CN1246370C - Method for preparing aniline oligomer/polyimide gradient film - Google Patents

Abstract

The invention belongs to the field of macromolecular materials, and specifically relates to a preparation method of a novel aniline oligomer/polyimide gradient film: (1) dissolving diamine in an organic solvent to obtain a colorless transparent liquid, and then slowly adding diamine and diamine dianhydride with an amine molar ratio of 0.1 to 5:1, and a solid content of 1 to 50% in the solvent, then stirred at room temperature for 2 to 24 hours to obtain a light yellow transparent viscous liquid-polyamic acid solution; (2) Take the above product, add The aniline oligomer with the mass ratio of polyamic acid in the solution is 0.005～0.1:1, ultrasonically mixed for 10～30 hours to obtain a dark green transparent viscous liquid; (3) prepare a film on a support plate by scraping, Putting it into an oven and performing temperature programming treatment in the temperature range of 20° C. to 400° C. under vacuum condition, so as to obtain an aniline oligomer/polyimide gradient film. The film has excellent characteristics of electrical anisotropy on both sides, and has a wide range of applications in microelectronic materials.

Description

Preparation method of aniline oligomer/polyimide gradient membrane

Technical field:

The invention belongs to the field of polymer materials, and in particular relates to a preparation method of a novel aniline oligomer/polyimide gradient film. The gradient film prepared by the method has wide application in high-performance electromagnetic materials.

Background technique:

Conductive polymers are an emerging field of polymer science, especially intrinsic conjugated conductive polymers, which have great potential in the fields of chemical power sources, electromagnetic shielding, antistatic, information storage and processing, electrochromic materials, sensors, and stealth materials. Broad application prospects. Among many conjugated conductive polymers, polyaniline is considered to be the most likely conductive polymer to be applied in practice because of its cheap and easy-to-obtain raw materials, simple and convenient preparation, excellent electrochemical performance and good chemical stability. However, polyaniline has a rigid conjugated chain that leads to poor processability, thermal decomposition and inability to melt, and cannot be processed by conventional extrusion molding, injection molding, etc.; The solubility in is very poor, can't find a good solvent to dissolve it completely, and there are defects in its polymer molecule. Compared with it, the oligomer of monodisperse conductive polymer (oligomer is also a polymer of aniline, The degree of polymerization is very low, and the molecular formula is such as the following Scheme1) molecular weight is relatively small, so it can be dissolved in some common organic solvents preferably; On the other hand, from the perspective of application, the oligomer itself of monodisperse conductive polymer It can be regarded as a new material with great application prospect. The study of oligomers reveals that the oligomers of conductive polymers should have better application prospects than their polymers.

Polyaniline oligomers have many excellent properties as above, but they are conductive only in the doped state, and polyaniline oligomers are in powder form at room temperature and have almost no mechanical properties, so they cannot be directly applied. People have explored many One way, in which the blending modification is simple and easy to implement, and it is easy to apply to production. Polyimide is widely used in electronics, micro Electronics, optoelectronics and aerospace fields. Based on the excellent properties of polyimide and the good application background of aniline oligomers, the present invention selects polyimide as the base material, composes aniline oligomers in polyamic acid, and undergoes a thermal imidization process. Through the solvent evaporation, the aniline oligomers are gathered on the surface of the membrane to form a gradient gradient (that is, the component content changes gradually from one end of the membrane to the other end, and it changes continuously), and a new type of special membrane material with two-sided anisotropy, which not only maintains The excellent properties of polyimide endow it with functionality.

Invention content:

The purpose of the present invention is to prepare a new type of functional material with two-sided electrical anisotropy. The gradient film prepared by the method has excellent characteristics of two-sided electrical anisotropy, and has a wide range of applications in microelectronic materials.

The preparation method of the present invention is as follows:

(1) Dissolve diamine in an organic solvent (electromagnetic stirring) to obtain a colorless transparent liquid, then slowly add dianhydride with a molar ratio of 0.1 to 5:1 to diamine, the solid content in the solvent is 1 to 50%, and then Stir for 2-24 hours to obtain a light yellow transparent viscous liquid—polyamic acid solution;

(2) Take the above product, add aniline oligomer with a mass ratio of 0.005 to 0.1:1 to the polyamic acid in the solution, and mix ultrasonically for 10 to 30 hours to obtain a dark green transparent viscous liquid;

(3) Prepare a thin film on a support plate (such as a glass plate, iron plate, steel plate, alloy plate, etc.) Putting it into an oven to carry out a temperature-programmed treatment within a temperature range of 20° C. to 400° C. under vacuum conditions, so as to obtain an aniline oligomer/polyimide gradient film.

The diamine described in the above method is 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether or 1,4,-(3- Aminophenoxy)benzene, 1,4,-(4-aminophenoxy)benzene, 1,3,-(3-aminophenoxy)benzene or 1,3,-(4-aminophenoxy) One of benzene.

