CN105504280B - A kind of high temperature heat-shrink tube random copolymerization polyimides and preparation method thereof - Google Patents

Abstract

The invention discloses a random copolymerized polyimide for a high-temperature heat-shrinkable tube and a preparation method thereof, which relates to a high-temperature heat-shrinkable tube and a preparation method thereof. The purpose of the present invention is to solve the problem that the heat shrinkage temperature of the existing high-temperature heat-shrinkable tube is below 200°C, which cannot meet the heat shrinkage requirements in the high-temperature field. A random copolymerized polyimide for high-temperature heat-shrinkable tubes is composed of 4,4'-bis(4-aminophenoxy)biphenyl, bisphenol A diether dianhydride and 3,3',4,4'- Prepared from a mixture of benzophenone tetracarboxylic dianhydride. Method: 1. Preparation of diamine solution; 2. Preparation of dianhydride mixture solution; 3. Preparation of polyamic acid solution; 4. Thermal imidization to obtain a glass plate containing polyimide film; 5. Cleaning to obtain a shape Memory random copolymerized polyimide film; 6. Preparation of glass tube containing shape memory random copolymerized polyimide tube; 7. Cleaning and drying. The invention can obtain a random copolymerized polyimide for high-temperature heat-shrinkable tubes.

Description

A random copolymerized polyimide for high-temperature heat-shrinkable tube and its preparation method

technical field

The invention relates to a high-temperature heat-shrinkable tube and a preparation method thereof.

Background technique

Heat-shrinkable sleeve, also known as heat-shrinkable protective sleeve, has the functions of insulation, sealing, anti-corrosion, moisture-proof and connection. application. In 1960, Charlesby discovered the "shape memory effect" of cross-linked polyethylene, and prepared polyethylene heat-shrinkable tubes and heat-shrinkable films, which opened the prelude to the research on polymer shape memory materials. The Changchun Institute of Applied Chemistry of the Chinese Academy of Sciences developed and produced the first generation of heat-shrinkable sleeves for my country's first earth satellite.

Common heat-shrinkable tubes include PVC heat-shrinkable sleeves, which can shrink when heated above 98°C, and are easy to use. In recent years, some manufacturers have successively developed and produced new products such as heat-shrinkable sleeves with 135°C expansion, environmentally friendly polyolefin heat-shrinkable sleeves for automobiles, and double-wall heat-shrinkable sleeves for automobiles, making heat-shrinkable sleeves widely used in In many industries in the electrical field.

Existing methods prepare heat-shrinkable cable accessories. However, under many conditions, especially large-scale machinery and high-power motors, high-temperature heat-shrinkable tubes are required, and there are few studies on high-temperature heat-shrinkable tubes.

Heat-shrinkable materials use the principle of "elastic memory" of high molecular polymers, and are an important branch of shape memory polymers. Polyimide (PI) has the advantages of high thermal stability, excellent mechanical properties, and diverse processing methods, and has been widely used in automotive, microelectronics, optoelectronics, aerospace and other fields. Shape memory polyimide also has important application value in space deployment structure, variable aircraft aileron, high temperature sensor and driver.

Contents of the invention

The purpose of the present invention is to solve the problem that the heat shrinkage temperature of the existing high-temperature heat-shrinkable tube is below 200°C, which cannot meet the needs of heat shrinkage in the high-temperature field, and to provide a random copolymerized polyimide for high-temperature heat-shrinkable tubes and its preparation method .

A random copolymerized polyimide for high-temperature heat-shrinkable tubes is composed of 4,4'-bis(4-aminophenoxy)biphenyl, bisphenol A diether dianhydride and 3,3',4,4'- Prepared from a mixture of benzophenone tetracarboxylic dianhydride; the 4,4'-bis(4-aminophenoxy)biphenyl and bisphenol A diether dianhydride and 3,3',4,4 The molar ratio of the mixture of '-benzophenone tetracarboxylic dianhydride is 1:1; the mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride The molar ratio of bisphenol A type diether dianhydride to 3,3',4,4'-benzophenone tetracarboxylic dianhydride is A:B; the value range of A is 1≤A≤9; the value of B is The value range is 1≤B≤9.

