CN109912408B - Polyacid monomer and preparation method thereof, polyamide and preparation method thereof, and polyamide film - Google Patents
Polyacid monomer and preparation method thereof, polyamide and preparation method thereof, and polyamide film Download PDFInfo
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- CN109912408B CN109912408B CN201910212313.6A CN201910212313A CN109912408B CN 109912408 B CN109912408 B CN 109912408B CN 201910212313 A CN201910212313 A CN 201910212313A CN 109912408 B CN109912408 B CN 109912408B
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Abstract
The invention provides a polyacid monomer and a preparation method thereof, polyamide and a preparation method thereof, and a polyamide film, and belongs to the technical field of organic synthesis. The polyacid monomer provided by the invention has a structure shown in a formula I or a formula II, has a microporous structure, a flexible group (ether bond) and a hydroxyl structure, and is further polymerized with a diamine monomer to obtain polyamide. The polyamide film formed by the polyamide provided by the invention has better selective permeability and penetrability. In addition, the polyamide provided by the invention has better solubility.
Description
Technical Field
The invention relates to the technical field of organic synthesis, in particular to a polyamine monomer and a preparation method thereof, polyamide and a preparation method thereof, and a polyamide film.
Background
Gas separation membranes (GS) are mostly non-porous membranes and the gas permeation process follows a "solution-diffusion" mechanism. Aromatic polyamide has good heat resistance, mechanical strength and separation performance due to aromatic ring structure on the main chain and intermolecular hydrogen bonding, and is widely applied to the field of gas separation for 20 th century and 90 th year.
As a green separation technology, compared with separation technologies such as cryogenic separation and pressure swing adsorption separation, the separation process of the gas separation membrane technology has the advantages of high separation efficiency, simple operation, low energy consumption, greenness, no pollution and the like, is recognized as a novel gas separation technology with the most development and application prospect in the 21 st century, and is widely applied to the fields of medical food, biochemistry, energy environmental protection and the like. Compared with the traditional gas separation technology, the membrane separation has the advantages of low energy consumption, low investment, simple equipment and the like, and has important application in the aspects of oxygen/nitrogen separation, gas dehumidification, carbon dioxide recovery, hydrogen separation recovery and the like.
However, in general, the permeability and selectivity of a polymer membrane are in a mutually restrictive relationship, i.e., the permeability increases, the selectivity decreases, which is the so-called Trade-off effect. The prepared high-molecular gas separation membrane with high permeability and high selectivity has very profound influence on improving the gas separation efficiency and expanding the application range.
Disclosure of Invention
The invention provides a polyacid monomer, and a polyamide film prepared from the polyacid monomer provided by the invention has better gas selectivity and permeability.
The invention provides a polyacid monomer, which has a structure shown in a formula I or a formula II:
the invention provides a preparation method of a polyacid monomer with a structure shown in the formula I in the technical scheme, which comprises the following steps:
(1) heating, refluxing and cooling an acetone solution of hydrogen iodide and an acetic acid solution of catechol to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate spiro tetraphenol; the spiro tetraphenol has a structure represented by formula III:
(2) carrying out substitution reaction on the spiro tetraphenol obtained in the step (1) and p-fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain a tetracyanospiro compound, wherein the catalyst comprises one or two of potassium carbonate and cesium carbonate; the tetracyanospiro compound has a structure shown in formula IV:
(3) hydrolyzing the tetracyano spiro-compound obtained in the step (2) in an alkaline solution, and then adjusting the system to be acidic to generate the polyacid monomer with the structure shown as the formula I.
The invention provides a preparation method of a polyacid monomer with the structure shown in the formula II in the technical scheme, which comprises the following steps:
(a) heating, refluxing and cooling an acetone solution of hydrogen iodide, an acetic acid solution of catechol and an acetic acid solution of hydroxybenzene to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate the spiro trisphenol; the spiro trisphenol has a structure shown in formula V:
(b) carrying out substitution reaction on the spiro-trisphenol obtained in the step (a) and p-fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain a tetracyanospiro-compound, wherein the catalyst comprises one or two of potassium carbonate and cesium carbonate; the tricyano spiro compound has a structure shown in formula VI:
(c) hydrolyzing the tricyano spiro compound obtained in the step (b) in an alkaline solution, and then adjusting the system to be acidic to generate the polyacid monomer with the structure of formula II.
Preferably, the molar ratio of hydrogen iodide to catechol in the step (1) is 1: 2-5; the temperature of the hydrothermal treatment in the step (1) is 200-240 ℃, and the pressure is 1 MPa-0.5 GPa.
Preferably, the molar ratio of hydrogen iodide, catechol and hydroxybenzene in the step (a) is 1: 1-4; the temperature of the hydrothermal treatment in the step (a) is 200-240 ℃, and the pressure is 1 MPa-0.5 GPa.
Preferably, the molar ratio of the spirocyclic tetraphenol to the p-fluorobenzonitrile in the step (2) is 1: 4-9; the temperature of the substitution reaction is 120-150 ℃, and the time is 12-14 h;
the mol ratio of the spiro trisphenol to the p-fluorobenzonitrile in the step (b) is 1: 4-9; the temperature of the substitution reaction is 120-150 ℃, and the time is 12-14 h.
Preferably, the hydrolysis temperature in the step (3) and the hydrolysis temperature in the step (c) are respectively 80-100 ℃ and the hydrolysis time is respectively 15-20 h.