The dianhydride is 3,3',4,4'-biphenyltetraic dianhydride, 2,3',3,4'-biphenyltetraic dianhydride, 2,3',2,3'-biphenyltetra One of pyromellitic dianhydride, pyromellitic dianhydride (PMDA) or diphenyl ether tetra-acid dianhydride (ODPA).

The organic solvent is one or two or three of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc) or N-methylpyrrolidone (NMP) Mixed solvents.

The aniline oligomers may be benzene-terminated or amine-terminated aniline oligomers, wherein benzene-terminated aniline oligomers are more effective, especially benzene-terminated aniline tetramers.

As a preferred embodiment of the present invention, in the above method, the molar ratio of dianhydride to diamine is 0.2 to 2.5:1; the solid content in the solvent is 3 to 20%; the benzene-terminated aniline tetramer and polyamic acid The mass ratio is 0.008-0.08:1.

As a further preferred embodiment of the present invention, in the above method, the molar ratio of dianhydride to diamine is 0.8 to 1.5:1; the solid content in the solvent is 7 to 15%; the benzene-terminated aniline tetramer and poly The mass ratio of amic acid is 0.01-0.05:1.

Features of the invention patent:

1. The present invention selects benzene-terminated aniline tetramer (Scheme 1), which has good stability in polyamic acid, does not react with diamine and dianhydride monomers, and is soluble (soluble in DMF, DMAc or solvents such as THF).

Scheme 1 Benzene-terminated aniline tetramer

2. The preparation of polyimide involved in the present invention includes the following two steps: the synthesis of polyamic acid and the temperature-programmed thermal imidization.

Polyimide is made of diamine and dianhydride as raw materials, and strong polar aprotic solvents such as DMF, DMAc, NMP, etc. are used as solvents. Its structure and preparation method are as follows:

3. The patent of the present invention is to add a certain amount of aniline tetramer to the polyamic acid to make it evenly dispersed in the polyamic acid, and then prepare the membrane material, and imidize the polyamic acid through temperature programming. The aniline is brought to the surface of the film by the solvent, and the aniline oligomers are enriched on the surface of the film and distributed in a gradient in the polyimide film.

4, the film that the present invention obtains has two-sided anisotropy (aniline oligomer has conductive property, and polyimide is an insulating material, and the electrical performance of two sides of the gradient film that obtains has very big difference), while keeping the excellent properties of polyimide Performance (such as thermal properties and mechanical properties), but also some properties of aniline (such as electrical conductivity, anti-corrosion properties, etc.).

Description of drawings

Figure 1: Reflected UV-Vis spectra on both sides of the gradient film

Fig. 1 (1) is that doping amount is the reflection ultraviolet-visible spectrogram of two sides of 1% gradient film,

Fig. 1 (2) is the two-sided reflection ultraviolet-visible spectrogram of 2% gradient film for doping amount,

Fig. 1 (3) is the two-sided reflection ultraviolet-visible spectrum figure of 5% gradient film for doping amount;

Figure 2: SEM image of the side surface of the gradient film with a doping amount of 1%;

Figure 3: DSC scan of a gradient film with a doping amount of 1%;

Figure 4: Thermogravimetric loss (TGA) curve of the gradient film under air;

Fig. 4 (1) is the thermal gravity loss (TGA) curve figure of undoped film,

Fig. 4 (2) is the thermal gravity loss (TGA) curve figure of the gradient film of 1% doping amount;

Table 1: Contact angle values of gradient film (FT200 type produced by HARVEY, MAIN&CO.LTD.) Contact surfaces 0% 1% 2% 5% air surface glass surface 74.9075.30 67.8473.45 74.4780.27 69.7565.27

Table 2: Mechanical tensile test results of gradient film (using AG-I electronic universal testing machine produced by Shimadzu Corporation) Tetramer content Modulus GPa Breaking strength MPa Elongation at break% 0% 1% 2% 5% 2.72.92.82.9 103107104106 32.825.314.911.2

As shown in Figure 1, the UV-Vis absorption patterns on both sides of the gradient film are different, which proves that the tetramer content on the air side is more, and the content on the glass side is lower, which proves that the composition content of the two sides is different, of which 1% The difference between 2% and 2% is obvious, and the two-sided anisotropy of the gradient film is obvious.

Fig. 1 (1), (2), (3) represents that doping amount is 1%, 2%, the film of 5% respectively, and curve 1 represents the absorption curve of the film that doping amount is 0%; Curve 2 represents the film Absorption curve for the air side; curve 3 represents the absorption curve for the glass side of the film; curve 4 represents the absorption curve for air.

Figure 2 is a scanning electron micrograph of the side of the 1% gradient film, and it can be seen that the two sides are obviously different.