A preparation method of random copolymerized polyimide for high-temperature heat-shrinkable tubes is completed according to the following steps:

1. Add 4,4'-bis(4-aminophenoxy)biphenyl into the aprotic polar solvent, and then stir until 4,4'-bis(4-aminophenoxy)biphenyl Benzene is completely dissolved to obtain a diamine solution;

The volume ratio of the amount of 4,4'-bis(4-aminophenoxy)biphenyl described in step 1 to the aprotic polar solvent is 0.05mol:(100mL～150mL);

2. Dissolving a mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in an aprotic polar solvent to obtain a dianhydride mixture solution;

The volume ratio of the mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride to the aprotic polar solvent is 0.05mol :(100mL～150mL);

Bisphenol A diether dianhydride and 3,3',4 , the molar ratio of 4'-benzophenonetetracarboxylic dianhydride is A:B; the value range of A is 1≤A≤9; the value range of B is 1≤B≤9;

3. Add the dianhydride mixture solution to the diamine solution in 3 to 5 times, and then polymerize for 15h to 20h at room temperature, nitrogen atmosphere and stirring speed of 300r/min to 400r/min to obtain polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, and then raise the temperature of the vacuum drying oven from room temperature to 70°C at a rate of 1°C/min～2°C/min 90°C, then keep warm at 70°C~90°C for 2h~3h, then raise the temperature from 70°C~90°C to 150°C~170°C at a rate of 1°C/min~2°C/min, and then heat it at 150°C~170°C ℃ for 2h~3h, then raise the temperature from 150℃~170℃ to 190℃~210℃ at a rate of 1℃/min~2℃/min, then keep warm at 190℃~210℃ for 2h~3h, and then The heating rate of 1℃/min～2℃/min is raised from 190℃～210℃ to 230℃～260℃, and then kept at 230℃～260℃ for 1h～2h to complete thermal imidization, and then vacuum dry Box is cooled to room temperature naturally, obtains the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film in an aprotic polar solvent to obtain a shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube , and then put the glass tube into the temperature of 150 ° C ~ 200 ° C for 120 h ~ 200 h to obtain a glass tube containing a shape memory random copolymer polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 10% to 15%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imine tube is dried at a temperature of 120° C. for 5 hours to 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes.

Advantages of the present invention:

1. The present invention adopts 4,4'-bis(4-aminophenoxy)biphenyl as the diamine monomer, and adopts bisphenol A diether dianhydride and 3,3',4,4'-benzophenone The mixture of tetraformic acid dianhydride is used as the dianhydride monomer to prepare the shape memory random copolymer polyimide film;

2. The shape-memory random copolymerized polyimide film prepared by the present invention can be dissolved in a protic solvent, and a high-temperature thermoplastic pipe can be obtained by solvent volatilization;

3. The random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared by the present invention has good shape memory performance and has broad application prospects in the high-temperature field;

4. The _Tg of the random copolymerized polyimide for high-temperature heat-shrinkable tubing prepared by the present invention is 216°C to 228°C, and the storage modulus at _Tg -20°C glass state is 1.72GPa to _1.88GPa ; The storage modulus at +20℃ in the rubber state is 4.3MPa～5.8MPa;

5. The high-temperature heat-shrinkable tube prepared by the present invention has good shape memory effect.

The invention can obtain a random copolymerized polyimide for high-temperature heat-shrinkable tubes.

Description of drawings

Fig. 1 is the infrared spectrogram of the random copolymerization polyimide of the high-temperature heat-shrinkable tubing that embodiment one prepares;

Fig. 2 is the dissipation factor figure of random copolymerized polyimide for the high-temperature heat-shrinkable tube prepared in embodiment one;

Fig. 3 is the storage modulus figure of random copolymerized polyimide for the high-temperature heat-shrinkable tubing prepared in embodiment one;

Fig. 4 is the temporary shape obtained when the high-temperature heat-shrinkable tube prepared in Example 1 is deformed at 230°C and fixed at room temperature;

Fig. 5 shows the status of the high-temperature heat-shrinkable tube prepared in Example 1 returning to its original shape in an atmosphere of 230°C.

Detailed ways

Specific embodiment 1: A random copolymerized polyimide for high-temperature heat-shrinkable tubes is composed of 4,4'-bis(4-aminophenoxy)biphenyl, bisphenol A diether dianhydride and 3,3', Prepared from a mixture of 4,4'-benzophenone tetracarboxylic dianhydride; the 4,4'-bis(4-aminophenoxy)biphenyl and bisphenol A diether dianhydride and 3,3 The molar ratio of the mixture of ',4,4'-benzophenone tetracarboxylic dianhydride is 1:1; the bisphenol A type diether dianhydride and 3,3',4,4'-benzophenone tetra The molar ratio of bisphenol A diether dianhydride to 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the mixture of formic dianhydride is A:B; the value range of A is 1≤A≤ 9; the value range of B is 1≤B≤9.