The invention provides polyamide, which has a structure shown in a formula VII:
wherein one of the four R substituents is H and the remaining three R substituents are
Or all four R substituents are
Wherein AR has a structure according to any one of formulas 1 to 4:
the invention provides a preparation method of polyamide in the technical scheme, which comprises the following steps:
under the protective atmosphere, carrying out polycondensation reaction on a polyacid monomer, a salt forming agent and a diamine monomer in a polar organic solvent, and then cooling to obtain polyamide; the polyacid monomer is the polyacid monomer in the technical scheme or the polyacid monomer prepared by the method in the technical scheme.
The invention provides a polyamide film, which comprises the polyamide in the technical scheme or the polyamide prepared by the method in the technical scheme; the thickness of the polyamide film is 60-70 um.
The invention provides a polyacid monomer which has a structure shown in a formula I or a formula II. The polyacid monomer provided by the invention has a spiro microporous structure and a flexible group (ether bond), and the polyacid monomer provided by the invention is further polymerized with a diamine monomer to obtain polyamide. The polyamide polymer provided by the invention has a microporous structure, and the existence of the microporous structure enables gas micromolecules to easily permeate, so that the selective permeability of a membrane is increased; the polyamide polymer provided by the invention is a hyperbranched polymer, and due to the existence of the hyperbranched structure, larger gaps exist between the polymer and the polymer, and the polymer has a larger permeability coefficient. In addition, the existence of flexible groups (ether bonds) in the polyamide provided by the invention increases the free volume and flexibility of polymer molecular chains, so that a solvent is easy to permeate, and the problem of poor solubility of the traditional gas separation membrane caused by rigid chains is solved. The embodiment result shows that the polyamide film prepared from the polyamide has the characteristic of high permeability while ensuring good selectivity in the field of gas separation; the polyamide prepared by the polyacid monomer provided by the invention is prepared by adding DMAC, DMF, NMP, DMSO, THF and CHCl3Has better solubility.
Drawings
FIG. 1 is a nuclear magnetic spectrum of a polyacid monomer prepared in example 1 of the present invention;
FIG. 2 is an infrared spectrum of polyamide prepared in application examples 1 to 3 of the present invention.
Detailed Description
The invention provides a polyacid monomer, which has a structure shown in a formula I or a formula II:
the invention also provides a preparation method of the polyacid monomer in the technical scheme, which comprises the following steps:
when the polyacid monomer has a structure shown in formula I, the preparation method of the polyacid monomer comprises the following steps:
(1) heating, refluxing and cooling an acetone solution of hydrogen iodide and an acetic acid solution of catechol to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate spiro tetraphenol; the spiro tetraphenol has a structure represented by formula III:
(2) carrying out substitution reaction on the spiro tetraphenol obtained in the step (1) and p-fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain a tetracyanospiro compound, wherein the catalyst comprises one or two of potassium carbonate and cesium carbonate; the tetracyanospiro compound has a structure shown in formula IV:
(3) hydrolyzing the tetracyano spiro-compound obtained in the step (2) in an alkaline solution, and then adjusting the system to be acidic to generate the polyacid monomer with the structure shown as the formula I.
The method comprises the steps of heating, refluxing and cooling an acetone solution of hydrogen iodide and an acetic acid solution of catechol to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate the spiro tetraphenol.
The method comprises the steps of heating, refluxing and cooling an acetone solution of hydrogen iodide and an acetic acid solution of catechol to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate the spiro tetraphenol. In the invention, the molar ratio of hydrogen iodide in the acetone solution of hydrogen iodide to catechol in the acetic acid solution of catechol is preferably 1: 2-5, and more preferably 1: 3-4. In the present invention, the mass concentration of hydrogen iodide in the acetone solution of hydrogen iodide is preferably 80% to 99%, and more preferably 85%; the mass concentration of catechol in the catechol acetic acid solution is preferably 10% to 55%, more preferably 20% to 50%, and more preferably 30% to 40%, and the mass concentration of acetic acid in the catechol acetic acid solution is preferably 10% to 40%, and more preferably 20% to 30%. In the present invention, the acetone functions to provide a reaction environment, and the acetic acid functions as a catalyst. In the invention, the heating reflux temperature is preferably 117-125 ℃, more preferably 118-122 ℃, and the time is preferably 10-12 h; the heating reflux is preferably carried out under nitrogen protection. In the invention, the heating reflux has the function of fully heating the system, improving the reaction progress degree and shortening the reaction progress time. After the heating reflux is finished, the mixed solution is cooled to obtain a supersaturated solution. The present invention is not particularly limited to the particular embodiment of cooling, and may be practiced in a manner well known to those skilled in the art.
After the supersaturated solution is obtained, the invention carries out hydrothermal treatment on the supersaturated solution to precipitate the spiro tetraphenol. In the invention, the temperature of the hydrothermal treatment is preferably 200-240 ℃, more preferably 210-230 ℃, the time is preferably 5-8 h, and the pressure is preferably 1-0.5 GPa, more preferably 100-400 MPa. In the present invention, it is preferable that white crystals are precipitated from the supersaturated solution under the above-mentioned conditions of high temperature and high pressure. According to the invention, the white crystals are preferably washed to obtain the spirocyclic tetraphenol, the washing detergent preferably comprises glacial acetic acid and dichloromethane, and the washing detergent preferably adopts glacial acetic acid and dichloromethane to wash alternately.
In the present invention, the spirocyclic tetraphenol has the structure shown in formula III:
after obtaining the spiro-tetraphenol, the invention carries out substitution reaction on the spiro-tetraphenol and the fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain the tetracyano spiro-compound.
