KR100546079B1 - Polymer Electrolyte Complex Membrane for Separation of Polar Organic Mixture and Its Manufacturing Method - Google Patents

Abstract

The present invention relates to a polymer electrolyte complex membrane for separating a polar organic mixture and a method of manufacturing the same, and more particularly, to form an anionic polymer matrix doped layer on a hydrophilized porous polymer support, and to complex with anions present on the surface of the matrix. By preparing a polymer complex membrane in which a complex layer of a cationic metal forming a sequential layer is formed and improving the desorption phenomenon of the doped layer during the complex reaction by hydrophilization of the porous polymer support, more efficient intermolecular morphology control at the molecular level The present invention relates to a polymer electrolyte complex membrane for separating a polar organic mixture having similar physical and chemical properties and a method for preparing the same.

Separation of polymer electrolyte complex membrane, hydrophilized porous polymer support, and polar organic mixture

Description

Polyelectrolyte complex membranes for separating polar organic mixtures and method for preparation the same}             

Figure 1 shows an electron scanning micrograph (× 200) of the cut surface of the hydrophilized polymer support prepared in Example 1 according to the present invention.

Figure 2 shows an electron scanning micrograph (x1000) of the cut surface of the polymer electrolyte complex membrane prepared in Example 1 according to the present invention.

The present invention relates to a polymer electrolyte complex membrane for separating a polar organic mixture and a method of manufacturing the same, and more particularly, to form an anionic polymer matrix doped layer on a hydrophilized porous polymer support, and to complex with anions present on the surface of the matrix. By preparing a polymer complex membrane in which a complex layer of a cationic metal forming a sequential layer was formed and improving the desorption phenomenon of the doped layer during the complex reaction by hydrophilization of the porous polymer support, morphology between units lattice at a more efficient molecular level The present invention relates to a polymer electrolyte complex membrane for separating polar organic mixtures having similar physical and chemical properties and to a method of manufacturing the same.

Permeation evaporation and vapor permeation are effective for separation of azeotrope, mixture with similar boiling point, isomer mixture, etc., and are suitable for dehydration process and deorganization process to remove small amount of dissolved components in organic mixture. have. However, in the case of mixtures with too little difference in physico-chemical properties such as water-methanol, it is difficult to expect effective separation of materials with conventional membranes for dehydration processes such as ultrafiltration, microfiltration, nanofiltration and reverse osmosis membranes. In addition, it is generally low, and currently there is a state in which a separator suitable for the separation of materials has not been developed.

In this regard, currently developed inorganic membranes for water-methanol separation include silica membranes [Membrane, Vol. 25 (2000), page 73; Ceramics Transition, Vol. 31 (1992), page 411], Zeolite-A Type Membrane [Microporous Material, Vol. 12 (1997), page 305], Zeolite Type X and Y Type Membrane [In ACS Symposium Series 744, Membrane Formation , Washington DC (2000), page 330, Modernite membranes [Microporous Material, Vol. 7 (1996), page 299], etc., double zeolite NaA type (US Pat. No. 5,526,86 (1996); International Congress on Membranes and Membrane Processes, ICOM '99, Toronto, Canada, 1999; The membrane shows permeability of 0.2 to 0.5 kg / m ² · hr and 2100 to 2500 selectivity at 50 ° C with respect to the water and methanol mixture composition 5 and 10 weight ratio. On the other hand, in the case of the polymer membrane, a polyimide membrane [Koubunnshironnbunnshu, Vol. 46 (1989), page 405] and a crosslinked polyvinyl alcohol series membrane [Journal of Applied Polymer Science, Vol. 79 (2001), page 703; Separation and Purification Technology, Vol. 12 (1999), page 77; Vol. 105 (1997), page 145; Journal of Applied Polymer Science, Vol. 68 (1998), page 1717] have been developed, but are not effective in terms of permeability and selectivity [The permeability and selectivity of polyimide membrane is 1 × 10 ^-3 , 20 for 20 weight ratio of water-methanol mixture composition].

