Preparation method and application of solvent-resistant polyamide composite membrane

Abstract

The invention discloses a preparation method and application of a solvent-resistant polyamide composite membrane. The method comprises the following preparation steps: taking a triamino compound containing a polar group and a diacyl chloride compound as reaction monomers, and preparing a polyamide polymer by adopting a solvent-free mechanical grinding method; stirring the polymer in an organic solvent, and ultrasonically crushing to obtain a membrane casting solution; and coating the membrane casting solution on a solvent-resistant base membrane, and drying to obtain the solvent-resistant polyamide composite membrane. The solvent-resistant polyamide composite membrane prepared by the preparation method disclosed by the invention has good pore channel uniformity and size adjustability; the high-activity polar group provides good selectivity for multi-system separation, and compared with the traditional easily aged polyamide membrane, the prepared polyamide membrane has good long-term stability; the green solventless preparation process has high environmental friendliness, and provides a choice for large-scale application of polyamide.

Description

Technical Field

[0001] The invention relates to a method for preparing a solvent-resistant polyamide composite membrane and application thereof, and belongs to the field of polymer preparation technology, green energy saving and environmental protection, the field of high molecular polymers, and particularly the field of membrane separation. Background Art

[0002] In the field of ultra-clean high-purity organic system or binary azeotropic system separation, since simple distillation cannot achieve the extraction and separation of ultra-pure substances, membrane separation has become a promising alternative for the separation of pure organic systems or azeotropic mixtures. Polymer membranes have received extensive attention in the separation field due to their simple preparation process, adjustable chemical properties, and ease of large-scale application. However, since the solubility parameters of polymer membranes and some organic solvents are relatively close, based on the principle of "like dissolves like", polymer membranes will produce a certain amount of swelling. Swelling will increase the distance between polymer membrane molecules, thereby changing the retention of small molecules, and ultimately leading to a decrease in separation performance.

[0003] Polyamide membranes have been widely used in the field of gas separation due to their rigid skeleton structure and adjustable porous structure. For liquid separation, this structure can provide a higher free volume and abundant mass transfer channels for liquid separation; at the same time, the rigid skeleton can strengthen the binding between polymer molecular segments, greatly improving the swelling resistance of the polymer in the form of strong chemical bond interaction rather than weak interaction forces such as intermolecular hydrogen bonding and van der Waals forces. Summary of the invention

[0004] The technical problem to be solved by the present invention is that traditional distillation cannot separate ultra-clean high-purity organic systems or binary azeotropic systems, and there are problems such as great difficulty in processing and high energy consumption. The separation by membrane separation method also has problems such as low anti-swelling property of polymer membrane and poor separation performance. The present invention provides a method for preparing a solvent-resistant polyamide composite membrane to make up for the deficiencies of the prior art and meet the needs of production and life.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A method for preparing a solvent-resistant polyamide composite film, the method comprising the following steps:

[0007] (1) using an amino compound and a diacyl chloride compound as reaction monomers, mixing and grinding the two compounds and an acid binding agent by mechanical grinding to obtain a crude product; washing the crude product with deionized water and methanol, respectively, precipitating, filtering and drying to obtain a solvent-resistant polyamide polymer;

[0008] (2) The polymer is stirred in an organic solvent and ultrasonically crushed to obtain a casting solution; the casting solution is coated on a solvent-resistant base film and dried to obtain a solvent-resistant polyamide composite film.

