CN110903648A

CN110903648A - Polyimide compound and preparation method thereof

Info

Publication number: CN110903648A
Application number: CN201911070594.2A
Authority: CN
Inventors: 汪亚民
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2020-03-24

Abstract

The invention provides a polyimide compound and a preparation method thereof, wherein the molecular structure of the polyimide compound comprises an assembly molecular structure and a polyimide molecular structure, wherein the assembly molecular structure comprises polycyclodextrin poly (β -CD) serving as a host molecule and a styrene derivative a-PS containing nitrogen-oxygen heterocycle serving as a guest molecule, the general formula of the molecular structure adopted by the polyimide compound is poly (β -CD)/a-PS/PI..

Description

Polyimide compound and preparation method thereof

Technical Field

The invention relates to the field of functional materials, in particular to a polyimide composite material which can be used for a substrate of a display panel, but is not limited to the field.

Background

It is known that with the continuous development of modern technology, new materials play an increasingly important role in industrial production. For example, the polyimide material developed in the industry is a high-performance polymer with excellent thermal stability, mechanical properties and good electrical properties, and is widely applied to the fields of aerospace, microelectronics, flexible panels and the like.

Taking the polyimide material applied to the substrate material of the AMOLED display panel as an example, the polyimide material, as the most initial process flow of the 15 mask process, will directly contact the nozzle (nozzle) during the spraying process, so that the film formed thereon is easily damaged by human, thereby reducing the yield.

Furthermore, the polyimide film layer is inevitably subjected to external force damage which generates an indispensable force in the subsequent use process, so that the service life of the polyimide material is shortened. Meanwhile, polyimide is very expensive in the field of OLED, and the raw material PI liquid used in the field of OLED is very expensive, so that the polyimide can cause huge waste of resources after being used once and is high in cost; furthermore, the polyimide material formed by subsequent crosslinking and curing is difficult to recycle, and causes pressure on the environment and energy.

If the polyimide material has self-repairing performance, on one hand, unnecessary loss of the polyimide material can be reduced, for example, the polyimide material is not discarded when cracks appear in subsequent detection; on the other hand, the maintenance cost of the polyimide material in the use process is also reduced.

Most importantly, the polyimide material with the self-repairing capability can increase the possibility of improving the production yield of subsequent products, but the polyimide materials used in the field of AMOLED do not have the self-repairing function at present. Therefore, there is a need to develop a new polyimide material to overcome the defects of the prior art.

Disclosure of Invention

One aspect of the present invention is to provide a polyimide composite which has a certain degree of self-healing ability of the material itself.

The technical scheme adopted by the invention is as follows:

a polyimide compound has a molecular structure comprising an assembly molecular structure and a polyimide molecular structure, wherein the assembly molecular structure comprises polycyclodextrin poly (β -CD) serving as a host molecule and a styrene derivative a-PS containing a nitrogen-oxygen heterocycle serving as a guest molecule, and the adopted molecular structure general formula is poly (β -CD)/a-PS/PI, wherein the guest molecule a-PS adopts the structural general formula:

further, in various embodiments, the polyimide composite is prepared from a precursor polyamic acid poly (β -CD)/a-PS/PAA, which adopts a molecular structure formula as follows:

further, in various embodiments, the preparation raw materials used for the polycyclodextrin as the host molecule include cyclodextrin and epichlorohydrin.

Further, in various embodiments, the ratio between the cyclodextrin and the epichlorohydrin is in the range of 0.75 to 1.5.

Further, in various embodiments, the molar ratio between the host molecule and the guest molecule of the assembly is 1:5 to 1: 3.

Further, in various embodiments, the mass ratio between the host molecule and the guest molecule of the assembly is (10-65): 1.

