Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The terms "first," "second," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance. In addition, those whose specific conditions are not specified in the examples are conducted under the conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
According to a first aspect of the present invention, there is provided a polyimide resin having a self-repairing function, which is mainly made of the following raw materials:
the catalyst comprises a diamine monomer, a dianhydride monomer, a blocking agent, a dehydrating agent and a catalyst, wherein the blocking agent comprises maleic anhydride and furfuryl amine.
Maleic anhydride and furfuryl amine are simultaneously used as end capping agents to cap the main structure of the polyimide, and the end capping groups of the generated polyimide resin with the self-repairing function are maleimide groups and furan groups. The polyimide resin with self-repairing function is substantially a mixture, including but not limited to polyimide resin with maleimide group as a terminal group, polyimide resin with furan group as a terminal group, and polyimide resin with maleimide group and furan group as two terminal groups.
By taking maleic anhydride and furfuryl amine as end capping agents, conjugated diene (furfuryl amine) and substituted olefin (maleic anhydride) structures can be introduced into a main structure of the polyimide resin, based on dynamic reversible Diels-Alder reaction, a cyclohexene structure is cracked at a higher temperature to generate furfuryl amine and maleic anhydride, and the furfuryl amine and the maleic anhydride react spontaneously to produce the cyclohexene structure in the process of cooling, so that self-repairing of the polyimide resin is realized in a heating mode, and a schematic diagram of a self-repairing mechanism is shown in figure 1.
In FIG. 1, 180 ℃ and 260 ℃ are retro Diels-Alder reactions, and cyclohexene is cracked to produce furfurylamine and maleic anhydride structures; at the temperature of 30-90 ℃, furfuryl amine and maleic anhydride are subjected to Diels-Alder reaction to generate a substituted cyclohexene structure.
The temperatures typical for the retro Diels-Alder reaction, but not limiting, are 180 deg.C, 190 deg.C, 200 deg.C, 210 deg.C, 220 deg.C, 230 deg.C, 240 deg.C, 250 deg.C or 260 deg.C. Typical but non-limiting temperatures for diels-alder reactions of furfurylamine with maleic anhydride are 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃ or 60 ℃.
As an alternative embodiment of the present invention, the diamine monomer includes any one of 2,2' -bis trifluoromethyl-4, 4' -diaminobiphenyl, 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene, 9-bis (4-aminophenyl) fluorene, 2-bis [4- (4-aminophenoxy) phenyl ] propane, 2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane or 4,4' -bis (3-aminophenoxy) diphenylsulfone, or a combination of at least two thereof.
As an alternative embodiment of the present invention, the dianhydride monomer includes any one or a combination of at least two of 4, 4-hexafluoroisopropyl phthalic anhydride, 1,2,3, 4-cyclobutane tetracarboxylic dianhydride, 4' -oxydiphthalic anhydride, biphenyl tetracarboxylic dianhydride, or bisphenol a type diether dianhydride.
As an alternative embodiment of the present invention, the dehydrating agent comprises any one of acetic anhydride, propionic anhydride or butyric anhydride, or a combination of at least two thereof.
As an alternative embodiment of the invention, the catalyst comprises any one of pyridine, 3-methylpyridine, triethylamine or isoquinoline or a combination of at least two thereof.
As an alternative embodiment of the present invention, the molar weight ratio of diamine monomer to dianhydride monomer is 1: (0.95-1.05). Typical but non-limiting molar weight ratios of diamine monomer to dianhydride monomer are 1: 0.95, 1: 0.96, 1: 0.97, 1: 0.98, 1: 0.99, 1: 1.00, 1: 1.01, 1: 1.02, 1: 1.03, 1: 1.04 or 1: 1.05.
as an alternative embodiment of the present invention, maleic anhydride comprises 1 to 5% of the total molar amount of diamine monomer and dianhydride monomer. Typical but non-limiting mole percentages of maleic anhydride to the total moles of diamine monomer and dianhydride monomer are 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, or 5.0%.
As an alternative embodiment of the present invention, furfuryl amine comprises 1 to 5% of the total molar amount of diamine monomer and dianhydride monomer. Typical but non-limiting mole percentages of furfuryl amine based on the total moles of diamine monomer and dianhydride monomer are 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, or 5.0%.
