KR20020003424A - Zeolite-filed glassy polymer membranes with 2,4,6-triaminopyrimidine and its preparation method - Google Patents

Abstract

PURPOSE: A method for fabricating a zeolite-filed glassy polymer membrane containing 2,4,6-triaminopyrimidine as a compatibilizer to induce hydrogen bonding between zeolite and glassy polymer is provided to obtain a separation membrane without permitting of interfacial voids between glassy polymer and zeolite but higher gas permselectivity for carbon dioxide gas exhausted from internal engine. CONSTITUTION: In the present invention, zeolite is selected from zeolite A, X, Y, ZSM-5, mordenite, chabazite, clinoptilolite, silicalite-1, SZ350HUA, SZ390HUA, which have a Si/Al ratio varying from 1 to 500; glassy polymer is a mixture containing at least two polymers selected from polyimide, polyamide, polyamideimide, polysulfone polyarylate, polycarbonate, polyphenylene oxide. In one embodiment of the present invention, PI (polyimide) solution is first prepared by dissolving PI in DMSO (dimethyl sulfoxide), and then zeolite and TAP are added in turn with the ratio 3:7. The solutions are cast on a glass plate with a cast knife of 150μm clearness, and then dried for 12hrs at 80deg.C followed by drying 6hrs at 100deg.C. After the membranes are detached form the glass plate, residual solvents are removed by drying for 3days in a vacuum oven kept at 120deg.C.

Description

Separation membrane prepared by adding zeolite to glassy polymer using 2,4,6-triaminopyrimidine and its preparation method {Zeolite-filed glassy polymer membranes with 2,4,6-triaminopyrimidine and its preparation method}

The present invention relates to a separator prepared by adding zeolite to a glassy polymer using 2,4,6-triaminopyrimidine, and a method for preparing the same, and is effective in a simple process using a compatibilizer to add zeolite to a glassy polymer. A blend was obtained to prepare a membrane having a high gas selectivity therefrom and to prepare a vitreous polymer membrane containing zeolite without interfacial voids between the vitreous polymer and the zeolite.

The first attempt to introduce zeolites into polymers was by Te Hennepe et al. (US Pat. No. 4,925,562), and the introduction of zeolites into rubbery polymers to produce pervaporation membranes.

Currently, research is underway to use zeolites in gas separation membranes.

In other words, the research to date has reached the limit of making a gas separation membrane having effective permeability and selectivity only by the polymer itself, so that a better separation membrane is obtained by using zeolite.

So far, attempts to introduce zeolites into polymers can be broadly divided into methods of introducing zeolites into rubbery polymers and methods of introducing zeolites into glassy polymers.

In general, rubbery polymers have high permeability and low selectivity, while glassy polymers have low permeability and high selectivity. When the zeolite is added to the rubbery polymer, the interfacial void between the polymer and the zeolite does not occur, but the selectivity does not increase so much, and when the zeolite is added to the glassy polymer, there is a problem that the interfacial void is generated (J. Appl. Polym. Sci., Vol. 54, p. 409, 1994). If the zeolite is added to the glassy polymer and only the interfacial void can be effectively removed, high permeability and selectivity can be obtained at the same time.

In the case of the glassy polymer membrane containing zeolite, several methods have been attempted to solve this problem. One method is to blend the glassy polymer and the zeolite using an extrusion method (J. Membr. Sci., Vol. 93, p. 283, 1994), and the other is to use silylation (J. Phys. Chem., Vol. 100, p. 3753, 1996).

In the former case, zeolite 13X powder was mixed in polysulfone pellets and extruded twice at 340 ° C., followed by vacuum drying at 200 ° C. for 16 hours after each extrusion. In the latter case, the zeolite is silylated with an aminoalkoxysilane by chemical reaction, and then a silylated zeolite is added and cured at 220 ° C. while polymerizing polyamic acid, a precursor of polyimide. It was.

However, the extrusion method yielded almost the same level of permeability and selectivity as pure polymer membranes. In the latter case, there was no difference compared to the addition of silylated compounds to the polymer in the xylene adsorption experiment. However, it is difficult to determine the presence or absence of interfacial voids between the polymer and the zeolite simply by adsorption experiments.

In addition to the extrusion method, the uniform distribution of the zeolite becomes a problem, and high temperature processing may affect the polymer.