Specific embodiment two: This embodiment is a method for preparing random copolymerized polyimide for high-temperature heat-shrinkable tubes, which is completed according to the following steps:

1. Add 4,4'-bis(4-aminophenoxy)biphenyl into the aprotic polar solvent, and then stir until 4,4'-bis(4-aminophenoxy)biphenyl Benzene is completely dissolved to obtain a diamine solution;

The volume ratio of the amount of 4,4'-bis(4-aminophenoxy)biphenyl described in step 1 to the aprotic polar solvent is 0.05mol:(100mL～150mL);

2. Dissolving a mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in an aprotic polar solvent to obtain a dianhydride mixture solution;

The volume ratio of the mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride to the aprotic polar solvent is 0.05mol :(100mL～150mL);

Bisphenol A diether dianhydride and 3,3',4 , the molar ratio of 4'-benzophenonetetracarboxylic dianhydride is A:B; the value range of A is 1≤A≤9; the value range of B is 1≤B≤9;

3. Add the dianhydride mixture solution to the diamine solution in 3 to 5 times, and then polymerize for 15h to 20h at room temperature, nitrogen atmosphere and stirring speed of 300r/min to 400r/min to obtain polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, and then raise the temperature of the vacuum drying oven from room temperature to 70°C at a rate of 1°C/min～2°C/min 90°C, then keep warm at 70°C~90°C for 2h~3h, then raise the temperature from 70°C~90°C to 150°C~170°C at a rate of 1°C/min~2°C/min, and then heat it at 150°C~170°C ℃ for 2h~3h, then raise the temperature from 150℃~170℃ to 190℃~210℃ at a rate of 1℃/min~2℃/min, then keep warm at 190℃~210℃ for 2h~3h, and then The heating rate of 1℃/min～2℃/min is raised from 190℃～210℃ to 230℃～260℃, and then kept at 230℃～260℃ for 1h～2h to complete thermal imidization, and then vacuum dry Box is cooled to room temperature naturally, obtains the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film in an aprotic polar solvent to obtain a shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube , and then put the glass tube into the temperature of 150 ° C ~ 200 ° C for 120 h ~ 200 h to obtain a glass tube containing a shape memory random copolymer polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 10% to 15%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imine tube is dried at a temperature of 120° C. for 5 hours to 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes.

The advantage of this implementation mode:

1. In this embodiment, 4,4'-bis(4-aminophenoxy)biphenyl is used as the diamine monomer, and bisphenol A diether dianhydride and 3,3',4,4'-diphenyl The mixture of ketone tetracarboxylic dianhydride is used as dianhydride monomer to prepare shape memory random copolymer polyimide film;

2. The shape-memory random copolymer polyimide film prepared in this embodiment can be dissolved in a protic solvent, and a high-temperature thermoplastic tube can be obtained by solvent volatilization;

3. The random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in this embodiment has good shape memory performance and has broad application prospects in high-temperature fields;

4. The _Tg of random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in this embodiment is 216°C-228°C, and the storage modulus at _Tg -20°C glass state is 1.72GPa-1.88GPa; _g The storage modulus in the rubber state at +20°C is 4.3MPa～5.8MPa;

5. The high-temperature heat-shrinkable tube prepared in this embodiment has a good shape memory effect.

In this embodiment, a random copolymerized polyimide for high-temperature heat-shrinkable tubes can be obtained.

Specific embodiment three: the difference between this embodiment and specific embodiment two is: the aprotic polar solvent described in step one is N,N-dimethylformamide, N,N-dimethylacetamide or N - Methylpyrrolidone. Other steps are the same as in the second embodiment.

Embodiment 4: The difference between this embodiment and Embodiment 2 to 3 is that the aprotic polar solvent described in Step 2 is N,N-dimethylformamide, N,N-dimethyl Acetamide or N-methylpyrrolidone. Other steps are the same as those in the second to third embodiments.

Embodiment 5: The difference between this embodiment and Embodiment 2 to 4 is that the aprotic polar solvent described in step 6 is N,N-dimethylformamide, N,N-dimethyl Acetamide or N-methylpyrrolidone. Other steps are the same as those in Embodiments 2 to 4.

Specific embodiment 6: The difference between this embodiment and one of specific embodiments 2 to 5 is: the amount of 4,4'-bis(4-aminophenoxy)biphenyl described in step 1 and the amount of aprotic The volume ratio of the polar solvent is 0.05mol:110mL. Other steps are the same as those in Embodiments 2 to 5.

Embodiment 7: This embodiment differs from Embodiment 2 to Embodiment 6 in that: the amount of 4,4'-bis(4-aminophenoxy)biphenyl described in step 1 and the amount of aprotic The volume ratio of the polar solvent is 0.05mol:120mL. Other steps are the same as those in Embodiments 2 to 6.