As a preferred embodiment, the molar ratio of maleic anhydride and furfuryl amine is 1: 1.
as an alternative embodiment of the invention, the amount of dehydrating agent used is 2 to 4 times the molar equivalent of the diamine monomer. The dehydrating agent is typically, but not limited to, 2 times, 3 times or 4 times the molar equivalent of the diamine monomer.
As an alternative embodiment of the invention, the catalyst is used in an amount of 1 to 2 times the molar equivalent of the diamine monomer. The amount of catalyst used is typically, but not limited to, 1-fold, 1.5-fold, or 2-fold the molar equivalent of diamine monomer.
Through the limitation of the variety and the dosage proportion of various raw materials, the prepared polyimide resin has higher molecular weight, so that the film prepared by the polyimide resin has more excellent mechanical property.
It is to be noted that the term "comprising" as used herein means that it may include other raw materials acceptable in the field of polyimide resins in addition to the raw materials, and these other raw materials may impart different properties to the polyimide resin. In addition, the term "comprising" as used herein may be replaced by "being" or "made from … …" as closed.
According to the second aspect of the present invention, there is also provided a method for preparing a polyimide resin having a self-repairing function, comprising the steps of:
mixing a diamine monomer, a dianhydride monomer, furfuryl amine, maleic anhydride, a dehydrating agent and a catalyst, and reacting to obtain the polyimide resin with the self-repairing function.
The preparation method of the polyimide resin with the self-repairing function, provided by the invention, has the advantages of stable process and simplicity in operation, and is suitable for large-scale industrial production.
As an alternative embodiment of the present invention, a method for preparing a polyimide resin having a self-repairing function includes the steps of:
mixing a diamine monomer, a dianhydride monomer and a first solvent, and carrying out a first reaction to obtain a polyamic acid solution;
and mixing maleic anhydride, furfuryl amine and the polyamic acid solution to perform a second reaction, and then adding a catalyst and a dehydrating agent to perform a third reaction to obtain the polyimide resin with the self-repairing function.
As an alternative embodiment of the invention, the temperature of the first reaction is between 15 and 25 ℃ and the time of the first reaction is between 6 and 12 hours. The temperature of the first reaction is typically, but not limited to, 15 deg.C, 16 deg.C, 18 deg.C, 20 deg.C, 22 deg.C, 24 deg.C or 25 deg.C; typical but non-limiting temperatures are 6h, 8h, 10h or 12 h.
As an alternative embodiment of the invention, the temperature of the second reaction is between 15 and 25 ℃ and the time of the second reaction is between 1 and 2 hours. Typical but non-limiting temperatures for the second reaction are 15 ℃, 16 ℃, 18 ℃, 20 ℃, 22 ℃, 24 ℃ or 25 ℃; typical but non-limiting temperatures are 1h, 1.5h or 2 h.
As an alternative embodiment of the invention, the temperature of the third reaction is 15-25 ℃ and the time of the third reaction is 6-12 h. Typical but non-limiting temperatures for the third reaction are 15 ℃, 16 ℃, 18 ℃, 20 ℃, 22 ℃, 24 ℃ or 25 ℃; typical but non-limiting temperatures are 6h, 8h, 10h or 12 h.
Through the specific limitation of each step and reaction condition in the preparation method of the polyimide resin with the self-repairing function, diamine, dianhydride, maleic anhydride and furfuryl amine monomers can be completely reacted to form polyimide macromolecules.
According to the third aspect of the present invention, there is also provided a polyimide film having a self-repairing function, the polyimide film being a colorless transparent film and mainly made of the following raw materials: a polyimide resin and a second solvent;
wherein the polyimide resin is the polyimide resin with the self-repairing function.
In view of the self-repairing function of the polyimide resin, the polyimide film using the polyimide resin also has the same advantages, namely the polyimide film has the self-repairing function, the repair can be completed only through simple temperature rising and cooling procedures, and the repair effect is not reduced along with the increase of the number of times of repetition.
Moreover, the polyimide film has high transmittance and high mechanical strength, does not relate to the use of a small molecular cross-linking agent, and thus does not influence the heat resistance of the film; in addition, the polyimide film is non-toxic and pollution-free, and cannot influence production and living environments.
As an alternative embodiment of the present invention, the second solvent includes any one of propylene glycol methyl ether acetate, N' -dimethylacetamide, N-methylpyrrolidone, or γ -butyrolactone, or a combination of at least two thereof;
in an alternative embodiment of the present invention, the polyimide film may have a light transmittance of not less than 85%, for example, 85%, 86%, 87%, 88%, 89%, 90%, 91%, or the like.
