CN110681266B - Method for separating small molecule solvent in aprotic polar solvent - Google Patents
Method for separating small molecule solvent in aprotic polar solvent Download PDFInfo
- Publication number
- CN110681266B CN110681266B CN201810733836.0A CN201810733836A CN110681266B CN 110681266 B CN110681266 B CN 110681266B CN 201810733836 A CN201810733836 A CN 201810733836A CN 110681266 B CN110681266 B CN 110681266B
- Authority
- CN
- China
- Prior art keywords
- solvent
- pervaporation membrane
- aprotic polar
- small molecule
- separating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
- B01D61/362—Pervaporation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/10—Supported membranes; Membrane supports
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/58—Other polymers having nitrogen in the main chain, with or without oxygen or carbon only
- B01D71/62—Polycondensates having nitrogen-containing heterocyclic rings in the main chain
- B01D71/64—Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1042—Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1046—Polyimides containing oxygen in the form of ether bonds in the main chain
- C08G73/105—Polyimides containing oxygen in the form of ether bonds in the main chain with oxygen only in the diamino moiety
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1046—Polyimides containing oxygen in the form of ether bonds in the main chain
- C08G73/1053—Polyimides containing oxygen in the form of ether bonds in the main chain with oxygen only in the tetracarboxylic moiety
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1067—Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
- C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G73/1067—Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
- C08G73/1071—Wholly aromatic polyimides containing oxygen in the form of ether bonds in the main chain
Abstract
The invention relates to a method for separating a small molecular solvent from an aprotic polar solvent, which mainly solves the problems of high requirements on equipment for separating the aprotic polar solvent, high energy consumption and complex device and process in the prior separation technology. The invention provides a method for separating small molecule solvent in aprotic polar solvent, which adopts a pervaporation membrane separation device and comprises a step of filling feed liquid of a mixture of the aprotic polar solvent and the small molecule solvent on the upper part of a pervaporation membrane, wherein a cavity at the lower part of the pervaporation membrane is connected with a vacuum device, so that the small molecule solvent in the feed liquid diffuses towards a cavity at the lower part through the pervaporation membrane, the pervaporation membrane is a polyimide pervaporation membrane comprising a supporting layer and a separating layer, the separating layer is positioned on the supporting layer, and the separating layer is a multilayer polyimide membrane.
Description
Technical Field
The invention relates to a method for separating a small molecular solvent from an aprotic polar solvent.
Background
Aprotic polar solvents such as Dimethylformamide (DMF), dimethylacetamide (DMAc) and the like are widely applied in the fields of pesticides, medicines, organic synthesis, synthetic leather and the like. The separation, recovery and treatment of an aprotic polar solvent such as an amide solvent after use have become an important research in the industrial field. However, the common distillation and rectification separation methods in the existing separation and recovery technology have the problems of high energy consumption, complex recovery equipment and process and the like, and simultaneously, the separation and recovery cost is greatly improved for improving the tolerance of a separation device to the aprotic polar solvent. The Pervaporation (PV) technology is used as a novel membrane separation technology and is better applied to the aspect of organic solvent recovery. However, the general polymer membrane material is easy to swell or even dissolve in such solvents, so that the conventional pervaporation membrane is difficult to separate and recover such solvent systems.
Polyimide (PI) is a high polymer material which is developed in the 60 th century and has an imide ring structure in a main chain, has good heat resistance, mechanical properties and solvent resistance, and has a certain research foundation in the field of pervaporation membrane separation. The PI pervaporation membrane prepared by Qiao et al is used for separating isopropanol/water, the separation factor reaches 3508, and the permeation flux is 0.432 kg.m-2·h-1. Polotskaya et al synthesized PI composite membrane (BTDA-ODA/PAN) for separating 10% methanol/cyclohexane solution, and the result shows that the PI/PANI membrane has better selectivity to methanol and the permeation flux at 50 ℃ is 0.046 kg.m-2·h-1. In 2011, Park et al have demonstrated that PI membranes have better tolerance in aprotic polar solvents such as DMF, DMAc, and the like, further show the advantages of separation methods using PI as pervaporation separation membranes, and have broad prospects in the aspect of organic solvent separation.
Patent reports that the chemical imidization method for preparing the polyimide pervaporation membrane and separating the n-octane/n-heptane-thiophene system is relatively simple in process, but the chemical imidization method cannot enable the PI to reach a sufficient imidization degree, greatly reduces the stability of the PI membrane in an aprotic polar solvent, and is not suitable for separating the solvent system involved in the patent. The separation method using the polyimide pervaporation membrane has good separation effect on the small molecular solvent in the aprotic polar solvent, can be stably used for a long time, has low energy consumption, has lower theoretical cost than the conventional distillation and rectification process at the present stage, and has obvious advantages.
