KR20070061929A - Method of manufacturing for aromatic polyamide composite membrane - Google Patents

Abstract

Provided is a method for manufacturing an aromatic polyamide composite membrane having high exclusion rate of salts and water permeability by using a dendritic polymer, that is, a multi-functional compound. The method comprises applying a multi-functional aromatic amine-containing aqueous solution onto a porous polymeric support and then bringing the resultant into contact with a multi-functional aromatic acid chloride-containing organic solution such that a reaction product produced by surface condensation polymerization of the multi-functional aromatic amine and the multi-functional aromatic acid chloride can be applied onto the porous polymeric support, wherein a dendritic polymer that is a multi-functional compound into which one compound selected from a boron compound, a silicon compound, a phosphorous compound and a sulfur compound is introduced, is added to any one or both of the multi-functional aromatic amine-containing aqueous solution and the multi-functional aromatic acid chloride-containing organic solution.

Description

Method for manufacturing aromatic polyamide composite membrane {Method of manufacturing for aromatic polyamide composite membrane}

The present invention relates to a method for producing an aromatic polyamide composite membrane, and more particularly, to a method for producing an aromatic polyamide composite membrane having a high salt rejection rate and water permeability by containing a dendritic polymer which is a multifunctional group compound. will be.

Aromatic polyamide composite membranes (reverse osmosis membranes) have excellent salt rejection and water permeability, and are applied to fields such as domestic water purifiers, industrial ultrapure water production, wastewater treatment, and desalination of seawater. Is in progress.

Aromatic polyamide composite membranes are prepared by coating a reaction product resulting from interfacial polycondensation of a multifunctional aromatic amine with a multifunctional aromatic acid chloride on the surface of a porous polymeric support as described in US Pat. No. 4,277,344.

The improvement of the performance of the aromatic polyamide composite membrane is to improve the salt rejection rate and at the same time to have a high amount of water permeation characteristics. To achieve this goal, various additives have been added to existing processes using meta-phenylenediamine or triaminobenzene as the multifunctional aromatic amine, and trimesic acid chloride or isophthaloyl dichloride as the multifunctional aromatic acid chloride. Instructions have been tried.

US Patent No. 4,872,984 adds tertiary amine or tetraalkylammonium hydroxide with strong acid, and US Patent No. 6,723,241 reports that it is possible to improve the performance of the separator by adding a phosphorus compound. However, these additives remain as a physical bond in the composite membrane, there is a problem that can be eluted from the membrane during the use of the reverse osmosis membrane.

Starburst dendrimer represented by polyamidoamine (PAMAM) has a structural feature with a large number of reactors at the end, and can be used in biotechnology such as biosensors by replacing the end group according to the purpose It can also be applied to chemical sensors, adsorption membranes in liquid or gas phase, separators, low dielectric materials or lithography processes.

In Korean Patent No. 10-0356282, the surface of a polymer film or a polymer film is modified by plasma or ultraviolet irradiation, and then coated with a dendritic polymer and a dendritic polymer substituted with an active material to induce covalent bonds at the membrane interface to newly form a surface. A method of making this modified separator is presented. However, the above method has a disadvantage in that the adhesion between the dendritic polymer and the separator is close to the physical bond, so that the applied and detachable dendritic polymer can be easily detached.

In the present invention, a compound selected from boron compounds, silicon compounds, phosphorus compounds, and sulfur compounds is introduced into the polymer chain during the chemical reaction process for preparing the aromatic amide composite membrane, and the membrane is prepared by adding and reacting a dendritic polymer which is a multifunctional compound. It is possible to solve the conventional problem that the dendritic polymer is easily separated from the composite membrane during use due to the strong bonding of the dendritic polymer and the aromatic amide composite membrane with improved salt excretion and water permeability.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is coated with an aqueous solution containing a multifunctional aromatic amine on the porous polymer support and then contacted with an organic solution containing a multifunctional aromatic acid chloride to the surface of the porous polymer support and the multifunctional aromatic amine and multifunctional aromatic acid chloride When preparing the aromatic polyamide composite membrane by coating the reaction product produced by the interfacial polycondensation reaction of the polymer, the organic solvent containing the multifunctional aromatic amine and the organic solution containing the multifunctional aromatic acid chloride One compound selected from boron compounds, silicon compounds, phosphorus compounds, and sulfur compounds is introduced into the polymer chain, and a dendritic polymer, which is a multifunctional compound, is added.