Further, another aspect of the present invention provides a method for preparing the polyimide composite according to the present invention, comprising the steps of:

s1, preparing an assembly, namely dispersing the host molecule material polycyclodextrin into water, adding the guest molecule material of the styrene derivative containing the nitrogen-oxygen heterocycle into the water, stirring the mixture at room temperature for 12-36 h, and then obtaining powder of the assembly material in a freeze-drying mode;

step S2, preparing a target precursor polyamic acid by dispersing the assembly powder obtained in step S1 into a mixed solvent of dimethyl acetyl (DMAC) and N-methyl pyrrolidone (NMP), adding hydroxyethyl methacrylate (HEMA) and Butyl Acrylate (BA) and uniformly stirring at the temperature of 40-70 ℃, adding diphenylamine ether and a polyamic acid-containing PI solution dissolved in N-methyl pyrrolidone (NMP) and uniformly stirring again to obtain a solution containing a precursor polyamic acid poly (β -CD)/a-PS/PAA, and

s3, preparing a target polyimide compound, namely, poly (β -CD)/a-PS/PI, heating the precursor polyamic acid solution to 80-100 ℃, heating the precursor polyamic acid solution to 250 ℃ at a speed of 2-5 ℃/min, keeping the temperature for 0.5-1.5 h, reducing the temperature of the solution to room temperature, and suspending the solution on a substrate.

Further, in various embodiments, in the step S1, the host molecular material polycyclodextrin is dispersed into the water by ultrasonic means.

Further, in a different embodiment, in the step S1, the method further includes a substep S11 of preparing the host molecular material, in which cyclodextrin is dissolved in a NaOH solution, epichlorohydrin is added after the solution temperature reaches 25 to 35 ℃, the mixture is stirred for 2.0 to 5.0 hours to enable the two to react sufficiently, and then acetone is added to stop the reaction; after removing acetone by rotary evaporation, dissolving the residual substances in deionized water, and adjusting the pH value of the solution to 10-12; dialyzing the solution for 5-9 days, wherein the value of the cut-off molecular weight in the solution is within the range of 3000-12000, and finally, separating the product by freeze-drying to obtain the main molecular material.

Further, in a different embodiment, in the step S11, the cyclodextrin is sonicated for 20-50 min while being dissolved in the NaOH, so that the cyclodextrin is sufficiently dissolved.

Further, in a different embodiment, in the step S11, the stirring speed of the epichlorohydrin after being added to the cyclodextrin solution is 500-800 rpm.

Further, in a different embodiment, in the step S2, the PI solution containing polyamic acid used therein may be a PI solution of PAA-49 type, but is not limited thereto.

Further, in a different embodiment, in the step S2, a volume ratio of the dimethyl acetyl (DMAC) and the N-methyl pyrrolidone (NMP) used therein is 1:1 to 3: 9.

Further, in a different embodiment, in step S2, dibutyltin dilaurate (DBTDL) is added as a catalyst in the reaction, and is used for catalyzing the reaction to generate the precursor polyamic acid poly (β -CD)/a-PS/PAA.

Compared with the prior art, the invention has the beneficial effects that: the invention relates to a polyimide compound, which adopts a composite molecular structure of an assembly structure molecule combined with a polyimide molecular structure, and the self-repairing performance of the polyimide compound is endowed by taking a modified guest molecule selected in the assembly molecular structure as the basis of the inclusion effect of a host and a guest and simultaneously introducing O-H and N-H bonds in the guest molecule to endow the material with hydrogen bond interaction in the molecule and host-guest interaction among molecules.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a surface effect diagram of the polyimide composite according to the present invention after a surface scratch test is performed after film formation; and

FIG. 2 is a graph showing the surface effect of the film shown in FIG. 1 after self-healing.

Detailed Description

The technical scheme of the polyimide composite and the preparation method thereof according to the present invention will be further described in detail with reference to the accompanying drawings and examples.

One embodiment of the invention provides a polyimide compound, the molecular structure of which comprises an assembly molecular structure and a polyimide molecular structure, wherein the assembly molecular structure comprises polycyclodextrin poly (β -CD) as a host molecule and a styrene derivative a-PS containing a nitrogen-oxygen heterocycle as a guest molecule, the polyimide compound adopts a molecular structure general formula of poly (β -CD)/a-PS/PI, and the guest molecule a-PS adopts a structural general formula of:

further, the preparation raw material of the polyimide compound is polyamic acid poly (β -CD)/a-PS/PAA which is a precursor thereof, and the general formula of the molecular structure adopted by the polyimide compound is as follows:

the polyimide composite related to the invention is generated through the polymerization reaction of the precursor polyamic acid, wherein the molecular structure of the assembly body existing in the molecular structure of the precursor polyamic acid realizes hydrogen bonding due to non-covalent bonds formed between the object molecules and the object molecules, namely O-H bonds and N-H bonds formed by dotted lines in the general formula of the molecular structure of the precursor polyamic acid, and the two bonds do not form stable covalent bonds but bonds with non-covalent structures, because on one hand, the object molecules can be included with the cyclodextrin molecules of the host body, and simultaneously, O-H bonds and N-H bonds can be formed between the terminal hydroxyl groups of the polyamic acid (PAA), so that the polyimide composite related to the invention formed by subsequent polymerization is endowed with self-repairing capability.

