Method for improving self-repairing performance of polyurethane
By introducing graphene quantum dot ionic liquid into polyurethane materials, the problems of vulnerability and insufficient self-repair capabilities of traditional polyurethane materials are solved, and the long-lasting self-repair capabilities of the material are achieved, extending the service life and improving safety.
Patent Information
- Application Number
- CN202510204589.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-05-27
AI Technical Summary
Traditional polyurethane materials are prone to microcracks or damage during use, resulting in reduced performance and shortened service life. The self-repairing ability of existing self-repair polymer materials is limited, especially if they fail after use of external self-repair systems.
Graphene quantum dots are prepared in ionic liquid and used to modify polyurethane elastomers to form graphene quantum dot ionic liquid (GQDs-IL) to enhance the self-healing ability of polyurethane materials.
Effectively regulate the hydrogen bond density and strength of polyurethane elastomers, significantly improve their self-repair capabilities, and enable the material to be automatically repaired after damage, extending its service life and improving safety.
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of self - healing polyurethanes, and specifically relates to a method for improving the self - healing performance of polyurethanes. Background Art
[0002] Due to their good mechanical properties and chemical stability, traditional polyurethane materials are widely used in coatings, adhesives, foams, elastomers, etc. However, the formation of micro - cracks or damage during use may lead to a decline in performance, thereby shortening the service life of polyurethane materials and compromising safety.
[0003] The ability of plants and animals in nature to autonomously repair injuries has inspired scientists to propose the concept of self - healing. Self - healing polymer materials are mainly divided into two categories: intrinsic self - healing polymers and extrinsic self - healing polymers. Intrinsic self - healing polymers achieve self - healing by rationally designing the inherent chemical structure of the material itself and using reversible chemical bonds or interactions when exposed to external stimuli; extrinsic self - healing polymers rely on introducing microcapsules or micro - pipeline networks containing repair agents into the matrix. When the material is damaged and forms micro - cracks, the embedded microcapsules also rupture, releasing the repair agent, which is then sucked into the cracks by capillary action, and the catalyst added to the matrix promotes the polymerization of the repair agent, thereby achieving the repair of the material. For example, Chinese Patent 2024111737814 with a publication date of November 29, 2024, discloses a preparation method of a super - flexible ionic liquid - conductive self - healing polyurethane elastomer. By introducing ionic liquids into the polyurethane elastomer system through surface modification, a super - flexible ionic liquid - conductive self - healing polyurethane elastomer is generated. This material can achieve efficient self - healing under mild room - temperature conditions, and its tensile strength can recover 60% of the initial value. However, after the extrinsic self - healing system is used once, its self - healing ability fails, while the intrinsic self - healing function can continuously exert its efficacy because it depends on the reversible transformation of chemical bonds in the molecular structure.
[0004] Therefore, it is of great significance to develop a polyurethane elastomer with persistent self - healing ability. Summary of the Invention
[0005] Aiming at the above problems existing in the prior art, the purpose of the present invention is to provide a method for improving the self - healing performance of polyurethanes. This method is to prepare graphene quantum dots using ionic liquids and modify polyurethane elastomers with graphene quantum dot ionic liquids (GQDs - IL), modifying polyurethane elastomers with almost no self - healing ability into polyurethane elastomers with good self - healing ability.
[0006] To solve the above problems, the technical solutions adopted by the present invention are as follows: A method for improving the self - healing performance of polyurethanes, comprising the following steps: S1. Mix graphene oxide, imidazolium tetrafluoroborate ionic liquid, and amide solvent, then place the mixture in a hydrothermal reactor. After sealing the hydrothermal reactor and heating it, upon completion of the reaction, an amide solution of graphene quantum dot ionic liquid is obtained. S2. Dissolve thermoplastic polyurethane elastomer in an amide solvent, then add the amide solution of graphene quantum dot ionic liquid and form a film to obtain a modified polyurethane film with self-healing ability.
[0007] Preferably, the oxygen content of the graphene oxide is 24 - 30%.
[0008] Preferably, the imidazolium tetrafluoroborate ionic liquid is one or more of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethylmethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, and 1,2-dimethyl-3-ethylimidazolium tetrafluoroborate.
[0009] Preferably, the amide solvent is N,N-dimethylformamide or N,N-dimethylacetamide.
[0010] Preferably, in S1, the mass content of graphene oxide is 1 - 5%, the mass content of imidazolium tetrafluoroborate ionic liquid is 50 - 80%, and the mass content of amide solvent is 20 - 50%.