In addition, the method using the silylation reaction has a disadvantage in that it is difficult to control the silylation reaction as a monolayer on the zeolite surface and the silylation reaction conditions are difficult.

The present invention has been made in view of the above-described conventional problems, and by using a compatibilizer to add zeolite to a glassy polymer, an effective blend can be obtained by a simple process, and a membrane having high gas selectivity can be prepared therefrom. It is an object of the present invention to prepare a vitreous polymer membrane containing zeolite without interfacial voids between the polymer and the zeolite.

In order to achieve the above object, the present invention has a low affinity between the glassy polymer and the zeolite. Thus, when the two are mixed to prepare a membrane in which the zeolite is dispersed in the glassy polymer, interfacial voids are generated between the two. When interfacial voids occur, most of the materials that permeate the separator, such as gas, pass through these voids, and thus the selective resolution as a separator is lost. Therefore, a stable blend can be obtained only by introducing a method that can increase the interaction between them. That is, in general, polymer blends that do not mix well with each other often use a compatibilizer to increase miscibility, so a compatibilizer that can effectively work between the glassy polymer and the zeolite can be used. The interface between the two It was researched and developed with the idea that the voids can be removed.

In the present invention, TAP (2,4,6-triaminopyrimidine, Acros Organics Co., Ltd.) was used as a compatibilizer, and TAP has three primary amine groups to induce strong hydrogen bonds between various substances. The functional group capable of hydrogen bonding with the amine group of TAP is hydroxyl group, carboxyl group, amine group, carbonyl group, sulfone group, cyan group ( cyanide group), TAP can be used as a compatibilizer when the glassy polymer and zeolite have such functional groups.

The glassy polymer having the functional group includes polyimide, polyamide, polyimideamide, polysulfone, polycarbonate, polyarylate, polyphenylene oxide, cellulose, cellulose acetate, and the like. Matrimide 5218 CH polyimide, Ciba-Geigy Co., Ltd.) was used.

All kinds of zeolites can be used, in particular 5A (Aldrich Chemical Company Inc.), 13X (Aldrich Chemical Company Inc.), NaY (Aldrich Chemical Company Inc.) was used.

Polyimide has a carbonyl group, and zeolite has a hydroxyl group on its surface.

Therefore, hydrogen bonding is possible between these reactors and the TAP, and by using this, the affinity between the zeolite and the glassy polymer can be increased and a separator can be prepared without interfacial pores.

In addition, when the Si / Al ratio (2) or more, simply dissolved in a solvent such as dimethyl sulfoxide with a polyimide and zeolite alone to form a mixed solution, a phase separation occurs and the polyimide layer and the zeolite layer appears.

In this case, the addition of TAP does not cause phase separation, and a stable mixed solution can be obtained.

In addition, preferred solvents in the present invention include dimethyl sulfoxide and dimethylformamide, but the former has better solubility in TAP.

Looking at the present invention in more detail as follows.

First, in the present invention, the ratio of polyimide and zeolite under a selected solvent is fixed at 7: 3 by weight ratio, and then, for zeolite 13X, TAP is 1/2 of zeolite weight, 2/3 for zeolite NaY, and 5 for zeolite 5A. The solution is prepared by adding / 6, and forming the solution in the form of a separator such as a flat film, and then evaporating the solvent at a temperature of 20-150 ° C., particularly 80-100 ° C., to prepare a membrane free of interfacial pores. Therefore, the amount of TAP used in the present invention is preferably used above the concentrations mentioned above depending on the type of zeolite.

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

Examples 1 to 3

Polyimide and zeolite 13X are dissolved in dimethyl sulfoxide (Junsei Chemical Co., Ltd.) in a 7: 3 weight ratio to make a 20% by weight mixed solution.

At this time, the polyimide was completely dissolved, and then zeolite was added thereto and stirred for at least one day until uniformly dispersed.

The mixed solution thus prepared was added with 33-34% by weight of TAP based on the weight of the zeolite and stirred until it was completely dissolved to form another mixed solution, which was cast to a thickness of 150 μm on a glass plate using a casting knife.

Then, the solution was cast on a glass plate and dried at 80 ° C. for 12 hours and at 100 ° C. for 6 hours to evaporate the solvent, and then separated from the glass plate and dried for 3 days under vacuum at 100 ° C. to remove residual solvent to prepare a separator. .