The spirocyclic tetraphenol, the p-fluorobenzonitrile, the catalyst and the organic solvent are mixed to form mixed feed liquid. In the invention, the molar ratio of the spirocyclic tetraphenol to the p-fluorobenzonitrile is preferably 1: 4-9, and more preferably 1: 5-8. In the present invention, the catalyst includes one or both of potassium carbonate and cesium carbonate; the preferable molar ratio of the spiro tetraphenol to the catalyst is 1: 5-7. In the present invention, the organic solvent preferably includes N-methylpyrrolidone, N-dimethylformamide, or N, N-dimethylacetamide; the total mass of the spiro tetraphenol and the p-fluorobenzonitrile in the mixed material liquid accounts for 15-25% of the mass of the organic solvent.
In the invention, after the spiro tetraphenol and the p-fluorobenzonitrile are preferably mixed, the temperature is raised to the substitution reaction temperature, and then the catalyst is added. The spiro tetraphenol and the p-fluorobenzonitrile are preferably mixed under the protection of nitrogen, and the spiro tetraphenol and the p-fluorobenzonitrile are preferably mixed and then stirred for 0.5h at room temperature, then the temperature is raised to the substitution reaction temperature, and the catalyst is added. In the invention, the temperature of the substitution reaction is preferably 120-150 ℃, and more preferably 130-140 ℃; the time is preferably 12-14 h, and the heating rate of heating to the substitution reaction temperature is preferably 10-20 ℃/min; the invention preferably adopts a microwave heating mode to carry out the substitution reaction, and the frequency of the microwave is preferably 2-3 GHz. After the substitution reaction is finished, preferably, the substitution reaction product is discharged into a mixed system with the volume ratio of N, N-dimethylformamide to deionized water being 1:1, the system is heated to the reflux temperature, poor solvent deionized water is added until precipitation just occurs, stirring is carried out until precipitation does not disappear, and then solid-liquid separation, solid drying and recrystallization are sequentially carried out to obtain the tetracyano spiro compound.
In the present invention, the tetracyanospirocyclic compound has the structure of formula IV:
after the tetracyano spiro compound is obtained, the tetracyano spiro compound is hydrolyzed in an alkaline solution, and then a system is adjusted to be acidic, so that the polyacid monomer with the structure shown as a formula I is generated.
In the present invention, the alkaline solution is preferably an aqueous sodium hydroxide solution, and the mass concentration of the aqueous sodium hydroxide solution is preferably 40% to 50%, and more preferably 45%; the molar ratio of the tetracyanospiro compound to sodium hydroxide is preferably 1:8.5 to 9.5, and more preferably 1: 8.8. In the present invention, the hydrolysis is preferably carried out in an organic solvent; the organic solvent is preferably a mixed solvent of water and absolute ethyl alcohol in a volume ratio of 1: 0.5-1.5. In the invention, the hydrolysis temperature is preferably 80-100 ℃, more preferably 90 ℃, and the time is preferably 15-20 h. In the invention, the tetracyano spiro compound is hydrolyzed under alkaline condition to generate carboxylate.
After the hydrolysis is completed, the system is adjusted to be acidic, and the polyacid monomer with the structure shown as the formula I is generated. After the hydrolysis is finished, preferably evaporating ethanol, collecting filtrate, cooling and discharging the filtrate into deionized water, then adjusting the pH value of the system to 1.5-2.5, preferably 2, so that carboxylate radicals in carboxylate salts are converted into carboxyl groups to generate the polyacid monomer with the structure shown in the formula I. The present invention is not particularly limited to the regulator for regulating the system to acidity, as long as the pH of the system can be regulated to acidity. And (3) adjusting the pH value of the system to be acidic, and then separating out a white substance, preferably collecting the white substance, and then sequentially performing suction filtration, washing and drying on the white substance to obtain the polyacid monomer with the structure shown in the formula I.
When the polyacid monomer has a structure shown in formula II, the preparation method of the polyacid monomer comprises the following steps:
(a) heating, refluxing and cooling an acetone solution of hydrogen iodide, an acetic acid solution of catechol and an acetic acid solution of hydroxybenzene to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate the spiro trisphenol; the spiro trisphenol has a structure shown in formula V:
(b) carrying out substitution reaction on the spiro-trisphenol obtained in the step (a) and p-fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain a tetracyanospiro-compound, wherein the catalyst comprises one or two of potassium carbonate and cesium carbonate; the tricyano spiro compound has a structure shown in formula VI:
(c) hydrolyzing the tricyano spiro compound obtained in the step (b) in an alkaline solution, and then adjusting the system to be acidic to generate the polyacid monomer with the structure of formula II.
The method comprises the steps of heating, refluxing and cooling an acetone solution of hydrogen iodide, an acetic acid solution of catechol and an acetic acid solution of hydroxybenzene to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate the spiro trisphenol. In the invention, the molar ratio of hydrogen iodide in the acetone solution of hydrogen iodide to catechol in the acetic acid solution of catechol and the molar ratio of hydroxybenzene in the acetic acid solution of hydroxybenzene is preferably 1: 1-4, and more preferably 1: 2-3. In the present invention, the mass concentration of hydrogen iodide in the acetone solution of hydrogen iodide is preferably 80% to 99%, and more preferably 85%; the mass concentration of the catechol in the catechol acetic acid solution is preferably 10-55%, more preferably 20-50%, and more preferably 30-40%, and the mass concentration of the acetic acid in the catechol acetic acid solution is preferably 10-40%, and more preferably 20-30%; the mass concentration of the hydroxybenzene in the acetic acid solution of the hydroxybenzene is preferably 10% to 85%, and more preferably 20% to 50%, and the mass concentration of the acetic acid in the acetic acid solution of the hydroxybenzene is preferably 10% to 40%, and more preferably 20% to 30%. In the present invention, the acetone functions to provide a reaction environment, and the acetic acid functions as a catalyst. In the invention, the heating reflux time is preferably 10-15 h; the heating reflux is preferably carried out under nitrogen protection. In the invention, the heating reflux has the function of fully heating the system, improving the reaction progress degree and shortening the reaction progress time. After the heating reflux is finished, the mixed solution is cooled to obtain a supersaturated solution. The present invention is not particularly limited to the particular embodiment of cooling, and may be practiced in a manner well known to those skilled in the art.