[0009] In the above preparation method: in step (1), the amino compound is selected from parasmin, tris(4-aminophenyl)amine, 1,3,5-triaminobenzene, 2,7,15-triamino-3,6,14-tribromotriptylene, 4,4'4"-triaminotriphenylmethane, 2,6,14-triaminotriptylene, 2,7,14-triaminotriptylene, 4,5,6-triaminopyrimidine, 2,4,5-triaminopyridine, 3,4,5-triaminopyridine, 2,4,6-triamino-5-pyrimidinecarbonitrile, 2,4,5-triamino-6-chloropyrimidine, 2,3,4-triaminopyridine, 1,3,5-tris(aminomethyl)-2,4,6-triethylbenzene, 4, Any one of 5,6-triamino-2(1h)-pyrimidinone, 2,5,6-triamino-3-methylpyrimidin-4(3H-)-one, 1,3,5-triaminobenzene, 3,5,7-triamino-1,2,4-thiazolo[4,3-a]-1,3,5-thiazine, 1,4,5-triamino-8-(methylamino)anthraquinone, 1,4,5-triamino-2,3-dichloro-8-hydroxyanthraquinone, 1,4,5-triaminoanthraquinone, 2-mercapto-4,5,6-triaminopyrimidine, triamterene, 2,4,6-quinazolinetriamine, 2-methylthiopyrimidine-4,5,6-triamine, 4-aminophenolphosphorothioate, and tris(3-aminopropyl)amine;

[0010] Preferably, the amino compound is selected from any one of pararubin, tris(4-aminophenyl)amine, 4,4'4"-triaminotriphenylmethane, 2,6,14-triaminotriptylene, 2,7,14-triaminotriptylene, 2,3,4-triaminopyridine and 1,3,5-triaminobenzene.

[0011] In the above preparation method: in step (1), the diacyl chloride compound is selected from 4,4-oxydi(benzoyl chloride), 4,4'-dichlorodiphenyl ether, 2,6-pyridine dicarboxylic acid chloride, phthaloyl chloride, chloropivaloyl chloride, 2,6-naphthalene dicarboxylic acid dichloride, 4,4'-benzil chloride, 2,3,5,6-tetrachloroterephthaloyl chloride, 2,2'-oxydiacetyl chloride, 2,5-di(chloroformyl)thiophene , diethylene glycol bischloroformate, diethylmalonyl dichloride, terephthaloyl chloride, 3,5-pyridine dicarbonyl chloride, 2,5-furan dicarbonyl chloride, azobenzene-4,4'-dicarbonyl chloride, 1,3-adamantanedicarboxylic acid chloride, ethyl oxalyl chloride, isopropylphosphinoyl chloride, dimethylmalonyl chloride, phenylphosphinoyl chloride, methylenebis(phosphinoyl chloride), tetrakis(2-chloroethyl)phosphinoyl chloride, hexafluoroglutaryl chloride 、 Any one of 1,4-cyclohexanediyl chloride, 2,6-naphthalene dichloride, and isophthaloyl chloride;

[0012] Preferably: the diacyl chloride compound is selected from 4,4-oxybis(benzoyl chloride), hexafluoroglutaryl chloride 、 Any one of 1,4-cyclohexanedicarboxylic acid chloride, 2,6-naphthalene dicarboxylic acid chloride, isophthaloyl dichloride, azobenzene-4,4'-dicarbonyl chloride, and 1,3-adamantanedicarboxylic acid chloride;

[0013] The molar ratio of the amino compound to the diacyl chloride compound is 1:0.5-2.

[0014] In the above preparation method: in step (1), the acid binding agent is any one or two of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium bicarbonate, and potassium carbonate;

[0015] The mass ratio of the acid binding agent to the amino-containing compound is 1:0.1 to 10.0;

[0016] Preferably, the mass ratio of the acid binding agent to the amino-containing compound is 1:0.3-3.0.

[0017] In the above preparation method: in step (1), in a nitrogen atmosphere and a temperature environment of 0-50°C, the mechanical grinding speed is 10-500r / min, and the grinding reaction time is 2-240min;

[0018] Preferably: the grinding speed is 20-90 r / min; the grinding reaction time is 10-60 min.

[0019] In the above preparation method: in step (2), the viscosity of the casting liquid is 0-10000 mPa·s; preferably, the viscosity of the casting liquid is 80-2000 mPa·s.

[0020] In the above preparation method: in step (2), the method of drying the organic solvent is air drying or vacuum drying; the temperature range of air drying is 30 to 240°C.