Embodiment 8: The difference between this embodiment and one of Embodiments 2 to 7 is that in step 4, the polyamic acid solution is evenly coated on a clean glass plate, and then placed in a vacuum drying oven, and then vacuum The drying oven is heated from room temperature to 90°C at a heating rate of 1°C/min, and then kept at 90°C for 2 hours, then raised from 90°C to 170°C at a heating rate of 1°C/min, and then kept at 170°C for 2 hours. Then raise the temperature from 170°C to 210°C at a heating rate of 1°C/min, then hold at 210°C for 2 hours, then raise the temperature from 210°C to 250°C at a heating rate of 1°C/min, and then hold at 250°C for 1 hour. After thermal imidization is completed, the vacuum drying oven is naturally cooled to room temperature to obtain a glass plate containing a polyimide film. Other steps are the same as those in Embodiments 2 to 7.

Specific embodiment nine: the difference between this embodiment and one of specific embodiments two to eight is: in step four, the polyamic acid solution is evenly coated on a clean glass plate, then placed in a vacuum drying oven, and then vacuum The drying oven is heated from room temperature to 80°C at a heating rate of 1°C/min, and then kept at 80°C for 2 hours, then raised from 80°C to 170°C at a heating rate of 1°C/min, and then kept at 170°C for 2 hours. Then raise the temperature from 170°C to 210°C at a heating rate of 1°C/min, then hold at 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a heating rate of 1°C/min, and then hold at 260°C for 1 hour. After thermal imidization is completed, the vacuum drying oven is naturally cooled to room temperature to obtain a glass plate containing a polyimide film. Other steps are the same as those in Embodiments 2 to 8.

Embodiment 10: The difference between this embodiment and one of Embodiments 2 to 9 is that in step 4, the polyamic acid solution is evenly coated on a clean glass plate, and then placed in a vacuum drying oven, and then the vacuum The drying oven is heated from room temperature to 80°C at a heating rate of 1°C/min, and then kept at 80°C for 2 hours, then raised from 80°C to 170°C at a heating rate of 1°C/min, and then kept at 170°C for 2 hours. Then raise the temperature from 70°C to 210°C at a heating rate of 2°C/min, and then keep it at 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a heating rate of 2°C/min, and then keep it at 260°C for 1 hour. After thermal imidization is completed, the vacuum drying oven is naturally cooled to room temperature to obtain a glass plate containing a polyimide film. Other steps are the same as those in Embodiments 2 to 9.

Adopt the following examples to verify the beneficial effects of the present invention:

Embodiment 1: A kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps:

1. Add 0.05mol 4,4'-bis(4-aminophenoxy)biphenyl to 110mL N,N-dimethylacetamide, and stir until 4,4'-bis(4 -aminophenoxy)biphenyl is completely dissolved to obtain a diamine solution;

2. Dissolve a mixture of 0.04mol bisphenol A diether dianhydride and 0.01mol 3,3',4,4'-benzophenone tetracarboxylic dianhydride in 90mL N,N-dimethylacetamide to obtain Dianhydride mixture solution;

3. Add the dianhydride mixture solution to the diamine solution in 5 times, and then polymerize for 15 hours under room temperature, nitrogen atmosphere and a stirring speed of 400r/min to obtain a polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, then heat the vacuum drying oven from room temperature to 90°C at a rate of 1°C/min, and then heat it up at a temperature of 90°C. Keep warm at ℃ for 2 hours, then raise the temperature from 90°C to 170°C at a rate of 1°C/min, then keep at a temperature of 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a rate of 1°C/min, and then Insulate at a temperature of 210°C for 2 hours, then raise the temperature from 210°C to 250°C at a rate of 1°C/min, and then hold at a temperature of 250°C for 1 hour to complete thermal imidization, and then let the vacuum oven cool naturally To room temperature, obtain the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film into N,N-dimethylacetamide to obtain the shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube, and then put the glass tube into a temperature of 150° C. to dry for 200 hours to obtain a glass tube containing a shape-memory random copolymerized polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 10%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imine tube was dried at a temperature of 120° C. for 5 hours to obtain a high-temperature heat-shrinkable tube.

Use an infrared spectrometer to test the high-temperature heat-shrinkable tube prepared in Example 1 with random copolymerized polyimide, as shown in Figure 1;

Fig. 1 is the infrared spectrogram of the random copolymerization polyimide for the high-temperature heat-shrinkable tube prepared in Example 1; As can be seen from Fig. 1, the random copolymerization polyimide for the high-temperature heat-shrinkable tube prepared in Example 1 is highly imide oxidized polyimide.

Use a dynamic mechanical analyzer to test the random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in Example 1, as shown in Figure 2; Figure 2 is the random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in Example 1 It can be seen from Figure 2 that the T _g of the random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in Example 1 is 216°C, which ensures that it can be applied in high-temperature fields.