After the supersaturated solution is obtained, the invention carries out hydrothermal treatment on the supersaturated solution to separate out the spiro trisphenol. In the present invention, the temperature of the hydrothermal treatment is preferably 200 to 240 ℃, more preferably 210 to 230 ℃, and the pressure is preferably 1 to 0.5GPa, more preferably 100 to 400 MPa. In the present invention, it is preferable that the supersaturated solution precipitate white crystals under the above-mentioned conditions of high temperature and high pressure. The white crystals are preferably washed to obtain the spiro trisphenol, the washing detergent preferably comprises glacial acetic acid and dichloromethane, and the white crystals are preferably washed alternately by the glacial acetic acid and the dichloromethane.
In the present invention, the spirocyclic trisphenol has a structure represented by formula V:
after the spiro-trisphenol is obtained, the spiro-trisphenol and the fluorobenzonitrile are subjected to substitution reaction in the presence of a catalyst and an organic solvent to obtain the tricyano-spiro-compound.
The invention mixes the spiro-trisphenol, the p-fluorobenzonitrile, the catalyst and the organic solvent to form mixed feed liquid. In the invention, the molar ratio of the spirocyclic trisphenol to the p-fluorobenzonitrile is preferably 1: 4-9, and more preferably 1: 5-8. In the present invention, the catalyst includes one or both of potassium carbonate and cesium carbonate; the preferable molar ratio of the spiro trisphenol to the catalyst is 1: 5-7. In the present invention, the organic solvent preferably includes N-methylpyrrolidone, N-dimethylformamide, or N, N-dimethylacetamide; the total mole number of the spiro-trisphenol and the p-fluorobenzonitrile in the mixed material liquid and the volume ratio of the organic solvent are preferably 7-7.5 mmol/mL.
In the invention, after the spiro trisphenol and the p-fluorobenzonitrile are preferably mixed, the temperature is raised to the substitution reaction temperature, and then the catalyst is added. The invention preferably mixes the spiro-trisphenol and the p-fluorobenzonitrile under the protection of nitrogen, and the invention preferably mixes the spiro-trisphenol and the p-fluorobenzonitrile, then stirs for 0.5h at room temperature, then heats up to the substitution reaction temperature, and then adds the catalyst. In the invention, the temperature of the substitution reaction is preferably 120-150 ℃, and more preferably 130-140 ℃; the time is preferably 12-14 h, and the heating rate of heating to the substitution reaction temperature is preferably 10-20 ℃/min; the invention preferably adopts a microwave heating mode to carry out the substitution reaction, and the frequency of the microwave is preferably 2-3 GHz. After the substitution reaction is completed, the present invention preferably discharges the substitution reaction product in N, N-dimethylformamide: in a mixed system with the volume ratio of deionized water of 1:1, heating the system to a reflux temperature, adding poor solvent deionized water until precipitation is just generated and stirring is carried out and precipitation does not disappear, and then carrying out solid-liquid separation, solid drying and recrystallization in sequence to obtain the tricyano spiro compound.
In the present invention, the tricyano spiro compound has the structure of formula IV:
after the tricyano spiro compound is obtained, the tricyano spiro compound is hydrolyzed in an alkaline solution, and then a system is adjusted to be acidic, so that the polyacid monomer with the structure shown as a formula II is generated.
In the invention, the alkaline solution is preferably an aqueous sodium hydroxide solution, and the mass concentration of the aqueous sodium hydroxide solution is preferably 45%; the molar ratio of the tricyano spiro compound to sodium hydroxide is preferably 1: 6.6. In the present invention, the hydrolysis is preferably carried out in an organic solvent; the organic solvent is preferably a mixed solvent of water and absolute ethyl alcohol in a volume ratio of 1: 1. In the invention, the hydrolysis temperature is preferably 90 ℃, the heating rate is preferably 20 ℃/min, and the time is preferably 15-20 h. In the invention, the tricyano spiro compound is hydrolyzed under alkaline condition to generate carboxylate.
After the hydrolysis is completed, the system is adjusted to be acidic, and the polyacid monomer with the structure of formula II is generated. After the hydrolysis is finished, preferably evaporating ethanol, collecting filtrate, cooling and placing the filtrate in deionized water, and then adjusting the pH value of the system to 2 to convert carboxylate radicals in carboxylate into carboxyl groups to generate the polyacid monomer with the structure shown in the formula II. The present invention is not particularly limited to the regulator for regulating the system to acidity, as long as the pH of the system can be regulated to acidity. And (3) adjusting the pH value of the system to be acidic, and then separating out a white substance, preferably collecting the white substance, and then sequentially performing suction filtration, washing and drying on the white substance to obtain the polyacid monomer.
The invention provides polyamide, which has a structure shown in a formula VII:
wherein one of the four R substituents is H and the remaining three R substituents are
Or all four R substituents are
Wherein AR has a structure according to any one of formulas 1 to 4:
in the present invention, the structure represented by formula VII is a structural unit of the polyamide.