As an alternative embodiment of the present invention, the mechanical strength of the polyimide film is not less than 90 MPa.
As an alternative embodiment of the present invention, the repair efficiency of the polyimide film is not less than 20%, and the repair efficiency of the polyimide film is preferably 50 to 90%. Typical but not limiting repair efficiencies of polyimide films are 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%.
As an optional embodiment of the invention, the temperature of the repair treatment of the polyimide film is 180-260 ℃; typical but non-limiting temperatures for the repair process are 180 deg.C, 190 deg.C, 200 deg.C, 210 deg.C, 220 deg.C, 230 deg.C, 240 deg.C, 250 deg.C or 260 deg.C. The temperature of the repair treatment is too high (higher than 260 ℃), which easily causes yellowing of the film, and the temperature of the repair treatment is too low (lower than 180 ℃), which easily causes low reaction rate and incomplete repair, so the temperature of the repair treatment is preferably controlled within a specific numerical range.
As an optional embodiment of the present invention, the repair treatment time of the polyimide film is 3 to 5 min. Typical but non-limiting repair treatments take 3min, 3.5min, 4min, 4.5min or 5 min.
The temperature and time of the repairing treatment are limited, so that the substituted cyclohexene is subjected to reverse reaction to generate the conjugated diene and substituted olefin structure.
According to a fourth aspect of the present invention, there is also provided a method for producing the polyimide film described above, comprising the steps of:
and mixing the polyimide resin and a second solvent to prepare the film, thereby obtaining the polyimide film with the self-repairing function.
The preparation method is simple to operate, stable in process and suitable for large-scale industrial production.
As a preferred embodiment of the present invention, a method for preparing a polyimide film having a self-repairing function includes the steps of:
dissolving the polyimide resin in a second solvent, and drying at 60-80 ℃ for 20-40 minutes, at 120-150 ℃ for 20-40 minutes and at 220-250 ℃ for 40-60 minutes in a nitrogen atmosphere to obtain the polyimide film with the self-repairing function.
By further limiting the preparation method of the polyimide film, the second solvent can be completely volatilized.
According to the fifth aspect of the invention, a flexible and foldable display screen cover base film is also provided, which is made of the polyimide resin with the self-repairing function or the polyimide film with the self-repairing function.
In view of the advantages of the polyimide resin or the polyimide film with the self-repairing function, the flexible foldable display screen cover plate base film using the polyimide resin or the polyimide film has the same advantages, and the flexible foldable display screen cover plate base film has potential application value in the field of flexible foldable display.
The present invention will be further described with reference to specific examples and comparative examples.
Example 1
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein the diamine monomer is 2,2 '-bis (trifluoromethyl) -4,4' -diaminobiphenyl, the dianhydride monomer is 4, 4-hexafluoroisopropyl phthalic anhydride, and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 1 percent of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 1 percent of the total mole amount of the diamine monomers and the dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) 16.01g (50mmol) of 2,2' -bistrifluoromethyl-4, 4' -diaminobiphenyl was dissolved in 150g of a first solvent (N, N ' -dimethylacetamide) under a stream of dry nitrogen gas, followed by addition of 22.21g (50mmol) of 4, 4-hexafluoroisopropylphthalic anhydride thereto and first reaction was carried out at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) adding 98mg (1mmol) of maleic anhydride and 97mg (1mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 2
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein the diamine monomer is 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene, the dianhydride monomer is 4,4' -oxydiphthalic anhydride, and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 2% of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 2% of the total mole amount of the diamine monomers and dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) 21.42g (50mmol) of 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene was dissolved in 150g of the first solvent (N, N '-dimethylacetamide) under a stream of dry nitrogen gas, followed by addition of 15.51g (50mmol) of 4,4' -oxydiphthalic anhydride thereto and first reaction at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) adding 196mg (2mmol) of maleic anhydride and 194mg (2mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 h;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 3
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 4,4' -bis (3-aminophenoxy) diphenyl sulfone, the dianhydride monomer is bisphenol A type diether dianhydride, and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 1 percent of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 1 percent of the total mole amount of the diamine monomers and the dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) 14.71g (50mmol) of 4,4 '-bis (3-aminophenoxy) diphenylsulfone was dissolved in 150g of a first solvent (N, N' -dimethylacetamide) under a stream of dry nitrogen gas, and 26.02g (50mmol) of bisphenol A type diether dianhydride was then added thereto, and a first reaction was carried out at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) adding 98mg (1mmol) of maleic anhydride and 97mg (1mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 4