Accordingly, the present inventors have made efforts to prepare polymer membranes having effective selectivity and permeability for polar organic mixtures having similar physical properties, resulting in a hydrophilized porous polymer support having an nano-sized micropores, an anionic polymer matrix doping layer, and the matrix surface. By preparing a polymer complex membrane in which a membrane layer of a cationic metal forming a complex bond with an anion present in the polymer layer was sequentially laminated, and improving the desorption phenomenon of the doping layer during the complex reaction by hydrophilization of the porous polymer support, at a more efficient molecular level The present invention was completed by knowing that morphology control between unit grids is possible.

Accordingly, the present invention provides a polymer electrolyte complex membrane and a method for preparing the same, which are formed by a solid-liquid complex method in the presence of a hydrophilized porous polymer support and are effective for separating a polar organic mixture having a small difference in chemical and physical properties. There is a purpose.

The present invention (1) hydrophilized porous polymer support; (2) an anionic polymer matrix doped layer formed on the support; And (3) a polymer electrolyte complex membrane for separating polar organic mixtures, which is formed by sequentially stacking a membrane layer of a cationic metal forming a complex bond with an anion present on the surface of the matrix doped layer.

In addition, the present invention is one or two or more polymers selected from polysulfone, polyisulfone, polyimide, polyamide, polyacrylonitrile and polyvinylidene fluoride, alumina having hydroxy group, ionic layer silicate and A step 1 of forming a hydrophilized porous polymer support prepared by mixing a polymer mixed solution prepared by mixing one or two or more inorganic fillers selected from hydrophilic titania into a solution-immersion type;

Coating the surface of the hydrophilized porous support with an anionic polymer solution to form an anionic polymer matrix doping layer; And

A polymer electrolyte complex membrane for separating a polar organic mixture comprising three steps of coating a 2-3 trivalent cation aqueous metal solution on the surface of the matrix doped layer to form an adhesion layer by anion and cation reacting on the surface of the matrix doped layer. There is another feature of the manufacturing method.

Hereinafter, the present invention will be described in more detail.

The present invention is a hydrophilized porous polymer support formed by mixing a typical microporous layer support compound and a specific inorganic filler in a predetermined ratio, a doped layer of a solid polymer matrix formed by mixing an anionic polymer on the polymer support, The present invention relates to a polymer electrolyte complex membrane capable of controlling molecular morphologies between unit grids at a molecular level by sequentially stacking a layer of anion and a cationic polymer present on a doped matrix surface by a solid-liquid complex method.

Conventional complex membranes using anionic polymers and cationic polymers have been published by the present inventors [Korean Patent Publication No. 2001-37062, Korean Patent Registration No. 376379]. However, the above-mentioned complex film has a problem in that the doping layer is detached as the doping layer is complexed according to the deformation of the support when the morphology between the unit grids is controlled. The present invention improves the binding force of the anionic polymer matrix layer doped using a hydrophilized porous polymer support formed by mixing a predetermined amount of a microporous support compound and a specific inorganic filler used in the preparation of a known support, a polymer electrolyte complex By improving the stability of the membrane, it is easy to efficiently separate polar organic compounds having similar physical and chemical properties.

In addition, the complex membrane may be modified and used by a method of steam-permeation heat treatment, and the morphology between the unit grids of the complex membrane may include molecular size and vapor pressure of the vapor phase provided according to the heat treatment temperature based on the metal ions of the complex structure. The physico-chemical properties determine the size of the complex structure composed of molecular sieves in the membrane, and the permeability of the vapor phase is determined by the degree of miscibility of the prepared matrix, resulting in the orientation of the polymer chain in the permeate plane. It is controlled in a form that affects morphology.

Looking at each layer of the polymer electrolyte complex membrane for separating the polar organic mixture according to the present invention in detail.

First, a hydrophilized porous polymer support is prepared by phase-transferring a polymer solution in which a polymer used to form a known microporous support and a specific inorganic filler are mixed at a predetermined ratio. That is, the mixed homogeneous polymer solution is cast to a certain thickness and at the same time, a hydrophilized porous polymer film prepared by a solution-immersion type phase transition, which is immersed in a non-solvent, is used as a support in the present invention. The hydrophilized porous polymer support thus formed forms a polymer membrane having an asymmetric structure of ultrafiltration pores with a pore size in the range of 10 to 1000 mm 3. The polymer may be used, for example, one or two or more selected from polysulfone, polyisulfone, polyimide, polyamide, polyacrylonitrile, and polyvinylidene fluoride, and the inorganic filler may be, for example, a hydroxyl group. One or two or more selected from alumina, ionic layer silicate and hydrophilic titania having When the polymer and the inorganic filler are used in an amount of 15 to 25% by weight and 0.1 to 35% by weight with respect to the solvent, when the amount of the polymer is less than 15% by weight, the mechanical properties of the support decrease, and when the amount exceeds 25% by weight, It is difficult to prepare a solution, and there is a problem in preparing a porous support, and when the amount of the inorganic filler is less than 0.1% by weight, the coating layer may be detached in the complex reaction step. This increasing problem occurs.

