Polyimide preparation method and application thereof

A technology of polyimide and polyamic acid, applied in the field of resin, can solve the problems of poor fluidity, insoluble and insoluble, application limitation, etc., and achieve the effect of improving solubility and solubility.

Inactive Publication Date: 2018-01-19

CHINA UNIV OF PETROLEUM (EAST CHINA)

4 Cites 9 Cited by

AI-Extracted Technical Summary

Problems solved by technology

Generally speaking, polyimide resin can be divided into two categories: thermoplastic and thermosetting. Although thermoplastic polyimide resin has good impact toughness, it has high melt viscosity and poor fluidity, which makes it difficult to combine with carbon fiber. The disadvantages of preparing carbon fiber/polyimide composite materials, although thermosetting polyimide resins have higher high temperature resistance, low melt...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Abstract

The invention provides a polyimide preparation method and an application thereof. The method comprises the following steps: 1) under inert gas protection, dissolving an aromatic diamine monomer 3, 3'-dimethyl-4,4'-diaminodiphenylmethane in a polar aprotic solvent to obtain an aromatic diamine monomer solution, then adding dianhydride in batch in the solution, and reacting the materials at the temperature of -20-40 DEG C to obtain an polyamide acid solution having viscosity; and 2) adding a chemical imidization reagent in the polyamide acid solution for a reaction to obtain a polyimide solution; wherein the chemical imidization reagent comprises a dehydrating agent and a catalyst. The polyimide is taken as a base material, an interfacial polymerization method is employed for preparing an organic solvent-resistant nanofiltration membrane, and the polyimide has the advantages of good stability, good mechanical property and excellent dissolvability.

Application Domain

Semi-permeable membranesFibre types

Technology Topic

Protic solventSolubility +9

Image

Examples

Experimental program(3)
Effect test(2)

Example Embodiment

[0022] Example 1

[0023] Under the protection of inert gas and the temperature at -10 ℃ ~ 10 ℃, the aromatic diamine monomer 3,3'-dimethyl-4,4'-diaminodiphenylmethane was dissolved in a certain amount of N, In N-dimethylformamide, the solid content of the monomer was controlled to be 10%. After the diamine was completely dissolved, a certain amount of 3,3',4,4'-benzophenone tetraacid dianhydride, diamine and The molar ratio of 3,3',4,4'-benzophenone tetraacid dianhydride is 1:1.01, and the reaction temperature is controlled at 5 ℃, and the reaction is carried out for 10 to 13 hours, and then a certain amount of chemical imidization reagent acetic anhydride/pyridine is added. , continue to stir and react for a period of time to obtain a polyimide solution, and obtain a polyimide solid after precipitation, washing and vacuum drying with ethanol water.

[0024] After testing, the polyimide obtained in this example has a weight-average molecular weight Mw of 3*10 6 , the average chain spacing is 0.54nm; the temperature when thermal decomposition is 10% is 500 ° C; the glass transition temperature is 275 ° C; solvent.

Example Embodiment

[0025] Example 2

[0026] The aromatic diamine monomer 3,3'-dimethyl-4,4'-diaminodiphenylmethane is dissolved in a certain amount of N,N under the protection of inert gas and the temperature is 5℃~10℃. -In dimethylformamide, the solid content of the monomer is controlled to be 6%. After the diamine is completely dissolved, a certain amount of 3,3',4,4'-dianisole tetraacid dianhydride, diamine and The molar ratio of the dianhydride is 1:0.99, and the reaction is carried out for 10-13 hours under the control of the reaction temperature at 5°C. Add a certain amount of chemical imidization reagent acetic anhydride/picoline, continue to stir and react for a period of time to obtain a polyimide solution, and obtain a polyimide solid after precipitation, washing and vacuum drying with ethanol water.

[0027] After testing, the polyimide obtained in this example has a weight-average molecular weight Mw of 3.5*10 6 , the average chain spacing is 0.56nm; the temperature when thermal decomposition is 10% is 510 ° C; the glass transition temperature is 290 ° C; solvent.

Example Embodiment

[0028] Example 3

[0029] Preparation of composite nanofiltration membrane:

[0030] 1) Take 10 g of the polyimide solid prepared in Example 1 above, dissolve it in 85 ml of polar protic solvent at room temperature, dissolve evenly, filter it with a 300-mesh steel wire mesh, and then debubble it in a vacuum for later use. Under the conditions of dust-free, 25°C, and humidity of 50-70%, the above-mentioned casting liquid is coated on PET non-woven fabric, the wet film thickness is 250um, and the film is phase-converted in water or ethanol to obtain polyimide. basement membrane.

[0031] 2) The polyimide-based film prepared above is immersed in alcohol for a period of time to remove residual moisture in the film by solvent exchange, and then immersed in a certain concentration of diamine/alcohol solvent for cross-linking for a period of time. The membrane was stored in an alcohol solvent to prevent the membrane pores from collapsing and was used to prepare a PA/PI composite nanofiltration membrane.

[0032] 3) The film obtained in step 2) was immersed in 2% piperazine/water solution for 2 minutes, and the residual amine solution on the surface of the film was thoroughly dried with an air knife, then entered into a 1% TMC/n-hexane solution for 1 minute, and immediately dried and placed. The reaction was continued for 4-10 min in a 40°C-60°C oven, and the prepared composite nanofiltration membrane was stored in deionized water at 4°C for use.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Login to view more

PUM

Property	Measurement	Unit
Glass transition temperature	275.0	°C
Tensile strength	70.66	mPa
Glass transition temperature	290.0	°C
tensile		MPa
Particle size		Pa
strength	10

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine

Login to view more

Methods and compositions for thermally treating a conduit used for hydrocarbon production or transmission to help remove paraffin wax buildup

InactiveUS20080069961A1Promote meltingImprove solubilityOrganic-compounds/hydrides/coordination-complexes catalystsHollow article cleaningParaffin waxExothermic reaction

Owner:HALLIBURTON ENERGY SERVICES INC

Nanometer miconazole nitrate emulsion medicine and its prepn process

InactiveCN1931164AImprove solubilityImprove bioavailabilityOrganic active ingredientsAntimycoticsPolymer chemistryOil phase

Owner:NORTHWEST A & F UNIV

Classification and recommendation of technical efficacy words

Improve solubility

Polyimide preparation method and application thereof

A technology of polyimide and polyamic acid, applied in the field of resin, can solve the problems of poor fluidity, insoluble and insoluble, application limitation, etc., and achieve the effect of improving solubility and solubility.

AI-Extracted Technical Summary

Problems solved by technology

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

Similar technology patents

Nimodipine emulsion injection liquid and method for preparing the same

Preparation method of high energy water with small molecules

New technique for preparing cellulose carbate through urea embedding method

Methods and compositions for thermally treating a conduit used for hydrocarbon production or transmission to help remove paraffin wax buildup

Nanometer miconazole nitrate emulsion medicine and its prepn process

Classification and recommendation of technical efficacy words

Nanoparticle synthesis and the formation of inks therefrom

Substituted pentacene semiconductors

Method of preparing a polymer using aliphatic solutions of aminoalkyllithium compounds

Moldable poly(arylene ether) thermosetting compositions, methods, and articles

Bamboo charcoal cellulose fiber and manufacturing method thereof