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 2,2 '-bis trifluoromethyl-4, 4' -diaminobiphenyl, the dianhydride monomer is 4, 4-hexafluoroisopropyl phthalic anhydride and 1,2,3, 4-cyclobutane tetracarboxylic dianhydride (the molar ratio of the two is 1: 1), and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 2% of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 2% of the total mole amount of the diamine monomers and dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) 16.01g (50mmol) of 2,2' -bistrifluoromethyl-4, 4' -diaminobiphenyl was dissolved in 150g of a first solvent (N, N ' -dimethylacetamide) under a stream of dry nitrogen gas, followed by addition of 11.11g (25mmol) of 4, 4-hexafluoroisopropylphthalic anhydride and 4.90g (25mmol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride thereto and first reaction at 25 ℃ for 10 hours to give a polyamic acid solution;
(b) adding 196mg (2mmol) of maleic anhydride and 194mg (2mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 h;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 5
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene, the dianhydride monomer is 1,2,3, 4-cyclobutane tetracarboxylic dianhydride and 4,4' -oxydiphthalic anhydride (the molar ratio of the two is 1: 1), and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 3 percent of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 3 percent of the total mole amount of the diamine monomers and the dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) 21.42g (50mmol) of 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene was dissolved in 150g of a first solvent (N, N '-dimethylacetamide) under a stream of dry nitrogen gas, followed by adding 4.90g (25mmol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride and 7.76g (25mmol) of 4,4' -oxydiphthalic anhydride thereto, and subjecting to a first reaction at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) adding 294mg (3mmol) of maleic anhydride and 291mg (3mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 6
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 2,2 '-bis trifluoromethyl-4, 4' -diaminobiphenyl and 9, 9-bis (4-aminophenyl) fluorene (the molar ratio of the two is 1: 1), the dianhydride monomer is 1,2,3, 4-cyclobutane tetracarboxylic dianhydride, and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 5% of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 5% of the total mole amount of the diamine monomers and dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) under a stream of dry nitrogen, 8.01g (25mmol) of 2,2' -bistrifluoromethyl-4, 4' -diaminobiphenyl and 8.71g (25mmol) of 9, 9-bis (4-aminophenyl) fluorene were dissolved in 150g of a first solvent (N, N ' -dimethylacetamide), followed by addition of 9.81g (50mmol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride thereto and first reaction was allowed to proceed at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) 490mg (5mmol) of maleic anhydride and 486mg (5mmol) of furfuryl amine were added to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 7
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 2, 2-bis [4- (4-aminophenoxy) phenyl ] propane and 2, 2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane, the dianhydride monomer is 4, 4-hexafluoroisopropyl phthalic anhydride, and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 4% of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 4% of the total mole amount of the diamine monomers and dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) 10.26g (25mmol) of 2, 2-bis [4- (4-aminophenoxy) phenyl ] propane and 12.96g (25mmol) of 2, 2-bis [4- (4-aminophenoxy) phenyl ] hexafluoropropane were dissolved in 150g of the first solvent (N, N' -dimethylacetamide) under a dry nitrogen stream, followed by addition of 22.21g (50mmol) of 4, 4-hexafluoroisopropylphthalic anhydride thereto and first reaction was carried out at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) 392mg (4mmol) of maleic anhydride and 388mg (4mmol) of furfuryl amine were added to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 8
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 2,2 '-bis-trifluoromethyl-4, 4' -diaminobiphenyl, the dianhydride monomer is 1,2,3, 4-cyclobutane tetracarboxylic dianhydride and biphenyl tetracarboxylic dianhydride (the molar ratio of the two is 1: 1), and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 3 percent of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 3 percent of the total mole amount of the diamine monomers and the dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) under a flow of dry nitrogen, 16.01g (50mmol) of 2,2' -bistrifluoromethyl-4, 4' -diaminobiphenyl was dissolved in 150g of a first solvent (N, N ' -dimethylacetamide), followed by addition of 4.90g (25mmol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride and 7.36g (25mmol) of biphenyltetracarboxylic dianhydride thereto, and first reaction was allowed to proceed at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) adding 294mg (3mmol) of maleic anhydride and 291mg (3mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 9
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 2,2 '-bis trifluoromethyl-4, 4' -diaminobiphenyl and 9, 9-bis (4-aminophenyl) fluorene (the molar ratio of the two is 1: 1), the dianhydride monomer is 4, 4-hexafluoroisopropyl phthalic anhydride and 1,2,3, 4-cyclobutane tetracarboxylic dianhydride (the molar ratio of the two is 1: 1), and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 3 percent of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 3 percent of the total mole amount of the diamine monomers and the dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) under a stream of dry nitrogen, 8.01g (25mmol) of 2,2' -bistrifluoromethyl-4, 4' -diaminobiphenyl and 8.71g (25mmol) of 9, 9-bis (4-aminophenyl) fluorene were dissolved in 150g of a first solvent (N, N ' -dimethylacetamide), followed by addition of 11.11g (25mmol) of 4, 4-hexafluoroisopropylphthalic anhydride and 4.90g (25mmol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride thereto, and a first reaction was carried out at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) adding 294mg (3mmol) of maleic anhydride and 291mg (3mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 10
The embodiment provides a polyimide resin with a self-repairing function, which is mainly prepared from the following raw materials:
diamine monomer, dianhydride monomer, furfuryl amine, maleic anhydride, dehydrating agent and catalyst.