In the chain of the dendritic polymer which is the above-mentioned multifunctional compound, one compound selected from boron compounds, silicon compounds, phosphorus compounds and sulfur compounds is introduced.

The dendritic polymer as the multifunctional compound is a dendritic polymer whose terminal is substituted with an amine or a dendritic polymer whose terminal is substituted with an acid chloride. Specifically, a polyamidoamine (PAMAM, Starburst dendrimer) having an amine terminal may be used, and the terminal of the starburst dendrimer may be substituted with an acid chloride.

In addition, a starburst dendrimer having a branched polymer form for more than 0.5 generations may be used as the dendritic polymer as the multifunctional compound.

Further, in the step of synthesizing the dendrimer, a new dendrimer having boron, silicon, phosphorus or sulfur compounds introduced into the dendrimer may be used by partially reacting with a boron compound, silicon compound, phosphorus compound or sulfur compound. As such, when using a dendrimer in which other compounds are introduced, the dendrimer terminal may be replaced in whole or in part with an amine or an acid chloride to prepare a reverse osmosis composite membrane.

In the case of a composite membrane prepared by adding a dendritic polymer having a boron compound, silicon compound, phosphorus compound or sulfur compound to the dendrimer structure, the structural characteristics of the dendrimer and the chemical properties according to the introduced boron compound, silicon compound, phosphorus compound or sulfur compound As a result of the structural properties of the polymer, it has a high salt rejection rate and a high flow rate as compared with the conventional aromatic amide composite membrane.

The dendritic polymer may contain a heter element and / or a functional group in its chain.

The heter element is nitrogen or oxygen, and the functional group is an amide group, an acetate group or an ether group.

In addition, as the dendritic polymer, a dendritic polymer in which a central compound is replaced with another amine, a boron compound, a silicon compound, a phosphorus compound, or a sulfur compound, etc. may be used instead of the existing ammonia.

More preferably, a dendritic polymer having a terminal substituted with an amine is added to an aqueous solution containing a multifunctional aromatic amine, and a dendritic polymer having a terminal acid substituted also is added to an aqueous solution containing a multifunctional aromatic acid chloride. It is good to add.

As the multifunctional aromatic amine, meta phenylenediamine, piperazine or triaminobenzene may be used, and as the multifunctional aromatic acid chloride, trimesic acid chloride or isophthaloyl dichloride may be used.

The porous polymer support is a polymer membrane prepared to have a pore size of nanofiltration or ultrafiltration, and the polymer used therein is polysulfone, polyethersulfone, polyamide, polyethylene, polypropylene, polyacetate, polyacrylonitrile. And polymer groups such as polyvinylidene fluoride.

Dipping or spraying may be used to apply an aqueous solution containing a multifunctional aromatic amine onto the porous polymer support. After application, an air knife, a roll, or a sponge may be used to remove the aqueous solution excessively applied to the surface of the porous polymer support.

The content of the multifunctional aromatic amine in the aqueous solution containing the multifunctional aromatic amine is preferably 0.1 to 25% by weight, more preferably 0.2 to 10% by weight.

When the content is less than 0.1% by weight, it is not evenly applied to the porous polymer support, and when the content is more than 25% by weight, the thickness of the composite membrane becomes thick, thereby decreasing the permeate flow rate.

Moreover, it is preferable that pHs of the aqueous solution containing said multifunctional aromatic amine are 7-12.

Meanwhile, a method of contacting the porous polymer support coated with the aqueous solution containing the multifunctional aromatic amine with an organic solution containing the multifunctional aromatic acid chloride, dipping the porous polymer support into the aqueous solution containing the multifunctional aromatic acid chloride. Or spraying the aqueous solution on the porous polymer support may be adopted.

The content of the multifunctional aromatic acid chloride in the organic solution containing the multifunctional aromatic acid chloride is preferably 0.01 to 10% by weight, more preferably 0.02 to 5% by weight.

When the content is less than 0.01% by weight, the interfacial condensation polymerization does not proceed smoothly, and when the content exceeds 10% by weight, the thickness of the composite membrane becomes thick, thereby reducing the permeate flow rate.