The invention also provides a preparation method of the polyamide in the technical scheme, which comprises the following steps:
under the protective atmosphere, carrying out polycondensation reaction on a polyacid monomer, a salt forming agent and a diamine monomer in a polar organic solvent, and then cooling to obtain polyamide; the polyacid monomer is the polyacid monomer in the technical scheme or the polyacid monomer prepared by the method in the technical scheme.
In the present invention, the protective atmosphere preferably comprises nitrogen or argon. In the invention, the salt forming agent is preferably potassium carbonate, and the molar ratio of the polyacid monomer to the salt forming agent is preferably 1: 2-2.5. In the invention, the molar ratio of the polyacid monomer to the diamine monomer is preferably 1: 2-4; the mass ratio of the total mass of the polyacid monomers, the salt forming agent and the diamine monomers to the organic solvent is preferably 15-20: 100. According to the invention, preferably, the polyacid monomers are dissolved in the organic solvent, then the salt forming agent is added, the stirring is carried out for 2-3 h at room temperature, and then the mixture is mixed with the diamine monomers.
In the present invention, the structure of the diamine monomer is preferably: h2N-AR-NH2(ii) a The AR has a structure represented by any one of formulas 1 to 4:
after the mixing is completed, the present invention performs a polycondensation reaction. In the present invention, the polycondensation reaction preferably includes two stages of pre-polycondensation and deep polycondensation in this order; the temperature of the pre-polycondensation is preferably 120-200 ℃, and the time is preferably 15-20 h; the temperature of the deep polycondensation is preferably 265-300 ℃, and the time is preferably 2-3 h.
After the polycondensation reaction is completed, the reaction system is preferably cooled to obtain polyamide in the present invention. The present invention does not require any particular embodiment of the cooling, and in the present embodiment, a natural cooling mode is preferably used. In the present invention, the temperature after cooling is preferably 20 to 30 ℃, and more preferably 25 ℃. The viscous polyamide is preferably washed alternately by deionized water and ethanol, the deionized water washing is favorable for removing a salt forming agent, and the ethanol washing is favorable for removing residual organic solvent. In the present invention, the washed polycondensation reaction product is preferably dried to obtain polyamide. In the present invention, the drying is preferably drying under reduced pressure; the drying temperature is preferably 100 ℃ and the drying time is preferably 12 h.
The invention also provides a polyamide film, which comprises the polyamide in the technical scheme or the polyamide prepared by the method in the technical scheme; the thickness of the polyamide film is 60-70 um.
In the present invention, the method for producing the polyamide film is preferably: dissolving the polyamide in an N, N-dimethylacetamide solvent to form a polyamide solution;
and coating the polyamide solution on the surface of a substrate, and sequentially carrying out temperature programming and cooling to obtain the polyamide film.
In the present invention, the solid content of the polyamide solution is preferably 10% to 20%.
The present invention does not particularly require the kind of substrate, and a substrate for preparing a thin film, which is well known to those skilled in the art, may be used.
In the present invention, the programmed temperature rise preferably includes four stages, specifically, a first stage, a second stage, a third stage, and a fourth stage; the temperature of the first stage is preferably 60-80 ℃, and the time is preferably 4-5 h; the temperature of the two stages is preferably 80-100 ℃, the further preferred temperature is 90 ℃, and the time is preferably 12-14 h; the temperature of the three stages is preferably 110-130 ℃, further preferably 120 ℃, and the time is preferably 4-5 h; the temperature of the four stages is preferably 140 ℃ to 160 ℃, more preferably 150 ℃, and the time is preferably 4h to 5 h.
In the present invention, the cooling is preferably natural cooling.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.
Example 1
Adding 85g of 99% by mass HI aqueous solution into 15mL of acetone to form a mixed solution, and adding the formed mixed solution into 170g of catechol-containing acetic acid aqueous solution, wherein the mass concentration of catechol in the catechol-containing acetic acid aqueous solution is 48%, and the mass concentration of acetic acid in the catechol-containing acetic acid aqueous solution is 40%. Heating and refluxing the obtained solution at 120 ℃ for 10h, then cooling to room temperature to obtain a supersaturated solution, precipitating a white microcrystalline compound from the obtained supersaturated solution at 220 ℃ and under high temperature and high pressure of 0.3GPa by a hydrothermal crystallization method, filtering, and alternately washing with glacial acetic acid and dichloromethane for three times to obtain 18.0432g of the spiro tetraphenol compound.
Adding 15mmol of prepared spiro tetraphenol compound, 64mmol of p-fluorobenzonitrile, 12mL of N-methylpyrrolidone into a 250mL three-neck flask with a mechanical stirring device, stirring until the total solid content of a reaction system is 15%, completely dissolving raw materials, heating to 150 ℃ by adopting a microwave with the frequency of 150GHz at the heating rate of 10 ℃/min under the protection of nitrogen, and adding 75mmol of potassium carbonate catalyst. Detecting by TLC until the raw material point disappears, namely ending the reaction, and stopping the reaction; after the reaction is finished, the system is discharged into a mixed system with the volume ratio of N, N-dimethylformamide to deionized water being 1:1, the system is heated to the reflux temperature, poor solvent deionized water is added until precipitation just occurs, and the mixture is stirred and does not disappear to obtain 11.1725g of tetracyano spiro tetraphenol compound.
