CN109627212B - Diacid monomer and preparation method thereof, and polyamide and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of organic chemistry, in particular to a diacid monomer and a preparation method thereof, and a polyamide and a preparation method thereof. The diacid monomer provided by the present invention contains a "spiro center" (two rings share one atom), has a non-coplanar structure, increases the rigidity of the molecular chain, and makes the polyamide prepared from the diacid monomer of the present invention. The main chain of the medium polymer cannot rotate freely, which hinders the effective stacking between the molecular chains, resulting in the formation of continuous micropores inside the polyamide, with many holes and loose molecular structure. Therefore, the polyamide prepared from the diacid monomer of the present invention is prepared. The membrane can improve the gas permeability and solubility under the premise of maintaining selectivity; in addition, the polyamide prepared from the diacid monomer provided by the present invention has good solubility.

Description

A kind of diacid monomer and its preparation method and polyamide and its preparation method

technical field

The invention relates to the technical field of organic chemistry, in particular to a diacid monomer and a preparation method thereof, and a polyamide and a preparation method thereof.

Background technique

Gas membrane separation technology is a new type of green separation technology, which has the advantages of high separation efficiency, simple operation, low energy consumption, green and pollution-free, etc. It has been widely used in the fields of medicine, food, biochemistry, energy and environmental protection. Polymer polymer membrane has good separation performance, excellent mechanical properties and physical and chemical properties, so it has become a commonly used gas separation membrane material. Gas separation membrane technology is an important part of many applications of membrane separation technology. , the third generation of gas separation technology after pressure swing adsorption. Compared with traditional gas separation technology, membrane separation has the advantages of low energy consumption, low investment and simple equipment, and has important applications in O ₂ /N ₂ separation, gas dehumidification, CO ₂ recovery, H ₂ separation and recovery, etc.

Polyamide (PA) is a class of high molecular polymers containing imide rings on the main chain. It was synthesized by Bogert and Renshaw in 1908. In 1962, DuPont developed polyamide film products, and then various PA products such as plastics, Laminates, varnished fabrics, adhesives, coatings and fiber impregnations have come out one after another, and polyamide films have been used in gas separation membrane research. With the continuous development and progress of social science and technology, people's application standards for polyamide films in the field of gas membranes are getting higher and higher. The main problems of the current polyamide film are that the permeability of the polyamide film is low, and the solubility of the polyamide film is poor.

SUMMARY OF THE INVENTION

In view of the above problems existing in the polyamide film, the present invention designs a diacid monomer through molecular structure, and the polyamide film obtained from the diacid monomer of the present invention has the advantages of high permeability and good solubility while ensuring good selectivity. specialty.

The invention provides a kind of diacid monomer, has the structure shown in formula I:

Described R' is methyl or trifluoromethyl;

The R substituent group is selected from one of the structures shown in formula II;

Preferably, the diacid monomer has the structure shown in formula III to formula VI:

The present invention also provides the preparation method of the diacid monomer described in the above technical solution,

When R' in described formula I is methyl, the preparation method of described diacid monomer comprises the following steps:

(1) microwave reaction is carried out with bisphenol A and methanesulfonic acid, and the microwave reaction product is discharged in an ice-water bath, and the solid is collected; the solid is heated and sublimated to obtain a methyl diphenol compound;

(2) after the methyl diphenol compound obtained in the step (1), the pyridine monocyano compound and the solvent are mixed, high pressure reaction and normal pressure reaction are carried out successively, and the normal pressure reaction product is discharged into deionized water to obtain dicyano compound;

(3) carrying out microwave reaction with the dicyano compound obtained in the step (2) and acid, and discharging the microwave reaction product in a deionized water system, and then applying a pressure of 20 to 30 Pa to the deionized system to obtain the structure of formula I R' is a diacid monomer of methyl;

When R' is a trifluoromethyl group in the formula I, the preparation method of the diacid monomer comprises the following steps:

(a) bisphenol AF and trifluoroacetic acid are heated and reacted, and the heated reaction product is discharged in an ice-water bath to obtain a trifluoromethyl diphenol compound;

(b) after mixing the trifluoromethyl diphenol compound, pyridine monocyano compound and solvent obtained in the step (a), carry out high pressure reaction and normal pressure reaction successively, and discharge the normal pressure reaction product into deionized water , to obtain a dicyano compound;

(c) carrying out microwave reaction with the acid and the dicyano compound obtained in the step (b), the microwave reaction product is discharged in a deionized water system, and then a pressure of 20 to 30 Pa is applied to the deionized system to obtain the structure of formula I R' is the diacid monomer of trifluoromethyl;

The pressure of the high-pressure reaction in the step (2) and the step (b) is independently 5-10 Mpa.

Preferably, the molar ratio of bisphenol A and methanesulfonic acid in the step (1) is 1:5-8; the frequency of the microwave reaction in the step (1) is 180-220 GHz, and the heating rate of the microwave reaction is 18～22℃/min.

Preferably, the molar ratio of bisphenol AF and trifluoroacetic acid in the step (a) is 1:10～12; the temperature of the heating reaction in the step (a) is 180～220°C, and the time of the heating reaction is 15 ~20h.

Preferably, in the step (2), the molar ratio of the methyl diphenol compound and the pyridine monocyano compound is 1:2-2.4.

Preferably, the temperature of the high-pressure reaction in the step (2) and the step (b) is independently 20-30° C., and the time is 45-50 h.

Preferably, the molar ratio of the dicyano compound to the acid in the step (3) and the step (c) is independently 1:12-16; the temperature of the microwave reaction is independently 100-110°C, and the time is independently For 6 ~ 8h.

The present invention also provides a preparation method of polyamide, comprising the following steps:

Under nitrogen protection, polycondensation reaction of diacid monomer and diamine monomer is carried out in the presence of salt-forming agent and organic solvent to obtain polyamide; the diacid monomer is the diacid monomer described in the above technical solution; The diamine monomer is 1,4-cyclohexanediamine, p-cyclohexyldiamine, 4,4'-diaminodicyclohexyl ether or 4,4'-diaminodicyclohexyl ketone.

The present invention also provides the polyamide prepared by the method described in the above technical solution.