[0021] A solvent-resistant polyamide composite film is prepared by adopting the method.

[0022] In the technical solution of the present invention, the solvent-resistant polyamide composite membrane prepared by the above method is used for pre-membrane pressure purification of ultra-clean high-purity organic systems or separation of binary mixtures;

[0023] The ultra-clean high-purity organic system is at least two of isopropanol, ethanol, methanol, acetone, 2-butanone, propylene glycol methyl ether, and propylene glycol methyl ether acetate;

[0024] Binary systems include but are not limited to: dimethyl carbonate / methanol, isopropanol / water, toluene / water, ethanol / water, methanol / methyl tert-butyl ether;

[0025] The feed temperature on the raw material side is -10~80℃, and the pressure is 0.05~5.0MPa;

[0026] Preferably, the feed temperature on the raw material side is 10-40°C and the pressure is 0.5-3 MPa.

[0027] In the technical solution of the present invention, the pressures mentioned are gauge pressures unless otherwise specified.

[0028] Beneficial effects of the present invention: The solvent-resistant polyamide composite membrane proposed in the present invention has the advantages of strong resistance to swelling and excellent separation performance. The pure organic system is mainly aimed at the general organic high-purity reagents in the "bottleneck" chip manufacturing. The swelling-resistant polyamide composite membrane can accurately intercept large-sized particles and VOCs, and realize the precise purification of high-purity organic system reagents. In the binary azeotropic system, the difference in molecular dynamics diameter is utilized, and the pore size of the solvent-resistant polyamide is precisely controlled, and the distribution of the pore size is controlled to achieve efficient purification of small molecules or low-boiling point organic solvents in the binary azeotropic system. This technology has the advantages of breaking through foreign technology blockades and independent control of the entire process. The protection of the present invention is conducive to accelerating and improving the technical advantages in this field, and therefore has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a surface image of the polyamide composite membrane in Example 1 of the present invention;

[0030] Figure 2 It is a cross-sectional view of the polyamide composite membrane in Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with embodiments, but the protection scope of the present invention is not limited thereto:

[0032] Example 1

[0033] The temperature was 0°C, pararubin (0.3 g, 1 mmol) was weighed and placed in a mortar, and then the mortar was transferred to a glove box filled with nitrogen. 0.5 g K 2 CO 3 As an acid-binding agent, it was mixed evenly with para-red, and 4,4-oxydi(benzoyl chloride) (0.44 g, 1.5 mmol) was added into a mortar and ground at a grinding speed of 60 r / min. After grinding for 30 minutes, the powder was poured into methanol for cleaning, and the washing liquid was stirred evenly and filtered. The operation was repeated three times to obtain a polymer filter cake. The filter cake was placed in a forced air drying oven and dried at 60°C to obtain a polymer powder.

[0034] Weigh 0.15g polymer powder into a 20mL inoculum bottle, add 5mL N,N-dimethylformamide solvent, stir for 24h until dissolved, ultrasonically crush and disperse the casting liquid for 45min, and obtain a casting liquid with a viscosity of 150mPa·s. After vacuum degassing, apply it on the nylon base film. Move the coated film parallel to an 80℃ forced air drying oven and dry it for 48h to fully evaporate the solvent. Vacuum dry it at 80℃ for 24h to remove the residual solvent in the film, and you can get a solvent-resistant polyamide composite film. The surface and cross section of the prepared film are as shown in the attached figure. Figure 1 and 2 shown.

[0035] The thickness of the coated dry film layer was controlled to be 1.176 μm by a textured scraper. The prepared solvent-resistant polyamide composite membrane was used for ultra-clean high-purity organic solvent separation. The raw materials were G2 grade isopropanol and ethanol solutions.

[0036] By adjusting the temperature and pressure on the feed side, the product purity is shown in the following table.