Disclosure of Invention
The invention aims to solve the technical problems that in the prior art, a separation device for the aprotic polar solvent has high energy consumption and high cost, and recovery equipment and a process are complex, and a common polymer membrane has short service life of the membrane due to poor solvent resistance and low separation efficiency and is difficult to separate and purify the aprotic polar organic solvent; the invention provides a method for separating small molecule solvent in aprotic polar solvent, which uses polyimide pervaporation membrane, can stably and effectively separate small molecule solvent in aprotic polar solvent, is resistant to high pressure difference and not easy to damage, has high separation efficiency and simple process, and has the characteristics of low cost and wide application prospect compared with the prior separation technology.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a method for separating small molecule solvent in aprotic polar solvent adopts a pervaporation membrane separation device, and comprises the steps that the upper part of a pervaporation membrane is filled with feed liquid of a mixture of the aprotic polar solvent and the small molecule solvent, and a cavity at the lower part of the pervaporation membrane is connected with a vacuum device, so that the small molecule solvent in the feed liquid diffuses to a lower cavity through the pervaporation membrane; wherein the pervaporation membrane is a polyimide pervaporation membrane; the polyimide pervaporation membrane is characterized by comprising a supporting layer and a separating layer; the separation layer is positioned on the support layer, the separation layer is a multilayer polyimide film, and the support layer is an inorganic substance or an organic substance with a pore structure of more than 0.01 mu m.
In the above technical solution, the multilayer polyimide film is preferably obtained by imidizing a polyamic acid film prepared by at least two solvent removal methods, and the remaining layers except for the first layer in contact with the support layer are all solvent removal methods of diffusing in a poor solvent of polyamic acid.
In the technical scheme, the mass concentration of the aprotic polar solvent in the feed liquid is 5-99.9%.
In the technical scheme, the temperature of the feed liquid of the pervaporation membrane separation device is preferably 10-150 ℃, and more preferably 10-95 ℃.
In the technical scheme, the absolute pressure of a cavity at the lower part of the pervaporation membrane separation device is preferably 0-99 kPa, and more preferably 0-50 kPa.
In the above technical solution, the aprotic polar organic solvent preferably includes at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and tetrahydrofuran.
In the above technical solution, the small molecule solvent preferably includes at least one of water, methanol, and ethanol.
In the technical scheme, the total number of layers of the multilayer polyimide film is preferably 2-10 layers, and more preferably 2-6 layers.
In the technical scheme, the total thickness of the separation layer is preferably 2-80 μm.
In the technical scheme, the supporting layer is preferably an inorganic or organic supporting layer with a pore structure of 0.1-1 mu m, and more preferably an inorganic ceramic supporting layer.
In the technical scheme, the thickness of the supporting layer is preferably 0.5-100 mm, and more preferably 1-5 mm.
In the above technical solution, the solvent removing method used for the first layer of the multilayer polyimide film is preferably a self-heating method or a method of diffusing in a poor solvent of polyamic acid, and the solvent removing method used for the second layer and the above polyamic acid film is preferably a method of diffusing in a poor solvent of polyamic acid.
In the technical scheme, the micromolecular solvent in the feed liquid diffuses towards the lower cavity through the pervaporation membrane to obtain a penetrating liquid of micromolecular solvent components with high proportion; obtaining residual liquid at the upper part of the pervaporation membrane, namely the purified aprotic polar solvent, or returning the residual liquid to feed liquid, and obtaining the purified aprotic polar solvent after multiple times of circulating osmotic separation to finish the separation.
In the above technical solution, the preparation method of the polyimide pervaporation membrane preferably includes the following steps:
a) attaching a layer of polyamic acid solution to the surface of the supporting layer;
b) removing the solvent in the polyamic acid solution by a solvent removal method of heating or diffusing in a poor solvent of the polyamic acid to form a polyamic acid film;
c) imidizing the polyamic acid film obtained in the step b) into a polyimide film;
d) attaching a layer of polyamic acid solution on the surface of the polyimide film obtained in the previous step;
e) removing the solvent in the polyamic acid solution layer by a solvent removal method of diffusing in a poor solvent of the polyamic acid to form a polyamic acid film;
f) imidizing the polyamic acid membrane obtained in the step e) into a polyimide membrane, and obtaining a polyimide pervaporation membrane with a separation layer which is two layers of polyimide membranes;
or repeating the step d), the step e) and the step f) on the polyimide membrane obtained in the step f) to obtain a polyimide pervaporation membrane with the separation layer comprising more than two polyimide membranes;
wherein the poor solvents in step b) and step e) are different from each other.
In the above technical solution, the polyamic acid is preferably selected from the structures represented by the general formula (1):
Wherein Ar is1、Ar3The tetravalent aromatic residue having at least one carbon six-membered ring, more preferably an aromatic residue represented by the following structural formula (1):
In the above structural formula (1), R1Is preferably selected from
And the like.
