Aramid paper modified dynamic high polymer composite material with wear resistance and preparation method thereof
By introducing copolymerization of hydrogen bonds, fluorene groups, carbon-fluorine bonds, silicon-oxygen bonds, and dynamic imine bonds, a wear-resistant aramid paper-modified dynamic polymer composite material was prepared. This solved the problems of insufficient mechanical properties and tribological properties of aramid paper, realized the recyclability of the material, and improved the overall performance and environmental adaptability of the material.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JIANGSU OCEAN UNIV
- Filing Date
- 2026-03-31
- Publication Date
- 2026-06-23
AI Technical Summary
Traditional aramid paper suffers from insufficient mechanical properties, tribological properties, or environmental adaptability. Existing dynamic polyimide materials face problems such as insufficient mechanical strength, limited functionality, or stringent recycling conditions, leading to difficulties in material recycling, resource waste, and environmental pollution.
By introducing hydrogen bonds, fluorene groups, carbon-fluorine bonds, silicon-oxygen bonds, and dynamic imine bonds, dynamic polyimide solutions are prepared by copolymerization and then composited with aramid paper. Dynamic polyimide composite aramid paper is prepared by solution casting and multi-path recycling methods are provided, including immersion in amino compound solutions and degradation of a mixture of dilute hydrochloric acid and tetrahydrofuran sprayed down, to achieve complete separation and recycling of the material.
This material achieves high strength, low coefficient of friction, and hydrophobic surface properties. It can be fully recycled under mild conditions while maintaining its performance, thus solving the problem of difficult recycling of traditional composite materials.
Smart Images
Figure CN122257296A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of dynamic polymer composite material synthesis technology, specifically relating to a wear-resistant aramid paper modified dynamic polymer composite material and its preparation method. Background Technology
[0002] Aramid paper, as a high-performance aromatic polyamide paper-based material, is widely used in electrical insulation, aerospace, rail transportation, and protective equipment due to its excellent high-temperature resistance, high mechanical strength, good electrical insulation properties, and chemical stability. However, traditional aramid paper often suffers from insufficient mechanical properties, tribological properties, or environmental adaptability in practical applications, necessitating composite modification to improve its overall performance. Currently, common composite methods often employ thermosetting resins or irreversible chemical cross-linking systems. While these methods can improve performance to some extent, they also lead to difficulties in material recycling, resulting in resource waste and environmental pollution. Especially under the "dual-carbon" strategy, developing aramid paper composite materials that combine high performance and recyclability has become an important research direction in this field.
[0003] Dynamic polymers have become a research hotspot in the field of polymer materials in recent years. Their molecular structures contain dynamic covalent bonds (such as imine bonds, disulfide bonds, and transesterification bonds), which can undergo reversible breakage and recombination under specific stimuli (such as heat, acid, and solvents), thereby achieving material repair, remodeling, and recycling. Among them, dynamic polyimides show great potential in constructing recyclable composite materials due to their advantages such as simple synthesis, tunable structure, and mild response conditions. However, existing dynamic polyimide materials often face problems such as insufficient mechanical strength, limited functionality, or demanding recycling conditions. Combining dynamic polyimides with aramid paper promises to introduce controllable dynamic properties while retaining the intrinsic properties of aramid paper, achieving high-performance composites and closed-loop recycling. However, related research is still relatively lacking, especially regarding recycling methods that achieve complete separation of aramid paper and polymer under multi-path, mild conditions, which have not yet been systematically reported. Summary of the Invention