The solvent is an organic solvent that can be dissolved in both a polymer material and an inorganic filler, and for example, dimethylacetamide, methylpyrrolidone and dimethyl sulfoxide may be used, and the non-solvent used in the phase transition is usually pure water. It is good.

Next, the surface of the hydrophilized porous polymer support is coated with an anionic polymer solution to form an anionic polymer matrix doping layer. The anionic polymer may be an anionic polysaccharide-based polymer alone or one or two or more selected from the anionic polysaccharide-based polymer and linear polyacrylic acid, sodium polystyrenesulfonate and polyvinyl alcohol. Anionic polysaccharide-based polymers are pyranose cyclic polymers or linear chain polymers having ionic groups and many hydroxyl groups in the side chains, for example, agaroses, carrageenans, alginates, celluloses, and dextrans. , Glycosaminoglycans, teicophosphates, xylans, polysaccharides and agarose sulfates, more specifically alginic acid, kappa-carrageenan, iota-carrageenan, lambta-carrageenan, kappa-perselanan , Chondroitin-4-sulfate, chondroitin-6-sulfate, dermatan sulfate, heparan sulfate, keratan sulfate, hyaluronate, heparin, succiniglycans. Teicoinic acid, cellulose sulfate, sodium carboxymethyl cellulose, xylan sulfate, cellulose chianthate, starch phosphate ethers and sulfates, metal chelate phosphorylated chitin and chitosan, and the like can be used.

As described above, the present invention uses the anionic polysaccharide polymer alone or adds and mixes a certain amount of compounds such as anionic polymer and polyvinyl alcohol to the polymer in order to give mechanical strength and higher sorption permeation characteristics. To form. In the case of mixing and using the above materials, it is preferable to use about 0.1 to 60% by weight with respect to the anionic polysaccharide polymer, respectively, when the amount is less than 0.1% by weight, the desired effect is not obtained, and 60% by weight is used. If exceeded, there is a problem in that the miscibility between materials greatly decreases. Anionic polymers have anionic groups in the form of short chain repeating units, and have a property of inducing a higher density complex structure into the matrix. For example, it is preferable to use linear polyacrylic acid or sodium polystyrenesulfonate. .

The aqueous solution of the above-mentioned compound uniformly mixed at room temperature for at least 12 hours is coated on a surface of a hydrophilized porous support by a known method, followed by drying at room temperature for 12 to 24 hours to form an anionic polymer matrix doping layer. The coating is not particularly limited by a known method, but in the present invention, a dip-coating method is used, and the doped layer thus formed has a high permeability and high selectivity to maintain a thickness in the range of 0.01 to 20 μm. Do.

Next, the solid anionic polymer matrix and a polyvalent cation aqueous metal solution are immersed in a complex reaction by a mutual penetration method to prepare an electrolyte polymer complex membrane.

Unlike the polysaccharide-based cationic polymers used in Korean Patent Laid-Open Publication No. 2001-37062, the cationic metal has a complex structure formed inside the matrix in an aqueous solution state, and is not laminated to the matrix. The thickness of the active layer is characterized by a thin, divalent cation selected from barium, cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, mercury, strontium, nickel, zinc and tin or 3 selected from aluminum, chromium and iron A valent cation can be used. The cationic metal is preferably used in an amount of 0.1 to 35% by weight with respect to water, and when the amount is less than 0.1% by weight, there is a problem in that complex formation takes much time. Rigid structures in time can lead to problems with film formation. Moreover, it is preferable to make ignition time ignite about 1 to 12 minutes.