[0037] raw material Feed temperature (℃) Feed pressure (MPa) Product Purity Isopropyl alcohol 10 1.5 G4 Grade Isopropyl alcohol 20 2 G4 Grade Isopropyl alcohol 30 2.5 G5 Grade Isopropyl alcohol 40 3 G4 Grade Ethanol 10 0.5 G4 Grade Ethanol 20 1 G5 Grade Ethanol 30 1.5 G4 Grade Ethanol 40 2 G4 Grade

[0038] Example 2

[0039] Compared with Example 1, different amino-containing compounds were used. The details are shown in the following table. The other conditions for preparing the solvent-resistant polyamide film were the same as those in Example 1.

[0040] A 1.174 μm solvent-resistant polyamide composite membrane was used to separate feed concentrations of 30% DMC and 70% methanol. The feed side temperature was 30°C and the pressure was 2 MPa. The flux and separation factor as well as the corresponding amino monomer changes are shown in the following table.

[0041] Amino monomer name Molar amount <![CDATA[Flux (kg / (m 2 ·h))]]> Separation Factor Tris(4-aminophenyl)amine 1mmol 11.25 13.00 4,4'4"-Triaminotriphenylmethane 1mmol 10.98 13.89 2,6,14-Triaminotriptycene 1mmol 11.64 12.91 2,7,14-Triaminotriptycene 1mmol 12.13 12.42 2,3,4-Triaminopyridine 1mmol 11.03 13.66 1,3,5-Triaminobenzene 1mmol 11.19 13.41

[0042] Example 3

[0043] Compared with Example 1, different diacyl chloride compounds were used, as shown in the following table. Specific parameters are as follows:

[0044] A 1.17 μm solvent-resistant polyamide composite membrane was used to separate feed concentrations of 30% DMC and 70% methanol. The feed side temperature was 30°C and the pressure was 2 MPa. The flux and separation factor as well as the corresponding changes in acyl chloride monomers are shown in the following table.

[0045]

[0046] Example 4

[0047] Compared with Example 1, different acid-binding agents were used. The specific parameters are as follows: The remaining conditions for preparing the solvent-resistant polyamide membrane are the same as those in Example 1. The prepared membrane was used for isopropanol dehydration, wherein the feed concentration was 68% isopropanol and 32% water. The feed side temperature was 35°C and the pressure was 2.5 MPa. The flux and separation factor and the corresponding results of the acid-binding agent changes are shown in the following table.

[0048] Acid binding agent name Mass(g) <![CDATA[Flux (kg / (m 2 ·h))]]> Separation Factor Potassium carbonate 0.5 4.03 18.75 Sodium carbonate 0.5 5.10 16.43 Sodium bicarbonate 0.5 4.74 17.16 Potassium bicarbonate 0.5 4.20 18.13 Sodium hydroxide 0.5 6.31 14.25 Potassium hydroxide 0.5 7.11 13.44

[0049] Example 5

[0050] Compared with Example 1, a different reaction temperature, namely the ambient temperature during the mechanical grinding process, was used. The specific parameters are as follows: The remaining conditions for preparing the solvent-resistant polyamide membrane are the same as those in Example 1.

[0051] The prepared membrane was used for the separation of dimethyl carbonate and methanol, where the feed concentration was 70% methanol and 30% dimethyl carbonate. The feed side temperature was 20°C and the pressure was 1.5 MPa. The flux and separation factor and the corresponding reaction temperature changes are shown in the following table.

[0052] Reaction temperature (℃) <![CDATA[Flux (kg / (m 2 ·h))]]> Separation Factor 0 (Example 1) 10.36 13.17 5 12.48 11.59 10 13.31 11.00 20 13.48 10.15 40 13.59 10.14 50 13.61 10.14

[0053] Example 6

[0054] Compared with Example 1, different grinding speeds were adjusted during the mechanical grinding process.

[0055] The rest of the preparation process of the solvent-resistant polyamide membrane is the same as that of Example 1.