[0004] To address the problems existing in the prior art, this invention provides a wear-resistant aramid paper-modified dynamic polymer composite material and its preparation method. This invention introduces hydrogen bonds, fluorene groups, carbon-fluorine bonds, silicon-oxygen bonds, and dynamic imine bonds. A dynamic polyimide solution is obtained through copolymerization of two different diamine monomers. Recyclable dynamic polyimide composite aramid paper is then prepared by solution casting. This paper not only possesses excellent mechanical and tribological properties but can also be completely recycled through various methods, achieving the goal of circular use. It is suitable for applications such as electrical insulation, high-temperature protection, wear-resistant sealing, and lightweight structural materials.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A wear-resistant aramid paper-modified dynamic polymer composite material is disclosed. The material comprises amino and aldehyde monomers in different molar ratios, copolymerized with a crosslinking agent to obtain a dynamically crosslinked polyimide. This polyimide-based aramid paper is then prepared by solution casting and composited with aramid paper. The resulting polyimide-based aramid paper exhibits a coefficient of friction of 0.35-0.4, a friction loss rate of <5%, a high tensile strength of up to 110 MPa, and a water contact angle of 102°. The dynamic polymer structure is as follows:
[0006] A method for preparing a wear-resistant aramid paper-modified dynamic polymer composite material, characterized by the following steps: Step 1: Weigh a certain amount of terephthalaldehyde (TA) and dissolve it in a magnetic stirring cup containing solvent. After complete dissolution, add diamine monomers of different molar ratios to the stirring cup and stir to react. After the reaction is complete, add tris(2-aminoethyl)amine (TREN) for crosslinking. After the crosslinking reaction is completed, a dynamic polyimide solution is obtained. Step 2: Lay the aramid paper flat on the polytetrafluoroethylene mold, then pour the dynamic polyimide solution evenly on it, and then put it into a forced-air drying oven to dry the solvent. Finally, place the aramid paper modified dynamic polymer composite material in a vacuum oven for complete cross-linking and curing.
[0007] Furthermore, in step 1, the solvent is one or a mixture of several conventional organic solvents such as N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and chloroform. The molar ratio of the different diamine monomers is 0:10-10:0, and the total molar ratio of aldehyde and amino groups is 1:1. The aramid paper is made of aramid 1313 and aramid 1414, and the number of aramid paper layers is ≤3.
[0008] Furthermore, in step 2, the temperature of the forced-air drying oven is 50-100 °C, and the temperature of the vacuum drying oven is 110-180 °C.
[0009] A method for recycling wear-resistant aramid paper-modified dynamic polymer composite materials, the method is as follows: S1: Weigh a certain amount of diamine monomer and dissolve it in a solvent. Then, aramid paper modified dynamic polymer composite material is immersed in it. After a period of time, the dynamic polyimide is completely dissolved into a polyimide oligomer solution, and the aramid paper is completely peeled off. Finally, the aramid paper is taken out, rinsed several times with solvent, and then placed in a forced-air drying oven to dry the surface solvent. S2: Prepare a low-concentration dilute hydrochloric acid solution, then mix the dilute hydrochloric acid with tetrahydrofuran (THF) in a certain proportion. Next, immerse the dynamic polyimide composite aramid paper in the mixed solution. After a period of time, the dynamic polyimide is completely degraded. Take out the aramid paper, rinse it several times with dilute hydrochloric acid, then rinse it with ethanol, and put it into a forced-air drying oven to dry.
[0010] Furthermore, in S1, the mass of the diamine monomer is 1-15% of the solvent mass, and the solvent is one of the conventional organic solvents N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and chloroform. The soaking time of the dynamic polyimide composite aramid paper is 2-12 h, the temperature of the forced-air drying oven is 50-100 °C, and the drying time is 6-24 h.
[0011] Furthermore, in S2, the concentration of the dilute hydrochloric acid is 0.1-1.5 mol / L, the volume ratio of the dilute hydrochloric acid to THF is 1:1-1:9, the soaking time of the wear-resistant aramid paper modified dynamic polymer composite material is 0.5-24 h, the temperature of the forced-air drying oven is 60-120 °C, and the drying time is 1-24 h.