Further, the present invention will be further described below with reference to a method for preparing the polyimide composite according to the present invention.

One embodiment of the present invention provides a method for preparing the polyimide composite according to the present invention, which comprises the steps of:

step S1, a step of preparing an assembly, specifically including:

substep S11, preparing a main molecular material, namely dissolving 10.0g of cyclodextrin (0.88mmol) in 16-30 mL of NaOH (33-50 wt%) solution, carrying out ultrasonic treatment for 30min until the cyclodextrin is fully dissolved, cooling the solution to 30 ℃, quickly adding 6.89mL of epoxy chloropropane, stirring for 2.0-5.0 hours at the stirring speed of 600rpm, stopping the reaction by using a large amount of acetone (150 mL), removing the acetone by rotary evaporation, dissolving the rest substances in deionized water, adjusting the pH of the solution to 10-12 by using HCl, dialyzing the solution for 5-9 days, intercepting the related molecular weight within the range of 3000-12000, and carrying out freeze-drying to separate a product to obtain the main molecular material poly (β -CD);

a substep S12, providing a styrenic derivative material a-PS (the specific molecular structure general formula is referred to above) of the object molecule nitrogen-containing oxygen heterocycle, wherein the styrenic derivative material a-PS is used as a basis for inclusion of a host and an object, and simultaneously introduces an O-H bond and an N-H bond, so that intramolecular hydrogen bond interaction and intermolecular host-object interaction are endowed to a subsequently prepared material;

and a substep S13 of preparing an assembly, wherein 100-650 mg of the host molecular material poly (β -CD) is ultrasonically dispersed into 13.3mL of pure water, 10mg of the guest molecular material styrene derivative material containing nitrogen-oxygen heterocycle (20-50 eq.) is added, stirred at room temperature for 24h and then freeze-dried to obtain the assembly powder.

Step S2, a step of preparing a target precursor polyamic acid, specifically including:

ultrasonically dispersing the assembly powder obtained in the step S1 into a mixed solvent of 12mL of dimethyl acetyl (DMAC) and N-methyl pyrrolidone (NMP) (the volume ratio v/v of the two is 1:1 to 3:9), adding 1-1.9 mL of hydroxyethyl methacrylate (HEMA) and 1.0-9.9 mL of Butyl Acrylate (BA) into the mixed solvent, uniformly stirring the mixture at the temperature of 55 ℃, adding 3.7-5.8 mL of diphenylamine ether and 3-5 mL of PI liquid of PAA-49 type dissolved in N-methyl pyrrolidone (NMP) into the mixed solvent, and uniformly stirring the mixture again to obtain a solution containing a precursor of poly polyamic acid (β -CD)/a-PS/PAA, and

step S3, preparing a target polyimide compound, which comprises the following steps:

heating the solution containing the precursor polyamic acid poly (β -CD)/a-PS/PAA obtained in the step S2 to 90 ℃, adding 3-9 mL of dibutyltin dilaurate (DBTDL) serving as a catalyst for a small amount of reaction to perform reaction catalysis, heating the solution to 250 ℃ at the speed of 3 ℃/min, keeping the temperature for 1h, reducing the temperature to room temperature, and then, hanging and coating the solution on a glass substrate to form the target polyimide composite poly (β -CD)/a-PS/PI.

Further, refer to fig. 1 and 2, which are graphs showing the comparison between the polyimide composite according to the present invention before and after self-repairing after suffering from damage after film formation. As shown in fig. 1, scratch damage is evident in the middle of the film layer, and after about 10min, the complete self-repairing scratch of the film layer substantially disappears as shown in fig. 2. The self-repairing performance does not exist in the existing common polyimide materials which do not introduce host-guest interaction and intramolecular hydrogen bond interaction.