The present invention provides a diacid monomer, the diacid monomer provided by the present invention has the structure shown in formula I, the diacid monomer provided by the present invention contains a "spiro center" (two rings share one atom), and has The non-coplanar structure increases the rigidity of the molecular chain, so that the main polymer chain in the polyamide prepared from the diacid monomer of the present invention cannot rotate freely, which hinders the effective stacking between the molecular chains, resulting in the formation of a continuous polyamide inside the polyamide. Micropores, more holes, and loose molecular structure, so the polyamide film prepared from the diacid monomer of the present invention can improve the gas permeability under the premise of maintaining selectivity; in addition, the diacid provided by the present invention The presence of the flexible group (ether bond) in the monomer increases the free volume and flexibility of the polymer molecular chain, facilitates the penetration of the solvent, and improves the solubility of the polyamide prepared from the diacid monomer. The results of the examples show that the polyamides prepared from the diacid monomers provided by the present invention have good solubility in DMAC, DMF, NMP, DMSO, THF and CHCl ₃ ; and the polyamides prepared from the polyamides of the present invention have good solubility. In the field of gas separation, amide membranes can ensure good selectivity and have the characteristics of high permeability.

Description of drawings

Fig. 1 is the nuclear magnetic spectrum of the diacid monomer that embodiment 3 prepares;

Fig. 2 is the infrared spectrogram of the diacid monomer that embodiment 4 prepares;

Fig. 3 is the infrared spectrogram of the polyamide prepared by embodiment 7～10;

Fig. 4 is the DSC spectrogram of the polyamides prepared in Examples 7-10;

5 is a thermogravimetric diagram of the polyamides prepared in Examples 7-10.

Detailed ways

The invention provides a kind of diacid monomer, has the structure shown in formula I:

Described R' is methyl or trifluoromethyl;

The R substituent group is selected from one of the structures shown in formula II;

In the present invention, the diacid monomer preferably has a structure represented by formula III to formula VI:

The present invention also provides the preparation method of the diacid monomer described in the above technical solution,

When R' in described formula I is methyl, the preparation method of described diacid monomer comprises the following steps:

(1) microwave reaction is carried out with bisphenol A and methanesulfonic acid, and the microwave reaction product is discharged in an ice-water bath, and the solid is collected; the solid is heated and sublimated to obtain a methyl diphenol compound;

(2) after the methyl diphenol compound obtained in the step (1), the pyridine monocyano compound and the solvent are mixed, high pressure reaction and normal pressure reaction are carried out successively, and the normal pressure reaction product is discharged into deionized water to obtain dicyano compound;

(3) carrying out microwave reaction with the dicyano compound obtained in the step (2) and acid, and discharging the microwave reaction product in a deionized water system, and then applying a pressure of 20 to 30 Pa to the deionized system to obtain the structure of formula I R' is a methyl diacid monomer.

In the present invention, microwave reaction of bisphenol A and methanesulfonic acid is carried out, the microwave reaction product is discharged in an ice-water bath, and the solid is collected; the solid is heated and sublimated to obtain a methyl diphenol compound.

In the present invention, the process of preparing methyl diphenol compound from described bisphenol A and methanesulfonic acid is shown in formula VII:

In the present invention, microwave reaction of bisphenol A and methanesulfonic acid is carried out to obtain a microwave reaction product. In the present invention, the molar ratio of the bisphenol A and methanesulfonic acid is preferably 1:5-8, more preferably 1:6-7. In the present invention, the frequency of the microwave reaction is preferably 180-220GHz, more preferably 190-210GHz, and more preferably 200GHz; the power of the microwave reaction is preferably 1100-1300W, more preferably 1200W; the heating rate of the microwave reaction is preferably It is 18-22 degreeC/min, More preferably, it is 20 degreeC/min. In the present invention, the microwave reaction is preferably carried out under nitrogen protection. In the present invention, the microwave reaction is preferably stopped after TLC detects the disappearance of the raw material point.

After the microwave reaction product is obtained, the present invention discharges the microwave reaction product into an ice-water bath, preferably through solid-liquid separation and drying to obtain a solid. In the present invention, the method of solid-liquid separation is preferably suction filtration. In the present invention, the solid substance obtained by solid-liquid separation is preferably dried to obtain a solid.

After the solid is obtained, the present invention heats and sublimes the solid, and preferably collects the sublimated product to obtain the methyl diphenol compound. In the present invention, the temperature of the sublimation by heating is preferably 155-165° C. In the present invention, the purity of the product methyl diphenol compound is preferably improved by heating and sublimating the solid.

After the methyl diphenol compound is obtained, in the present invention, after the methyl diphenol compound, the pyridine monocyano compound and the solvent are mixed, the high pressure reaction and the normal pressure reaction are carried out in sequence, and the normal pressure reaction product is discharged into deionized water, A dicyano compound is obtained.

In the present invention, the methyl diphenol compound, the pyridine monocyano compound and the solvent are mixed to obtain a mixture. In the present invention, the structure of the pyridine monocyano compound is preferably as shown in formula VIII:

wherein X is a halogen atom F, Cl or Br.

In the present invention, the molar ratio of the methyl diphenol compound and the pyridine monocyano compound is preferably 1:2 to 2.4, more preferably 1:2.2 to 2.3. In the present invention, the solid content of the mixture of the methyl diphenol compound, the pyridine monocyano compound and the solvent is preferably 15-20%, more preferably 16-18%.

After the mixture is obtained, the present invention sequentially performs high-pressure reaction and normal-pressure reaction on the mixture to obtain a normal-pressure reaction product. In the present invention, the pressure of the high-pressure reaction is preferably 5-10 MPa, more preferably 6-9 MPa, the temperature of the high-pressure reaction is preferably 20-30°C, and more preferably 25°C; the time of the high-pressure reaction is preferably It is 45 to 50 hours, more preferably 46 to 49 hours. After the high-pressure reaction is completed, the present invention preferably removes the reaction pressure and continues to carry out the normal-pressure reaction, and the temperature of the normal-pressure reaction is preferably 20 to 30° C., more preferably 25° C. The time of the normal-pressure reaction is preferably 5 to 6h .

