0131842, a method of removing contaminants by introducing cleaning additives such as a surfactant and a solvent such as water to enable better cleaning using carbon dioxide fluid is provided. In the present invention, Korean Patent 0469339 relates to a method of developing a variety of surfactants and removing contaminants using the same, and has suggested various surfactants. In addition, Korean Patent 0701762 proposes a method for removing water-soluble and fat-soluble contaminants using a partial fluorine-based random copolymer.

However, these surfactants have a relatively high molecular weight, so that they do not have high solubility in carbon dioxide, and are difficult to remove contaminants between fine gaps, and remain dry on the support after dry cleaning.

An object of the present invention is to prepare an effective surfactant applicable to supercritical carbon dioxide by preparing a compound having a low molecular weight block copolymer of a carbon dioxide component and a small carbon dioxide component.

An object of the present invention is to prepare an effective surfactant applicable to supercritical carbon dioxide by preparing a compound having a low molecular weight block copolymer of a carbon dioxide component and a small carbon dioxide component.

In order to achieve this purpose, Atom Transfer Radical is a block copolymer surfactant having a total molecular weight of 70,000 or less including a polymer partially fluorinated with a carbon dioxide component and polyethylene glycol having a molecular weight of 20,000 or less as a small carbon dioxide component. Manufactured using Polymerization (ATRP) or Reversible Addition Fragmentation Chain Transfer Polymerization (RAFT) to increase the solubility for carbon dioxide and remove contaminants between fine cracks. The present invention has been completed to provide excellent removal efficiency of contaminants in a small amount without leaving residue.

The present invention provides a method for producing a block copolymer surfactant compound in which an organic compound exhibiting a carbon dioxide component and a small carbon dioxide component is combined.

As described above, the present invention can synthesize a narrow molecular weight copolymer by atomic transfer radical polymerization, and synthesize a copolymer in which metal residues are not left by reversible addition-decomposition transfer polymerization. And by using a carbon dioxide fluid containing a surfactant in the contaminated support, the surfactant can remove the contaminants from the support to be taken out inside the carbon dioxide fluid to remove the contaminants in a short time, and used Carbon dioxide can be recycled and recycled. In addition, carbon dioxide, which is harmless to the environment, is used to prevent environmental pollution and can be practically used in various fields. In addition, it is designed and manufactured with low molecular weight to penetrate into fine parts to remove contaminants, dissolve well in carbon dioxide in a small amount, favor emulsion formation with water, and contain a large amount of water in the residue removal process. As well as reducing the residue removal time, there is an effect that can easily and completely separate the removed residue from the support.

Specifically, in the surfactant of the present invention, the carbon dioxide component is provided by a partially fluorinated polymer, and the small carbon dioxide component is a block copolymer provided by polyethylene glycol having a molecular weight of 20,000 or less, and the polymer composition can be freely changed. Thus, surfactant performance can be controlled. The solubility in carbon dioxide increases as the content of carbon dioxide increases, so that polyethylene glycol having a molecular weight of 20,000 or less can also reduce the size of the partially fluorinated block, which is a parent carbon dioxide component, to implement a surfactant having a total molecular weight of 100,000 or less. As a preferred embodiment of the present invention, the synthesized present invention provides a surfactant represented by the formula (1).

Formula 1

Wherein m is from 10 to 455, n is from 2 to 100, and R is CH ₂ CF ₂ CF ₂ CF ₃ (dihydro fluorobutyl methacrylate, FBMA), CH ₂ CF ₂ CF ₂ CF ₂ CF ₃ (dihydro fluoropentyl methacrylate, FPMA), CH ₂ CH ₂ (CF ₂ ) ₅ CF ₃ (tetrahydro fluorooctyl methacrylate, 1H2H-FOMA) _, CH ₂ (CF ₂ ) ₆ CF ₃ (dihydro fluorooctyl methacrylate, 1H-FOMA) _, CH ₂ CH ₂ (CF ₂ ) _3-12 CF ₃ (zonyl TM).

The above-described invention provides a structure of a surfactant that reacts with methoxy poly (ethylene oxide, MPEO) and partially fluorinated monomers and is carbon dioxide and retains contaminant cleaning ability.