Ar2、Ar4Preferably a tetravalent aromatic residue comprising at least one carbon six-membered ring, more preferably an aromatic residue represented by the following structural formula (2):
In the above structural formula (2), R2H-, CH-, is preferably selected3-、Cl-、Br-、F-、CH3O-, COOH-, etc.
In the technical scheme, the solid content of the polyamic acid solution is preferably 5-25%.
In the above technical solution, the viscosity of the polyamic acid solution is preferably 1 × 103～5×105cP。
In the above technical solution, the method for attaching a layer of polyamic acid solution to the support is preferably at least one of spin coating, doctor blade coating, or dipping.
In the above technical solution, the solvent removing method for preparing the multilayer polyimide film includes a heating method or a method of diffusing a solvent immersed in a poor solvent of polyamic acid.
In the technical scheme, the temperature of solvent diffusion in the heating method is preferably 40-180 ℃, and is preferably 50-120 ℃; the time for removing the solvent by heat preservation is preferably 0.1-60 min.
In the above technical solution, the poor solvent is preferably at least one of pure water, ethanol, acetone, and a polar aprotic organic solvent aqueous solution.
In the technical scheme, the imidization temperature in the high-temperature environment is 200-450 ℃, and preferably 240-350 ℃.
The separation method using the polyimide pervaporation membrane innovatively uses the multilayer polyimide pervaporation membrane, so that the separation method achieves the pervaporation separation effect of efficiently and stably separating small molecular solvents in aprotic polar solvents; the separation method adopting the technical scheme of the invention has the advantages of good separation effect, simple operation and low energy consumption, can be used for separating the aprotic polar organic solvent to keep the separation effect, meets the requirements of separation, recovery, purification and the like of the solvent in industrial production, and obtains better technical effect.
The test equipment and test conditions used in the present invention are:
swelling degree: preparing a support-free PI film sample, cutting the PI film sample into squares, drying the PI film sample in an oven at 100 ℃ for 1h, and weighing the mass w1Then soaking the mixture in a pure DMAc solvent at 60 ℃ for 48 hours, and weighing the mixture by mass w2The degree of swelling is (w)2-w1)/w1×100％。
Pervaporation separation device: the pervaporation membrane is arranged in a pervaporation membrane separator, the upper part of the membrane is filled with feed liquid, a cavity at the lower part of the membrane is a gas phase, a vacuum pump is connected, and a larger component differential pressure is kept between the feed liquid side and the permeate side, so that each component in the feed liquid permeates the pervaporation membrane and diffuses towards the permeate side, and the schematic diagram of the testing device is shown in figure 1. The feed liquid temperature and the pressure after the membrane were controlled, and the permeate side was collected by a condenser. According to the quality of the permeate collected (M)i) And the concentration of permeant therein (y)i) It can be calculated according to the formula:
In order to comprehensively express the pervaporation separation performance, a pervaporation separation index PSI is adopted, and PSI is alpha.J.
The separation method adopting the technical scheme of the invention has excellent solvent resistance, good separation effect and low energy consumption, the swelling degree in the aprotic polar solvent is less than 5 wt%, and high permeation flux and better separation factor can be ensured at the same time, and the permeation flux is more than 350 g/(m)2H) separation factor > 20, separation index > 7000 g/(m)2H), a good technical effect is obtained.
Drawings
Fig. 1 is a pervaporation performance testing device.
The invention is further illustrated by the following examples.
Detailed Description
[ example 1 ]
1. Preparing stock solution: 14.7g of 2, 2' -bis [4- (4-aminophenoxyphenyl)]Dissolving propane (BAPP) and 1.8g 3-diaminobenzoic acid (DABA) in 146.1g N, N-dimethylacetamide, stirring until completely dissolved, adding 15.5g benzophenone dianhydride (BTDA) powder (molar ratio of dianhydride to diamine is 1:1), and stirring for full reaction to obtain final product with apparent viscosity of 5 × 103A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a spin coating method, horizontally immersing the inorganic ceramic support in ethanol for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the solvent in a drying oven at 100 ℃ for 20min, and preserving the heat at 260 ℃ for 30min to perform imidization, thus obtaining the prepared PI pervaporation membrane a coated with the PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the temperature in a 100 ℃ oven for 20min, preserving the temperature at 260 ℃ for 30min, and carrying out imidization to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylacetamide aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 90 wt%, the temperature of the feed liquid is 60 ℃, and the pressure behind the pervaporation membrane is 0.5 kPa.