The complex membrane prepared as described above improves the detachment phenomenon of the doped layer during the complex reaction by hydrophilization of the porous polymer support, and is formed by the solid-liquid complex method, thereby controlling the morphology between unit grids at the molecular level. It is a polymer electrolyte complex membrane that is effective for separating polar organic mixtures with little difference in chemical and physical properties.

In addition, when the polymer electrolyte complex membrane prepared above is modified in a vapor-permeation heat treatment form in a closed space at a temperature of 90 to 120 ° C. for 1 to 4 hours, a molecular sieve effect may be smaller than that of methanol molecules.

Hereinafter, the present invention will be described in detail with reference to the following Examples, but the present invention is not limited by the Examples.

Example  One : Blended  Sodium Alginate / Carrageenan (95/5) Complex  Produce

Sodium alginate (bulk product) and carrageenan were added to pure water in a separate container at a ratio of 2% by weight relative to pure water, followed by stirring at room temperature for at least 24 hours to prepare a homogeneous polymer electrolyte solution. Each prepared solution was mixed with sodium alginate and carrageenan solution in a mixing ratio of 95/5 by weight, and then stirred at room temperature for 12 hours or more to prepare a uniform doping solution.

In addition, 5% by weight of alumina and 15% by weight of polyisimide are mixed with a solvent, dimethylacetamide, and stirred at room temperature for at least 24 hours to prepare a polymer solution for preparing a support, and then a casting knife is placed in a clean room. The polymer solution was phase-transformed by casting to a thickness of 120 μm and immersing in a large amount of non-solvent pure water. The above-described phase-transferred polymer support was dried at room temperature for at least 12 hours to prepare an alumina polydisperse polymer support having pores of ultrafiltration level (fraction molecular weight of about 30000).

The polymer support was introduced into a 95/5% by weight ratio of sodium alginate / carrageenan mixed solution by a dip-coating method on a surface of the support and dried at room temperature for 24 hours. The sodium alginate / carrageenan composite membrane thus prepared was subjected to complex reaction in a 5 wt% divalent calcium aqueous solution for a predetermined time, immersed and washed three times in pure water, and then dried at room temperature in a clean room for at least 12 hours. Carrageenan complex composite membranes were prepared.

In order to have the methanol exclusion molecular sieve effect of the complex membrane prepared above, the complex composite membrane was modified by allowing the water / methanol mixed solution vaporized at 110 ° C. to exit from the doping layer toward the support. Using the modified complex membrane, permeation experiments were performed on a water / methanol (50/50 mole%) mixture and the results are shown in Table 1 below.

Comparative example  One : Blended  Sodium Alginate / Carrageenan (95/5) Complex  Produce

The same procedure as in Example 1, except that the sodium alginate / carrageenan complex membrane prepared in 80 ㎛ thickness without the preparation and doping process of the support under the same permeation conditions as in Example 1 by measuring the permeability and selectivity of water-methanol Is shown in Table 1.

Membrane type Permeability (g / m ² hr) Selectivity Example 1 (composite membrane) > 2400 > 10 ³ Comparative Example 1 (Uniform Film) 60 8 × 10 ³

Example  2 : Blended  Sodium Alginate / Polyvinyl alcohol (95/5) Complex Of composite membrane  Produce

In the same manner as in Example 1, the doping solution was used as a mixed solution of sodium alginate and polyvinyl alcohol, and the results of measuring the permeability and selectivity of water-methanol under the same permeation conditions as in Example 1 Table 2 Shown in

Comparative example  2 : Blended  Sodium Alginate / Polyvinyl alcohol (95/5) Complex  Produce

In the same manner as in Example 1, but the sodium alginate / polyvinyl alcohol complex membrane prepared in 80 ㎛ thickness without the support preparation process and doping process by measuring the permeability and selectivity of water-methanol under the same permeation conditions The results are shown in Table 2.

Membrane type Permeability (g / m ² hr) Selectivity Example 2 (composite membrane) > 1800 > 10 ³ Comparative Example 2 (Uniform Film) 40 6 × 10 ³

Comparative example  3: Hydrophilized  Porosity Support  If not used

In the same manner as in Example 1, the sodium alginate / carrageenan complex membrane prepared using a support using a polyimide, which is a microporous polymer, by measuring the permeability and selectivity of water-methanol under the same permeation conditions as in Example 1 The results are shown in Table 3.