In a preferred embodiment of this embodiment, the end groups of the methoxy polyethylene (PEO) are synthesized using an esterification reaction to synthesize a macroinitiator (MPEO-Br) and mix MPEO-Br / CuCl The method can be improved by using a halogen catalyst system, which can synthesize a narrow molecular weight distribution copolymer by atomic transfer radical polymerization with a partial fluorine monomer.

In another embodiment, a PEO-based macro-CTA is synthesized by replacing the terminal group of Methoxy poly (ethylene oxide, PEO) with 3- (benzylthiocarbonothioylthio) propanoic acid (CTA) using a RAFT agent. And a copolymer in which no metal residues remain by reversible addition-decomposition transfer polymerization with the partial fluorine monomer.

In a more preferred embodiment, the block copolymer surfactants produced by the polymerization of the above-described MPEOs with partially fluorinated monomers according to the present invention provide a method for improving the effectiveness of extracting contaminants of carbon dioxide alone when used in combination with supercritical carbon dioxide. Compared with conventional surfactants, it is economical and has an excellent cleaning effect.

The use of non-toxic, non-flammable, inert, inexpensive and environmentally harmless carbon dioxide as an organic solvent replacement to remove numerous contaminants from various supports has led to the use of surfactants to effectively remove contaminants from supports in carbon dioxide fluids. As required, the surfactants in this study show very good performance both in terms of cleaning effect and economics.

For example, conventional surfactants have a relatively high molecular weight and are difficult to remove contaminants in the minute gaps. However, the surfactants of the present study are designed to have a low molecular weight so that they can penetrate into the fine parts and residues after dry cleaning There is an advantage that does not leave.

Unlike conventional surfactants, which are difficult to use due to their lack of affinity with water, the surfactants in this study exhibit good properties of being well soluble in carbon dioxide and absorbing water.

The present invention utilizes surfactants in carbon dioxide fluids to separate contaminants from contaminated supports, which may be in any form, such as metals, glass, ceramics, synthetic polymers, natural polymers, and natural materials.

The above contaminants may be in the form of polar and non-polar compounds, polymers, ionic materials, inorganic compounds, organic compounds, as well as photoresists, pharmaceuticals, dust, dirt, food waste, and the like.

In a preferred embodiment of this aspect, it may be in gaseous, liquid or supercritical state, preferably liquid and supercritical states.

In addition, the carbon dioxide fluid may be used alone, or may be used together with additives such as water, alcohol, and acid base.

Carbon dioxide fluid can be used with 0.1 to 10 percent by weight of additives, which can improve the cleaning effect than when carbon dioxide alone is used.

The present invention is to develop a surfactant for more effective cleaning in the carbon dioxide fluid, these materials can be a surface active agent in the carbon dioxide fluid to disperse the materials having a relatively low solubility in the carbon dioxide fluid described above. . In general, surfactants are present at the boundary between the contaminant and carbon dioxide phase, which lowers the internal tension between the two components, resulting in a good transport of the contaminant into carbon dioxide. Used as a percentage.

The surfactants described above may be dissolved or dispersed during or before contacting the carbon dioxide fluid with the contaminated support, or alternatively the polymer may be contacted with the contaminated support prior to the addition of carbon dioxide.

The invention is explained in more detail in the following non-limiting examples.

≪ Example 1 >

Giant initiator  synthesis

The synthesis first proceeds with the synthesis of a bromo-terminal macro initiator by reacting methoxy polyethylene glycol (MPEO) with 2-bromo isobutyryl bromide (BIB).

When the reaction was synthesized using 7.5 g (10 mmol) of MPEO having a molecular weight of 750, the mixture was stirred by mixing 1.83 g (15 mmol) of DMAP and 1 g (10 mmol) of TEA in 10 mL of solvent CH ₂ Cl _{2 in} a flask. I was. After maintaining the temperature of the flask with DMAP and TEA added to 0 ℃, CH ₂ Cl ₂ 5.75 g (25 mmol) of BIB was dissolved in 10 mL and added rapidly. After completely substituted with nitrogen gas, the reaction was performed with MPEO and esterification reaction. In order to disperse yellow, 7.5 g (10 mmol) of MPEO dissolved in 100 mL of CH ₂ Cl ₂ was dropped for 1 hour to allow the reaction to proceed very slowly. The temperature was then raised to room temperature and stirred for 18 hours to further proceed with the reaction.