[0056] The prepared membrane was used for the separation of dimethyl carbonate and methanol, where the feed concentration was 15% methanol and 85% methyl tert-butyl ether. The feed side temperature was 20°C and the pressure was 1.5 MPa. The flux and separation factor and the corresponding reaction temperature changes are shown in the following table.

[0057] Grinding speed (r / min) <![CDATA[Flux (kg / (m 2 ·h))]]> Separation Factor 30 1.47 924 40 1.53 933 50 1.55 936 60 (Example 1) 1.60 941 70 1.57 938 80 1.55 937 90 1.54 935

[0058] Example 7

[0059] Compared with Example 1, different reaction times, i.e. different grinding times, were adjusted during the mechanical grinding process. The specific parameters are as follows:

[0060] The rest of the preparation of solvent-resistant polyamide membrane is the same as Example 1. The prepared solvent-resistant polyamide composite membrane is used for ultra-clean high-purity reagent separation, the raw material is G2 grade isopropanol, the raw material temperature is 30° C., the pressure is 1.5 MPa, and the purity of the obtained product is shown in the following table.

[0061] Reaction time (min) Product Grade 10 G3 Grade 15 G4 Grade 20 G4 Grade 25 G4 Grade 30 (Example 1) G5 Grade

[0062] Example 8

[0063] Compared with Example 1, the effects of different polymer contents and corresponding casting solution viscosities on separation performance were compared. The specific parameters are as follows:

[0064] The membrane was used for ultra-clean high-purity reagent separation. The raw material was G2 grade propylene glycol monomethyl ether. The raw material temperature was 40°C and the pressure was 2.9 MPa. The purity of the obtained product is shown in the following table.

[0065] Polymer mass (g) Viscosity Product Purity 0.1 80 G2 Level 0.15 150 G2 Level 0.25 320 G3 Grade 0.3 500 G2 Level

Claims

1. A method for preparing a solvent-resistant polyamide composite film, characterized in that: The method comprises the following steps: (1) using an amino compound and a diacyl chloride compound as reaction monomers, mixing and grinding the two compounds and an acid binding agent by mechanical grinding to obtain a crude product; washing the crude product with deionized water and methanol, respectively, precipitating, filtering and drying to obtain a solvent-resistant polyamide polymer; (2) The polymer is stirred in an organic solvent and ultrasonically crushed to obtain a casting solution; the casting solution is coated on a solvent-resistant base film and dried to obtain a solvent-resistant polyamide composite film.

2. The preparation method according to claim 1, characterized in that: In step (1), the amino compound is selected from paracyanine, tris(4-aminophenyl)amine, 1,3,5-triaminobenzene, 2,7,15-triamino-3,6,14-tribromotriptylene, 4,4'4"-triaminotriphenylmethane, 2,6,14-triaminotriptylene, 2,7,14-triaminotriptylene, 4,5,6-triaminopyrimidine, 2,4,5-triaminopyridine, 3,4,5-triaminopyridine, 2,4,6-triamino-5-pyrimidinecarbonitrile, 2,4,5-triamino-6-chloropyrimidine, 2,3,4-triaminopyridine, 1,3,5-tris(aminomethyl)-2,4,6-triethylbenzene, 4,5,6-triaminopyridine, Any one of triamino-2(1h)-pyrimidinone, 2,5,6-triamino-3-methylpyrimidin-4(3H-)-one, 1,3,5-triaminobenzene, 3,5,7-triamino-1,2,4-thiazolo[4,3-a]-1,3,5-thiazine, 1,4,5-triamino-8-(methylamino)anthraquinone, 1,4,5-triamino-2,3-dichloro-8-hydroxyanthraquinone, 1,4,5-triaminoanthraquinone, 2-mercapto-4,5,6-triaminopyrimidine, triamterene, 2,4,6-quinazolinetriamine, 2-methylthiopyrimidine-4,5,6-triamine, 4-aminophenolphosphorothioate, and tris(3-aminopropyl)amine; Preferably, the amino compound is selected from any one of pararubin, tris(4-aminophenyl)amine, 4,4'4"-triaminotriphenylmethane, 2,6,14-triaminotriptylene, 2,7,14-triaminotriptylene, 2,3,4-triaminopyridine and 1,3,5-triaminobenzene.