[0012] The above technical solution can achieve the following beneficial effects: This invention provides a fully recyclable dynamic polyimide composite aramid paper and its multi-path recycling method. Through the reversible polymerization reaction of aldehyde and amino groups, multiple functional groups such as fluorene groups, carbon-fluorine bonds, and silicon-oxygen bonds are simultaneously introduced into the dynamic polyimide structure. Combined with the exchange characteristics of the dynamic imide bonds, the material's properties are controllable and recyclable. The prepared aramid paper-modified dynamic polymer composite material exhibits excellent comprehensive properties: a tensile strength as high as 110 MPa, a friction coefficient of only 0.35, a wear rate of less than 5%, and a water contact angle of 102°. It combines high strength, excellent wear resistance, and significant hydrophobic surface properties, making it suitable for applications requiring high-performance tribology and humid environments. More importantly, this invention proposes two mild and efficient recycling pathways: one is to achieve the exchange depolymerization of the dynamic polyimide and complete peeling of the aramid paper through immersion in an amino compound solution; the other is to utilize acidic hydrolysis in a mixed system of dilute hydrochloric acid and tetrahydrofuran to completely degrade the polyimide layer, thereby achieving clean recycling of the aramid paper. Both methods can be completed in a short time, and the recycled aramid paper retains its structural integrity and performance, truly achieving efficient separation and recycling of the reinforcement and matrix in composite materials. This invention not only significantly improves the mechanical and surface properties of aramid paper composites, but also solves the key problems of difficult recycling and low resource utilization in traditional composite materials through dynamic chemical design and multi-path recycling strategies, providing innovative ideas and technical approaches for the development of high-performance, sustainable paper-based composite materials. Attached Figure Description
[0013] Figure 1 This is a physical image of the aramid paper-modified dynamic polymer composite paper obtained in an embodiment of the present invention.
[0014] Figure 2This is a comparison diagram of the mechanical properties of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention and the dynamic polyimide obtained in the comparative example.
[0015] Figure 3 This is a comparison chart showing the contact angle values over time of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention and the dynamic polyimide obtained in the comparative example.
[0016] Figure 4 This is a comparison chart of the friction coefficients of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention and the dynamic polyimide obtained in the comparative example.
[0017] Figure 5 This is a bar chart comparing the friction loss rates of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention with those of the dynamic polyimide obtained in the comparative example.
[0018] Figure 6 This is a flowchart illustrating the degradation process of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention via an amino solution.
[0019] Figure 7 This is a flowchart illustrating the degradation of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention using dilute hydrochloric acid. Detailed Implementation
[0020] The appendix of the present invention is described below. Figure 1-7 The embodiments are described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.
[0021] In the following examples and comparative examples, the coefficient of friction and wear rate were measured using a plastic sliding friction and wear tester (M-200A, Beijing Guance Precision Instrument Equipment Co., Ltd.); the tensile strength was measured using a universal tensile testing machine (UTM4304, Shenzhen Sansi Zongheng Technology Co., Ltd.), in accordance with GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3 Test conditions for films and sheets". Example
[0022] This embodiment prepares aramid paper-modified dynamic polymer composite material according to the following steps: Step 1: Weigh 15.1 g N1-Methylpyrrolidone (NMP) was placed in a glass beaker and stirred at 300 rpm on a magnetic stirrer. Then, 0.805 g (6 mmol) of terephthalaldehyde (TA) was weighed and dissolved in the solvent. After stirring for 10 minutes, 0.769 g (2 mmol) of 9,9-bis(4-amino-3-fluorophenyl)fluorene FFDA and 0.249 g (1 mmol) of aminopropyl-terminated polydimethylsiloxane (PDMS) were weighed and added to the solution at 10-minute intervals. The mixture was stirred and reacted for 2 hours. Then, 0.292 g (2 mmol) of tris(2-aminoethyl)amine (TREN) was weighed and added to the solution for crosslinking and curing for 1 minute to obtain a dynamic polyimide solution.
[0023] Step 2: Lay a piece of aramid paper (approximately 20 × 10 cm) flat in a polytetrafluoroethylene (PTFE) mold. Then, pour the dynamic polyimide solution evenly into the PTFE mold. Next, place the PTFE mold in a 60 ℃ forced-air oven to dry for 24 hours. Finally, remove the PTFE mold from the forced-air oven and place it in a 150 ℃ vacuum oven to cure for 1 hour to obtain the aramid paper-modified dynamic polymer composite material.