[0011] Preferably, in S1, the reaction temperature of the hydrothermal reactor is 170 - 200 °C, and the reaction time is 5 - 24 hours.
[0012] Preferably, in S2, the solid content is 50% when dissolving the thermoplastic polyurethane elastomer in the amide solvent.
[0013] Preferably, in S2, the mass ratio of graphene quantum dot ionic liquid to thermoplastic polyurethane elastomer is 3 - 15:100.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: In the present invention, graphene quantum dots containing a large number of hydroxyl groups are prepared in an ionic liquid. When modifying the polyurethane elastomer with the graphene quantum dot ionic liquid, the ionic liquid can act as a plasticizer to dissociate hydrogen bonds, while the quantum dots form hydrogen bonds. Therefore, the ionic liquid containing graphene quantum dots can effectively regulate the hydrogen bond density and strength of the polyurethane elastomer, and modify the polyurethane elastomer with almost no self-healing ability into a polyurethane elastomer with good self-healing ability. Detailed implementation manners
[0015] The present invention will be further described below in conjunction with specific embodiments.
[0016] Example 1 Place 1g of graphene oxide (oxygen content of 24-30%), 65g of 1-ethyl-3-methylimidazolium tetrafluoroborate and 34g of N,N-dimethylformamide (DMF) in a 200mL hydrothermal kettle, stir for a while, and seal the hydrothermal kettle after mixing evenly. Place the sealed hydrothermal kettle in an oven at 185°C and maintain the temperature for 6.5 hours. Take the hydrothermal kettle out of the oven, cool it to room temperature, open the sealing cover, and obtain a transparent N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL).
[0017] The M70 brand TPU of Meirui New Materials Co., Ltd. (Meirui New Materials) was selected. 13.2g of M70 was dissolved in 13.2g of DMF, and 100g of the prepared N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL) was weighed and mixed in the M70 solution. The mixed solution was poured into a flat mold and dried at 80°C to obtain a GQDs-IL modified TPU film.
[0018] The film was scratched with a paper cutter to create a 1 cm long and 0.5 cm deep scratch. After being placed at 25°C for 24 hours, the scratch disappeared when observed with the naked eye. The M70 TPU film for comparison showed almost no scratch change under the same conditions.
[0019] Example 2 0.95 g of graphene oxide (oxygen content of 24-30%), 60 g of 1-butyl-3-methylimidazolium tetrafluoroborate and 35 g of N,N-dimethylacetamide (DMA) were placed in a 200 mL hydrothermal kettle, stirred for a while, and the hydrothermal kettle was sealed after mixing evenly. The sealed hydrothermal kettle was placed in a 195°C oven and maintained at the temperature for 18 hours. The hydrothermal kettle was taken out of the oven, cooled to room temperature, and the sealing cover was opened to obtain a transparent N,N-dimethylacetamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL).
[0020] Select E185L brand TPU from Meirui New Materials. Dissolve 10.2g of E185L in 10.2g of DMF, weigh 85.2g of the prepared N,N-dimethylacetamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL), and mix it in the E185L solution. Pour the mixed solution into a flat mold and dry it at 80°C to obtain a GQDs-IL modified TPU film.
[0021] The film was scratched with a paper cutter to create a 1 cm long and 0.5 cm deep scratch. After being placed at 45°C for 20 hours, the scratch disappeared when observed with the naked eye. The scratch on the E185L TPU film was almost unchanged under the same conditions.
[0022] Example 3 Place 4.8g of graphene oxide (oxygen content of 24-30%), 75g of 1,2-dimethyl-3-ethylimidazolium tetrafluoroborate and 20.2g of N,N-dimethylformamide (DMF) in a 200mL hydrothermal kettle, stir for a while, and seal the hydrothermal kettle after mixing evenly. Place the sealed hydrothermal kettle in a 175°C oven and keep the temperature for 16.5 hours. Take the hydrothermal kettle out of the oven, cool it to room temperature, open the sealing cover, and obtain a transparent N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL).
[0023] Select L80 brand TPU from Meirui New Materials. Dissolve 13.2g of A185 in 13.2g of DMF, weigh 40g of the prepared N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL), and mix it in the L80 solution. Pour the mixed solution into a flat mold and dry it at 80°C to obtain a GQDs-IL modified TPU film.
[0024] This film was scratched with a paper cutter to create a 1 cm long and 0.5 cm deep scratch. After being placed at 25°C for 24 hours, the scratch disappeared when observed with the naked eye. The scratches on the L80 TPU film, a control, remained almost unchanged under the same conditions.