The content of the dendritic polymer added to at least one of an aqueous solution containing a multifunctional aromatic amine and an organic solution containing a multifunctional aromatic acid chloride is 0.001 to 5% by weight, preferably 0.005 to 0.5% by weight based on the weight of each aqueous solution. It is good to be.

Freon, isoparaffin mixture, or C5-C20 hydrocarbons can be used as an organic solvent. The interfacial polycondensation reaction time is 5 seconds to 10 minutes, preferably 10 seconds to 2 minutes. If the reaction time is less than 5 seconds, the reaction does not proceed evenly on the surface of the support, and the salt rejection rate property is lowered. If the reaction time exceeds 10 minutes, the thickness of the composite film becomes thick and the water permeability is reduced.

The aromatic polyamide composite membrane prepared as above is washed with an aqueous solution containing ultrapure water or a low concentration of carbonate and dried. The temperature of the wash water should be maintained at a suitable temperature between 20 ~ 50 ℃.

The aromatic polyamide composite membrane prepared by the above invention can overcome the disadvantages of the additive dissolution because the dendritic polymer used as an additive is combined with the separator by a chemical reaction, and due to the characteristics of the dendritic polymer It has excellent salt rejection and high flow rate.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples. However, the scope of the present invention is not limited by these examples.

Example  One

The porous polymeric support casted with porous polysulfone having a thickness of 150 μm was dipped into an aqueous solution containing 2 wt% of metaphenylenediamine and 0.1 wt% of phosphorus compound (starburst dendrimer) (generation 1) for 1 minute and then The aqueous solution was removed using a roll. The dipping porous polymer support was reacted with 0.2% by weight of trimezoyl chloride organic solution for about 1 minute. After completion of the reaction, the resultant was dried in air for 1 minute, and then washed for 30 minutes with a low concentration aqueous solution of carbonate at room temperature to prepare an aromatic polyamide composite membrane.

Example  2

The porous polymer support cast with the porous polysulfone having a thickness of 150 μm was dipped in 2 wt% aqueous metaphenylenediamine solution for 1 minute, and then the excess aqueous solution was removed using a roll.

The dipping porous polymer support was reacted with an organic solution containing a starburst dendrimer (generation 1) in which 0.2% by weight of trimesoyl chloride and 0.05% by weight of phosphorus compound were introduced and the terminal was substituted with an acid chloride. I was. After completion of the reaction, the resultant was dried for 1 minute in air and washed with a low concentration of carbonate solution at room temperature for 30 minutes to prepare an aromatic polyamide composite membrane.

Example  3 to Example  7

Types of starburst dendrimers added to the aqueous solution containing metaphenyldiamine

Except for the modification as shown in Table 1 was prepared in the same manner as in Example 1 aromatic polyamide North Union membrane.

Manufacture conditions division Dendrimer Type Example 3 Starburst Dendrimer (Generation 0.5) Example 4 Starburst Dendrimer (Generation 1.5) Example 5 Starburst Dendrimer (Generation 2) Example 6 Starburst Dendrimer (Generation 4) Example 7 Starburst Dendrimer (Generation 5)

Example  8 to Example  12

An aromatic polyamide composite membrane was prepared in the same manner as in Example 2, except that the type of the starburst dendrimer in which the terminal added to the trimezoyl chloride organic solution was substituted with the acid chloride was changed as shown in Table 2.

Manufacture conditions division Starburst Dendrimer Type Example 8 Starburst Dendrimer (Generation 0.5) Example 9 Starburst Dendrimer (Generation 1.5) Example 10 Starburst Dendrimer (Generation 2) Example 11 Starburst Dendrimer (Generation 4) Example 12 Starburst Dendrimer (Generation 5)

Example  13

The porous polymeric support casted with porous polysulfone having a thickness of 150 µm was dipped in an aqueous solution containing 2% by weight of metaphenylenediamine and 0.1% by weight of a silicon compound containing starburst dendrimer (generation 1) for 1 minute. The aqueous solution was removed using a roll. The dipping porous polymer support was reacted with 0.2% by weight of trimezoyl chloride organic solution for about 1 minute. After the reaction was completed, the resultant was dried for 1 minute in air and washed for 30 minutes with a low concentration aqueous solution of carbonate at room temperature to prepare an aromatic polyamide composite membrane.