Here, the permeability to the gas of the separator prepared according to an embodiment of the present invention as described above was measured using a low-pressure constant-volume method.

That is, the plate-type membrane is fixed to the membrane holder consisting of two parts of stainless steel, and the upper and lower pressures of the membrane are evacuated to 0.014 mmHg or less using a vacuum pump while maintaining the temperature at 35 ° C. All remaining gas was removed.

Then, the vacuum pump was shut off, and the gas to be measured at the upper end of the separator was injected with a gauge pressure of 760 mmHg.

Gas passing through the membrane is collected in the gas collector connected to the lower end of the membrane, thereby increasing the pressure in the gas collector.

This pressure increase in the gas collector was measured using a pressure transducer, and the gas permeability was measured from the slope of the pressure increase rate with respect to time at a time when the rate of pressure increase in the gas collector with respect to time is constant.

Gases measured permeability are CO ₂ , O ₂ , N ₂ , and measured gas permeability is expressed as P (X), and the unit is indicated as Barrer in Table 1 below (1 Barrer = 10 ^-10). cm ³ (STP) cm / cm ² sec cmHg).

Example number Weight ratio of TAP to zeolite (%) P (CO ₂ ) (barrer) P (O ₂ ) (barrer) P (N ₂ ) (barrer) P (CO ₂ ) / P (N ₂ ) P (O ₂ ) / P (N ₂ ) One 33 2.199 0.556 2.199 66.04 16.70 2 34 0.764 0.138 0.764 70.74 12.78 3 35 0.516 0.110 0.516 79.38 16.92

Comparative Examples 1 and 2

In order to compare the permeation performance of the separator prepared in Example 1, the polyimide / zeolite prepared in the same manner as in Example 1 without adding the permeability (US Patent No. 5015270) and TAP of pure polyimide membrane ( 7: 3 weight ratio) The permeability of the separator is shown in Table 2.

Comparative example number Membrane Type P (CO ₂ ) (barrer) P (O ₂ ) (barrer) P (N ₂ ) (barrer) P (CO ₂ ) / P (N ₂ ) P (O ₂ ) / P (N ₂ ) One Polyimide 7.41 1.35 0.20 37.05 6.75 2 Polyimide / Zeolite 13X 81.6 41.54 37.09 2.2 1.12

Examples 4-6

The polyimide, zeolite 5A and TAP were dissolved in dimethyl sulfoxide in a 7: 3: 2.5 to 2.6 weight ratio, a solution was prepared in the same manner as in Example 1, a membrane was prepared therefrom, and the gas permeability was measured. 3 is shown.

Example number Weight ratio of TAP to zeolite (%) P (CO ₂ ) (barrer) P (O ₂ ) (barrer) P (N ₂ ) (barrer) P (CO ₂ ) / P (N ₂ ) P (O ₂ ) / P (N ₂ ) 4 83 0.0831 0.020 0.0011 75.55 18.18 5 85 0.0775 0.0184 0.0012 64.58 15.33 6 87 0.0690 0.0176 0.00098 70.41 17.96

Examples 7-9

In the case of zeolite NaY, polyimide and TAP are first dissolved in dimethyl sulfoxide at a weight ratio of 1: 0.29 to 0.30, and then dissolved in zeolite to make a uniform mixed solution. At this time, the polyimide and zeolite NaY are 7: 3 by weight, and in the state excluding TAP, the polyimide and zeolite are a mixed solution of 20% by weight. The separation membrane was prepared in the same manner as in Example 1 using the prepared mixed solution, and the gas permeability was measured. The results are shown in Table 4.

Example Number % Weight ratio of TAP to zeolite P (CO ₂ ) (barrer) P (O ₂ ) (barrer) P (N ₂ ) (barrer) P (CO ₂ ) / P (N ₂ ) P (O ₂ ) / P (N ₂ ) 7 67 0.324 0.0704 0.0046 70.43 15.30 8 68 0.215 0.0467 0.0032 67.19 14.59 9 70 0.166 0.0431 0.0025 66.4 17.24

Example 10

Polyimide, zeolite 13X and TAP were dissolved in dimethyl sulfoxide in a weight ratio of 7: 3: 1.47, a solution was prepared in the same manner as in Example 1, a membrane was prepared therefrom, and the permeability of various gases was measured. Table 5 shows.

