KR100356571B1 - Amphiphilic polyurethane nano-particle for the remediation of wastewater and contaminated soil - Google Patents

Abstract

1. The present invention relates to the preparation of fine crosslinked polymer particles having amphoteric properties and to the removal of hydrophilic / hydrophobic contaminants from soil and wastewater using the same.

2. The present invention is easy to apply than conventional methods for removing contaminants from soil and waste water, has high efficiency, and economically advantageous method to prepare polymer particles having amphoteric properties and use them in soil and waste water treatment. There is this.

3. In order to achieve the above object, the present invention prepares the particles of the crosslinked polymer using the amphoteric urethane acrylate oligomer having the structure of the formula (1) using emulsion-free polymerization.

[Formula 1]

A-B-C-B-A

A is a material having a double bond and a reactor such as a hydroxy or amino group, and the compound belonging to the formula A includes any one selected from the group consisting of hydroxy methacrylate and hydroxy acrylate,

B is a substance having two or more isocyanate groups capable of reacting with A to form a urethane or urea bond.

The compound belonging to the formula B includes any one selected from the group consisting of toluene diisocyanate, isophorone diisocyanate, methylene diisocyanate,

C is a substance having an ionic group together with two hydroxy groups capable of forming a urethane or urea bond with an isocyanate such as dimethylol propionic acid and methyl ethanol amine and a polyol such as polytetramethylene glycol and polypropylene glycol. One.

Monomers added thereto are materials having a double bond such as styrene, styrene sulfonate sodium salt, divinylbenzene, methyl methacrylate and butyl acrylate.

4. The present invention has the purpose of simplifying the removal of harmful hydrophobic contaminants adsorbed on soil or dissolved in waste water.

Description

Amphiphilic polyurethane nano-particle for the remediation of wastewater and contaminated soil}

The present invention relates to soil contamination treatment and wastewater treatment using an emulsion of crosslinked nanoparticles having an amphoteric structure. More particularly, nanoparticles having amphoteric properties are prepared, and hydrophobic contamination from wastewater and soil using the same. It is a study on the application to the process of removing substances.

Hydrophobic contaminants (e.g. naphthalene, phenanthrene, chlorinated hydrocarbons, etc.) are hydrophobic substances that are extremely soluble in water, but they are very harmful to the human body, even in the very smallest amounts of water soluble. Various attempts are underway. Conventionally used methods include a combustion method and a flushing method. Combustion is the simplest method, but it has the disadvantage of requiring a large amount of expense to process a small amount of soil and a huge investment facility for combustion. The method using the water washing method has an advantage compared to the combustion method in terms of economics, and has the advantage of easy processing after use, but has the disadvantage that the efficiency is very poor. For this reason, recently, a method of using a surfactant has been widely studied, and various efforts for practical use have been made. The method using the surfactant has the advantage of being efficient and easy to apply, but it requires a second facility due to the adsorption of the surfactant into the soil and difficulty in recycling after use. Therefore, a separate facility is required for recycling. Do. Recently, ultrafine membranes have been used with the use of surfactants. This is to recycle the surfactant using an ultra-precision membrane for the recovery of the surfactant.

The present invention is a technique for solving the above problems, the nano-sized polymer particles having an amphoteric cross-linked structure is not only easy to contact by contacting with water, but also has a hydrophobic property in the inside, so it is also highly prone to hydrophobic contaminants. Mars is visible. Therefore, by appropriately adjusting the ionicity and hydrophobicity, the efficiency can be maximized. Since the size of the particles is nano-size to maximize the contact area with water, it is possible to increase the efficiency, cross-linked structure has the advantage that the removal and recycling is advantageous. That is, it can be easily removed by treating a small amount of salt such as calcium chloride without any device.

Figure 1- (a) shows the results of soil pollution treatment through the Betch test.

Figure 1- (b) shows the soil pollution treatment results through column experiments.

In order to achieve the above object, the present invention prepares a copolymer made of a compound having a structure of Formula 1 below.

[Formula 1]

A-B-C-B-A

A is a substance having a double bond and a reactor such as a hydroxy or amino group,

The compound belonging to Formula A includes any one selected from the group consisting of hydroxy methacrylate and hydroxy acrylate,

B is a substance having two or more isocyanate groups capable of reacting with A to form a urethane or urea bond.

The compound belonging to the formula B includes any one selected from the group consisting of toluene diisocyanate, isophorone diisocyanate, methylene diisocyanate,

C is a substance having an ionic group together with two hydroxy groups capable of forming a urethane or urea bond with an isocyanate such as dimethylol propionic acid and methyl ethanol amine and a polyol such as polytetramethylene glycol and polypropylene glycol. One.