Use a dynamic mechanical analyzer to test the random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in Example 1, as shown in Figure 3; Figure 3 is the random copolymerized polyimide for high-temperature heat-shrinkable tubes prepared in Example 1 storage modulus graph. It can be seen from Figure 3 that there are two platforms in the high and low temperature section of the storage modulus curve. The storage modulus is 1.72GPa at 196°C (T _g -20°C) glassy state; at high temperature 236°C (T _g +20°C) The storage modulus in the rubber state is 4.3MPa; the storage modulus drops sharply between the two platforms, corresponding to the glass transition process of the material, and this sharp change in modulus is the shape memory property of the polymer necessary condition.

Fig. 4 is the temporary shape obtained when the high-temperature heat-shrinkable tube prepared in Example 1 is deformed at 230°C and fixed at room temperature;

Figure 5 shows the state of the high-temperature heat-shrinkable tube prepared in Example 1 returning to its original form in an atmosphere of 230°C;

It can be seen from Fig. 4 and Fig. 5 that the high-temperature heat-shrinkable tube prepared in Example 1 has a good shape memory effect.

Embodiment 2: A kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps:

1. Add 0.05mol 4,4'-bis(4-aminophenoxy)biphenyl to 120mL N,N-dimethylacetamide, and stir until 4,4'-bis(4 -aminophenoxy)biphenyl is completely dissolved to obtain a diamine solution;

2. Dissolve a mixture of 0.035mol bisphenol A diether dianhydride and 0.015mol 3,3',4,4'-benzophenone tetracarboxylic dianhydride in 90mL N,N-dimethylacetamide to obtain Dianhydride mixture solution;

3. Add the dianhydride mixture solution to the diamine solution in 5 times, and then polymerize for 16 hours under room temperature, nitrogen atmosphere and a stirring speed of 400r/min to obtain a polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, then heat the vacuum drying oven from room temperature to 80°C at a rate of 1°C/min, and then heat it up at a temperature of 80°C. ℃ for 2 hours, then raise the temperature from 80°C to 170°C at a rate of 1°C/min, then keep at a temperature of 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a rate of 1°C/min, and then Insulate at a temperature of 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a rate of 1°C/min, and then hold at a temperature of 260°C for 1 hour to complete thermal imidization, and then let the vacuum oven cool naturally To room temperature, obtain the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film into N,N-dimethylacetamide to obtain the shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube, and then put the glass tube into a temperature of 150° C. to dry for 200 hours to obtain a glass tube containing a shape-memory random copolymerized polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 12%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imide tube was dried at a temperature of 120° C. for 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes.

The T _g of the high-temperature heat-shrinkable tube prepared in Example 2 is 218° C., which ensures that the high-temperature heat-shrinkable tube prepared in Example 2 can be applied to the field of high-temperature heat-shrinkable tubes. The storage modulus of the high-temperature heat-shrinkable tube prepared in Example 2 is 1.75 GPa in the glass state at 198°C (T _g -20°C); the storage modulus in the rubber state at 238°C (T _g +20°C) is 4.5 MPa. The high-temperature heat-shrinkable tube prepared in Example 2 has a good shape memory effect.

Embodiment three: a kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps:

1. Add 0.05mol 4,4'-bis(4-aminophenoxy)biphenyl to 120mL N,N-dimethylformamide, and stir until 4,4'-bis(4 -aminophenoxy)biphenyl is completely dissolved to obtain a diamine solution;

2. Dissolve a mixture of 0.03mol bisphenol A diether dianhydride and 0.02mol 3,3',4,4'-benzophenone tetracarboxylic dianhydride in 90mL N,N-dimethylformamide to obtain Dianhydride mixture solution;

3. Add the dianhydride mixture solution to the diamine solution in 5 times, and then polymerize for 17 hours under room temperature, nitrogen atmosphere and a stirring speed of 400r/min to obtain a polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, then heat the vacuum drying oven from room temperature to 80°C at a rate of 1°C/min, and then heat it up at a temperature of 80°C. Keep warm at ℃ for 2 hours, then raise the temperature from 80°C to 170°C at a rate of 1°C/min, then keep at a temperature of 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a rate of 2°C/min, and then Insulate at a temperature of 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a rate of 2°C/min, and then hold at a temperature of 260°C for 1 hour to complete thermal imidization, and then let the vacuum oven cool naturally To room temperature, obtain the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film into N,N-dimethylformamide to obtain the shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube, and then put the glass tube into a temperature of 150° C. to dry for 200 hours to obtain a glass tube containing a shape-memory random copolymerized polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 13%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imide tube was dried at a temperature of 120° C. for 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes.

The _Tg of the high-temperature heat-shrinkable tube prepared in Example 3 is 220° C., which ensures that the high-temperature heat-shrinkable tube prepared in Example 3 can be applied to the field of high-temperature heat-shrinkable tubes. The storage modulus of the high-temperature heat-shrinkable tube prepared in Example 3 is 1.78GPa in the glass state at 200°C (T _g -20°C); the storage modulus in the rubber state at a high temperature of 240°C (T _g +20°C) is 4.8 MPa. The high-temperature heat-shrinkable tube prepared in Example 3 has a good shape memory effect.