[0024] The physical example of the aramid paper-modified dynamic polymer composite material prepared in this embodiment is shown below. Figure 1 As shown.
[0025] This embodiment recycles dynamic polyimide composite aramid paper according to the following steps: Method 1: Weigh 0.249 g of PDMS and dissolve it in NMP. Then, immerse about 1 g of rectangular dynamic polyimide composite aramid paper in the solution. After 2.5 h, the dynamic polyimide is completely dissolved into a polyimide oligomer solution, and the aramid paper is completely peeled off. Finally, remove the aramid paper, rinse it three times with NMP, and place it in a 70 ℃ forced-air oven to dry the surface solvent for 12 hours.
[0026] Method 2: Prepare a 1 mol / L dilute hydrochloric acid solution, then mix the dilute hydrochloric acid and tetrahydrofuran (THF) at a volume ratio of 1:4. Next, immerse about 1 g of rectangular dynamic polyimide composite aramid paper in the mixed solution. After 12 hours, the dynamic polyimide is completely degraded. Remove the aramid paper, rinse it three times with dilute hydrochloric acid, and then dry it in a 70 ℃ forced-air oven for 1 hour.
[0027] The flowchart for Method 1, which involves recycling aramid paper to modify dynamic polymer composites, is shown below. Figure 6 As shown.
[0028] The flowchart for Method 2, which involves recycling aramid paper to modify dynamic polymer composites, is shown below. Figure 7 As shown.
[0029] Comparative example:
[0030] This embodiment prepares dynamic polyimide according to the following steps: Weigh 15.1 g of NMP and place it in a glass beaker. Stir the beaker at 300 rpm using a magnetic stirrer. Then, weigh 0.805 g (6 mmol) of TA and dissolve it in the solvent. Stir for 10 minutes. Next, weigh 0.769 g (2 mmol) of FFDA and 0.249 g (1 mmol) of PDMS and add them to the solution at 10-minute intervals. Stir the reaction for 2 hours. Then, weigh 0.292 g (2 mmol) of TREN and add it to the solution. Crosslink and cure for 1 minute to obtain a dynamic polyimide solution. Pour the solution into a polytetrafluoroethylene mold and dry it in a 60 ℃ forced-air oven for 24 hours. Finally, remove the polytetrafluoroethylene mold from the forced-air oven and place it in a 150 ℃ vacuum oven to cure for 1 hour to obtain a dynamic polyimide film.
[0031] Figure 2 This is a comparison of the mechanical properties of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention and the dynamic polyimide obtained in the comparative example. The tensile strength of the embodiment is 113.3±3.4 MPa, and the Young's modulus is 1749.1±220.1 MPa; the tensile strength of the comparative example is 68.3±1.7 MPa, and the Young's modulus is 890.8±42.9 MPa. Compared with the comparative example, the tensile strength is increased by approximately 65%, and the Young's modulus is increased by approximately 95%.
[0032] Figure 3 This is a comparison chart showing the contact angle values over time of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention and the dynamic polyimide obtained in the comparative example. The initial contact angle value of the embodiments is 102°; the initial contact angle value of the comparative example is 90°. The initial contact angle of the embodiments is 12° higher than that of the comparative example.
[0033] Figure 4 This is a comparison chart of the friction coefficients of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention and the dynamic polyimide obtained in the comparative example. The friction coefficient of the embodiments is 0.35; the friction coefficient of the comparative example is 0.6. The friction coefficient is reduced by approximately 50% compared to the comparative example.
[0034] Figure 5 This is a bar chart comparing the friction loss rates of the aramid paper-modified dynamic polymer composite material obtained in the embodiments of the present invention with those of the dynamic polyimide obtained in the comparative example. The friction loss rate of the embodiments is 4.6 ± 1.3%; the friction coefficient of the comparative example is 8.3 ± 1.9%. The friction loss rate of the embodiments is reduced by approximately 45% compared to the comparative example. The above descriptions are all preferred embodiments of the present invention. For those skilled in the art, various equivalent modifications to the present invention without departing from the principle of the present invention are within the protection scope of the appended claims.