[0025] Example 4 Place 2g of graphene oxide (oxygen content of 24-30%), 55g of 1-ethylmethyl-3-methylimidazolium tetrafluoroborate and 43g of N,N-dimethylformamide (DMF) in a 200mL hydrothermal kettle, stir for a while, and seal the hydrothermal kettle after mixing evenly. Place the sealed hydrothermal kettle in an oven at 185°C and maintain the temperature for 10.5 hours. Take the hydrothermal kettle out of the oven, cool it to room temperature, open the sealing cover, and obtain a transparent N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL).
[0026] Wanhua Chemical's WANTHANE® L80 brand TPU was selected. 13.2 g of WANTHANE® L80 TPU was dissolved in 13.2 g of DMF, and 56 g of the prepared N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL) was weighed and mixed with the WANTHANE® L80 TPU solution. The mixed solution was poured into a flat mold and dried at 80°C to obtain a GQDs-IL modified TPU film.
[0027] This film was scratched with a paper cutter to create a 1 cm long and 0.5 cm deep scratch. After being placed at 35°C for 24 hours, the scratch disappeared when observed with the naked eye. The scratches on the WANTHANE® L80 TPU film, which was used as a control, remained almost unchanged under the same conditions.
[0028] Example 5 2.1 g of graphene oxide (oxygen content 24 - 30%), 50 g of 1-butyl-3-methylimidazolium tetrafluoroborate, and 48 g of N,N-dimethylformamide (DMF) were placed in a 200 mL hydrothermal reactor, stirred briefly, and after mixing evenly, the hydrothermal reactor was sealed. The sealed hydrothermal reactor was placed in an oven at 185 °C and maintained at this temperature for 13.5 hours. The hydrothermal reactor was taken out of the oven, cooled to room temperature, and the seal was opened to obtain a transparent N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL).
[0029] TPU of grade TPU-1-76A from Shanghai Huide Technology Co., Ltd. was selected. 13.2 g of TPU of grade TPU-1-76A was dissolved in 13.2 g of DMF, and 66 g of the prepared N,N-dimethylformamide solution (I) of graphene quantum dot ionic liquid (GQDs-IL) was weighed and mixed into the solution of TPU of grade TPU-1-76A. The mixed solution was poured into a flat mold and dried at 80 °C to obtain a GQDs-IL modified TPU film.
[0030] A scratch 1 cm long and 0.5 cm deep was made on this film with a paper cutter, and it was placed at 25 °C for 24 hours. Observed with the naked eye, the scratch disappeared. For the control TPU-1-76A TPU film, under the same conditions, the scratch hardly changed.
[0031] The GQDs-IL modified TPU films of Examples 1 - 5 were aged under the conditions of 50 °C for 72 hours. After aging, a scratch 1 cm long and 0.5 cm deep was made with a paper cutter, and it was placed at 25 °C for 24 hours. Observed with the naked eye, the scratches of the modified TPU films of all examples disappeared.
Claims
1. A method for improving the self-repairing properties of polyurethane, characterized in that: The following steps are involved: S1, mixing graphene oxide, imidazole tetrafluoroborate ionic liquid, and amide solvent and placing the mixture in a hydrothermal reactor, sealing the hydrothermal reactor and heating it, and after the reaction is completed, obtaining an amide solution of graphene quantum dot ionic liquid; S2, dissolving a thermoplastic polyurethane elastomer in an amide solvent, and then adding an amide solution of a graphene quantum dot ionic liquid to form a film, thereby obtaining a modified polyurethane film with self-healing ability.
2. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: The oxygen content of the graphene oxide is 24-30%.
3. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: The imidazolium tetrafluoroborate ionic liquid is one or more of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethylmethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, and 1,2-dimethyl-3-ethylimidazolium tetrafluoroborate.
4. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: The amide solvent is N,N-dimethylformamide or N,N-dimethylacetamide.
5. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: In S1, the mass content of graphene oxide is 1-5%, the mass content of imidazole tetrafluoroborate ionic liquid is 50-80%, and the mass content of amide solvent is 20-50%.
6. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: In S1, the reaction temperature of the hydrothermal reactor is 170-200° C., and the reaction time is 5-24 hours.
7. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: In S2, the thermoplastic polyurethane elastomer is dissolved in an amide solvent to have a solid content of 50%.
8. The method for improving the self-repairing properties of polyurethane according to claim 1, characterized in that: In S2, the mass ratio of graphene quantum dot ionic liquid to thermoplastic polyurethane elastomer is 3-15:100.