All reagents were purified before the reaction and the reaction was carried out in a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, concentrated and precipitated in cold diethyl ether, and a silica gel column was used to remove impurities generated during the reaction of the obtained MPEO-Br.

The end group of the macroinitiator synthesized using FT-IR was confirmed that the -OH band of PEO disappeared through the reaction.

Giant initiator  Block copolymer surfactant synthesis using

Synthesis of block copolymer surfactants was carried out in vacuum in a 100 mL flask using 1 g (1.3 mmol) of a macroinitiator with 0.13 g (1.3 mmol) of CuCl and 0.4 g (2.6 mmol) of bipy in a 100 mL flask. It was dried for 2 hours and then replaced with nitrogen (3 ×) to remove oxygen. 6 mL of dried benzene and trifluorotoluene (volume ratio 50:50) and 5 g (9.4 mmol) of Zonyl TM (trade name: Fw = 532) sold by DuPont, USA were substituted for 30 minutes in a nitrogen atmosphere. It stirred by heating at 130 degreeC. After reacting for 5 hours in a nitrogen atmosphere, the reaction was stopped by cooling to room temperature.

To obtain the pure block copolymer, Zonyl TM monomer was removed with cold diethyl ether and separated three times for 24 hours in purified water at room temperature to remove unreacted PEO macroinitiator. The resulting product can then be treated with a fluorinated solvent (FC-5080) twice at room temperature to remove the Zonyl TM monomer.

The purified copolymer was dissolved in chloroform and CFCl ₃ (1: 4 solution), then passed through active Al ₂ O ₃ to remove the catalyst and dried completely in vacuo at room temperature for 24 hours.

As a result of analysis by ¹ H-NMR using CDCl ₃ and FC-113 (1: 4 solution), a block copolymer having a molecular weight of PEO of 750 and a molecular weight of Zonyl ™ of 4,000 was obtained.

Block copolymer surfactants of various sizes were synthesized using the molecular weight of MPEO and various kinds of partially fluorinated monomers.

<Example 2>

PEO - Based Macro - CTA  ( PEO - RAFT agent ) Synthesis

Dissolve 2 g (1.0 mmol) of molecular weight 2,000 MPEO in a 150 mL round flask with 40 mL toluene, then 0.54 g (2.0 mmol) of 3- (benzylthiocarbonothioylthio) propanoic acid, 0.12 g (1.0 mmol) of DMAP and 25 methylene chloride mL was added. After stirring using a magnetic bar and keeping the temperature of the mixed flask at 0 ° C, 0.41 g (2.0 mmol) of DCC dissolved in 10 mL of CH ₂ Cl ₂ was added. After this time the temperature was raised to room temperature and the reaction proceeded further with stirring for 20 hours. After 20 hours, the obtained PEO-based macro-CTA was filtered, concentrated, precipitated in cold diethyl ether, dried for 24 hours in an oven at 35 ° C. and confirmed by NMR.

PEO - Based Macro - CTA Block Copolymer Surfactant Synthesis

Synthesis of the block copolymer surfactant was performed using a PEO-RAFT agent with a molecular weight of 2000, in a 100 mL flask containing 0.50 g (0.22 mmol) of PEO-RAFT agent, 0.8 g (1.70 mmol) of PFOMA, and 0.009 g (0.5 μmol) of AIBN. It was dissolved using 3 mL of DMF and a TFT cosolvent (volume ratio of 50:50), substituted in a nitrogen atmosphere for 30 minutes, and heated and stirred at 70 ° C. After reacting for 6 hours in a nitrogen atmosphere, the reaction was stopped by cooling to room temperature. After the reaction was concentrated and precipitated in cold diethyl ether to remove the FOMA monomer, and separated in purified water at room temperature to remove the unreacted PEO-RAFT agent. It was then dried completely in vacuo at room temperature for 24 hours.

As a result of analysis by ¹ H-NMR using CDCl ₃ and FC-113 (1: 4 solution), a block copolymer having a molecular weight of MPEO of 2,000 and a molecular weight of FOMA of 4,000 was obtained. Block copolymer surfactants of various sizes were synthesized using the molecular weight of MPEO and various kinds of partially fluorinated monomers.

&Lt; Example 3 >

Performance Evaluation of Surfactants

In order to find out how much the synthesized surfactant dissolves in carbon dioxide and how well the water is hydrated, the performance test through the cloud point measurement was conducted.