Claims
1. A wear-resistant aramid paper-modified dynamic polymer composite material, characterized in that: The material comprises amino and aldehyde monomers in different molar ratios, and a crosslinking agent, copolymerized to obtain dynamically crosslinked polyimide. Then, it is composited with aramid paper using a solution casting method to prepare dynamic polyimide composite aramid paper. The resulting polyimide composite aramid paper has a coefficient of friction of 0.35-0.4, a friction loss rate of <5%, a tensile strength as high as 110 MPa, and a water contact angle of 102°. The dynamic polymer structure is as follows: 。 2. A method for preparing a wear-resistant aramid paper-modified dynamic polymer composite material, characterized in that, The method is as follows: Step 1: Weigh a certain amount of terephthalaldehyde (TA) and dissolve it in a magnetic stirring cup containing solvent. After complete dissolution, add diamine monomers of different molar ratios to the stirring cup and stir to react. After the reaction is complete, add tris(2-aminoethyl)amine (TREN) for crosslinking. After the crosslinking reaction is completed, a dynamic polyimide solution is obtained. Step 2: Lay the aramid paper flat on the polytetrafluoroethylene mold, then pour the dynamic polyimide solution evenly on it, and then put it into a forced-air drying oven to dry the solvent. Finally, place the aramid paper modified dynamic polymer composite material in a vacuum oven for complete cross-linking and curing.
3. The preparation method according to claim 2, characterized in that: In step 1, the solvent is one or a mixture of several conventional organic solvents such as N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and chloroform. The molar ratio of the different diamine monomers is 0:10-10:0, and the total molar ratio of aldehyde and amino groups is 1:
1. The aramid paper is made of aramid 1313 and aramid 1414, and the number of aramid paper layers is ≤3.
4. The preparation method according to claim 2, characterized in that: The temperature of the forced-air drying oven in step 2 is 50-100°C, and the temperature of the vacuum drying oven is 110-180°C.
5. A method for recycling the wear-resistant aramid paper-modified dynamic polymer composite material of claim 1, characterized in that: The method is as follows: S1: Weigh a certain amount of diamine monomer and dissolve it in a solvent, then immerse the aramid paper-modified dynamic polymer composite material in it. After a period of time, the dynamic polyimide was completely dissolved into a polyimide oligomer solution, and the aramid paper was completely peeled off. Finally, the aramid paper was taken out, rinsed several times with solvent, and then placed in a forced-air drying oven to dry the surface solvent. S2: Prepare a low-concentration dilute hydrochloric acid solution, then mix the dilute hydrochloric acid with tetrahydrofuran (THF) in a certain proportion. Next, immerse the dynamic polyimide composite aramid paper in the mixed solution. After a period of time, the dynamic polyimide is completely degraded. Take out the aramid paper, rinse it several times with dilute hydrochloric acid, then rinse it with ethanol, and put it into a forced-air drying oven to dry.
6. The recycling method according to claim 5, characterized in that: The mass of the diamine monomer in S1 is 1-15% of the mass of the solvent, and the solvent is one of the conventional organic solvents N-methylpyrrolidone, dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and chloroform. The soaking time of the dynamic polyimide composite aramid paper is 2-12 h, the temperature of the forced-air drying oven is 50-100 °C, and the drying time is 6-24 h.
7. The recycling method according to claim 5, characterized in that: The concentration of the dilute hydrochloric acid in S2 is 0.1-1.5 mol / L, the volume ratio of the dilute hydrochloric acid to THF is 1:1-1:9, the soaking time of the wear-resistant aramid paper modified dynamic polymer composite material is 0.5-24 h, the temperature of the forced-air drying oven is 60-120 °C, and the drying time is 1-24 h.