Example  14

The porous polymeric support casted with porous polysulfone having a thickness of 150 μm was dipped in an aqueous solution containing 2 wt% of metaphenylenediamine and 0.1 wt% of boron compound for 1 minute and then dipped in an aqueous solution containing starburst dendrimer (generation 1). The aqueous solution was removed using a roll. The dipping porous polymer support was reacted with 0.2% by weight of trimezoyl chloride organic solution for about 1 minute. After the reaction was completed, the resultant was dried for 1 minute in air and washed for 30 minutes with a low concentration aqueous solution of carbonate at room temperature to prepare an aromatic polyamide composite membrane.

Comparative Example  One

The porous polymeric support casted with porous polysulfone having a thickness of 150 μm was immersed in 2% by weight of aqueous metaphenylenediamine solution for 1 minute, and then the excess aqueous solution was removed by using a roll, and 0.2% by weight of trimezoyl chloride organic solution was used. The reaction was immersed in about 1 minute.

After the reaction was completed, the resultant was dried for 1 minute in air and washed for 30 minutes with a low concentration aqueous solution of carbonate at room temperature to prepare an aromatic polyamide composite membrane.

The aromatic polyamide composite membranes prepared in Examples 1 to 14 and Comparative Example 1 were measured at a flow rate and salt rejection rate of 225 psi with a 2000 ppm NaCl aqueous solution, and the results are shown in Table 3.

Measurement result division Flow rate (gfd) Salt Exclusion Rate (%) Example 1 18.1 97.6 Example 2 18.0 97.9 Example 3 17.9 98.1 Example 4 18.6 98.5 Example 5 18.9 98.6 Example 6 17.4 97.1 Example 7 17.1 97.3 Example 8 17.8 98.3 Example 9 18.4 98.6 Example 10 18.8 98.5 Example 11 16.9 97.8 Example 12 16.8 97.5 Example 13 19.1 98.7 Example 14 17.9 99.1 Comparative Example 1 16.2 97.5

In the aromatic amide composite membrane prepared by the present invention, the dendritic polymer used as an additive is combined with a separator by a chemical reaction, thereby solving the dissolution problem of the additive.

In addition, due to the characteristics of the dendritic polymer, the salt rejection rate and water permeability of the aromatic amide composite membrane are greatly improved.

Claims (8)

After applying an aqueous solution containing a multifunctional aromatic amine to the porous polymer support, it is contacted with an organic solution containing a multifunctional aromatic acid chloride to interface the axes of the multifunctional aromatic amine and the multifunctional aromatic acid chloride on the surface of the porous polymer support. In preparing the aromatic polyamide composite membrane by coating the reaction product produced by the polymerization reaction, a boron compound in any one or both of an aqueous solution containing the multifunctional aromatic amine and an organic solution containing a multifunctional aromatic acid chloride, A method for producing an aromatic polyamide composite membrane, wherein a compound selected from silicon compound, phosphorus compound and sulfur compound is introduced into the polymer chain and a dendritic polymer which is a multifunctional group compound is added. The method for producing an aromatic polyamide composite membrane according to claim 1, wherein the dendritic polymer which is a multifunctional compound is a dendritic polymer whose terminal is substituted with an amine or a dendritic polymer whose terminal is substituted with an acid chloride. The method for producing an aromatic polyamide composite membrane according to claim 1, wherein the dendritic polymer, which is a multifunctional group compound, is a starburst dendrimer having a branched polymer form for 0.5 generations or more. The method for producing an aromatic polyamide composite membrane according to claim 1, wherein the dendritic polymer contains a heter element in its chain. The method for producing an aromatic polyamide composite membrane according to claim 4, wherein the heter element is nitrogen or oxygen. The aromatic polyamide composite membrane according to claim 1, wherein the silicon compound introduced into the dendritic polymer chain is one compound selected from the group consisting of chlorosilane, alkylsilane, arylsilane, aloxysilane and aminesilane. Manufacturing method. The phosphorus compound introduced into the dendritic polymer chain is composed of alkyl phosphine, aryl phosphine, alkyl phosphate, aryl phosphate, alkoxy phosphine, alkyl phosphite, aryl phosphite, alkoxy phosphite and phosphazine. A method for producing an aromatic polyamide composite membrane, characterized in that one compound selected from the group. The method for producing an aromatic polyamide composite membrane according to claim 1, wherein the sulfur compound introduced into the dendritic polymer chain is one compound selected from the group consisting of a sulfide compound, a sulfonate compound and a sulfoxide compound.