The cloud point measurement used a high pressure reactor system with a sapphire window to confirm phase behavior in carbon dioxide. By using a piston inside the reactor to vary the pressure of the solvent to change the density of the solvent it is possible to measure the cloud point indicating the performance of the surfactant on the carbon dioxide.

This is done by placing a certain amount of surfactant in the reactor and then adjusting the temperature and pressure parameters so that the optically clear, single phase phase becomes cloudy due to reduced pressure (usually the solute is dissolved in the solvent. Precipitated and clouded by light scattering (cloud point) were observed.

As a result, PEO- b -PFOMA (2K-5.5K) was found to melt up to 1.2 weight percent of the maximum carbon dioxide, and it was found that the dissolving power was excellent at more than 30 ℃. The maximum optimal Wo is between 90 and 135, given that the EO group has two or three capacities.

In another measurement, PEO- b- PZonylTM (750-4K) was found to have a Wo of 34 to 51 but relatively high solubility in carbon dioxide by 1.8 weight percent using PEO with a molecular weight of 750. It can be seen that Wo is relatively high because it may contain more EO groups than the same amount as the active agent.

< Comparative example  1>

Cleaning of inorganic contaminants on metal surfaces

A metal support (1 cm × 1 cm) containing inorganic contaminants on the surface was placed in a 10 cc high pressure container containing a magnetic bar, filled with carbon dioxide, and subjected to a temperature and pressure of 40 ° C. and 5000 psi. After stirring for 10 minutes while maintaining the same temperature and pressure 12 mL of carbon dioxide flowed at a rate of 3 mL / min and then discharged while flowing 30 mL of carbon dioxide at a rate of 10 mL / min. After that, the result of exhausting all carbon dioxide in the container was confirmed by SEM, and it was confirmed that the residue still remained.

< Example  4>

Cleaning of inorganic contaminants on metal surfaces

A metal support (1 cm × 1 cm) containing inorganic contaminants on the surface and 0.05 g of PEO- b -PFPMA (2K-7K) surfactant were placed in a 10 cc high pressure container containing a magnetic bar, followed by water mixed with carbon dioxide (0.05 mL) were charged together and 40 ° C., 5000 psi temperature and pressure were applied. After stirring for 10 minutes while maintaining the same temperature and pressure 12 mL of carbon dioxide flowed at a rate of 3 mL / min and then discharged while flowing 30 mL of carbon dioxide at a rate of 10 mL / min. After that, the result of exhausting all carbon dioxide in the container was confirmed by SEM, and a clean metal surface was obtained without any residue.

< Comparative example  2>

Supercritical Carbon Dioxide Only  From cotton fabric Kimchi soup  Cleaning of stains

0.03 g of kimchi broth was buried on a clean surface (1 cm × 1 cm) using a pipette, and then the surface was placed in a 10 cc high-pressure container containing a magnetic bar, filled with carbon dioxide, and subjected to a temperature and pressure of 40 ° C. and 4000 psi. . After stirring for 10 minutes and while maintaining the same temperature and pressure 12 mL of carbon dioxide was flowed at a rate of 3 mL / min and discharged while flowing 30 mL of carbon dioxide at a rate of 10 mL / min. Thereafter, as a result of discharging all the carbon dioxide in the container, there was almost no cleaning effect.

Supercritical carbon dioxide  From cotton fabrics using existing surfactants Kimchi soup  Cleaning of stains

Experiments with the same amount of kimchi broth stain with 0.04 g of conventional surfactant resulted in a cleaning effect of 50% by weight.

< Example  5>

From cotton fabrics using carbon dioxide and surfactants Kimchi soup  Cleaning of stains

Experiments with the same amount of kimchi broth stain with 0.04 g of PEO- b- PZonylTM (2K-7K) surfactant resulted in a cleaning effect of 80% by weight.

Cleaning of Kimchi Broth Stain from Cotton Fabrics by Adding Carbon Dioxide, Surfactant and Water

When 0.04 g of PEO2K- b- PZonylTM7K surfactant and water (0.04 mL) were added together, the same amount of kimchi broth stain as the above method was used, and the cleaning effect was 85% by weight.