Monomers added thereto are materials having a double bond such as styrene, styrene sulfonate sodium salt, divinylbenzene, methyl methacrylate and butyl acrylate.

The production of the polymer particles according to the present invention is possible by emulsion-free copolymerization of a monomer having a double bond with urethane acrylate. The mixture of the urethane acrylate, the monomer, and the oil-soluble initiator may be emulsified by a phase transition emulsification method, and then polymerized at 70 ° C. for 5 hours at a stirring speed of 100 rpm to prepare an amphoteric crosslinked polymer particle emulsion.

<Preparation Example 1 of Nano-Scaled Crosslinked Particles Having Bilaterality (hereinafter referred to as Preparation Example 1)>

[Formula 2]

9.95 g of urethane acrylate, 0.05 g of divinylbenzene, and 0.03 g of azobisbutylonitrile, which is an oil-soluble initiator, are added dropwise to 90 g of water, followed by vigorous stirring to emulsify the phase transition emulsification. The emulsion is prepared using the method. It is heated up to 70 degreeC. The polymerization was carried out by stirring at 100 rpm for 5 hours while maintaining this temperature. In this manner, copolymers having various ratios were prepared. The preparation composition ratio is shown in Table 2 below.

TABLE 1

Where UAA is urethane acrylate, DVB is divinylbenzene, and NaSS is styrene sulfonate sodium salt. The number after UAA indicates the ratio of hydrophobicity and hydrophilicity. UAA is an anionic substance and requires salt treatment with a base such as triethylamine or sodium hydroxide. In case of DVB, -D is added to sample name. In case of using NaSS, -N is added.

Experimental Example 1

Based on the experimental procedure and the composition ratio of Example 1, various types of amphoteric crosslinked polymer particles were prepared. The size of the particles varies depending on their composition, but they range in size from about 30 to 120 nanometers. This can have a very large contact area in the soil treatment process, thereby maximizing the removal efficiency.

Experimental Example 2

Hydrophobicity using various polymer particles produced by the above method

We examined the efficiency of removal of phenanthryl seuren in soil containing contaminants. This experiment was using a phenanthryl seuren having a ¹⁴ C radioactive isotope line by observing the activity change of the radioisotope by scintillation spectroscopy . Removal experiments were performed using two methods, the Batch method and the column method. The results of the column experiments are shown in Figures 1- (a) and 1- (b) below.

As shown in Figure 1 above, the results of the batch test showed a nearly 80% efficiency. The results of column experiments show an efficiency of 90% or more when an emulsion of about 10 pores is poured. It can be seen that the smaller the degree of hydrophilicity, that is, the higher the degree of hydrophobicity, the higher the yield. When hydrophobic divinylbenzene was added as a monomer, it was confirmed that the yield is increased because the hydrophobicity is greater. The salt recovery with triethylamine shows more recovery because of the increase in contact time at the time of passage of the column as the viscosity of the emulsion increases.

The present invention is to prepare a nano-sized polymer particles having a zwitterionic, and to use them to remove hydrophilic / hydrophobic contaminants from waste water and soil, and according to the control of hydrophobicity and hydrophilicity, high removal efficiency and post-use recovery and It is a very useful invention in terms of a process using particles with easy recycling efficiency.

Claims (2)

Amphoteric cross-linked copolymer nanoparticles for wastewater and soil pollution treatment having the structure of Formula 1 [Formula 1] A-B-C-B-A A is a substance having a double bond and a reactor such as a hydroxy or amino group, The compound belonging to Formula A includes any one selected from the group consisting of hydroxy methacrylate and hydroxy acrylate, B is a substance having two or more isocyanate groups capable of reacting with A to form a urethane or urea bond. The compound belonging to the formula B includes any one selected from the group consisting of toluene diisocyanate, isophorone diisocyanate, methylene diisocyanate, C is a substance having an ionic group together with two hydroxy groups capable of forming a urethane or urea bond with an isocyanate such as dimethylol propionic acid and methyl ethanol amine and a polyol such as polytetramethylene glycol and polypropylene glycol. One. Monomers added thereto are materials having a double bond such as styrene, styrene sulfonate sodium salt, divinylbenzene, methyl methacrylate and butyl acrylate. Use of hydrophilic / hydrophobic pollutants in wastewater and soil using copolymer nanoparticles of claim 1