The invention relates to a polyimide compound, which adopts a composite molecular structure of an assembly structure molecule combined with a polyimide molecular structure, and the self-repairing performance of the polyimide compound is endowed by taking a modified guest molecule selected in the assembly molecular structure as the basis of the inclusion effect of a host and a guest and simultaneously introducing O-H and N-H bonds in the guest molecule to endow the material with hydrogen bond interaction in the molecule and host-guest interaction among molecules.

The technical scope of the present invention is not limited to the contents described in the above description, and those skilled in the art can make various changes and modifications to the above-described embodiments without departing from the technical spirit of the present invention, and these changes and modifications should fall within the scope of the present invention.

Claims

1. The polyimide compound is characterized in that the molecular structure of the assembly comprises polycyclodextrin poly (β -CD) as a host molecule and a styrene derivative a-PS of a nitrogen-containing oxygen heterocycle as a guest molecule;

the molecular structure general formula adopted by the polyimide compound is poly (β -CD)/a-PS/PI;

wherein the guest molecule a-PS adopts a structural general formula as follows:

2. the polyimide composite of claim 1, wherein the polyamic acid poly (β -CD)/a-PS/PAA as a raw material precursor has a general molecular structure:

3. the polyimide composite of claim 1; the preparation method is characterized in that the preparation raw materials of the polycyclodextrin comprise cyclodextrin and epichlorohydrin.

4. The polyimide composite of claim 3; the preparation method is characterized in that the ratio of the cyclodextrin to the epichlorohydrin is within the range of 0.75-1.5.

5. The polyimide composite of claim 1; the method is characterized in that the molar ratio of a host molecule to a guest molecule of the assembly is 1: 5-1: 3.

6. The polyimide composite of claim 1; the method is characterized in that the mass ratio of a host molecule to a guest molecule of the assembly is (10-65): 1.

7. A preparation method for preparing the polyimide composite according to claim 1; the method is characterized by comprising the following steps:

s1, preparing an assembly, namely dispersing the host molecular material polycyclodextrin into water, adding the guest molecular material into the water, stirring the mixture at room temperature for 12-36 hours, and then obtaining powder of the assembly material in a freeze-drying mode;

s2, preparing a target precursor polyamic acid, namely dispersing the assembly powder obtained in the S1 into a mixed solvent of dimethyl acetyl and N-methyl pyrrolidone, then adding hydroxyethyl methacrylate and butyl acrylate, uniformly stirring at the temperature of 40-70 ℃, then adding diphenylamine ether and a polyimide-containing PI solution dissolved in N-methyl pyrrolidone, and uniformly stirring again to obtain a solution containing a precursor polyamic acid poly (β -CD)/a-PS/PAA, and

s3, preparing a target polyimide compound, namely, heating the precursor polyamic acid solution to 80-100 ℃, heating the precursor polyamic acid solution to 250 ℃ at a speed of 2-5 ℃/min, keeping the temperature constant for 0.5-1.5 h, reducing the temperature of the solution to room temperature, and suspending the solution on a substrate to form the target polyimide compound, namely poly (β -CD)/a-PS/PI.

8. The production method according to claim 7; the method is characterized in that in the step S1, the method further comprises a substep S11 of preparing the main molecular material, wherein the substep comprises the steps of dissolving cyclodextrin in a NaOH solution, adding epoxy chloropropane after the solution temperature reaches 25-35 ℃, stirring for 2.0-5.0 hours to enable the two to fully react, and then adding acetone to stop the reaction;

after removing acetone by rotary evaporation, dissolving the residual substances in deionized water, and adjusting the pH value of the solution to 10-12; dialyzing the solution for 5-9 days, wherein the value of the cut-off molecular weight in the solution is within the range of 3000-12000, and finally, separating the product by freeze-drying to obtain the main molecular material.

9. The production method according to claim 8; characterized in that in the step S11, the cyclodextrin is dissolved in the NaOH to be subjected to ultrasonic treatment for 20-50 min; and the stirring speed of the epoxy chloropropane added into the cyclodextrin solution is 500-800 rpm.

10. The production method according to claim 7; wherein the volume ratio of the dimethylacetol to the N-methylpyrrolidone used in step S2 is 1:1 to 3: 9.