< Example  6>

Cotton fabric Coffee stain  washing

Pipette 0.05 g of coffee into a clean side (1 cm × 1 cm) using a pipette and place the side in a 10 cc high-pressure container containing 0.05 g of PEO- b -PFPMA (750-4K) surfactant and magnetic bar. After filling the mixture of carbon dioxide and water (0.05 mL) together and added a temperature and pressure of 40 ℃, 5000 psi. After stirring for 10 minutes while maintaining the same temperature and pressure 12 mL of carbon dioxide flowed at a rate of 3 mL / min and then discharged while flowing 30 mL of carbon dioxide at a rate of 10 mL / min. Thereafter, all of the carbon dioxide in the container was discharged, resulting in a cleaning effect of 90% by weight.

< Example  7>

Washing of grape juice stain from cotton cloth which added bleach

0.1 g grape juice was applied to a clean cotton (1 cm x 1 cm) pipette, and then the cotton was washed with 0.05 g of PEO- b -PFPMA (750-4K) surfactant and 0.0005 g of chlorine hypochlorite. Into a 10 cc high-pressure container containing a magnetic bar, filled with a mixture of carbon dioxide and water (0.05 mL), and the temperature and pressure of 40 ℃, 5000 psi was applied. After stirring for 10 minutes while maintaining the same temperature and pressure 12 mL of carbon dioxide flowed at a rate of 3 mL / min and then discharged while flowing 30 mL of carbon dioxide at a rate of 10 mL / min. After all the carbon dioxide in the container was discharged there was a cleaning effect of 92% by weight.

Claims (10)

A method of removing various contaminants from a support, the method comprising contacting the support with a carbon dioxide fluid comprising an amphiphilic surfactant, associating the contaminant with the amphiphilic surfactant to separate from the support, and then In the amphipathic surfactant used to separate contaminants from the carbon dioxide fluid, the carbon dioxide component is provided by a partially fluorinated polymer and the small carbon dioxide component is a block copolymer provided by Methoxy poly (ethylene oxide). The surfactant production method characterized by the following formula (1).
Formula 1

Wherein m is from 10 to 455, n is from 2 to 100, and R is CH ₂ CF ₂ CF ₂ CF ₃ , CH ₂ CF ₂ CF ₂ CF ₂ CF ₃ , CH ₂ CH ₂ (CF ₂ ) ₅ CF _{3 ,} CH ₂ (CF ₂ ) ₆ CF _{3 ,} CH ₂ CH ₂ (CF ₂ ) _{3 to 12} CF ₃ . The halogenated catalyst system of claim 1, wherein the surfactant synthesizes a macroinitiator (PEO-Br) using an esterification reaction of the end group of Methoxy poly (ethylene oxide) (PEO), and a mixed halogen catalyst system of PEO-Br / CuCl. A method for producing a surfactant, characterized by synthesizing a copolymer of a narrow molecular weight distribution by atomic transfer radical polymerization with a partially fluorinated monomer. According to claim 1, The surfactant is a RAFT agent using a 3- (benzylthiocarbonothioylthio) propanoic acid to replace the end group of Methoxy poly (ethylene oxide) (PEO) to synthesize a PEO-based macro-CTA, and a fluorinated monomer and A method for producing a surfactant, characterized by synthesizing a copolymer in which no metal residues remain by reversible addition-decomposition transfer polymerization of the. The method of claim 1, wherein the small carbon dioxide component is prepared using a poly (ethylene oxide) having a molecular weight of 20,000 or less and a total molecular weight of 100,000 or less. In using the surfactant prepared in claim 1, the support comprises a metal, glass, ceramic, synthetic polymers, natural polymers, natural materials and the like. In using the surfactant prepared in claim 1, contaminants include polar and non-polar compounds, polymers, ionic materials, inorganic compounds, organic compounds, as well as photoresists, pharmaceuticals, dust, dirt, food waste, and the like. Cleaning method. In using the surfactant prepared in claim 1, the carbon dioxide fluid may be used alone or in combination with additives such as water, alcohols, acids, bases and the like. 8. The method of claim 7, wherein the carbon dioxide fluid can be used with 0.1 to 10 percent by weight of the additive when used in combination with an additive. A method according to claim 1, wherein the surfactant prepared in claim 1 is used in 0.001 to 30% by weight in carbon dioxide. A method according to claim 1, wherein the surfactant prepared in claim 1 is characterized in that the carbon dioxide fluid and the contaminated support can be dissolved or dispersed during or before contact or can be contacted with the contaminated support prior to the addition of carbon dioxide.