Hydrophilic form Permeability (g / m ² hr) Selectivity Example 1 (composite membrane) > 2.4 × 10 ³ > 10 ³ Comparative Example 3 (Composite Film) > 10 × 10 ³ <1

As shown in Tables 1 to 2, Examples 1 to 2 in the form of a composite membrane consisting of a hydrophilized porous polymer support, an anionic polymer matrix doping layer, and a complex layer formed by a complex reaction with a cation according to the present invention are compared. Compared with Examples 1 to 2, it was confirmed that the coating was improved in terms of permeability and selectivity.

In addition, Comparative Example 3 uses a polyimide microporous support instead of the hydrophilized porous support used in Example 1, and showed a marked difference in permeability and selectivity with or without hydrophilization of the support. The difference between the permeability and the selectivity was confirmed to be the result of desorption with the doped layer during the complex reaction.

As described above, the polymer electrolyte complex membrane composed of a hydrophilized porous polymer support, an anionic polymer matrix doping layer, and a complex layer formed by a complex reaction with a cation according to the present invention has very excellent permeability and, in particular, physical and chemical properties. This is very useful for the separation of polar organic mixtures such as water-methanol.

Claims (9)

(1) a hydrophilized porous polymer support; (2) an anionic polymer matrix doped layer formed on the support; And (3) A coating layer of a cationic metal forming a complex bond with an anion present on the surface of the matrix doped layer A polymer electrolyte complex membrane for separating polar organic mixtures, which is formed by being laminated in this order. The method of claim 1, wherein the hydrophilized porous polymer support One or two or more polymers selected from polysulfone, polyisulfone, polyisimide, polyamide, polyacrylonitrile and polyvinylidene fluoride, A polymer electrolyte complex membrane for separation of a polar organic mixture, characterized in that the polymer mixed solution of one or two or more inorganic fillers selected from alumina having a hydroxyl group, an ionic layered silicate, and a hydrophilic titania is formed into a solution-immersion phase. The polymer electrolyte complex membrane of claim 1 or 2, wherein the hydrophilized porous polymer support is a phase change membrane having a pore size in the range of 10 to 1000 mm 3. The method of claim 1, wherein the anionic polymer forming the matrix doped layer Anionic polysaccharide-based polymer alone, or a polar organic mixture separation polymer, characterized in that the anionic polysaccharide-based polymer and mixed with one or two or more selected from linear polyacrylic acid, sodium polystyrene sulfonate and polyvinyl alcohol Electrolyte complex membrane. The method of claim 4, wherein the anionic polysaccharide-based polymer It is one or two or more selected from agarose, carrageenan, alginate, cellulose, dextran, glycosaminoglycans, teicophosphates, chisilanes, polysaccharides and agarose sulfates. A polymer electrolyte complex membrane for separating polar organic mixtures. The method of claim 1, wherein the cationic metal is a divalent ion selected from barium, cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, mercury, strontium, nickel, zinc and tin, or aluminum, chromium and iron. Polymer electrolyte complex membrane for polar organic mixture separation, characterized in that the trivalent ions selected from. One or two or more polymers selected from polysulfone, polyisulfone, polyisimide, polyamide, polyacrylonitrile, and polyvinylidene fluoride, and one selected from alumina, ionic layered silicate, and hydrophilic titania having hydroxyl groups A step of forming a hydrophilized porous polymer support prepared by phase-transferring a polymer mixed solution prepared by mixing a species or two or more inorganic fillers into a solution-immersion type; Coating the surface of the hydrophilized porous support with an anionic polymer solution to form an anionic polymer matrix doping layer; And 3-step coating of an aqueous solution of a bivalent trivalent cation metal on the surface of the matrix doped layer to form a layered film by anionic and cation reacting on the surface of the doped layer of the matrix coating layer. Method for producing a polymer electrolyte complex membrane for polar organic mixture separation comprising a. The method of claim 7, wherein the matrix doped layer has a thickness of 0.01 to 20 μm. 8. The polar organic mixture separation of claim 7, further comprising, after forming the coating layer, further performing a vapor-permeation heat treatment in a closed space at a temperature of 90 to 120 DEG C for 1 to 4 hours. Method for producing a polymer electrolyte complex membrane for use.

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