Testing that the swelling degree of the PI film prepared by the method is 4%; the method is tested to separate the water permeation flux of the N, N-dimethylacetamide solution to be 382 g/(m)2H), separation factor 22.72, PSI 8679 g/(m)2·h)。
[ example 2 ]
1. Preparing stock solution: dissolving 22.1g of 4, 4-Biphenyldiamine (BZD) in 250.8g N, N-dimethylacetamide, stirring until the mixture is completely dissolved, adding 40.6g of benzophenone dianhydride (BTDA) powder (the molar ratio of dianhydride to diamine is 1.05:1), and continuously stirring until the mixture fully reacts to obtain the product with the apparent viscosity of 4.8 x 105A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a spin coating method, horizontally immersing the inorganic ceramic support in ethanol for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the solvent in a 50 ℃ oven for 60min, and preserving the heat at 240 ℃ for 60min to perform imidization, thus obtaining the PI pervaporation membrane a to be prepared with a PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a in ethanol for 10min to completely diffuse the solvent, taking out the prepared PI pervaporation membrane, then preserving the temperature in a 50 ℃ oven for 60min, preserving the temperature at 240 ℃ for 60min, and carrying out imidization to obtain the prepared PI pervaporation membrane b coated with a PI compact layer.
c) Coating a layer of PAA solution on the prepared PI pervaporation membrane b obtained in the step b) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane b in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the temperature in a 50 ℃ oven for 60min, preserving the temperature at 240 ℃ for 60min, and carrying out imidization to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylformamide aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 70 wt%, the temperature of the feed liquid is 30 ℃, and the pressure behind the pervaporation membrane is 5.0 kPa.
The swelling degree of the PI film prepared by the method is 2.5 percent(ii) a The method is tested to separate the N, N-dimethylformamide solution, and the water permeation flux is 270 g/(m)2H), separation factor 38.8, PSI 10476 g/(m)2·h)。
[ example 3 ]
1. Preparing stock solution: dissolving 24.0g of 4, 4-diaminodiphenyl ether (ODA) in 220.9g N-methyl-2-pyrrolidone, stirring until the mixture is completely dissolved, adding 39.3g of benzophenone dianhydride (BTDA) powder (the molar ratio of dianhydride to diamine is 0.99:1), and continuously stirring until the mixture is fully reacted to obtain the product with the apparent viscosity of 3.6 x 105A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a blade coating method, horizontally immersing the inorganic ceramic support into an N-methyl-2-pyrrolidone aqueous solution (20 wt%) for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the solvent in an oven at 80 ℃ for 40min, and preserving the heat at 300 ℃ for 10min to perform imidization, thus obtaining the prepared PI pervaporation membrane a coated with a PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a into N-methyl-2-pyrrolidone aqueous solution (20 wt%) for 10min to completely diffuse the solvent, taking out the membrane, then preserving the heat in an oven at 80 ℃ for 40min, and preserving the heat at 300 ℃ for 10min to perform imidization, thus obtaining the prepared PI pervaporation membrane b coated with a PI compact layer.
c) Coating a layer of PAA solution on the prepared PI pervaporation membrane b obtained in the step b) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane b in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the heat in an oven at 80 ℃ for 40min, and preserving the heat at 300 ℃ for 10min to perform imidization, thus obtaining the prepared PI pervaporation membrane c coated with a PI compact layer.
d) And c) attaching a layer of PI film on the prepared PI pervaporation film c through the preparation process of the step c), thus obtaining the pervaporation film coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in dimethyl sulfoxide aqueous solution separation equipment, the concentration of a feed liquid is 50 wt%, the temperature of the feed liquid is 50 ℃, and the pressure behind the pervaporation membrane is 0.1kPa in the separation process.
Testing that the swelling degree of the PI film prepared by the method is 5.2%; the method is tested to separate the water permeation flux in the dimethyl sulfoxide solution to be 78 g/(m)2H), separation factor 162, PSI 12636 g/(m)2·h)。
[ example 4 ]
1. Preparing stock solution: dissolving 24.0g of 4, 4-diaminodiphenyl ether (ODA) in 146.6g N, N-dimethylacetamide, stirring until the mixture is completely dissolved, adding 24.9g of pyromellitic dianhydride (PMDA) powder (the molar ratio of dianhydride to diamine is 0.95:1), and continuously stirring until the mixture fully reacts to obtain the product with the apparent viscosity of 2.2 x 105A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) covering a layer of PAA solution on an inorganic ceramic support by a dip-coating method, horizontally immersing the inorganic ceramic support in acetone for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the inorganic ceramic support in a 120 ℃ oven for 10min, and preserving the temperature at 350 ℃ for 20min to perform imidization, thus obtaining the prepared PI pervaporation membrane a covered with the PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by using a dipping and pulling method, horizontally immersing the prepared PI pervaporation membrane a in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the heat in a 120 ℃ oven for 10min, preserving the heat at 350 ℃ for 20min, and carrying out imidization to obtain the prepared PI pervaporation membrane b coated with the PI compact layer.
c) Coating a layer of PAA solution on the prepared PI pervaporation membrane b obtained in the step b) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane b in acetone for 10min to completely diffuse the solvent, taking out the membrane, then preserving the heat in a 120 ℃ oven for 10min, preserving the heat at 350 ℃ for 20min, and carrying out imidization to obtain the prepared PI pervaporation membrane c coated with the PI compact layer.
d) Coating a layer of PAA solution on the prepared PI pervaporation membrane c obtained in the step c) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane c in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the heat in a 120 ℃ oven for 10min, preserving the heat at 350 ℃ for 20min, and carrying out imidization to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylformamide ethanol solution separation equipment, the concentration of a feed liquid in the separation process is 80 wt%, the temperature of the feed liquid is 80 ℃, and the pressure behind the pervaporation membrane is 0.1 kPa.