Embodiment 4: A kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps:

1. Add 0.05mol 4,4'-bis(4-aminophenoxy)biphenyl to 120mL N,N-dimethylformamide, and stir until 4,4'-bis(4 -aminophenoxy)biphenyl is completely dissolved to obtain a diamine solution;

2. Dissolve a mixture of 0.025mol bisphenol A diether dianhydride and 0.025mol 3,3',4,4'-benzophenone tetracarboxylic dianhydride in 90mL N,N-dimethylformamide to obtain Dianhydride mixture solution;

3. Add the dianhydride mixture solution to the diamine solution in 5 times, and then polymerize for 18 hours under room temperature, nitrogen atmosphere and a stirring speed of 400r/min to obtain a polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, then heat the vacuum drying oven from room temperature to 80°C at a rate of 1°C/min, and then heat it up at a temperature of 80°C. Keep warm at ℃ for 2 hours, then raise the temperature from 80°C to 170°C at a heating rate of 2°C/min, then keep at a temperature of 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a heating rate of 2°C/min, and then Insulate at a temperature of 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a rate of 2°C/min, and then hold at a temperature of 260°C for 1 hour to complete thermal imidization, and then let the vacuum oven cool naturally To room temperature, obtain the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film into N,N-dimethylformamide to obtain the shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube, and then put the glass tube into a temperature of 150° C. to dry for 200 hours to obtain a glass tube containing a shape-memory random copolymerized polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 13%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imide tube was dried at a temperature of 120° C. for 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes.

The _Tg of the high-temperature heat-shrinkable tube prepared in Example 4 is 223° C., which ensures that the high-temperature heat-shrinkable tube prepared in Example 4 can be applied to the field of high-temperature heat-shrinkable tubes. The storage modulus of the high-temperature heat-shrinkable tube prepared in Example 4 is 1.88GPa at 203°C (T _g -20°C) in the glass state; the storage modulus at the high temperature of 243°C (T _g +20°C) in the rubber state is 5.1 MPa. The high-temperature heat-shrinkable tube prepared in Example 4 has a good shape memory effect.

Embodiment five: a kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps:

1. Add 0.05mol 4,4'-bis(4-aminophenoxy)biphenyl to 120mL N,N-dimethylformamide, and stir until 4,4'-bis(4 -aminophenoxy)biphenyl is completely dissolved to obtain a diamine solution;

2. Dissolve a mixture of 0.02mol bisphenol A diether dianhydride and 0.03mol 3,3',4,4'-benzophenone tetracarboxylic dianhydride in 90mL N,N-dimethylformamide to obtain Dianhydride mixture solution;

3. Add the dianhydride mixture solution to the diamine solution in 5 times, and then polymerize for 19 hours under room temperature, nitrogen atmosphere and a stirring speed of 400r/min to obtain a polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, then heat the vacuum drying oven from room temperature to 80°C at a rate of 1°C/min, and then heat it up at a temperature of 80°C. Keep warm at ℃ for 2h, then raise the temperature from 80℃ to 170℃ at a rate of 2℃/min, then keep at a temperature of 170℃ for 2h, then raise the temperature from 170℃ to 210℃ at a rate of 2℃/min, and then Insulate at a temperature of 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a rate of 1°C/min, and then hold at a temperature of 260°C for 1 hour to complete thermal imidization, and then let the vacuum oven cool naturally To room temperature, obtain the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape-memory random copolymerized polyimide film into N, N-dimethylformamide to obtain the shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube, and then put the glass tube into a temperature of 150° C. to dry for 200 hours to obtain a glass tube containing a shape-memory random copolymerized polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 14%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imide tube was dried at a temperature of 120° C. for 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes.

The T _g of the high-temperature heat-shrinkable tube prepared in Example 5 is 225° C., which ensures that the high-temperature heat-shrinkable tube prepared in Example 5 can be applied to the field of high-temperature heat-shrinkable tubes. The storage modulus of the high-temperature heat-shrinkable tube prepared in Example 5 is 1.85GPa in the glass state at 205°C (T _g -20°C); the storage modulus in the rubber state at a high temperature of 245°C (T _g +20°C) is 5.8 MPa. The high-temperature heat-shrinkable tube prepared in Example 5 has a good shape memory effect.

