CN109575275A - A kind of benzene containing dual-tert-butyl and diformazan based structures high dissolubility Nomex and its preparation method and application simultaneously - Google Patents

Abstract

The invention belongs to the field of high-performance aromatic polymers and preparations thereof, in particular to a class of highly soluble polyaramides containing both bis-tert-butylbenzene and dimethyl structures and a preparation method and application thereof. The high-quality aromatic diamine monomer containing bis-tert-butylbenzene and dimethyl structure and the commercial aromatic diacid monomer are added into the organic solvent, and under the action of a catalyst, the reaction is stirred at 100-140 ° C for 3-6h, and the end is completed. After reaction, further sedimentation, washing and drying, a fibrous polyaramide polymer containing both bis-tert-butylbenzene and dimethyl structure and high solubility can be obtained. The solubility of the polyaramide in a specific solvent can reach more than 30 wt %, and it has excellent film-forming properties, and the prepared polymer film has potential application value in the field of gas separation.

Description

A class of highly soluble polyaramides containing both bis-tert-butylbenzene and dimethyl structures and the same Preparation method and application

technical field

The invention belongs to the field of high-performance aromatic polymers and their preparation, in particular to a class of high-soluble polyaramides containing both bis-tert-butylbenzene and dimethyl structures and a preparation method and application thereof.

Background technique

Polyaramides are an important class of high-performance aromatic polymers, which have important application value in the field of membrane separation due to their excellent thermodynamic properties and easy molecular structure design. However, due to the rigidity of the molecular main chain and the strong intermolecular force, the conventional polyaramid is usually insoluble and infusible, and it is difficult to directly use its polymer solution to cast the film. At the same time, the molecular main chain structure of conventional polyaramide is relatively regular, and the gas permeability of the membrane material produced by it is relatively low, which cannot meet the requirements of high-efficiency gas separation equipment.

The study found that by introducing large substituted side groups into the molecular structure of aromatic polymers, the distance between the macromolecular chains of the polymer can be further increased, the dissolving film-forming properties of the polymer can be effectively improved, and the gas permeability of the membrane material can also be improved. sex. The free volume and number of large substituted side groups in the polymer molecular structure have a significant impact on the performance of the polymer membrane material. In theory, the larger the free volume of the large substituted side groups introduced and the greater the number of large substituted side groups introduced, the better the effect of modification. the better. However, the design and preparation of monomers containing multiple large free volumes and their polyaramides are usually difficult, and usually require multi-step reactions to complete. Therefore, there are few studies on them, and their preparation methods are rarely reported.

SUMMARY OF THE INVENTION

The patent of the present invention uses 3,5-di-tert-butylbenzaldehyde and o-toluidine as starting materials, and successfully prepares a kind of bis-tert-butylbenzene macrosubstituted side group and dimethyl structure through a simple one-step reaction. The aromatic diamine monomer was prepared by polycondensation of this monomer with a series of aromatic diacids, and a class of polyaramides containing both bis-tert-butylbenzene and dimethyl structures, a number of bis-tert-butylbenzene and dimethyl amides were prepared. The simultaneous introduction of the group endows the polyaramide with excellent solubility and can effectively improve the gas separation performance of the polymer membrane material.

The purpose of the patent of the present invention is to improve the dissolving film-forming properties of polyaramide polymers and further improve the gas separation performance of polymer membranes. Based on molecular design, a class of structures containing both bis-tert-butylbenzene and dimethyl groups is designed and prepared. Polyaramide; by introducing large free volume of bis-tert-butylbenzene and dimethyl structure into the main chain of the polymer molecule at the same time, this type of polymer has high solubility and excellent film-forming properties in specific solvents, The gas permeability of the polyaramid membrane material can be further effectively improved, and the polyaramid polymer has important potential application value in the field of gas separation membranes.

The invention provides a class of highly soluble polyaramides containing both bis-tert-butylbenzene and dimethyl structure, and its structural formula is:

in, respectively Repeating structural unit n=40-100.

The present invention also provides a preparation method of the above-mentioned high-soluble polyaramide polymer containing both bis-tert-butylbenzene and dimethyl structure, and the specific steps are:

Under nitrogen protection, the same amount of aromatic diamine monomers containing bis-tert-butylbenzene and dimethyl structure and commercial aromatic diacid monomers were added to the organic solvent, an appropriate amount of catalyst was added, and after stirring evenly at room temperature, the temperature was raised to After the reaction is stirred at 100-140° C. for 3-6 hours, the reaction is terminated, and further sedimentation, washing and drying can be performed to obtain a fibrous polyaramide polymer containing bis-tert-butylbenzene and a dimethyl structure with high solubility.

Wherein, the aromatic diamine monomer containing bis-tert-butylbenzene and dimethyl structure is 3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tertiary Butyltoluene, the structural formula is

The preparation method of the aromatic diamine monomer containing bis-tert-butylbenzene and dimethyl structure is as follows: heating 100 parts of o-toluidine to 80-100 DEG C under nitrogen protection, and then adding 40-45 A mixed solution of parts 3,5-di-tert-butylbenzaldehyde and 50-100 parts hydrochloric acid. After the dropwise addition, the reaction mixture was heated and refluxed at 155°C for 10-15 hours. Cool to 60°C, and add dropwise to neutrality with 10% aqueous sodium hydroxide solution. Excessive ethanol was added to produce a large amount of precipitation; filtered, washed with methanol, dried, and further recrystallized from toluene to obtain a white diamine product.

Described commercial aromatic diacid monomer is terephthalic acid, isophthalic acid, 4,4'-diphenyl ether diacid, 2,2-bis (4-carboxyphenyl) hexafluoropropane or 4, One of the 4'-diphenylsulfone diacids.

The organic solvent is selected from N-methylpyrrolidone, N,N-dimethylacetamide or N,N-dimethylformamide, and the quality of the solvent is 3 times the sum of the quality of the diamine monomer and the diacid monomer. ~6 times.

The catalysts are triphenyl phosphite and pyridine, wherein the amounts of triphenyl phosphite and pyridine are both 3,3'-dimethyl-4,4'-diaminophenyl-3",5" - 2 to 4 times the amount of di-tert-butyltoluene.

The concrete synthetic route of containing di-tert-butylbenzene and dimethyl structure aromatic diamine monomer and a class of highly soluble polyaramide polymers of the present invention is as follows:

(1) Synthesis of aromatic diamine monomer containing bis-tert-butylbenzene and dimethyl structure

(2) Synthesis of highly soluble polyaramide polymers containing both bis-tert-butylbenzene and dimethyl structures

The high-soluble polyaramide polymer film containing both bis-tert-butylbenzene and dimethyl structure prepared by the invention has important potential application value in the field of gas separation.

The beneficial effects of the present invention are:

(1) The present invention provides a kind of aromatic diamine monomer containing bis-tert-butylbenzene and dimethyl structure at the same time and a class of highly soluble polyaramides and a preparation method thereof. ;

(2) The highly soluble polyaramide polymer containing bis-tert-butylbenzene and dimethyl structure provided by the present invention, in N-methylpyrrolidone, N,N-dimethylacetamide, N,N-di It has high solubility in specific solvents such as methylformamide and dimethyl sulfoxide (the solubility can reach 30wt%), and it can easily use its solution to coat a film to obtain a polymer film; the prepared polymer film has important properties in the field of gas separation. potential application value.

Description of drawings

Figure 1 The composition of aromatic diamine monomer 3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene containing bis-tert-butylbenzene and dimethyl structure ¹ H NMR spectrum.

2 is the ¹ H NMR spectrum of the highly soluble polyaramide polymer containing bis-tert-butylbenzene and dimethyl structure in Example 1 (wherein the aromatic diacid monomer is terephthalic acid).

Detailed ways

Synthesis of Aromatic Diamine Monomers Containing Bi-tert-Butylbenzene and Dimethyl Structures Simultaneously

Example 1

100 parts of o-toluidine was heated to 80° C. under nitrogen protection, and then a mixed solution of 40 parts of 3,5-di-tert-butylbenzaldehyde and 50 parts of hydrochloric acid was added dropwise thereto. After the dropwise addition, the reaction mixture was heated and refluxed at 155°C for 12 hours. Cool to 60°C and add dropwise to neutrality with 10% aqueous sodium hydroxide solution. Excess ethanol was added to produce a large amount of precipitation; filtered, washed with methanol, dried, and further recrystallized from toluene to obtain a white diamine product with a yield of about 85%. ¹ H NMR (DMSO, 400 MHz) is shown in Figure 1 .

Example 2

100 parts of o-toluidine was heated to 100° C. under nitrogen protection, and then a mixed solution of 45 parts of 3,5-di-tert-butylbenzaldehyde and 100 parts of hydrochloric acid was added dropwise thereto. After the dropwise addition, the reaction mixture was heated and refluxed at 155°C for 15 hours. Cool to 60°C, and add dropwise to neutrality with 10% aqueous sodium hydroxide solution. Excessive ethanol was added to produce a large amount of precipitation; filtered, washed with methanol, dried, and further recrystallized from toluene to obtain a white diamine product with a yield of about 81%.

Synthesis of Highly Soluble Polyaramides Containing Di-tert-Butylbenzene and Dimethyl Structures Simultaneously

Example 3

In a 100ml dry three-necked flask equipped with nitrogen protection and a condenser, add 1.6585g (4mmol) of 3,3'-dimethyl-4,4'-diaminophenyl-3",5"-diaminophenyl tert-butyltoluene, 0.6645g (4mmol) of terephthalic acid, 5.9648g (16mmol) of triphenyl phosphite, 1.2658g (16mmol) of pyridine and 7.2ml of N-methylpyrrolidone, after stirring at room temperature, After the temperature was raised to 100°C and stirred for 6 hours, the reaction was completed by cooling down. The product was poured into ethanol for sedimentation, and further washed three times with hot water, filtered and dried to obtain a structure containing both di-tert-butylbenzene and dimethyl benzene. Highly soluble polyaramide polymer, the yield is 99%; ¹ H NMR (DMSO, 400 MHz) is shown in FIG. 2 .

Example 4

In a 100ml dry three-necked flask equipped with nitrogen protection and a condenser, add 1.6585g (4mmol) of 3,3'-dimethyl-4,4'-diaminophenyl-3",5"-diaminophenyl tert-butyltoluene, 0.6645g (4mmol) of terephthalic acid, 2.4824g (8mmol) of triphenyl phosphite, 0.6328g (8mmol) of pyridine and 14ml of N-methylpyrrolidone were stirred at room temperature and heated up. After stirring the reaction at 140 ° C for 3 hours, the temperature was lowered to complete the reaction, the product was poured into ethanol for sedimentation, and further washed three times with hot water, filtered and dried to obtain a high-density benzene containing di-tert-butylbenzene and dimethyl structure. Soluble polyaramide polymer in 99% yield.

Example 5

In a 100ml dry three-necked flask equipped with nitrogen protection and a condenser, add 1.6585g (4mmol) of 3,3'-dimethyl-4,4'-diaminophenyl-3",5"-diaminophenyl tert-butyltoluene, 1.033g (4mmol) of 4,4'-diphenylether diacid, 2.4824g (8mmol) of triphenyl phosphite, 0.6328g (8mmol) of pyridine and 15ml of N-methylpyrrolidone, room temperature After stirring evenly, the temperature was raised to 130 ° C and stirred for 5 hours, the reaction was completed by cooling down, the product was poured into ethanol for sedimentation, and further washed with hot water three times, filtered and dried to obtain a mixture containing bis-tert-butylbenzene at the same time. and dimethyl structure highly soluble polyaramide polymer with a yield of 98%.

Claims (10)

1. a class of high-soluble polyaramides containing bis-tert-butylbenzene and dimethyl structure simultaneously, is characterized in that: in the described polyaramide diamine structural unit, contains bis-tert-butylbenzene and dimethyl structure simultaneously, Its structural formula is: in, respectively Repeating structural unit n=40-100. 2. a preparation method containing di-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 1, is characterized in that: the step of described preparation method is: Under nitrogen protection, add the same amount of aromatic diamine monomer and aromatic diacid monomer containing bis-tert-butylbenzene and dimethyl structure into the organic solvent, add catalyst, stir evenly at room temperature, and heat up to 100～ After the reaction is stirred at 140° C. for 3-6 hours, the reaction is terminated, and further sedimentation, washing and drying can be performed to obtain a fibrous polyaramide polymer containing bis-tert-butylbenzene and a dimethyl structure with high solubility. 3. the preparation method that contains bis-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 2, it is characterized in that: described containing bis-tert-butylbenzene and dimethyl structure aromatic di- The amine monomer is 3,3'-dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene, the structural formula is 4. the preparation method that contains bis-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 3, it is characterized in that: described containing bis-tert-butylbenzene and dimethyl structure aromatic di- The preparation method of the amine monomer is as follows: heating 100 parts of o-toluidine to 80-100 DEG C under nitrogen protection, and then adding 40-45 parts of 3,5-di-tert-butylbenzaldehyde and 50-100 parts dropwise thereto. After the mixed solution of hydrochloric acid is added dropwise, the reactant mixture is heated and refluxed at 155 ° C for 10 to 15 hours, cooled to 60 ° C, and added dropwise to neutrality with 10% aqueous sodium hydroxide solution, and excess ethanol is added to produce a large amount of ethanol. Precipitated; filtered, washed with methanol, dried, and further recrystallized from toluene to give a white diamine product. 5. the preparation method that contains bis-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 2, is characterized in that: described aromatic diacid monomer is terephthalic acid, m-benzene One of dicarboxylic acid, 4,4'-diphenylether diacid, 2,2-bis(4-carboxyphenyl)hexafluoropropane or 4,4'-diphenylsulfone diacid. 6. the preparation method that contains bis-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 2, it is characterized in that: described organic solvent is selected from N-methylpyrrolidone, N,N - One of dimethylacetamide or N,N-dimethylformamide. 7. the preparation method that contains bis-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 2, it is characterized in that: the consumption of described organic solvent is diamine monomer and diacid monomer 3 to 6 times the quality and sum. 8. The preparation method of high-soluble polyaramide containing bis-tert-butylbenzene and dimethyl structure simultaneously as claimed in claim 2, wherein the catalyst is triphenyl phosphite and pyridine. 9. the preparation method that contains bis-tert-butylbenzene and dimethyl structure highly soluble polyaramide simultaneously as claimed in claim 8, is characterized in that: the consumption of triphenyl phosphite and pyridine is 3,3 '- 2 to 4 times the amount of dimethyl-4,4'-diaminophenyl-3",5"-di-tert-butyltoluene. 10 . The application of the highly soluble polyaramide containing bis-tert-butylbenzene and dimethyl structure simultaneously as claimed in claim 1 , wherein the highly soluble polyaramide is used in the field of gas separation. 11 .