Testing the swelling degree of the PI film prepared by the method to be 20%; the method is tested to separate the ethanol permeation flux of the N, N-dimethylformamide ethanol solution to 209 g/(m)2H), separation factor 34.1, PSI 7127 g/(m)2·h)。
[ example 5 ]
1. Preparing stock solution: dissolving 13.0g of p-Phenylenediamine (PDA) in 897.3g N, N-dimethylformamide, stirring until the mixture is completely dissolved, adding 34.2g of biphenyl tetracarboxylic dianhydride (BPDA) powder (the molar ratio of dianhydride to diamine is 0.97:1), and continuously stirring until the mixture fully reacts to obtain the product with the apparent viscosity of 1 × 103A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a spin coating method, taking out, then preserving heat for 1min in a baking oven at 100 ℃ to remove the solvent by a heating method, and preserving heat for 5min at 320 ℃ to perform imidization, thus obtaining the prepared PI pervaporation membrane a coated with a PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the temperature in a 50 ℃ oven for 60min, preserving the temperature at 240 ℃ for 60min, and carrying out imidization to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylacetamide aqueous solution separation equipment, the concentration of a feed liquid is 5 wt%, the temperature of the feed liquid is 45 ℃, and the pressure behind the pervaporation membrane is 50kPa during separation.
Testing that the swelling degree of the PI film prepared by the method is 3.7%; the method is tested to separate the water permeation flux of 188 g/(m) in the N, N-dimethylacetamide aqueous solution2H), separation factor 69.0, PSI 12972 g/(m)2·h)。
[ example 6 ]
1. Preparing stock solution: 9.8g of 2, 2' -bis [4- (4-aminophenoxyphenyl)]Dissolving propane (BAPP) and 2.4g4, 4' -diaminodiphenylmethane (MDA) in 215.5g N, N-dimethylacetamide, stirring until the mixture is completely dissolved, adding 11.7g benzophenone dianhydride (BTDA) powder (molar ratio of dianhydride to diamine is 1.01:1), and continuously stirring until the mixture is fully reacted to obtain the product with apparent viscosity of 3 × 103A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a dip-coating method, horizontally immersing the inorganic ceramic support in ethanol for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the inorganic ceramic support in a 60 ℃ oven for 30min, and preserving the heat at 250 ℃ for 40min to perform imidization, thus obtaining the prepared PI pervaporation membrane a coated with the PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the heat in a 60 ℃ oven for 30min, preserving the heat at 250 ℃ for 40min, and carrying out imidization to obtain the prepared PI pervaporation membrane b coated with a PI compact layer.
c) And (b) attaching a layer of PI film on the prepared PI pervaporation film b through the preparation process of the step b), thus obtaining the prepared pervaporation film c coated with a plurality of PI compact layers.
d) And c) attaching a layer of PI film on the prepared PI pervaporation film c through the preparation process of the step c), thus obtaining the prepared pervaporation film d coated with a plurality of PI compact layers.
e) And (b) attaching a layer of PI film on the prepared PI pervaporation film d through the preparation process of the step b), thus obtaining the prepared pervaporation film e coated with a plurality of PI compact layers.
f) And c) attaching a layer of PI film on the prepared PI pervaporation film e through the preparation process of the step c), thus obtaining the pervaporation film coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylformamide aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 99.5 wt%, the temperature of the feed liquid is 90 ℃, and the pressure behind the pervaporation membrane is 0.1 kPa.