After the normal pressure reaction is completed, the present invention discharges the obtained normal pressure reaction product into deionized water, preferably through solid-liquid separation, drying and recrystallization to obtain a dicyano compound. In the present invention, the method of solid-liquid separation is preferably suction filtration, and in the present invention, the solid substance obtained by solid-liquid separation is preferably dried. In the present invention, the method for recrystallization preferably comprises: dissolving the crude product to be recrystallized in a good solvent, heating to reflux, and then gradually adding a poor solvent, until the precipitation just precipitates out and does not disappear. In the present invention, the good solvent preferably includes resorcinol, N,N-dimethylformamide or tetrahydrofuran; the poor solvent preferably includes toluene or deionized water.

In the present invention, the process of preparing the dicyano compound from the methyl diphenol compound is shown in formula IX, taking 2-fluoro-5-cyanopyridine as an example:

After the dicyano compound is obtained, in the present invention, the dicyano compound is subjected to a microwave reaction with an acid, and the microwave reaction product is discharged into a deionized water system, and then a pressure of 20-30 Pa is applied to the deionized system to obtain the structure of formula I R' is a methyl diacid monomer.

In the present invention, the microwave reaction of the dicyano compound and the acid is preferably carried out in a mixed solvent, the mixed solvent preferably includes a solvent and a b solvent, and the a solvent preferably includes deionized water or chloroform; The b solvent preferably includes ethanol, ethylene glycol or glycerol; the volume ratio of the a solvent and the b solvent in the mixed solvent is preferably 1:0.5-1.5, more preferably 1:1. In the present invention, the molar ratio of the dicyano compound to the acid is preferably 1:12-16, more preferably 1:14-16; the acid preferably includes aqueous sulfuric acid, aqueous hydrochloric acid, aqueous trifluoroacetic acid or acetic acid In aqueous solution, the mass concentration of the sulfuric acid aqueous solution, hydrochloric acid aqueous solution, trifluoroacetic acid aqueous solution or acetic acid aqueous solution is independently preferably 40%-80%, more preferably 45%-70%, more preferably 50%-60%. In the present invention, the temperature of the microwave reaction is preferably 100 to 110° C., more preferably 105° C., and the time of the microwave reaction is preferably 6 to 8 hours, more preferably 7 hours.

After the microwave reaction is completed, the present invention preferably filters the microwave reaction product while hot, then discharges the filtrate into a deionized water system, and applies a pressure of 20 to 30 Pa, preferably 22 to 28 Pa, to the deionized system, and white matter is precipitated, In the present invention, suction filtration is preferably performed to collect the precipitated white matter, and then the precipitated white matter is successively washed with water to neutrality and dried in vacuum to obtain a diacid monomer whose structure R' of formula I is methyl.

In the present invention, the process of preparing the dicyano compound to obtain the diacid monomer of formula I whose structure R' is methyl is shown in formula X, with 4,4'-(2,2'3,3'- For example:

When R' is a trifluoromethyl group in the formula I, the preparation method of the diacid monomer comprises the following steps:

(a) bisphenol AF and trifluoroacetic acid are heated and reacted, and the heated reaction product is discharged in an ice-water bath to obtain a trifluoromethyl diphenol compound;

(b) after mixing the trifluoromethyl diphenol compound, pyridine monocyano compound and solvent obtained in the step (a), carry out high pressure reaction and normal pressure reaction successively, and discharge the normal pressure reaction product into deionized water , to obtain a dicyano compound;

(c) carrying out microwave reaction with the acid and the dicyano compound obtained in the step (b), the microwave reaction product is discharged in a deionized water system, and then a pressure of 20 to 30 Pa is applied to the deionized system to obtain the structure of formula I R' is a diacid monomer of trifluoromethyl.

In the present invention, bisphenol AF and trifluoroacetic acid are heated and reacted, and the heated reaction product is discharged in an ice-water bath to obtain a trifluoromethyl diphenol compound.

In the present invention, the preparation principle of the trifluoromethyl diphenol compound is shown in formula XI:

In the present invention, bisphenol AF and trifluoroacetic acid are heated and reacted to obtain a heated reaction product. In the present invention, the molar ratio of bisphenol AF and trifluoroacetic acid is preferably 1:10-12; the temperature of the heating reaction is preferably 180-220°C, more preferably 200°C; the time of the heating reaction Preferably it is 14-16h, More preferably, it is 15h.

After the heated reaction product is obtained, the present invention discharges the heated reaction product into an ice-water bath, preferably through solid-liquid separation and drying, to obtain a trifluoromethyl diphenol compound. In the present invention, the specific embodiment of the solid-liquid separation is preferably suction filtration. In the present invention, the solid substance obtained by the solid-liquid separation is preferably dried to obtain a trifluoromethyl diphenol compound.

After the trifluoromethyl diphenol compound is obtained, in the present invention, after the trifluoromethyl diphenol compound, the pyridine monocyano compound and the solvent are mixed, the high pressure reaction and the normal pressure reaction are carried out in sequence, and the normal pressure reaction product is discharged into a In deionized water, the dicyano compound is obtained.

In the present invention, a trifluoromethyl diphenol compound, a pyridine monocyano compound and a solvent are mixed to obtain a mixture. In the present invention, the molar ratio of the trifluoromethyl diphenol compound and the pyridine monocyano compound is preferably 1:2 to 2.4, more preferably 1:2.2 to 2.3. In the present invention, the solid content of the mixture formed by the trifluoromethyl diphenol compound, the pyridine monocyano compound and the solvent is preferably 15-20%, more preferably 16-18%.

After the mixture is obtained, the present invention sequentially performs high-pressure reaction and normal-pressure reaction on the mixture to obtain a normal-pressure reaction product. In the present invention, the pressure of the high-pressure reaction is preferably 5-10 MPa, more preferably 6-9 MPa, the temperature of the high-pressure reaction is preferably 20-30°C, and more preferably 25°C; the time of the high-pressure reaction is preferably It is 45 to 50 hours, more preferably 46 to 49 hours. After the high-pressure reaction is completed, the present invention preferably removes the reaction pressure and continues to carry out the normal-pressure reaction, and the temperature of the normal-pressure reaction is preferably 20 to 30° C., more preferably 25° C. The time of the normal-pressure reaction is preferably 5 to 6h .