Embodiment 6: A kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps:

1. Add 0.05mol 4,4'-bis(4-aminophenoxy)biphenyl to 100mL N-methylpyrrolidone, and then stir until 4,4'-bis(4-aminophenoxy) Base) biphenyl dissolves completely, obtains diamine solution;

2. Dissolve the mixture of 0.01mol bisphenol A diether dianhydride and 0.04mol 3,3',4,4'-benzophenone tetracarboxylic dianhydride in 90mL N-methylpyrrolidone to obtain a dianhydride mixture solution ;

3. Add the dianhydride mixture solution to the diamine solution in 5 times, and then polymerize for 20 hours under room temperature, nitrogen atmosphere and a stirring speed of 400r/min to obtain a polyamic acid solution;

The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1;

4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, then heat the vacuum drying oven from room temperature to 80°C at a rate of 1°C/min, and then heat it up at a temperature of 80°C. Keep warm at ℃ for 2 hours, then raise the temperature from 80°C to 170°C at a heating rate of 2°C/min, then keep at a temperature of 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a heating rate of 1°C/min, and then Insulate at a temperature of 210°C for 2 hours, then raise the temperature from 210°C to 260°C at a rate of 2°C/min, and then hold at a temperature of 260°C for 1 hour to complete thermal imidization, and then let the vacuum oven cool naturally To room temperature, obtain the glass plate that contains polyimide film;

5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film;

6. Dissolve the shape memory random copolymerized polyimide film into N-methylpyrrolidone to obtain the shape memory random copolymerized polyimide solution; pour the shape memory random copolymerized polyimide solution into the glass tube , and then put the glass tube in a temperature of 150°C and dry for 200 hours to obtain a glass tube containing a shape-memory random copolymerized polyimide tube;

The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 14%;

7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imine tube was dried at a temperature of 120° C. for 6 hours to obtain a high-temperature heat-shrinkable tube.

The _Tg of the high-temperature heat-shrinkable tube prepared in Example 6 is 228° C., which ensures that the high-temperature heat-shrinkable tube prepared in Example 6 can be applied to the field of high-temperature heat-shrinkable tubes. The storage modulus of the high-temperature heat-shrinkable tube prepared in Example 6 is 1.79GPa in the glass state at 208°C (T _g -20°C); the storage modulus in the rubber state at a high temperature of 248°C (T _g +20°C) is 5.6 MPa. The high-temperature heat-shrinkable tube prepared in Example 6 has a good shape memory effect.

Claims (7)