Example number Gas permeability (barrer) P (He) P (CO ₂ ) P (O ₂ ) P (N ₂ ) P (CH ₄ ) 10 4.969 0.640 0.124 0.00865 0.00481

Using the commercially available agent TAP When introducing the zeolite in the glassy polymer in accordance with the present invention, there is no interfacial gap through effective hydrogen bonding between the polymer and the zeolite with a gas, such as He, H _2, CO _2, O _2, N ₂ When the two-component or multi-component gas mixture is made of separation membrane having a high permeability can be prepared.

The membrane prepared by the present invention has an advantage of exhibiting a much higher selectivity than a polyimide membrane not added with zeolite or a membrane made of only polyimide and zeolite. In addition, the method of preparing the membrane is simple, and since the solution casting method is used instead of extrusion, it is possible to apply to the production of a composite membrane using a coating.

In addition, since the present invention is applicable to all polymers capable of hydrogen bonding as well as polyimide, the present invention can be greatly applied to separate CO ₂ or O ₂ from various gas mixtures. In the case of introducing a membrane process for separating and recovering carbon dioxide from combustion exhaust gas by using a membrane, the membrane has a very high permeability, and is very innovative compared to other separation processes.

Claims (8)

Various kinds of glassy polymers each having a functional group such as hydroxyl group, carboxyl group, amine group, carbonyl group, sulfone group, sulfone group and cyanide group Zeolite is dissolved in a solvent such as dimethyl sulfoxide or dimethyl formamide in a weight ratio of about 7: 3 to form a mixed solution, and the functional groups and hydrogen of the polymer and zeolite are contained in the mixed solution based on the weight of the zeolite. After adding an appropriate amount of compatibilizer having a primary amine group to which it is bonded, it is stirred until it is completely dissolved, and then a mixed solution is formed again. The mixed solution is dried at about 80 to 100 ° C. to evaporate the solvent. Prepared by adding zeolite to the glassy polymer, characterized in that it is made by drying under vacuum at 100 ℃ for 3 days to remove residual solvent Separation membrane production method. The method of claim 1, A method for preparing a separator prepared by adding zeolite to a glassy polymer, wherein the glassy polymer is selected from polymers capable of hydrogen bonding with amine groups. The method of claim 2, The glassy polymer may be selected from polyimide, polyamide, polyamideimide, polysulfone polyarylate, polycarbonate, polyphenylene oxide, and a mixture of two or more thereof. Method for producing a separator. The method of claim 1, The zeolite is a separator prepared by adding a zeolite to the glassy polymer, characterized in that the Si / Al ratio is configured to select from 1 to 500 of the zeolite. The method of claim 4, wherein The zeolite is a separator prepared by adding zeolite to a glassy polymer, characterized in that configured to select from zeolite A, X, Y, ZSM-5, mordenite, chabazite, clinoptilolite, silicalite-1, SZ350HUA, SZ390HUA. The method of claim 1, The compatibilizer is prepared by adding zeolite to a glassy polymer, characterized in that configured to be selected from the amine-based compound capable of inducing hydrogen bonding between the zeolite and polyimide. The method of claim 6, The compatibilizer is 2,4,6-triaminopyrimidine (2,4,6-triaminopyrimidine), characterized in that the separation membrane prepared by adding zeolite to the glassy polymer, characterized in that. Various kinds of glassy polymers each having functional groups such as hydroxyl group, carboxyl group, amine group, carbonyl group, sulfone group, sulfone group and cyanide group The zeolite is dissolved in a solvent such as dimethyl sulfoxide or dimethyl formamide in a weight ratio of about 7: 3 to form a mixed solution, and the functional groups and hydrogen of the polyimide and zeolite are contained in the mixed solution based on the weight of the zeolite. After adding an appropriate amount of compatibilizer having a primary amine group to which it is bonded, it is stirred until it is completely dissolved, and then a mixed solution is formed again. The mixed solution is dried at about 80 to 100 ° C. to evaporate the solvent. And zeolite is added to the glassy polymer, which is formed by drying under vacuum at 100 ° C. for 3 days to remove residual solvent. A membrane.