Testing that the swelling degree of the PI film prepared by the method is 8.0%; the water permeation flux in the N, N-dimethylformamide aqueous solution separated by the method is tested to be 17.9 g/(m)2H), separation factor 215.1, PSI 10340 g/(m)2·h)。
[ example 7 ]
1. Preparing stock solution: dissolving 20.0g of 4, 4-diaminodiphenyl ether (ODA) in 262.5g N, N-dimethylacetamide, stirring until the mixture is completely dissolved, adding 11.2g of benzophenone dianhydride (BTDA) powder and 15.1g of pyromellitic dianhydride (PMDA) powder (the molar ratio of dianhydride to diamine is 1.01:1), and continuously stirring until the mixture fully reacts to obtain the product with the apparent viscosity of 8 x 104A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a blade coating method, horizontally immersing the inorganic ceramic support in ethanol for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the solvent in a baking oven at 100 ℃ for 20min, preserving the heat at 300 ℃ for 20min, and carrying out imidization to obtain the prepared PI pervaporation membrane a coated with the PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a into N, N-dimethylacetamide aqueous solution (15 wt%) for 10min to completely diffuse the solvent, taking out the prepared PAA solution, keeping the temperature in a 100 ℃ oven for 20min, keeping the temperature at 300 ℃ for 20min, and imidizing to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N-methylpyrrolidone aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 40 wt%, the temperature of the feed liquid is 10 ℃, and the pressure behind the pervaporation membrane is 30 kPa.
Testing that the swelling degree of the PI film prepared by the method is 4.4%; the method is tested to separate the water permeation flux in the N-methyl pyrrolidone water solution to be 351 g/(m)2H), separation factor 32.8, PSI 11512 g/(m)2·h)。
[ example 8 ]
1. Preparing stock solution: 13g of p-Phenylenediamine (PDA) was dissolved197.8g N-methyl-2-pyrrolidone is stirred to be completely dissolved, 36.5g of 2,3,3',4' -diphenyl ether tetracarboxylic dianhydride (ODPA) powder dianhydride and diamine are added according to the molar ratio of 0.98:1, and the mixture is continuously stirred to be fully reacted, so that the apparent viscosity of the mixture is 1.4 multiplied by 104A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) coating a layer of PAA solution on an inorganic ceramic support by a spin coating method, horizontally immersing the inorganic ceramic support into N-methyl-2-pyrrolidone aqueous solution (25 wt%) for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the temperature in a drying oven at 100 ℃ for 30min, preserving the temperature at 300 ℃ for 30min, and carrying out imidization to obtain the prepared PI pervaporation membrane a coated with a PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, horizontally immersing the prepared PI pervaporation membrane a in pure water for 10min to completely diffuse the solvent, taking out the membrane, then preserving the temperature in a 100 ℃ oven for 30min, preserving the temperature at 300 ℃ for 30min, and carrying out imidization to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylacetamide aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 20 wt%, the temperature of the feed liquid is 40 ℃, and the pressure behind the pervaporation membrane is 0.1 kPa.
The swelling degree of the PI film prepared by the method is 5.9 percent; the method is tested to separate the water permeation flux of the N, N-dimethylacetamide aqueous solution to be 397 g/(m)2H), separation factor 19.8, PSI 7860 g/(m)2H). [ COMPARATIVE EXAMPLE 1 ]
1. Preparing stock solution: dissolving 24g of 4, 4-diaminodiphenyl ether (ODA) in 355.3g N, N-dimethylacetamide, stirring until the mixture is completely dissolved, adding 38.7g of benzophenone dianhydride (BTDA) powder dianhydride and diamine in a molar ratio of 1:1, and continuously stirring until the mixture fully reacts to obtain the product with the apparent viscosity of 1.7 x 104A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane: coating a layer of PAA solution on a glass plate by a blade coating method, horizontally immersing the glass plate in pure water for 10min to completely diffuse the solvent, taking out the glass plate, then keeping the temperature in an oven at 100 ℃ for 10min, and keeping the temperature at 300 ℃ for 10min to perform imidization.
3. And stripping the imidized PI film from the glass plate to obtain the PI pervaporation film.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylacetamide aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 80 wt%, the temperature of the feed liquid is 70 ℃, and the pressure behind the pervaporation membrane is 0.1 kPa.
Testing that the swelling degree of the PI film prepared by the method is 3.9%; the film is broken during the separation process, and the separation and purification effects cannot be achieved.
[ COMPARATIVE EXAMPLE 2 ]
A pervaporation membrane separation device with an inorganic ceramic supporting layer and a cellulose acetate separation layer is arranged in N, N-dimethylformamide aqueous solution separation equipment, the concentration of a feed liquid in the separation process is 90 wt%, the temperature of the feed liquid is 60 ℃, and the pressure behind the pervaporation membrane is 0.5 kPa.
The cellulose acetate membrane has certain solubility in the feeding liquid and poor solvent resistance, cannot stably play a role in pervaporation separation in the feeding liquid, and cannot play a role in separation and purification.
[ COMPARATIVE EXAMPLE 3 ]
1. Preparing stock solution: dissolving 13.0g of p-Phenylenediamine (PDA) in 897.3g N, N-dimethylformamide, stirring until the mixture is completely dissolved, adding 34.2g of biphenyl tetracarboxylic dianhydride (BPDA) powder (the molar ratio of dianhydride to diamine is 0.97:1), and continuously stirring until the mixture fully reacts to obtain the product with the apparent viscosity of 1 × 103A uniform transparent viscous polyamic acid solution of cP (25 ℃).