3. The preparation method according to claim 1, characterized in that: In step (1), the diacyl chloride compound is selected from 4,4-oxydi(benzoyl chloride), 4,4'-dichlorodiphenyl ether, 2,6-pyridine dicarboxylic acid chloride, phthaloyl chloride, chloropivaloyl chloride, 2,6-naphthalene dicarboxylic acid dichloride, 4,4'-benzil chloride, 2,3,5,6-tetrachloroterephthaloyl chloride, 2,2'-oxydiacetyl chloride, 2,5-di(chloroformyl)thiophene, diethylene glycol dichloride, Alcohol bischloroformate, diethylmalonyl dichloride, terephthaloyl chloride, 3,5-pyridine dicarbonyl chloride, 2,5-furan dicarbonyl chloride, azobenzene-4,4'-dicarbonyl chloride, 1,3-adamantanedicarboxylic acid chloride, ethyl oxalyl chloride, isopropylphosphonic acid dichloride, dimethylmalonyl chloride, phenylphosphonic acid dichloride, methylenebis(phosphonic acid dichloride), tetrakis(2-chloroethyl)phosphonic acid dichloride, hexafluoroglutaryl chloride 、 Any one of 1,4-cyclohexanediyl chloride, 2,6-naphthalene dichloride, and isophthaloyl chloride; Preferably, the diacyl chloride compound is selected from 4,4-oxybis(benzoyl chloride), hexafluoroglutaryl chloride 、 Any one of 1,4-cyclohexanedicarboxylic acid chloride, 2,6-naphthalene dicarboxylic acid chloride, isophthaloyl chloride, azobenzene-4,4'-dicarbonyl chloride, and 1,3-adamantanedicarboxylic acid chloride; The molar ratio of the amino compound to the diacyl chloride compound is 1:0.5-2.

4. The preparation method according to claim 1, characterized in that: In step (1), the acid binding agent is any one or two of sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium bicarbonate, and potassium carbonate; The mass ratio of the acid binding agent to the amino-containing compound is 1:0.1 to 10.0; Preferably, the mass ratio of the acid binding agent to the amino-containing compound is 1:0.3-3.

0.

5. The preparation method according to claim 1, characterized in that: In step (1), in a nitrogen atmosphere and a temperature environment of 0-50° C., the mechanical grinding speed is 10-500 r / min, and the grinding reaction time is 2-240 min; Preferably: the grinding speed is 20-90 r / min; the grinding reaction time is 10-60 min.

6. The preparation method according to claim 1, characterized in that: In step (2), the viscosity of the casting solution is 0-10000 mPa·s; preferably, the viscosity of the casting solution is 80-2000 mPa·s.

7. The preparation method according to claim 1, characterized in that: In step (2), the organic solvent is dried by air drying or vacuum drying; the air drying temperature range is 30 to 240°C.

8. A solvent-resistant polyamide composite film, characterized in that: The method is prepared by any one of claims 1 to 8.

9. The solvent-resistant polyamide composite membrane prepared according to claim 1 is used for pre-membrane pressure purification of ultra-clean high-purity organic systems or separation of binary mixtures; The ultra-clean high-purity organic system is at least two of isopropanol, ethanol, methanol, acetone, 2-butanone, propylene glycol methyl ether, and propylene glycol methyl ether acetate; Binary systems include but are not limited to: dimethyl carbonate / methanol, isopropanol / water, toluene / water, ethanol / water, methanol / methyl tert-butyl ether; The feed temperature on the raw material side is -10~80℃, and the pressure is 0.05~5.0MPa; Preferably, the feed temperature on the raw material side is 10-40°C and the pressure is 0.5-3 MPa.

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