Table 1 shows the test results of the contact angle of the gradient film. We can see that the contact angle values of the two sides are significantly different, and the parallel values are almost the same, which shows that the two sides are different.

To sum up, through four characterization methods of reflection ultraviolet-visible, scanning electron microscopy and contact angle, it is proved that the composition and content of the target product - aniline oligomer/polyimide gradient film are significantly different on both sides.

As shown in Figure 3, it is the DSC scan diagram of the aniline oligomer-polyimide gradient film. From this figure, we can see that the glass transition temperature of the 1% gradient film is 272 ° C, which proves that the gradient film maintains Polyimide has good thermal properties and has a high service temperature.

Fig. 4 is the thermogravity figure of aniline oligomer/polyimide gradient film under air, shown in Fig. 4 (1) and Fig. 4 (2), respectively is the TGA of 0% and 1% gradient film under air From the graph, it can be seen that the 5% thermal weight loss temperature of the 1% gradient film in air can reach about 530°C, which shows that this material has excellent thermal stability and thermal oxidation stability.

Table 2 shows the test results of the mechanical tensile properties of the aniline oligomer/polyimide gradient film. It can be seen that the gradient film maintains the good mechanical properties of the polyimide matrix material.

In summary, the three characterization methods of DSC, TGA and mechanical tensile test proved the good thermal and mechanical properties of the target product - aniline oligomer/polyimide gradient film.

In summary, through the performance test of the gradient film, it is proved that the aniline oligomer/polyimide gradient film prepared by us has good dispersion, obvious two-sided anisotropy, good mechanical and thermal properties, and has good application potential with foreground.

Detailed ways

The preparation embodiment of aniline oligomer-polyimide gradient film:

Example 1:

In an electromagnetic stirring device, 4,4'-diaminodiphenyl ether (4,4'-ODA) 8g (0.04mol) was dissolved in 150ml N,N-dimethylacetamide (DMAc) in a beaker to obtain a colorless transparent liquid , then slowly added 3,3',4,4'-biphenyltetraacid dianhydride (s-BPDA, 11.76g, 0.04mol), and then stirred at room temperature for 4 hours to obtain a light yellow transparent viscous liquid—polyamic acid solution .

Take 10.30g of the above-mentioned polyamic acid solution (wherein the polyamic acid solid content is 10%, that is, 1.03g) mixed with 10.3mg of benzene-terminated aniline tetramer, and use ultrasonic mixing for 20h to obtain a dark green transparent viscous liquid [w( aniline tetramer)/w (polyamic acid) = 1%].

Use a scraper to scrape a 300μm thick film on a glass plate, put it in an oven, and process the temperature program: (40°C/1 hour, 60°C/1 hour, 80°C/1 hour, 150°C/1 hour, 200°C/1 hour , 250° C./1 hour, under vacuum), a gradient film with a thickness of about 30 μm and a doping amount of 1% was obtained.

Tests have proved that the new membrane material has good dispersion, the obtained membrane has obvious anisotropy on both sides, good mechanical and thermal properties, and has broad application prospects. It can be seen that the membrane obtained under this treatment condition is better.

Example 2:

The method is as in Example 1, and the doped benzene-terminated aniline tetramer is increased to 20.6 mg to obtain a gradient film with a doping amount of 2%.

Example 3:

The method is as in Example 1, and the doped benzene-terminated aniline tetramer is increased to 51.5 mg, and its doping amount is 5% for gradient film.

Example 4:

The method is as in Example 1, and 150 ml of N-methylpyrrolidone (NMP) is replaced by N, N-dimethylacetamide (DMAc). The resulting membrane material has better dispersibility, and the obtained membrane has obvious opposite properties on both sides, and its mechanical and thermal properties are very good. good.

Example 5:

The method is as in Example 1, and N, N-dimethylacetamide (DMAc) is replaced with 150 ml of N, N-dimethylformamide (DMF). And thermal performance is very good.

Embodiment 6:

The method is as in Example 1, with 3,4'-diaminodiphenyl ether (3,4'-ODA, 0.04mol 8g) replacing 4,4'-diaminodiphenyl ether (4,4'-ODA, 0.04mol 8g). The glass transition temperature Tg of the film dropped by 5 degrees.

Embodiment 7:

The method is as in Example 1, with 3,3'-diaminodiphenyl ether (3,3'-ODA, 0.04mol 8g) replacing 4,4'-diaminodiphenyl ether (4,4'-ODA, 0.04mol 8g). The polyimide film changes from crystalline form to amorphous form, and the glass transition temperature drops by 12 degrees.

Embodiment 8:

The method is as in Example 1, with 1,4,-(3-aminophenoxy)benzene (1,4,3-APB, 0.04mol 11.76g) replacing 4,4'-diaminodiphenyl ether (4,4 '-ODA, 0.04mol 8g). The polyimide film changes from crystalline form to amorphous form, and the glass transition temperature drops by 20 degrees.