The structure of the product of the tetracyano spiro tetraphenol compound prepared by the invention is as follows:
adding 8mmol of the obtained tetracyano spiro-tetraphenol compound into a 250mL three-necked flask provided with a mechanical stirring device, adding 68mL of a mixed reaction system of deionized water and absolute ethyl alcohol in a volume ratio of 1:1, adding a 45% sodium hydroxide aqueous solution (containing 70.4mmol of sodium hydroxide) with the mass concentration of 3GHz and the output power of 900W serving as an energy source, heating the system to 90 ℃ at the heating rate of 20 ℃/min, reacting the system for 20h, detecting by TLC (thin layer chromatography) until a raw material point disappears, evaporating the ethanol, collecting filtrate, cooling the filtrate, placing the filtrate in deionized water, adjusting the pH value to 2 until a white substance is separated out, collecting a precipitate, performing suction filtration, washing a filter cake to be neutral by using the deionized water, and performing vacuum drying on the product at 100 ℃ for 12h to obtain 5.2533g of the polyacid monomer.
The polyacid monomer obtained in example 1 has the following structure:
example 2
Adding 5g of 99% by mass HI aqueous solution into 10mL of acetone to form a mixed solution, adding the formed mixed solution into 100mL of acetic acid solution containing 105mmol of catechol, wherein the mass concentration of acetic acid in the acetic acid solution is 40%, and then adding the mixed solution into 100mL of acetic acid solution containing 150mmol of hydroxybenzene, wherein the mass concentration of acetic acid in the acetic acid solution is 40%. Stirring, heating and refluxing for 15h under the protection of nitrogen gas, cooling to room temperature to obtain supersaturated solution, separating out white microcrystalline compound at 240 deg.C and 0.5GPa from the supersaturated solution by hydrothermal crystallization, filtering, and alternately washing with glacial acetic acid and dichloromethane for three times to obtain spiro trisphenol compound.
15mmol of spiro trisphenol compound, 64mmol of p-fluorobenzonitrile and 11mL of N-methylpyrrolidone are added into a 250mL three-neck flask provided with a mechanical stirring device, the mixture is stirred until the raw materials are completely dissolved, the temperature is raised to 150 ℃ by adopting a microwave with the frequency of 150GHz at the temperature rise rate of 10 ℃/min under the protection of nitrogen, and 105mmol of cesium carbonate catalyst is added. Detecting by TLC until the raw material point disappears, namely ending the reaction, and stopping the reaction; after the reaction is finished, discharging the system into a mixed system with the volume ratio of N, N-dimethylformamide to deionized water being 1:1, heating the system to the reflux temperature, adding poor solvent deionized water until precipitation is just carried out, stirring and the precipitation does not disappear, and obtaining 9.4159g of tricyano spiro compound, wherein the structure of the tricyano spiro compound is as follows:
adding 8mmol of tricyano spiro compound into a 250mL three-necked flask provided with a mechanical stirring device, adding 68mL of deionized water and anhydrous ethanol into a mixed reaction system with the volume ratio of 1:1, adding a 45% sodium hydroxide aqueous solution (containing 70.4mmol of sodium hydroxide) with the frequency of 2GHz and the output power of 900W as an energy source, heating the system to 90 ℃ at the heating rate of 20 ℃/min, reacting for 20h, detecting by TLC until the raw material point disappears, namely finishing the reaction, evaporating the ethanol, collecting the filtrate, cooling and placing the filtrate in deionized water, adjusting the pH value to 2 until white matters are separated out, collecting the precipitate, carrying out suction filtration, washing a filter cake with deionized water to be neutral, and carrying out vacuum drying on the product at 100 ℃ for 12h to obtain 4.3823g of polyacid monomer, wherein the polyacid monomer has the following structure:
application example 1
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 1 and 13mL of N, N-dimethylacetamide are added to ensure that the solid content of the system is 15 percent, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 3 hours at room temperature, 5mmol of phenylenediamine is added, the mixture reacts for 20 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly increased to 265 ℃, the mixture is further polycondensed for 2 hours, the polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by adopting deionization and ethanol to fully remove residual salt forming agents and solvents, the pressure is reduced at 100 ℃ for 12 hours to obtain 1.9799g of dry resin, the label is PA-1, and the obtained product has the following structure:
application example 2
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 1 and 13mL of N, N-dimethylacetamide are added, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 2 hours at room temperature, 6mmol of benzidine is added, the mixture reacts for 15 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly increased to 300 ℃, the mixture is further polycondensed for 2 hours, the polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, residual salt forming agents and solvents are fully removed, the pressure is reduced for 12 hours at 100 ℃, 2.4670g of dry resin is obtained, the label is PA-2, and the obtained product has the following structure:
application example 3
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 1 and 13mL of N, N-dimethylacetamide are added, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 2.5 hours at room temperature, 6mmol of diaminodiphenyl ether is added, the mixture reacts for 18 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly increased to 280 ℃, the mixture is further polycondensed for 2 hours, the polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, the residual salt former and solvent are fully removed, the temperature is reduced to 100 ℃ for 12 hours, 2.5693g of dry resin is obtained, the label is PA-3, and the obtained product has the structure as follows:
application example 4
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 1 and 13mL of N, N-dimethylacetamide are added, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 3 hours at room temperature, 6mmol of 4, 4' -diaminobenzophenone is added, the mixture reacts for 20 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly increased to 300 ℃, the mixture is further polycondensed for 2 hours, polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, residual salt forming agents and solvents are fully removed, the temperature is reduced to 100 ℃ for 12 hours, 2.6462g of dry resin is obtained, the dry resin is marked as PA-4, and the structure of the obtained product is as follows:
application example 5
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 2 and 13mL of N, N-dimethylacetamide are added, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 2 hours at room temperature, 5mmol of phenylenediamine is added, the mixture reacts for 20 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly raised to 265 ℃, the mixture is further polycondensed for 2 hours, the polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, residual salt forming agents and solvents are fully removed, the pressure is reduced for 12 hours at 100 ℃, 1.5955g of dry resin is obtained, the label is PA-5, and the obtained product has the following structure:
application example 6
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 2 and 13mL of N, N-dimethylacetamide are added, after the polyacid monomer is completely dissolved, 4mmol of potassium carbonate is slowly added to react at room temperature for 2h, 6mmol of benzidine is added to react at 200 ℃ for 20h under the protection of nitrogen, then the temperature is slowly increased to 300 ℃, the polycondensation is further carried out for 2h, the polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, the residual salt forming agent and solvent are fully removed, the pressure is reduced at 100 ℃ for 12h, 1.9607g of dry resin is obtained, the label is PA-6, and the obtained product has the structure as follows:
application example 7
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 2 and 13mL of N, N-dimethylacetamide are added, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 3 hours at room temperature, 5mmol of diaminodiphenyl ether is added, the mixture reacts for 20 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly raised to 265 ℃, the mixture is further polycondensed for 2 hours, the polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, residual salt forming agents and solvents are fully removed, the pressure is reduced for 12 hours at 100 ℃, 2.0375g of dry resin is obtained, the label is PA-7, and the obtained product has the following structure:
application example 8
In a 50mL three-necked flask provided with a nitrogen inlet and outlet, a magnetic stirrer, a thermometer and a condenser, under the protection of nitrogen, 2mmol of the polyacid monomer prepared in example 2 and 13mL of N, N-dimethylacetamide are added, 4mmol of potassium carbonate is slowly added after the polyacid monomer is completely dissolved, the mixture reacts for 3 hours at room temperature, 4mmol of 4, 4' -diaminobenzophenone is added, the mixture reacts for 20 hours at 200 ℃ under the protection of nitrogen, then the temperature is slowly increased to 300 ℃, the mixture is further polycondensed for 2 hours, polyamide is obtained after natural cooling, the obtained viscous polyamide is alternately washed for three times by deionization and ethanol, residual salt forming agents and solvents are fully removed, the temperature is reduced to 100 ℃ and is reduced for 12 hours, 2.0952g of dry resin is obtained, the dry resin is marked as PA-8, and the obtained product has the following structure:
structural characterization
The polyacid monomer prepared in example 1 was subjected to nuclear magnetic resonance test, and the test results are shown in fig. 1, and it can be seen from fig. 1 that the polyacid monomer prepared in the present invention has a structure consistent with the expected structure.
The polyamide prepared by the method disclosed by the invention is subjected to an infrared test, the test result is shown in figure 2, and as can be seen from figure 2, the polyamide prepared by the method disclosed by the invention has a structure consistent with the expected structure.
Performance testing
Solubility test
The solubility of the polyamides prepared in examples 1-4 was tested by the following test methods: the polyamide was dissolved in DMAC, DMF, NMP, DMSO, THF and CHCl, respectively3The concentration of polyamide in the different solvents was 10 mg/mL. The polyamide was tested for its solubility in different solvents, ++: fully dissolving at room temperature; +: heating for complete dissolution; + -: partial dissolution; - -: heating for insolubilization. The test results are shown in table 1.
TABLE 1 solubility of polyamides prepared in application examples 1 to 6
| Solvent/sample | Application example 1 | Application example 2 | Application example 3 | Application example 4 |
| DMAC | ++ | ++ | ++ | ++ |
| DMF | ++ | ++ | ++ | ++ |
| NMP | ++ | ++ | ++ | ++ |
| DMSO | ++ | ++ | ++ | ++ |
| THF | ++ | ++ | ++ | ++ |
| CHCl3 | ++ | ++ | ++ | ++ |
As can be seen from the test results in Table 1, the polyamide prepared from the polyacid monomer provided by the invention has better solubility. The polyacid monomer provided by the invention introduces groups such as aliphatic structures, ether bonds and the like, so that the polyamide prepared from the polyacid monomer has good solubility in most polar solvents.
Gas separation test
The polyamide film is prepared from the polyamide prepared in application examples 1-4, and the specific preparation method comprises the following steps:
dissolving polyamide in N, N-dimethylacetamide at a solid content of 15%, filtering through a 0.45-micron Teflon filter to remove insoluble substances to obtain a uniform polyamide solution, uniformly coating the solution on a clean 9cm × 9cm glass plate, placing the glass plate in an oven, raising the temperature by adopting a program, treating the glass plate sequentially at 60 ℃/4h, 90 ℃/12h, 120 ℃/4h and 150 ℃/4h, and naturally cooling to obtain the transparent polyamide film.
The polyamide films prepared in examples 1-4 were subjected to a gas separation test, the test results are shown in table 2, and the test method was:
the polyamide prepared by the invention adopts a self-made gas permeameter in the aspect of gas separation, and the specific method is as follows: the gas permeation properties of the polymer films were tested by a pressure differential method (constant volume pressure method). In the testing process, the testing film is sealed in a testing pool by epoxy resin, the upstream pressure is set to be 2atm, the downstream is vacuumized, after the downstream pressure is stabilized for a period of time, the testing is carried out at 35 ℃, the separation effect of the polymer film on gas is represented by a gas permeability coefficient, and the gas separation coefficient represents the selectivity of ideal gas.