2. Preparing a pervaporation membrane:
a) and (2) coating a layer of PAA solution on the inorganic ceramic support by a spin coating method, horizontally immersing the inorganic ceramic support in pure water for 10min to completely diffuse the solvent, taking out the inorganic ceramic support, then preserving the temperature in a 50 ℃ oven for 60min, preserving the temperature at 240 ℃ for 60min, and carrying out imidization to obtain the prepared PI pervaporation membrane a coated with the PI compact layer.
b) Coating a layer of PAA solution on the prepared PI pervaporation membrane a obtained in the step a) by a spin coating method, taking out, then keeping the temperature in a drying oven at 100 ℃ for 1min, removing the solvent by a thermal drying method, and keeping the temperature at 320 ℃ for 5min for imidization to obtain the pervaporation membrane coated with a plurality of PI compact layers.
A separation device of the polyimide pervaporation membrane obtained by the method is arranged in N, N-dimethylacetamide aqueous solution separation equipment, the concentration of a feed liquid is 5 wt%, the temperature of the feed liquid is 45 ℃, and the pressure behind the pervaporation membrane is 50kPa during separation.
Testing that the swelling degree of the PI film prepared by the method is 4.2%; the method is tested to separate the water permeation flux of the N, N-dimethylacetamide aqueous solution to 209 g/(m)2H), separation factor 23.5, PSI 4911 g/(m)2·h)。
Claims (10)
1. A method for separating small molecule solvent in aprotic polar solvent adopts a pervaporation membrane separation device, and comprises the steps that the upper part of a pervaporation membrane is filled with feed liquid of a mixture of the aprotic polar solvent and the small molecule solvent, and a cavity at the lower part of the pervaporation membrane is connected with a vacuum device, so that the small molecule solvent in the feed liquid diffuses to a lower cavity through the pervaporation membrane; wherein the pervaporation membrane is a polyimide pervaporation membrane; the polyimide pervaporation membrane is characterized by comprising a supporting layer and a separating layer; the separation layer is positioned on the support layer, the separation layer is a multilayer polyimide film, and the support layer is an inorganic substance or an organic substance with a pore structure of more than 0.01 mu m; the multilayer polyimide film is obtained by imidizing a polyamic acid film prepared by at least two solvent removal methods, and the rest layers except the first layer in contact with the support layer adopt a solvent removal method of diffusing in a poor solvent of polyamic acid.
2. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the mass concentration of the aprotic polar solvent in the feed liquid is 5 to 99.9%.
3. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the temperature of the feed liquid is 10 to 150 ℃.
4. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the absolute pressure of the cavity at the lower part of the pervaporation membrane is 0 to 99 kPa.
5. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the aprotic polar solvent comprises at least one of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and tetrahydrofuran.
6. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the small molecule solvent comprises at least one of water, methanol and ethanol.
7. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the number of the multilayer polyimide film is 2 to 10.
8. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the number of the polyimide films is 2 to 6.
9. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the total thickness of the separation layer is 2 to 80 μm.
10. The method for separating a small molecule solvent from an aprotic polar solvent according to claim 1, wherein the polyimide is selected from the group consisting of structures represented by general formula (1):
wherein Ar is1、Ar3Is a tetravalent aromatic radical having at least one carbon-six membered ring, Ar2、Ar4Is a divalent aromatic residue containing at least one carbon six-membered ring.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810733836.0A CN110681266B (en) | 2018-07-06 | 2018-07-06 | Method for separating small molecule solvent in aprotic polar solvent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810733836.0A CN110681266B (en) | 2018-07-06 | 2018-07-06 | Method for separating small molecule solvent in aprotic polar solvent |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110681266A CN110681266A (en) | 2020-01-14 |
| CN110681266B true CN110681266B (en) | 2021-11-30 |
Family
ID=69106910
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810733836.0A Active CN110681266B (en) | 2018-07-06 | 2018-07-06 | Method for separating small molecule solvent in aprotic polar solvent |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110681266B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111203109A (en) * | 2020-01-15 | 2020-05-29 | 南京工业大学 | Novel pervaporation circulation heat exchange system and method |