Embodiment 9:

The method is as in Example 1, with 1,4,-(4-aminophenoxy)benzene (1,4,4-APB, 0.04mol 11.76g) replacing 4,4'-diaminodiphenyl ether (4,4 '-ODA, 0.04mol 8g). The glass transition temperature drops by 5 degrees.

Example 10:

The method is as in Example 1, with 1,3,-(3-aminophenoxy)benzene (1,3,3-APB, 0.04mol 11.76g) replacing 4,4'-diaminodiphenyl ether (4,4 '-ODA, 0.04mol 8g). The polyimide film changes from crystalline form to amorphous form, and the glass transition temperature drops by 60 degrees.

Example 11:

The method is as in Example 1, and 2,3', 3,4'-biphenyltetraacid dianhydride (a-BPDA, 11.76g, 0.04mol) is replaced by 3,3',4,4'-biphenyltetraacid di Anhydride (s-BPDA, 11.76 g, 0.04 mol). The polyimide film changes from crystalline form to amorphous form, and the glass transition temperature increases by 50 degrees.

Example 12:

The method is as in Example 1, and 2,3', 2,3'-biphenyltetraacid dianhydride (i-BPDA, 11.76g, 0.04mol) is replaced by 3,3',4,4'-biphenyltetraacid di Anhydride (s-BPDA, 11.76 g, 0.04 mol). The polyimide film changes from crystalline form to amorphous form, and the glass transition temperature increases by 70 degrees.

Example 13:

The method is as in Example 1, replacing 3,3',4,4'-biphenyltetraic dianhydride (s-BPDA, 11.76g, 0.04mol) with pyromellitic dianhydride (PMDA, 8.72g, 0.04mol) . The color of the polyimide film deepens.

Example 14:

The method is as in Example 1, replacing 3,3',4,4'-biphenyltetraacid dianhydride (s-BPDA, 11.76g, 0.04mol) with diphenyl ether tetraacid dianhydride (ODPA, 12.4g, 0.04mol) ). The color of the polyimide film becomes lighter, and the glass transition temperature drops by 8 degrees.

Claims (6)

1, the preparation method of a kind of aniline oligomer/polyimide gradient film, its step is as follows:

(1) gets diamines and be dissolved in N, dinethylformamide, N, obtain colourless transparent liquid in N-N,N-DIMETHYLACETAMIDE or the N-Methyl pyrrolidone solvent, slow again adding and diamines mol ratio are 0.1～5: 1 dianhydride, solid content 1～50% in the solvent, then stirring at room 2～24h obtains light yellow transparent thick liquid-polyamic acid solution;

(2) get above-mentioned product, the polyamic acid mass ratio is 0.005～0.1: 1 aniline oligomer in adding and the solution, and ultrasonic mixing 10～30 hours obtains blackish green transparent thick liquid;

(3) method with blade coating prepares film on back up pad, puts into baking oven and carry out the temperature programming processing 20 ℃～400 ℃ temperature ranges under vacuum condition, thereby obtain aniline oligomer/polyimide gradient film.

2, the preparation method of aniline oligomer as claimed in claim 1/polyimide gradient film, it is characterized in that: diamines is 4,4 '-diamines yl diphenyl ether, 3,4 '-diaminodiphenyl oxide, 3,3 '-diaminodiphenyl oxide or 1,4 ,-(3-amino-benzene oxygen) benzene, 1,4,-(4-amino-benzene oxygen) benzene, 1,3 ,-(3-amino-benzene oxygen) benzene or 1,3, a kind of in-(4-amino-benzene oxygen) benzene.

3, the preparation method of aniline oligomer as claimed in claim 1/polyimide gradient film, it is characterized in that: dianhydride is 3,3 ', 4,4 '-BPDA, 2,3 ', 3,4 '-BPDA, 2,3 ', 2, a kind of in 3 '-BPDA, pyromellitic acid dianhydride or the phenyl ether tetracarboxylic dianhydride.

4, the preparation method of aniline oligomer as claimed in claim 1/polyimide gradient film is characterized in that: aniline oligomer is the end capped aniline tetramer of benzene.

5, as the preparation method of any one described aniline oligomer of claim 1-4/polyimide gradient film, it is characterized in that: the mol ratio of dianhydride and diamines consumption is 0.2～2.5: 1; Solid content is 3～20% in the solvent; Benzene ended aniline tetramer and polyamic acid mass ratio are 0.008～0.08: 1.

6, the preparation method of aniline oligomer as claimed in claim 5/polyimide gradient film, it is characterized in that: the mol ratio of dianhydride and diamines consumption is 0.8～1.5: 1; Solid content is 7～15% in the solvent; Benzene ended aniline tetramer and polyamic acid mass ratio are 0.01～0.05: 1.

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