TABLE 2 gas separation Performance of Polyamide films of application examples 1 to 4
As can be seen from Table 2, the polyamide film prepared from the polyamide provided by the invention has good gas separation performance, and has a permeability coefficient for nitrogen of 8-43 Barrer, a permeability coefficient for methane of 17-46 Barrer, a permeability coefficient for oxygen of 47-97 Barrer and a permeability coefficient for carbon dioxide of 245-392 Barrer. Therefore, the polyamide film prepared from the polyamide provided by the invention has higher permeability to gas.
The polyamide film provided by the invention has a gas separation coefficient of 9.1-34.1 for a mixed gas of carbon dioxide and nitrogen, a gas separation coefficient of 8.5-16.1 for a mixed gas of carbon dioxide and methane, and a gas separation coefficient of 2.3-7.1 for a mixed gas of oxygen and nitrogen, and the calculation method of the gas separation coefficient is αA/B＝PA/PB，PAAnd PBThe permeability coefficients of the two gases A and B are respectively. Therefore, the polyamide film prepared from the polyamide provided by the invention has high selectivity to gas, namely, after the polyamide film is prepared from the polyamide provided by the invention, the polyamide film has the characteristic of high permeability while good selectivity is ensured.
In conclusion, the polyamide prepared by the polyacid monomer provided by the invention is prepared by adding DMAC, DMF, NMP, DMSO, THF and CHCl3The polyamide membrane prepared from the polyamide has better solubility, can ensure good selectivity in the field of gas separation, and has the characteristic of high permeability.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A polyacid monomer having a structure of formula I or formula II:
2. a process for preparing a structural polyacid monomer of formula I in claim 1, comprising the steps of:
(1) heating, refluxing and cooling an acetone solution of hydrogen iodide and an acetic acid solution of catechol to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate spiro tetraphenol; the spiro tetraphenol has a structure represented by formula III:
(2) carrying out substitution reaction on the spiro tetraphenol obtained in the step (1) and p-fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain a tetracyanospiro compound, wherein the catalyst comprises one or two of potassium carbonate and cesium carbonate; the tetracyanospiro compound has a structure shown in formula IV:
(3) hydrolyzing the tetracyano spiro-compound obtained in the step (2) in an alkaline solution, and then adjusting the system to be acidic to generate the polyacid monomer with the structure shown as the formula I.
3. A process for preparing a structural polyacid monomer of formula II, as defined in claim 1, comprising the steps of:
(a) heating, refluxing and cooling an acetone solution of hydrogen iodide, an acetic acid solution of catechol and an acetic acid solution of hydroxybenzene to obtain a supersaturated solution, and then carrying out hydrothermal treatment on the supersaturated solution to precipitate the spiro trisphenol; the spiro trisphenol has a structure shown in formula V:
(b) carrying out substitution reaction on the spiro-trisphenol obtained in the step (a) and p-fluorobenzonitrile in the presence of a catalyst and an organic solvent to obtain a tetracyanospiro-compound, wherein the catalyst comprises one or two of potassium carbonate and cesium carbonate; the tricyano spiro compound has a structure shown in formula VI:
(c) hydrolyzing the tricyano spiro compound obtained in the step (b) in an alkaline solution, and then adjusting the system to be acidic to generate the polyacid monomer with the structure of formula II.
4. The preparation method according to claim 2, wherein the molar ratio of hydrogen iodide to catechol in the step (1) is 1: 2-5; the temperature of the hydrothermal treatment in the step (1) is 200-240 ℃, and the pressure is 1 MPa-0.5 GPa.
5. The method according to claim 3, wherein the molar ratio of hydrogen iodide, catechol, and hydroxybenzene in the step (a) is 1:1 to 4; the temperature of the hydrothermal treatment in the step (a) is 200-240 ℃, and the pressure is 1 MPa-0.5 GPa.
6. The preparation method according to claim 2, wherein the molar ratio of the spirocyclic tetraphenol to the p-fluorobenzonitrile in the step (2) is 1: 4-9; the temperature of the substitution reaction is 120-150 ℃, and the time is 12-14 h.
7. The preparation method according to claim 2, wherein the hydrolysis in the step (3) is carried out at a temperature of 80-100 ℃ for 15-20 h.
8. A polyamide having the structure of formula VII:
wherein one of the four R substituents is H and the remaining three R substituents are
Or all four R substituents are
Wherein AR has a structure according to any one of formulas 1 to 4:
9. a process for producing the polyamide as claimed in claim 8, comprising the steps of:
under the protective atmosphere, carrying out polycondensation reaction on a polyacid monomer, a salt forming agent and a diamine monomer in a polar organic solvent, and then cooling to obtain polyamide; the polyacid monomer is the polyacid monomer of claim 1 or prepared by the method of any one of claims 2 to 7.
10. A polyamide film, characterized in that the polyamide film comprises the polyamide according to claim 8 or the polyamide produced by the method according to claim 9; the thickness of the polyamide film is 60-70 mu m.
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| US4814496A (en) * | 1988-02-18 | 1989-03-21 | General Electric Company | Spiro(bis)indane bis(carboxyphenyl ethers) and derivatives thereof |
| JP2018027900A (en) * | 2016-08-16 | 2018-02-22 | Ｊｆｅケミカル株式会社 | Method for production of aromatic tetracarboxylic acid |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US4814496A (en) * | 1988-02-18 | 1989-03-21 | General Electric Company | Spiro(bis)indane bis(carboxyphenyl ethers) and derivatives thereof |
| JP2018027900A (en) * | 2016-08-16 | 2018-02-22 | Ｊｆｅケミカル株式会社 | Method for production of aromatic tetracarboxylic acid |
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