After the normal pressure reaction is completed, the present invention discharges the obtained normal pressure reaction product into deionized water, preferably through solid-liquid separation, drying and recrystallization to obtain a dicyano compound. In the present invention, the method of solid-liquid separation is preferably suction filtration, and in the present invention, the solid substance obtained by solid-liquid separation is preferably dried. In the present invention, the method for recrystallization preferably comprises: dissolving the crude product to be recrystallized in a good solvent, heating to reflux, and then gradually adding a poor solvent, until the precipitation just precipitates out and does not disappear. In the present invention, the good solvent preferably includes resorcinol, N,N-dimethylformamide or tetrahydrofuran; the poor solvent preferably includes toluene or deionized water.

After the dicyano compound is obtained, in the present invention, the dicyano compound is subjected to a microwave reaction with an acid, and the microwave reaction product is discharged into a deionized water system, and then a pressure of 20-30 Pa is applied to the deionized system to obtain the structure of formula I R' is a diacid monomer of trifluoromethyl.

In the present invention, the microwave reaction of the dicyano compound and the acid is preferably carried out in a mixed solvent, the mixed solvent preferably includes a solvent and a b solvent, and the a solvent preferably includes deionized water or chloroform; The b solvent preferably includes ethanol, ethylene glycol or glycerol; the volume ratio of the a solvent and the b solvent in the mixed solvent is preferably 1:0.5-1.5, more preferably 1:1. In the present invention, the molar ratio of the dicyano compound to the acid is preferably 1:12-16, more preferably 1:14-16; the acid preferably includes aqueous sulfuric acid, aqueous hydrochloric acid, aqueous trifluoroacetic acid or acetic acid In aqueous solution, the mass concentration of the sulfuric acid aqueous solution, hydrochloric acid aqueous solution, trifluoroacetic acid aqueous solution or acetic acid aqueous solution is independently preferably 40%-80%, more preferably 45%-70%, more preferably 50%-60%. In the present invention, the temperature of the microwave reaction is preferably 100 to 110° C., more preferably 105° C., and the time of the microwave reaction is preferably 6 to 8 hours, more preferably 7 hours.

After the microwave reaction is completed, the present invention discharges the obtained microwave reaction product into a deionized water system, and then applies a pressure of 20 to 30 Pa, preferably 22 to 28 Pa, to the deionized system to precipitate white matter, which is preferably collected by suction filtration in the present invention. The precipitated white matter is then washed with water to neutrality and dried in vacuum successively to obtain a diacid monomer whose structure R' of formula I is a trifluoromethyl group.

The present invention also provides a preparation method of polyamide, comprising the following steps:

Under nitrogen protection, polycondensation reaction of diacid monomer and diamine monomer is carried out in the presence of salt-forming agent and organic solvent to obtain polyamide.

In the present invention, the diacid monomer is the diacid monomer described in the above technical solution; the diamine monomer is 1,4-cyclohexanediamine, p-cyclohexyldiamine, 4,4'-diamine Aminodicyclohexyl ether or 4,4'-diaminodicyclohexyl ketone. In the present invention, the molar ratio of the diacid monomer and the diamine monomer is preferably 0.8-1.2:0.8-1.2, more preferably 1:1.

In the present invention, the diamine monomer is preferably represented by NH ₂ -X-NH ₂ , wherein X preferably has the structure shown in any one of formulas 1-4:

In the present invention, the diacid monomer and the organic solvent are preferably mixed first, and then the salt-forming agent and the diamine monomer are sequentially added to obtain a mixed material. In the present invention, the molar ratio of the diacid monomer and the salt-forming agent is preferably 1:2-3, more preferably 1:2.2-2.8, more preferably 1:2.4-2.6; the salt-forming agent is preferably Includes potassium carbonate, sodium hydride or sodium hydroxide. In the present invention, the organic solvent preferably includes N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone or dimethylsulfoxide. In the present invention, the solid content of the mixed material is preferably 15-20%, more preferably 16-18%. In the present invention, preferably, after adding the salt-forming agent, the reaction is carried out at room temperature for 2-3 hours, and then the diamine monomer is added.

After the mixed material is obtained, the present invention conducts the polycondensation reaction of the mixed material under nitrogen protection. In the present invention, the polycondensation reaction preferably includes a pre-polycondensation reaction and a deep polycondensation reaction that are carried out in sequence; the temperature of the pre-polycondensation reaction is preferably 180-220°C, more preferably 200°C; the time of the pre-polycondensation reaction is preferably It is 15 to 20 hours, more preferably 16 to 18 hours. After the pre-polycondensation reaction is completed, the present invention preferably continues the deep polycondensation reaction, and the temperature of the deep polycondensation reaction is preferably ≥ 265°C, more preferably 265-280°C, more preferably 270-275°C; the time of the deep polycondensation reaction Preferably it is 5-8h, More preferably, it is 6-7h.

In the present invention, the pre-polycondensation reaction and the deep polycondensation reaction are preferably carried out in the presence of a water-carrying agent. When a water-carrying agent exists in the polycondensation reaction system, the temperature of the pre-polycondensation reaction is preferably 180-200° C., and the time is preferably 15- 20h; the temperature of the deep polycondensation reaction is preferably ≥210°C, more preferably 210-230°C, and the time of the deep polycondensation reaction is preferably 15-18h, more preferably 16-17h. In the present invention, the water-carrying agent preferably includes toluene or xylene, and the dosage ratio of the diacid monomer and the water-carrying agent is preferably 1 mmol: 4.5-5.5 mL, more preferably 1 mmol: 5.0 mL.

After the polycondensation reaction is completed, the present invention preferably dissolves the polycondensation reaction product in deionized water after naturally cooling it, and then carries out ethanol reflux washing to remove the residual organic solvent; Methanol and deionized water in a mixed solvent with a volume ratio of 1:1, followed by reflux washing with ethanol to remove residual organic solvent. In the present invention, the washed polycondensation reaction product is preferably dried to obtain a polyamide. In the present invention, the drying is preferably drying under reduced pressure; the drying temperature is preferably 100° C., and the drying time is preferably 12 hours.

The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

Example 1: Preparation of methyl diphenol compound

In a 250mL three-necked flask equipped with a mechanical stirring device, add 10mmol of bisphenol A, 50mmol of methanesulfonic acid, and fully react under the protection of nitrogen for half an hour at room temperature, using a frequency of 200GHz, a microwave of 1200W at 20 The heating rate of ℃/min is warmed up to the melting temperature of the system above 180 ℃, and TLC detects that the reaction ends until the raw material point disappears, and the reaction is stopped. The obtained crude product was placed in a vacuum tube furnace, heated to sublime the crude product, and the sublimation obtained was collected to obtain a methyl diphenol compound, which was vacuum dried at 100 ° C for 12 hours to obtain 1.5980 g of a methyl diphenol compound. The obtained product structure is as follows Mode:

Example 2: Preparation of trifluoromethyl diphenol compound

Add the bisphenol AF of 10mmol, 100mmol trifluoroacetic acid in the tetrafluoro reaction vessel that the mechanical stirring device is housed, fully stir and dissolve at room temperature, place the tetrafluoro reaction vessel that the reaction raw materials are housed in the high temperature reactor, adjust the system heating The temperature was 200°C, the melting reaction was carried out for 15 hours, and the reaction was stopped; after the reaction, the system was discharged into an ice-water bath, suction filtered and dried to obtain a crude product, which was fully dissolved in the good solvent 1,4-dioxane In, add inferior solvent deionized water until just separate out and stir to separate out insoluble, suction filtration, drying obtains trifluoromethyl diphenol compound, the product structure obtained is as follows:

Example 3: Preparation of 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid

The first step of reaction: into a 250mL three-necked flask equipped with a mechanical stirring device, add 6.1682g methyl diphenol, 44mmol of 2-fluoro-5-cyanopyridine, 65mL of N-methylpyrrolidone, and the total amount of the reaction system. The solid content is 15%, stir until all the raw materials are dissolved, apply a high pressure of 10Mpa to the system, react at room temperature for 48 hours, the reaction is over, remove the pressure of the system, react under normal pressure for 5 hours, discharge the material into deionized water, suction filtration, and dry To obtain a crude product, the obtained crude product is dissolved in N,N-dimethylformamide, and after all dissolution, the system is heated to reflux temperature, and deionized water is added as a poor solvent until the precipitation is stirred and the precipitation does not disappear to obtain 9.7801 g of dicyano compound.

The second step reaction: 8mmol of the dicyano compound obtained in the first step reaction was added to a 250mL three-necked flask equipped with a mechanical stirring device, and 68mL of mixed solvent was added, wherein the mixed solvent was deionized with a volume ratio of 1:1. Water and anhydrous ethanol are formed, add 96mmol of sulfuric acid solution with a mass concentration of 45%, use a microwave with a frequency of 2450MHZ and an output power of 900W as an energy source to heat up the system to 105°C with a heating rate of 20°C/min. Reaction for 6～8h, TLC detects the disappearance of the starting material point, which is the end of the reaction, filter while hot (to prevent the precipitation of the product from temperature cooling), collect the filtrate and cool it and place it in deionized water, apply a pressure of 20MPa to the system, until white matter is precipitated, and the precipitate is collected. The product was filtered with suction, the filter cake was washed with deionized water until neutral, and the product was vacuum-dried at 100 °C for 12 h to obtain 3.0902 g of a diacid compound. The obtained product had the following structure:

The diacid monomer prepared in Example 3 was subjected to a nuclear magnetic test. The test results are shown in Figure 1. It can be seen from Figure 1 that the substance prepared by the present invention has the above-mentioned structure.

Example 4: Preparation of 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxo-3,3'-pyridinedioic acid

The first reaction: to a 250 mL three-necked flask equipped with a mechanical stirring device, add 20 mmol of methyl diphenol, 44 mmol of 3-fluoro-2-cyanopyridine, 65 mL of N,N-dimethylformamide, The total solid content of the reaction system is 15%. Stir until all the raw materials are dissolved, apply a high pressure of 5Mpa to the system, and react at room temperature for 48 hours. After the reaction is completed, remove the system pressure. Filtration, drying to obtain the crude product, dissolving the obtained crude product in N,N-dimethylformamide, after all dissolution, the system is heated to the reflux temperature, and the inferior solvent deionized water is added until the precipitation is stirred and the precipitation does not occur. disappeared to obtain 8.4502 g of a dicyano compound.

The second-step reaction: 8mmol of the dicyano compound obtained in the first-step reaction was added to a 250mL three-necked flask equipped with a mechanical stirring device, and 70mL of mixed solvent was added, wherein the mixed solvent was deionized with a volume ratio of 1:1. Water and ethylene glycol are formed, add 100mmol of hydrochloric acid aqueous solution with a mass concentration of 70%, the system is heated to 120 ° C, the system is reacted for 8h, TLC detects that the raw material point disappears and the reaction ends, filter while hot (to prevent temperature cooling product precipitation), collected, concentrated the obtained filtrate by rotary evaporation, collected the obtained white needles, and vacuum-dried the product at 100 ° C for 12 h to obtain 3.5908 g of a diacid compound, and the obtained product structure was as follows:

The diacid monomer prepared in Example 4 was characterized by infrared test. The test results are shown in Figure 2. It can be seen from Figure 2 that the substance prepared by the present invention has the above structure.

Example 5: Preparation of 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxoquinolinic acid

The first step reaction: in a 250mL three-necked flask equipped with a mechanical stirring device, add 20mmol of methyl diphenol, 44mmol of 2-fluoro-5-cyanoquinoline, the total solid content of the reaction system is 20%, stir until All the raw materials were dissolved, a high pressure of 10 MPa was applied to the system, the reaction was carried out at room temperature for 48 hours, the reaction was completed, the pressure of the system was removed, and after the reaction was carried out at normal pressure for 5 hours, the material was discharged into deionized water, suction filtered, and dried to obtain a crude product. Dissolved in tetrahydrofuran, after all dissolved, the system was heated to the reflux temperature, and deionized water was added as a poor solvent until the precipitation was just precipitated and the precipitation did not disappear to obtain 14.0764g of the dicyano compound.

The second-step reaction: add 8 mmol of the dicyano compound obtained in the first-step reaction into a 250 mL three-necked flask equipped with a mechanical stirring device, add 60 mL of deionized water and a mixed solvent with a volume ratio of glycerol of 1:1 , adding 96 mmol of trifluoroacetic acid solution with a mass fraction of 45%, using microwave as an energy source to rapidly heat up the system to 105 ° C, the system reacts for 6 to 8 h, and TLC detects that the reaction ends when the raw material point disappears, filter while hot ( To prevent the precipitation of the product by temperature cooling), collect the filtrate and cool it in deionized water until white matter is precipitated, collect the precipitate, suction filtration, wash the filter cake with deionized water to neutrality, and vacuum dry the product at 100 ° C for 12h to obtain 3.8045g of two Acid compound, the product structure obtained is as follows:

Example 6: Preparation of 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxoisoquinoline trifluoromethyl diacid

The first step reaction: in a 250mL three-necked flask equipped with a mechanical stirring device, add 20mmol of trifluoromethyl diphenol, 44mmol of 2-fluoro-5-cyanoisoquinoline, and the total solid content of the reaction system is 25% , stir until all the raw materials are dissolved, react at room temperature for 48 hours, the reaction is over, discharge the material into deionized water, suction filtration, and dry to obtain a crude product, dissolve the obtained crude product in resorcinol, and after all dissolved, the system is heated up. When the reflux temperature was 120° C., the poor solvent toluene was added until precipitation just occurred and the precipitation did not disappear to obtain 13.2907 g of a dicyano compound.

Second-step reaction: add 8 mmol of the dicyano compound obtained in the first-step reaction into a 250 mL three-necked flask equipped with a mechanical stirring device, add 60 mL of chloroform and glycerol in a mixed solvent with a volume ratio of 1:1 , adding 100 mmol of acetic acid solution with a mass fraction of 80%, using a microwave with a frequency of 2450 MHZ and an output power of 900 W as an energy source to heat the system to 150 ° C with a heating rate of 15 ° C/min, the system reacts for 6-8 h, TLC Detecting that the raw material disappears is the end of the reaction, filter while hot (to prevent the precipitation of the temperature cooling product), collect the filtrate and cool it in deionized water, apply a pressure of 30 MPa to the system until white needles are precipitated, collect the precipitate, and suction filtration , the filter cake was washed with deionized water until neutral, and the product was vacuum-dried at 100 °C for 12 h to obtain 3.0025 g of a diacid compound. The obtained product had the following structure:

Example 7: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid and 1,4-cyclohexanedi The specific process of preparing polyamide from amine is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of Potassium carbonate, react at room temperature for 2～3h, add 2mmol of 1,4-cyclohexanediamine monomer, react at 200℃ for 15～20h under nitrogen protection, then slowly heat up to the melting temperature of the diacid salt of 265℃, and further polycondensate 5h, naturally cooled to obtain polyamide, the obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, fully removed residual solvent, and decompressed at 100 ° C for 12h to obtain 1.1076g of dry resin, marked as PA-a, the obtained product The structure is as follows:

Example 8: Preparation of poly(4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid and p-cyclohexyldiamine amide, the specific process is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of Potassium carbonate, react at room temperature for 2～3h, add 2mmol of p-bicyclohexyldiamine monomer, react at 200℃ for 15～20h under nitrogen protection, then slowly heat up to the melting temperature of the diacid salt of 270℃, further polycondensate for 5h, and cool down naturally To obtain polyamide, the obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, fully removed residual solvent, and decompressed at 100 °C for 12 h to obtain 1.302 g of dry resin, marked as PA-b, and the obtained product structure was as follows:

Example 9: 3,3'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid and 4,4'-diamino Dicyclohexyl ether prepares polyamide, and the specific process is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of Potassium carbonate, react at room temperature for 2～3h, add 2mmol of 4,4'-diaminodicyclohexyl ether, react at 200℃ for 15～20h under nitrogen protection, then slowly heat up to the melting temperature of the diacid salt of 270℃, further Polycondensation was carried out for 6 hours, and the polyamide was naturally cooled to obtain polyamide. The obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, and the residual solvent was fully removed. The pressure was reduced at 100 °C for 12 hours to obtain 1.2202 g of dry resin, which was marked as PA-c. The product structure is as follows:

Example 10: 2,2'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid and 4,4'-diamino Dicyclohexyl ketone prepares polyamide, and the specific process is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of Potassium carbonate, react at room temperature for 2～3h, add 2mmol of 4,4'-diaminodicyclohexyl ketone, react at 200℃ for 15～20h under nitrogen protection, then slowly heat up to the melting temperature of the diacid salt at 270℃, Further polycondensation for 6h, natural cooling to obtain polyamide, the obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, fully removed residual solvent, and decompressed at 100 °C for 12h to obtain 1.3805g of dry resin, marked as PA-d, to obtain The product structure is as follows:

Example 11: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxoquinolinic acid and 1,4-cyclohexane Diamine prepares polyamide, the specific process is as follows

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxoquinolinic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of potassium carbonate, react at room temperature for 2~3h, add 2mmol of 1,4-cyclohexanediamine monomer, react at 200°C for 15~20h under nitrogen protection, then slowly heat up to the melting temperature of the diacid salt of 265°C, and further Polycondensation was carried out for 5 hours, and the polyamide was naturally cooled to obtain a polyamide. The obtained viscous polyamide was placed in deionized water, washed with ethanol for three times under reflux, and the residual solvent was fully removed, and the pressure was reduced at 100 °C for 12 hours to obtain 1.3406g of dry resin. The structure of the obtained product is as follows:

Example 12: Preparation of 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-6,6'-dioxoisopyridinedioic acid and p-bicyclohexyldiamine Polyamide, the specific process is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxoquinolinic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol The potassium carbonate was reacted at room temperature for 2 to 3 hours, 2 mmol of p-bicyclohexyldiamine monomer was added, and the reaction was carried out at 200 °C for 15 to 20 hours under nitrogen protection, and then slowly heated to above the melting temperature of the diacid salt of 265 °C, and further polycondensed for 6 hours. Naturally cooled to obtain polyamide, the obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, fully removed residual solvent, and decompressed at 100 ° C for 12 h to obtain 1.4002 g of dry resin. The obtained product structure is as follows:

Example 13: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-5,5'-dioxopyridinedioic acid and 4,4'-diamino Dicyclohexyl ether prepares polyamide, and the specific process is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxoquinolinic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of potassium carbonate, react at room temperature for 2~3h, add 2mmol of 4,4'-diaminodicyclohexyl ether, react at 200℃ for 15~20h under nitrogen protection, and then slowly heat up to the melting temperature of the diacid salt above 265℃ , further polycondensed for 8h, naturally cooled to obtain polyamide, the obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, fully removed the residual solvent, and decompressed at 100 °C for 12h to obtain 1.2509g of dry resin. The obtained product structure is as follows :

Example 14: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-5,5'-dioxoisoquinolinic acid and 4,4'- Diaminodicyclohexyl ketone prepares polyamide, and the specific process is as follows:

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of N,N-dimethylacetamide, to make the solid content of the system 15%, after all dissolved, slowly add 4mmol of Potassium carbonate, react at room temperature for 2～3h, add 2mmol of 4,4'-diaminodicyclohexyl ketone, react at 200℃ for 15～20h under nitrogen protection, then slowly heat up to the melting temperature of the diacid salt above 265℃ , further polycondensed for 8h, naturally cooled to obtain polyamide, the obtained viscous polyamide was placed in deionized water, washed three times with ethanol under reflux, fully removed the residual solvent, and decompressed at 100 °C for 12h to obtain 1.5805g of dry resin. The obtained product structure is as follows :

Example 15: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-5,5'-dioxo-trifluoromethylpicolinic acid and 1, 4-cyclohexanediamine prepares polyamide, and the specific process is as follows

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of N-methylpyrrolidone, to make the solid content of the system 15%, after all dissolved, slowly add 6mmol of potassium carbonate, 10mL Add 2 mmol of 1,4-cyclohexanediamine monomer, react at 200 °C for 15-20 h under nitrogen protection, then heat up to 210 °C for further polycondensation with water for 15 h, and naturally cool down to obtain polyamide, and the obtained viscous polyamide In deionized water, ethanol was refluxed for three times, the residual solvent was fully removed, and the pressure was reduced at 100 ° C for 12 h to obtain 1.3982 g of dry resin. The obtained product structure was as follows:

Example 16: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-5,5'-dioxo-trifluoromethylisoquinolinic acid with 4,4'-diaminodicyclohexyl ether prepares polyamide, the specific process is as follows

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxopyridinedioic acid, 13mL of dimethyl sulfoxide, to make the solid content of the system 15%, after all dissolved, slowly add 6mmol of sodium hydride, 10mL Add 2 mmol of 4,4'-diaminodicyclohexyl ether, react at 200 °C for 20 h under nitrogen protection, then heat up to 230 °C for further polycondensation with water for 18 h, and naturally cool down to obtain polyamide, and the obtained viscous polyamide In a mixed solvent of methanol:ionized water=1:1, ethanol was refluxed for three times to fully remove the residual solvent, and 1.0058g of dry resin was obtained under reduced pressure at 100°C for 12h, and the obtained product structure was as follows:

Example 17: 4,4'-(2,2'3,3'-tetrahydro-1,1'-spirobisindene)-5,5'-dioxo-trifluoromethylisoquinolinic acid with 4,4'-diaminodicyclohexyl ketone prepares polyamide, the specific process is as follows

In a 50 mL three-necked flask equipped with a nitrogen inlet and outlet, a magnetic stirring bar, a thermometer and a condenser, under the protection of nitrogen, 2.0 mmol of 4,4'-(2,2'3,3'-tetrahydro- 1,1'-spirobisindene)-6,6'-dioxoisoquinoline dioic acid, 14 mL of N,N-dimethylformamide to make the solid content of the system 18%, after all dissolved, slowly add 6 mmol of sodium hydroxide, 2 mmol of 4,4'-diaminodicyclohexyl ketone, reacted at 200 °C for 20 h under nitrogen protection, then heated to 270 °C for further polycondensation for 5 h, naturally cooled to obtain polyamide, and the obtained viscous polyamide was In the mixed solvent of methanol: ionized water = 1:1, ethanol was refluxed for three times, the residual solvent was fully removed, and the pressure was reduced at 100 ° C for 12 h to obtain 1.6091 g of dry resin, and the obtained product structure was as follows:

Structural Characterization and Performance Testing

The infrared spectrum test was carried out on the polyamides prepared in Examples 7-10, and the test results are shown in FIG. 3 . In the present invention, the polyamide synthesized in Example 7 is represented by PA-a, the polyamide synthesized in Example 8 is represented by PA-b, the polyamide synthesized in Example 9 is represented by PA-c, and the polyamide synthesized in Example 10 is represented by PA-c. Amides are represented by PA-d. It can be seen from FIG. 3 that the structure of the substance prepared by the present invention is consistent with the expected structure.

DSC tests were performed on the polyamides prepared in Examples 7-10, and the test results are shown in Figure 4 . It can be seen from FIG. 4 that the glass transition temperature of the polyamide provided by the present invention is above 230° C., and the thermal stability is good.

The thermal weight loss properties of the polyamides prepared in Examples 7-10 were tested, and the test results are shown in Figure 5. It can be seen from Figure 5 that the polyamides provided by the present invention have good thermal stability, 5% under nitrogen atmosphere. The thermogravimetric temperature is above 480℃. The present invention adopts TA2050 type thermogravimetric analyzer to measure in nitrogen atmosphere, the temperature rise range is 100-800 DEG C, and the flow rate of atmosphere gas is 10ml/min.

Solubility Test

The solubility of the polyamides prepared in Examples 7-10 was tested, and the test method was as follows: the polyamides were dissolved in DMAC, DMF, NMP, DMSO, THF, CHCl ₃ respectively, and the concentration of the polyamides in different solvents was 10 mg /mL. To test the solubility of polyamide in different solvents, ++: fully dissolved at room temperature; +: fully dissolved by heating; +-: partially dissolved; --: insoluble by heating. The test results are shown in Table 1.

Solubility of polyamides prepared in Table 1 Examples 7-10

Solvent/Sample Example 7 Example 8 Example 9 Example 10 DMAC ++ ++ ++ ++ DMF ++ ++ ++ ++ NMP ++ ++ ++ ++ DMSO ++ ++ ++ ++ THF ++ ++ ++ ++ CHCl₃ ++ ++ ++ ++

It can be seen from the test results in Table 1 that the polyamide prepared from the diacid monomer provided by the present invention has good solubility. The diacid monomer provided by the present invention introduces groups such as aliphatic structure and ether bond, so that the polyamide prepared from the diacid monomer of the present invention has good solubility in the above polar solvents.

Gas separation test

The polyamides prepared in Examples 7-10 of the present invention are prepared into polyamide films, and the specific preparation method is as follows:

The polyamides prepared in Examples 7-10 were respectively dissolved in N,N-dimethylacetamide with a solid content of 15%, configured into a polyamide solution, and filtered through a 0.45 μm Teflon filter to remove insoluble matter to obtain a homogeneous polymer. amide solution, the solution was evenly coated on a clean 9cm×9cm glass plate, placed in an oven with programmed temperature, followed by 60°C/4h, 90°C/12h, 120°C/4h and 150°C/4h after treatment , Natural cooling to transparent polyamide film.

The polyamide films prepared in Examples 7-10 were subjected to a gas separation test. The test results are shown in Table 2. The test method is:

The gas separation test of the polyamide prepared by the present invention adopts a self-made gas permeation instrument, and the specific method is as follows: the gas permeation property of the polymer film is tested by the differential pressure method (constant volume variable pressure method). During the test, the test film was sealed in the test cell with epoxy resin, the upstream pressure was set to 2atm, and the downstream was evacuated to a vacuum. To characterize the separation effect of the polymer film on the gas, the gas separation coefficient represents the selectivity of the ideal gas.

Table 2 Gas separation performance of the polyamide membranes of Examples 7-10

It can be seen from Table 2 that the polyamide provided by the present invention has good gas separation performance after being prepared into a polyamide film. The permeability coefficient of the polyamide film provided by the present invention to nitrogen is 1.12-4.21 Barrer, and the permeability coefficient to methane is 1.17～3.56Barrer, the permeability coefficient of oxygen is 4.20～11.21Barrer, and the permeability coefficient of carbon dioxide is 16.31～44.09Barrer. This shows that the polyamide film prepared by the polyamide provided by the present invention has a high permeability to gas.

The polyamide film provided by the invention has a gas separation coefficient of 10.47-15.67 for a mixed gas of carbon dioxide and nitrogen, a gas separation coefficient of 11.32-13.94 for a mixed gas of carbon dioxide and methane, and a gas separation coefficient of 2.66-2.66 to a mixed gas of oxygen and nitrogen. 4.99. In the present invention, the calculation method of the gas separation coefficient is α _A/B =P _A /P _B , and P _A and P _B are the permeability coefficients of the two gases A and B, respectively. This shows that the polyamide film prepared from the polyamide provided by the present invention has high selectivity to gas, that is, after the polyamide provided by the present invention is prepared into a polyamide film, it has a high permeability while ensuring good selectivity. specialty.

To sum up, the polyamide prepared from the diacid monomer provided by the present invention has good solubility in DMAC, DMF, NMP, DMSO, THF and CHCl ₃ , and the polyamide prepared from the polyamide of the present invention has good solubility. In the field of gas separation, amide membranes can ensure good selectivity and have the characteristics of high permeability.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a diacid monomer, has the structure shown in formula I:

Described R' is methyl or trifluoromethyl; The R substituent group is selected from one of the structures shown in formula II;

2. The diacid monomer according to claim 1, wherein the diacid monomer has the structure shown in formula III to formula VI:

3. the preparation method of the described diacid monomer of claim 1 or 2, When R' in described formula I is methyl, the preparation method of described diacid monomer comprises the following steps: (1) microwave reaction is carried out with bisphenol A and methanesulfonic acid, and the microwave reaction product is discharged in an ice-water bath, and the solid is collected; the solid is heated and sublimated to obtain a methyl diphenol compound; (2) after the methyl diphenol compound obtained in the step (1), the pyridine monocyano compound and the solvent are mixed, high pressure reaction and normal pressure reaction are carried out successively, and the normal pressure reaction product is discharged into deionized water to obtain dicyano compound; (3) microwave reaction is carried out with the dicyano compound obtained in the step (2) and the acid, the microwave reaction product is discharged in a deionized water system, and then a pressure of 20 to 30 Pa is applied to the deionized system to obtain the structure of formula I R' is a diacid monomer of methyl; When R' is a trifluoromethyl group in the formula I, the preparation method of the diacid monomer comprises the following steps: (a) bisphenol AF and trifluoroacetic acid are heated and reacted, and the heated reaction product is discharged in an ice-water bath to obtain a trifluoromethyl diphenol compound; (b) after the trifluoromethyl diphenol compound obtained in the step (a), the pyridine monocyano compound and the solvent are mixed, the high pressure reaction and the normal pressure reaction are carried out successively, and the normal pressure reaction product is discharged into deionized water , to obtain a dicyano compound; (c) carrying out microwave reaction with the acid and the dicyano compound obtained in the step (b), the microwave reaction product is discharged in a deionized water system, and then a pressure of 20 to 30 Pa is applied to the deionized system to obtain the structure of formula I R' is the diacid monomer of trifluoromethyl; The pressure of the high-pressure reaction in the step (2) and the step (b) is independently 5-10 Mpa. 4. preparation method according to claim 3, is characterized in that, in described step (1), the molar ratio of bisphenol A and methanesulfonic acid is 1:5～8; In described step (1), microwave reaction The frequency of the microwave reaction is 180-220 GHz, and the heating rate of the microwave reaction is 18-22 °C/min. 5. preparation method according to claim 3, is characterized in that, in described step (a), the molar ratio of bisphenol AF and trifluoroacetic acid is 1:10～12; The temperature is 180～220℃, and the time of heating reaction is 15～20h. 6 . The preparation method according to claim 3 , wherein the molar ratio of the methyl diphenol compound and the pyridine monocyano compound in the step (2) is 1:2 to 2.4. 7 . 7 . The preparation method according to claim 3 or 6 , wherein the temperature of the high-pressure reaction in the step (2) and the step (b) is independently 20-30° C., and the time is 45-50 h. 8 . 8. preparation method according to claim 3 is characterized in that, in described step (3) and step (c), the molar ratio of dicyano compound and acid is 1:12～16 independently; 3) The temperature of the microwave reaction in step (c) is independently 100-110° C., and the time is independently 6-8 h. 9. a preparation method of polyamide, comprises the following steps: Under nitrogen protection, polycondensation reaction of diacid monomer and diamine monomer is carried out in the presence of a salt-forming agent and an organic solvent to obtain a polyamide; the diacid monomer is the diacid monomer according to claim 1 or 2 The diamine monomer is 1,4-cyclohexanediamine, p-cyclohexyldiamine, 4,4'-diaminodicyclohexyl ether or 4,4'-diaminodicyclohexyl ketone. 10. The polyamide obtained by the method of claim 9.

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