| CN111804056A (en) * | 2020-07-20 | 2020-10-23 | 高跃 | Lubricating oil purifying equipment |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101690870A (en) * | 2005-10-14 | 2010-04-07 | 米利波尔公司 | Ultrafiltration membranes and methods of making and use of ultrafiltration membranes |
| CN102716680A (en) * | 2012-06-05 | 2012-10-10 | 中国科学院化学研究所 | Polyamide microporous membrane and preparation method thereof |
| CN103154335A (en) * | 2010-10-07 | 2013-06-12 | 纳幕尔杜邦公司 | Rapid thermal conversion of a polyamic acid fiber to a polyimide fiber |
| CN106925142A (en) * | 2017-05-04 | 2017-07-07 | 中国矿业大学(北京) | A kind of many separating layer infiltrating and vaporizing membranes and preparation method thereof |
| CN107281942A (en) * | 2017-06-28 | 2017-10-24 | 常州大学 | It is a kind of to be used to separate infiltration vaporization blending film of methanol tetrahydrofuran and preparation method thereof |
| CN108126538A (en) * | 2017-12-13 | 2018-06-08 | 常州大学 | PI composite membranes for infiltration evaporation separating amide/water and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10722850B2 (en) * | 2013-03-12 | 2020-07-28 | National University Of Singapore | Hollow fiber membrane for dehydration of organic solvents via pervaporation process and a method of fabricating the same |
-
2018
- 2018-07-06 CN CN201810733836.0A patent/CN110681266B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101690870A (en) * | 2005-10-14 | 2010-04-07 | 米利波尔公司 | Ultrafiltration membranes and methods of making and use of ultrafiltration membranes |
| CN103154335A (en) * | 2010-10-07 | 2013-06-12 | 纳幕尔杜邦公司 | Rapid thermal conversion of a polyamic acid fiber to a polyimide fiber |
| CN102716680A (en) * | 2012-06-05 | 2012-10-10 | 中国科学院化学研究所 | Polyamide microporous membrane and preparation method thereof |
| CN106925142A (en) * | 2017-05-04 | 2017-07-07 | 中国矿业大学(北京) | A kind of many separating layer infiltrating and vaporizing membranes and preparation method thereof |
| CN107281942A (en) * | 2017-06-28 | 2017-10-24 | 常州大学 | It is a kind of to be used to separate infiltration vaporization blending film of methanol tetrahydrofuran and preparation method thereof |
| CN108126538A (en) * | 2017-12-13 | 2018-06-08 | 常州大学 | PI composite membranes for infiltration evaporation separating amide/water and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 《PREPARATION OF ASYMMETRIC POLYIMIDE MEMBRANE FOR WATER-ETHANOL SEPARATION IN PERVAPORATIN BY THE PHASE INVERSION PROCESS》;YANAGISHITA, H etal;《JOURNAL OF MEMBRANE SCIENCE》;19940209;第86卷(第3期);全文 * |
| 《均苯型耐酰胺溶剂聚酰亚胺膜渗透汽化性能研究》;邓力等;《高校化学工程学报》;20180630;第32卷(第3期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110681266A (en) | 2020-01-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104829853B (en) | A kind of polyimide gas separating film and preparation method and application | |
| CN102716680B (en) | Polyamide microporous membrane and preparation method thereof | |
| US8394176B2 (en) | Polyimide gas separation membrane and gas separation method | |
| GB2102726A (en) | Producing aromatic polyimide separating membranes | |
| JPH04222832A (en) | Polyimide and gas separation material made by using it | |
| US4959151A (en) | Pervaporation method of separating liquid organic compound mixture through aromatic imide polymer asymmetric membrane | |
| EP3197592B1 (en) | Preparation of carbon molecular sieve (cms) hollow fiber membranes from pre-oxidized polyimides | |
| CN110681266B (en) | Method for separating small molecule solvent in aprotic polar solvent | |
| CN101837254A (en) | Method for preparing solvent-resistant polyimide nanofiltration membrane | |
| CN106279685A (en) | Polyimide material, its preparation method and application of based on Teller lattice alkali structure | |
| JP2018122280A (en) | Asymmetric membrane | |
| KR102152278B1 (en) | BCDA-based semi-alicyclic polyimide membrane materials for gas separation and the preparation method thereof | |
| CN110681272B (en) | Polyimide pervaporation membrane and preparation method thereof | |
| KR20140048056A (en) | Polyimide based polymeric compound and asymmetric hollow fiber membranes containing the same for gas separation | |
| WO2019151337A1 (en) | Asymmetric membrane | |
| CN114591503B (en) | Soluble poly (benzimidazole-co-imide) polymer and preparation and application thereof | |
| CN113244788A (en) | Synthetic method and application of polyimide gas separation membrane material | |
| KR101477710B1 (en) | Novel polyimide derivatives, preparation method thereof and polymer gas separation membrane comprising the same | |
| CN109054017B (en) | Hyperbranched polyimide containing phenanthrene ring structure and preparation method and application thereof | |
| JP2010202864A (en) | New polyimide | |
| JP2016137484A (en) | Gas separation membrane | |
| KR100398059B1 (en) | Fluorine-based polyimide composite membrane for gas separation | |
| JPH0679151A (en) | Polyimide separation film | |
| CN115869788B (en) | Polyimide random copolymer with triptycene structure, and preparation method and application thereof | |
| JP2874178B2 (en) | Aromatic polyimide separation membrane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |