CN108440754A - One kind is containing tertiary butyl substitution m-Terphenyl structure polyimide film material and preparation method thereof - Google Patents

Abstract

One kind replaces m-Terphenyl structure polyimide film material containing tertiary butyl, is synthetically prepared route facility, a step solwution method polycondensation can be used and be prepared.Its preparation process includes：Under nitrogen protection; first by equimolar than replace m-Terphenyl structure diamine monomer and dianhydride monomer to be dissolved in appropriate organic solvent containing tertiary butyl; 6~10h is reacted at 180~200 DEG C; obtain sticky polymer solution; reaction was completed; through sedimentation, filtering, drying obtain the polyimide polymer of threadiness；Polyimide polymer is further made into the solution of 5wt%~10wt%, film after filtering, vacuum drying can be obtained at 60~90 DEG C replaces m-Terphenyl structure polyimide film material containing tertiary butyl accordingly.There is the quasi-polyimide good dissolving film forming, institute's made membrane to have potential using value in the gases separation field such as collecting carbonic anhydride, oxygen-enriched, hydrogen withdrawal.

Description

A class of polyimide membrane materials containing tert-butyl substituted m-terphenyl structure and its preparation method

technical field

The invention belongs to the field of preparation of polyimide membrane materials, and in particular relates to a polyimide membrane material with a tert-butyl-substituted m-terphenyl structure and a preparation method thereof.

Background technique

Gas separation membrane technology is a new type of chemical separation technology that has developed rapidly in recent years. Compared with traditional separation technologies, gas separation membrane technology has the advantages of environmental protection, convenient operation, and high efficiency. It is used in carbon dioxide capture and separation, oxygen enrichment, hydrogen recovery, etc. The field of separation has important application prospects. Separation membrane materials are the core of gas separation technology. Among the polymer gas separation membrane materials that have been reported so far, polyimide has attracted extensive attention due to its excellent thermal properties, mechanical properties, and compression resistance. Although commercial polyimide membrane materials have good selective separation performance, their gas permeation flux is small, which still cannot meet the needs of high-efficiency gas separation technology. In addition, due to the structural characteristics of rigid molecular chains, polyimide polymers are usually difficult to dissolve and tolerate, and it is difficult to directly process them into thin films. amine film. However, high-temperature heat treatment not only consumes a lot of energy for industrial production, but also affects the quality of polymer films. Therefore, it is of great significance to further improve the film-forming properties and gas separation properties of polyimide polymers, and to design and prepare polyimide membrane materials that can be directly coated and have high gas permeation flux.

The study found that by introducing large substituted side groups and rigid non-coplanar structures into the molecular structure of polyimide, the free volume of the molecular structure of the polymer can be increased while maintaining its inherent rigid structure, which can better improve the stability of the polymer. Gas permeability, and can improve the dissolution and film formation of polymers. The molecular design and preparation of polyimides with large substituted side groups and rigid structures are quite challenging, and usually require multi-step reactions to prepare them. The patent of the present invention utilizes the prepared aromatic diamine monomer and dianhydride monomer containing tert-butyl substituted meta-terphenyl structure to undergo one-step solution polycondensation, and successfully prepares a class of meta-tertiary compounds containing large substituted tert-butyl group and rigidity at the same time. Benzene structure polyimide membrane material. The preparation process of this type of polyimide is relatively simple, and it has good dissolution and film formation properties. The membrane material has potential application value in the fields of carbon dioxide capture and separation, oxygen enrichment, and hydrogen recovery and utilization. .

Contents of the invention

The technical problem to be solved by the present invention adopts a relatively convenient synthetic route to prepare a class of polyimide membrane materials containing tert-butyl substituted meta-terphenyl structures, and simultaneously introduce large substituted side groups and rigid molecular structures into polyimide polymerization In the molecular structure of the polyimide polymer, the dissolution film formation and gas separation performance of the polyimide polymer are further improved.

The present invention provides a kind of polyimide membrane material containing tert-butyl substituted m-terphenyl structure, and the structural formula of this kind of polyimide is: Among them, the diamine structural unit contains tert-butyl and meta-terphenyl structures, and the dianhydride structural unit for n ranges from 40 to 80.

The patent of the present invention provides the preparation method of this type of polyimide film material, including: (1) under nitrogen protection, equimolar ratio of aromatic diamine monomer containing tert-butyl substituted m-terphenyl structure and dianhydride mono Put the monomer into a three-necked flask, add an appropriate amount of organic solvent and catalyst, stir at 80-100°C for half an hour until the monomer is completely dissolved, then continue to heat up to 180-200°C and react for 6-10 hours to obtain a viscous polymer solution. For reaction, the polymer solution is poured into ethanol for sedimentation, further filtered and dried to obtain a fibrous polyimide polymer containing a tert-butyl-substituted m-terphenyl structure.

(2) Add the polyimide polymer into an appropriate amount of organic solvent to form a solution of 5wt% to 10wt%, filter it and apply a film, and further vacuum dry it at 60-90°C for 12-24h to obtain the corresponding Tert-butyl substituted meta-terphenyl structure polyimide film material.

Wherein the aromatic diamine monomer containing tert-butyl substituted m-terphenyl structure described in step (1) is 3,5-bis(3-aminophenyl)-tert-butylbenzene, and the dianhydride monomer is One of pyromellitic dianhydride, biphenylellitic dianhydride, benzophenone anhydride, diphenyl ether anhydride or hexafluoroisopropyl dianhydride; the organic solvent is m-cresol or N-methyl The amount of pyrrolidone is 7-15 times of the mass of diamine and dianhydride monomers; the catalyst is isoquinoline, and its amount is 1%-3% of the mass of diamine.

The film-forming solvent in step (2) is N-methylpyrrolidone or N,N-dimethylacetamide. The specific synthetic route of this type of polyimide containing tert-butyl substituted m-terphenyl structure is as follows:

The beneficial effects of the present invention are:

(1) The polyimide film material prepared by the present invention can directly obtain a polyimide polymer by one-step solution polycondensation without converting polyamic acid into polyimide, and the synthesis and preparation process is simple and easy to industrialize;

(2) The polyimide membrane material prepared by the present invention has good solubility due to the introduction of large-volume tert-butyl side groups and meta-terphenyl structures in the molecular structure of the polymer. Film-forming properties, the prepared film has potential application value in the fields of gas separation membranes such as carbon dioxide capture and separation, oxygen enrichment, and hydrogen recovery.

Description of drawings

Fig. 1 is the ¹ H NMR spectrum of the polyimide prepared based on 3,5-bis(3-aminophenyl)-tert-butylbenzene and diphenyl ether dianhydride in Example 1.

Detailed ways

Example 1

Preparation of polyimide membrane material containing tert-butyl substituted m-terphenyl structure:

(1) Under nitrogen protection, 4mmol 3,5-bis(3-aminophenyl)-tert-butylbenzene and 4mmol diphenyl ether anhydride were added to a 100ml three-necked flask, and then 25ml m-cresol and 0.04mmol of isoquinoline, stirred at 80°C for half an hour until the monomer was completely dissolved, then continued to heat up to 180°C and reacted for 10h to obtain a viscous polymer solution. After the reaction was completed, the polymer solution was poured into ethanol to settle, and further After filtering and drying, a fibrous polyimide polymer containing a tert-butyl group-substituted m-terphenyl structure is obtained.

(2) Add the polyimide polymer into an appropriate amount of N-methylpyrrolidone solvent to make a 10wt% solution, filter and coat the film, and further vacuum-dry at 90°C for 12h to obtain the corresponding tert-containing Butyl-substituted meta-terphenyl structure polyimide film material.

Example 2

Preparation of polyimide membrane material containing tert-butyl substituted m-terphenyl structure:

(1) Under nitrogen protection, add 4mmol 3,5-bis(3-aminophenyl)-tert-butylbenzene and 4mmol hexafluoroisopropyldianhydride to a 100ml three-necked flask, and then add 30ml N -Methylpyrrolidone and 0.12mmol of isoquinoline, stirred at 100°C for half an hour until the monomers were completely dissolved, and then continued to heat up to 200°C for 6 hours to obtain a viscous polymer solution, to end the reaction, pour the polymer solution into Settling in ethanol, further filtering and drying to obtain a fibrous polyimide polymer containing a tert-butyl-substituted m-terphenyl structure.

(2) Add the polyimide polymer into an appropriate amount of N,N-dimethylacetamide solvent to make a 5wt% solution, filter and coat the film, and further vacuum dry at 60°C for 24 hours to obtain Corresponding polyimide membrane material containing tert-butyl substituted m-terphenyl structure.

Claims (5)

1. A class of polyimide membrane materials containing tert-butyl substituted m-terphenyl structures, characterized in that the structural formula of the polyimide polymer is Among them, the diamine structural unit contains tert-butyl and meta-terphenyl structures, and the dianhydride structural unit for n ranges from 40 to 80. 2. the preparation method of the polyimide membrane material containing tert-butyl substituted m-terphenyl structure as claimed in claim 1, is characterized in that: the step of described preparation method is (1) Under nitrogen protection, add aromatic diamine monomers and dianhydride monomers containing tert-butyl-substituted meta-terphenyl structures in equimolar ratios into a three-necked flask, add an appropriate amount of organic solvent and catalyst, and heat at 80-100°C Stir for half an hour until the monomer is completely dissolved, continue to heat up to 180-200°C and react for 6-10 hours to obtain a viscous polymer solution. After the reaction is completed, the polymer solution is poured into ethanol to settle, further filtered and dried to obtain fiber A polyimide polymer containing a tert-butyl substituted m-terphenyl structure. (2) Add the polyimide polymer into an appropriate amount of organic solvent to form a solution of 5wt% to 10wt%, filter it and apply a film, and further vacuum dry it at 60-90°C for 12-24h to obtain the corresponding Tert-butyl substituted meta-terphenyl structure polyimide film material. 3. the preparation method of the polyimide film material containing tert-butyl substituted meta-terphenyl structure as claimed in claim 2, described in step (1) containing tert-butyl substituted meta-terphenyl structure aromatic diamine mono body is 3,5-bis(3-aminophenyl)-tert-butylbenzene, and the dianhydride monomer is pyromellitic dianhydride, biphenyltetraic dianhydride, benzophenone anhydride, diphenyl ether Anhydride or one of hexafluoroisopropyldianhydride. 4. the preparation method of the polyimide film material containing tert-butyl substituted m-terphenyl structure as claimed in claim 2, the organic solvent described in step (1) is m-cresol or N-methylpyrrolidone, The dosage thereof is 7-15 times of the mass of the diamine and dianhydride monomers; the catalyst is isoquinoline, and the dosage thereof is 1%-3% of the mass of the diamine. 5. the preparation method that contains the polyimide membrane material of tert-butyl substituted meta-position terphenyl structure as claimed in claim 2, the film-making solvent described in step (2) is N-methylpyrrolidone or N,N-di Methylacetamide.