Wherein, the diamine monomer is 2,2' -bis-trifluoromethyl-4, 4' -diaminobiphenyl and 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene (the molar ratio of the two is 1: 1), the dianhydride monomer is 1,2,3, 4-cyclobutane tetracarboxylic dianhydride and 4,4' -oxydiphthalic anhydride (the molar ratio of the two is 1: 1), and the molar weight ratio of the diamine monomer to the dianhydride monomer is 1: 1, maleic anhydride accounts for 5% of the total mole amount of diamine monomers and dianhydride monomers, furfuryl amine accounts for 5% of the total mole amount of the diamine monomers and dianhydride monomers, acetic anhydride is used as a dehydrating agent, and pyridine is used as a catalyst.
The preparation method of the polyimide resin with the self-repairing function comprises the following steps:
(a) under a dry nitrogen flow, 8.01g (25mmol) of 2,2 '-bistrifluoromethyl-4, 4' -diaminobiphenyl and 10.71g (25mmol) of 1, 4-bis (4-amino-2-trifluoromethylphenoxy) benzene were dissolved in 150g of a first solvent (N, N '-dimethylacetamide), followed by addition of 4.90g (25mmol) of 1,2,3, 4-cyclobutanetetracarboxylic dianhydride and 7.76g (25mmol) of 4,4' -oxydiphthalic anhydride thereto, and a first reaction was carried out at 25 ℃ for 4 hours to obtain a polyamic acid solution;
(b) 490mg (5mmol) of maleic anhydride and 486mg (5mmol) of furfuryl amine were added to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Example 11
This example provides a polyimide resin having a self-repairing function, except that the raw materials and the polyimide resin were prepared by replacing 5% of maleic anhydride to 1% of the total molar amount of diamine monomers and dianhydride monomers and replacing 5% of furfuryl amine to 1% of the total molar amount of diamine monomers and dianhydride monomers, and the remaining raw materials, amounts, and preparation methods were the same as those of example 10.
Example 12
This example provides a polyimide resin having a self-repairing function, except that the raw materials and the polyimide resin were prepared by replacing 5% by weight of maleic anhydride and 0.5% by weight of furfuryl amine with respect to the total molar amount of diamine monomers and dianhydride monomers, and by replacing 5% by weight of furfuryl amine and 0.5% by weight of the total molar amount of diamine monomers and dianhydride monomers, and the remaining raw materials, amounts, and preparation methods were the same as those of example 10.
Example 13
This example provides a polyimide resin having a self-repairing function, except that the raw materials and the polyimide resin were prepared by replacing 5% by 6% of maleic anhydride and 5% by 6% of furfuryl amine with respect to the total molar amount of the diamine monomer and the dianhydride monomer, and the raw materials, the amounts, and the preparation method were the same as those of example 10.
Example 14-example 26
Examples 14 to 26 each provide a polyimide film having a self-repairing function, which is mainly prepared from the following raw materials: a polyimide resin and a second solvent;
wherein the polyimide resins are the polyimide resins with self-repairing function provided in examples 1 to 13, respectively; the second solvent comprises propylene glycol methyl ether acetate.