1. A random copolymerized polyimide for high-temperature heat-shrinkable tubes, characterized in that a random copolymerized polyimide for high-temperature heat-shrinkable tubes is composed of 4,4'-bis(4-aminophenoxy)biphenyl and prepared from a mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride; the 4,4'-bis(4-aminophenoxy)bis The molar ratio of the mixture of benzene and bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride is 1:1; the bisphenol A diether dianhydride and The molar ratio of bisphenol A type diether dianhydride to 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the mixture of 3,3',4,4'-benzophenone tetracarboxylic dianhydride is A:B; the value range of A is 1≤A≤9; the value range of B is 1≤B≤9. 2. a kind of random copolymerization polyimide for high-temperature heat-shrinkable tube as claimed in claim 1, it is characterized in that a kind of preparation method of random copolymerization polyimide for high-temperature heat-shrinkable tube is finished according to the following steps: 1. Add 4,4'-bis(4-aminophenoxy)biphenyl into the aprotic polar solvent, and then stir until 4,4'-bis(4-aminophenoxy)biphenyl Benzene is completely dissolved to obtain a diamine solution; The aprotic polar solvent described in step 1 is N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone; The volume ratio of the amount of 4,4'-bis(4-aminophenoxy)biphenyl described in step 1 to the aprotic polar solvent is 0.05mol:(100mL～150mL); 2. Dissolving a mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in an aprotic polar solvent to obtain a dianhydride mixture solution; The aprotic polar solvent described in step 2 is N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone; The volume ratio of the mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride to the aprotic polar solvent is 0.05mol :(80mL～150mL); Bisphenol A diether dianhydride and 3,3',4 , the molar ratio of 4'-benzophenonetetracarboxylic dianhydride is A:B; the value range of A is 1≤A≤9; the value range of B is 1≤B≤9; 3. Add the dianhydride mixture solution to the diamine solution in 3 to 5 times, and then polymerize for 15h to 20h at room temperature, nitrogen atmosphere and stirring speed of 300r/min to 400r/min to obtain polyamic acid solution; The mixture of bisphenol A diether dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride in the dianhydride mixture solution described in step 3 and the 4,4'-diamine solution The molar ratio of (4-aminophenoxy)biphenyl is 1:1; 4. Evenly coat the polyamic acid solution on a clean glass plate, then place it in a vacuum drying oven, and then raise the temperature of the vacuum drying oven from room temperature to 70°C at a rate of 1°C/min～2°C/min 90°C, then keep warm at 70°C~90°C for 2h~3h, then raise the temperature from 70°C~90°C to 150°C~170°C at a rate of 1°C/min~2°C/min, and then heat it at 150°C~170°C ℃ for 2h~3h, then raise the temperature from 150℃~170℃ to 190℃~210℃ at a rate of 1℃/min~2℃/min, then keep warm at 190℃~210℃ for 2h~3h, and then The heating rate of 1℃/min～2℃/min is raised from 190℃～210℃ to 230℃～260℃, and then kept at 230℃～260℃ for 1h～2h to complete thermal imidization, and then vacuum dry Box is cooled to room temperature naturally, obtains the glass plate that contains polyimide film; 5. Put the glass plate containing the polyimide film into distilled water to make the polyimide film fall off from the glass plate, and then rinse the polyimide film with distilled water to obtain the shape memory random copolymer polyamide imide film; 6. Dissolve the shape-memory random copolymerized polyimide film in an aprotic polar solvent to obtain a shape-memory random copolymerized polyimide solution; pour the shape-memory random copolymerized polyimide solution into a glass tube , and then put the glass tube into the temperature of 150 ° C ~ 200 ° C for 120 h ~ 200 h to obtain a glass tube containing a shape memory random copolymer polyimide tube; The aprotic polar solvent described in step 6 is N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone; The mass fraction of shape memory random copolymerized polyimide in the shape memory random copolymerized polyimide solution described in step 6 is 10% to 15%; 7. Put the glass tube containing the shape memory random copolymerized polyimide tube into distilled water, then make the shape memory random copolymerized polyimide tube fall off from the glass tube, and then put the shape memory random copolymerized polyimide tube into the distilled water. The imine tube is dried at a temperature of 120° C. for 5 hours to 6 hours to obtain random copolymerized polyimide for high-temperature heat-shrinkable tubes. 3. A method for preparing random copolymerized polyimide for high-temperature heat-shrinkable tubes according to claim 2, characterized in that the 4,4'-bis(4-aminophenoxy)linked polyimide described in step 1 The volume ratio of the amount of benzene to the aprotic polar solvent is 0.05mol:110mL. 4. A method for preparing random copolymerized polyimide for high-temperature heat-shrinkable tubes according to claim 2, characterized in that the 4,4'-bis(4-aminophenoxy)linked polyimide described in step 1 The volume ratio of the amount of benzene to the aprotic polar solvent is 0.05mol:120mL. 5. the preparation method of a kind of high-temperature heat-shrinkable tube according to claim 2 is characterized in that polyamic acid solution is evenly coated on a clean glass plate in step 4, and then placed In the vacuum drying oven, the temperature of the vacuum drying oven was raised from room temperature to 90°C at a rate of 1°C/min, and then kept at 90°C for 2 hours, and then the temperature was raised from 90°C to 170°C at a rate of 1°C/min. Then keep it at 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a rate of 1°C/min, then keep it at 210°C for 2 hours, and then raise the temperature from 210°C to 250°C at a rate of 1°C/min. Then heat-preserve at 250° C. for 1 hour to complete thermal imidization, and then naturally cool to room temperature in a vacuum drying oven to obtain a glass plate containing a polyimide film. 6. The preparation method of random copolymerization polyimide for a kind of high-temperature heat-shrinkable tube according to claim 2, it is characterized in that in step 4, the polyamic acid solution is evenly coated on a clean glass plate, and then placed In the vacuum drying oven, the temperature of the vacuum drying oven was raised from room temperature to 80°C at a rate of 1°C/min, and then kept at 80°C for 2 hours, and then the temperature was raised from 80°C to 170°C at a rate of 1°C/min. Then keep it at 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a rate of 1°C/min, then keep it at 210°C for 2 hours, and then raise the temperature from 210°C to 260°C at a rate of 1°C/min. Then heat-preserve at 260° C. for 1 hour to complete thermal imidization, and then let the vacuum drying oven cool down to room temperature naturally to obtain a glass plate containing a polyimide film. 7. The preparation method of random copolymerization polyimide for a kind of high-temperature heat-shrinkable tube according to claim 2, it is characterized in that in step 4, the polyamic acid solution is evenly coated on a clean glass plate, and then placed In the vacuum drying oven, the temperature of the vacuum drying oven was raised from room temperature to 80°C at a rate of 1°C/min, and then kept at 80°C for 2 hours, and then the temperature was raised from 80°C to 170°C at a rate of 1°C/min. Then keep it at 170°C for 2 hours, then raise the temperature from 170°C to 210°C at a rate of 2°C/min, then keep it at 210°C for 2 hours, and then raise the temperature from 210°C to 260°C at a rate of 2°C/min. Then heat-preserve at 260° C. for 1 hour to complete thermal imidization, and then let the vacuum drying oven cool down to room temperature naturally to obtain a glass plate containing a polyimide film.