Example 14-example 26 a method for preparing a polyimide film having a self-healing function, comprising the steps of:
dissolving 15g of polyimide resin into 85g of propylene glycol methyl ether acetate, and baking at 70 ℃ for 30 minutes, 150 ℃ for 30 minutes and 250 ℃ for 40 minutes under the nitrogen atmosphere to obtain the self-repairing polyimide film.
Comparative example 1
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 1 except that maleic anhydride and furfural were not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) the procedure was the same as in example 1, step (a);
(b) and adding 20.4g of acetic anhydride and 8.0g of pyridine into the polyamic acid solution to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain white polyimide resin.
Comparative example 2
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 3, except that maleic anhydride and furfural were not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) the procedure was the same as in example 3, step (a);
(b) and adding 20.4g of acetic anhydride and 8.0g of pyridine into the polyamic acid solution to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain white polyimide resin.
Comparative example 3
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 4 except that maleic anhydride and furfural were not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) same as example 4 step (a);
(b) and adding 20.4g of acetic anhydride and 8.0g of pyridine into the polyamic acid solution to perform a third reaction for 6 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain white polyimide resin.
Comparative example 4
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 6, except that maleic anhydride and furfural were not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) same as example 6 step (a);
(b) and adding 20.4g of acetic anhydride and 8.0g of pyridine into the polyamic acid solution to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain white polyimide resin.
Comparative example 5
This comparative example provides a polyimide resin, the kind and amount of which were the same as those in example 9, except that maleic anhydride and furfural were not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) same as in example 9, step (a);
(b) and adding 20.4g of acetic anhydride and 8.0g of pyridine into the polyamic acid solution to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain white polyimide resin.
Comparative example 6
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 10 except that maleic anhydride and furfural were not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) same as in example 10, step (a);
(b) and adding 20.4g of acetic anhydride and 8.0g of pyridine into the polyamic acid solution to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain white polyimide resin.
Comparative example 7
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 10 except that furfuryl amine was not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) same as in example 10, step (a);
(b) 490mg (5mmol) of maleic anhydride was added to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Comparative example 8
This comparative example provides a polyimide resin, the kind and amount of which were the same as those of example 10 except that maleic anhydride was not added to the raw materials.
The preparation method of the polyimide resin comprises the following steps:
(a) same as in example 10, step (a);
(b) adding 486mg (5mmol) of furfuryl amine to the polyamic acid solution to allow a second reaction to proceed for 2 hours;
and then adding 20.4g of acetic anhydride and 8.0g of pyridine to perform a third reaction for 12 hours, after the reaction is finished, slowly pouring the product solution into 1L of deionized water to separate out a white precipitate, filtering and collecting the precipitate, boiling and washing the precipitate for 3 times by using the deionized water, and drying the precipitate at 80 ℃ overnight to obtain the white polyimide resin with the self-repairing function.
Comparative examples 9 to 16
Comparative examples 9 to 16 each provide a polyimide film mainly made of the following raw materials: a polyimide resin and a second solvent;
wherein the polyimide resins are the polyimide resins provided in comparative examples 1 to 8, respectively; the second solvent comprises propylene glycol methyl ether acetate.
Comparative examples 9 to 16 provide polyimide films prepared in the same manner as in examples 14 to 26.
To verify the technical effects of the respective examples and comparative examples, the following experiments were conducted.
Experimental example 1
The mechanical properties (tensile strength), optical properties (light transmittance) and self-repairing performance (repairing efficiency) of the polyimide films provided in examples 14 to 26 and comparative examples 9 to 16 were measured, and the specific results are shown in table 1. Wherein, the tensile strength is detected by adopting an electronic universal tester, and the light transmittance is detected by adopting a spectrophotometer.
Testing of self-repairing performance: a scratch of 5cm (scratch does not penetrate the film) was scratched on the surface of the polyimide film prepared above using a scalpel, and then the film was left standing in an oven at 250 ℃ for 3 minutes, and the length of the scratch was observed and measured, and the repair efficiency was calculated from the length of the scratch before and after the self-repair by a formula (repair efficiency ═ scratch length after repair/initial scratch length × 100%).
TABLE 1
As can be seen from the data in table 1, the polyimide film with self-repairing function provided in the present invention has good comprehensive properties, and not only can obtain tensile strength of more than 90MPa and maintain optical transmittance higher than 85%, but also can effectively repair scratches on the surface of the polyimide film through the combination of dynamic reversible covalent bonds.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.