A recyclable carbon fiber fishing rod and its recycling method

Abstract

This invention discloses a recyclable carbon fiber fishing rod and its recycling method, belonging to the field of composite material technology. It includes carbon fiber cloth and a matrix resin, wherein the matrix resin is a reversibly crosslinked polyurethane. The reversibly crosslinked polyurethane is obtained by reacting polytetrahydrofuran ether diol, dicyclohexylmethane-4,4''-diisocyanate, butanediamine, and a dynamic crosslinking agent. The dynamic crosslinking agent is prepared by reacting 4,4''-dihydroxy-3,3'''-dimethoxybenzophenone with diisocyanate, followed by coupling under ultraviolet light irradiation. Through the innovation of the reversible crosslinking agent, this invention constructs a reversibly crosslinked polyurethane system, achieving high performance, recyclability, and self-healing of carbon fiber fishing rods. This completely solves the industry pain point of traditional CFRP waste downgrading or direct disposal, providing a new and efficient solution for the green and sustainable development of the polymer composite material industry.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a recyclable carbon fiber fishing rod and its recycling method. Background Technology

[0002] Carbon fiber reinforced polymer (CFRP) composites, due to their excellent properties such as lightweight, high strength, and high modulus, have been widely used in aerospace, automotive, and sporting goods industries. Carbon fiber fishing rods, as a typical example, are highly favored by fishing enthusiasts due to their light weight, high strength, and good sensitivity. Currently, most high-performance carbon fiber fishing rods on the market use thermosetting resins as the matrix material, which are compounded with carbon fiber cloth through processes such as prepreg, molding, or winding. After curing, the thermosetting resin forms a permanent three-dimensional cross-linked network, giving the fishing rod excellent mechanical properties and dimensional stability. However, it is precisely this permanent three-dimensional cross-linked structure that makes it difficult to effectively recycle and dispose of discarded carbon fiber fishing rods.

[0003] Currently, the main methods for treating traditional CFRP waste include landfill, incineration, and mechanical crushing. Landfill occupies a large amount of land resources and poses long-term environmental risks; although incineration can recover some heat energy, it produces toxic and harmful gases, causing secondary pollution; mechanical crushing can only break the composite material into low-value short fibers or powder for use as low-end fillers, and cannot achieve high-value reuse of carbon fiber.

[0004] Few existing technologies report the ability to gently and efficiently break down CFRP into renewable carbon fibers and reusable polymer materials. Therefore, there is an urgent need to develop a novel recyclable carbon fiber fishing rod and its recycling method, capable of achieving high-value recycling of both carbon fibers and the resin matrix while maintaining the rod's excellent mechanical properties. Summary of the Invention

[0005] The purpose of this invention is to provide a recyclable carbon fiber fishing rod and its recycling method. The carbon fiber fishing rod has superior mechanical properties and interfacial bonding strength compared to traditional thermosetting resin-based fishing rods. Its recycling method is mild and easy to operate, and can recycle high-value carbon fiber cloth without damage. At the same time, the matrix resin is upgraded and recycled into a high-performance elastomer material with self-healing properties, realizing the two-component high-value recycling of waste fishing rods.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a recyclable carbon fiber fishing rod, comprising carbon fiber cloth and a matrix resin, wherein the matrix resin is a reversibly cross-linked polyurethane, and the reversibly cross-linked polyurethane is prepared by the following method: Polytetrahydrofuran ether diol was stirred under vacuum at 120°C for 2 hours to remove residual moisture. After cooling to 80°C, dicyclohexylmethane-4,4'-diisocyanate and dibutyltin dilaurate were added. The mixture was stirred and reacted under a nitrogen atmosphere for 2 hours to obtain a hydroxyl-terminated prepolymer. After cooling to 60°C, anhydrous N,N-dimethylacetamide and a dynamic crosslinking agent were added, and the mixture was stirred and reacted for another 2 hours. Then, butanediamine was added, and the mixture was stirred and reacted at 45°C for another 24 hours to obtain a reversibly crosslinked polyurethane.

[0007] Furthermore, the ratio of polytetrahydrofuran ether diol, dicyclohexylmethane-4,4'-diisocyanate, dibutyltin dilaurate, N,N-dimethylacetamide, dynamic crosslinking agent, and butanediamine is 6.9-9 mmol: 6-6.9 mmol: 0.06-0.08 g: 30 mL: 4.5-6 mmol: 6.8-10.4 mmol.

[0008] Furthermore, the dynamic crosslinking agent is prepared by the following method: Step A1: 4,4'-dihydroxy-3,3'-dimethoxybenzophenone (CAS No. 5623-44-9), dicyclohexylmethane-4,4'-diisocyanate, and 1,4-diazabicyclo[2.2.2]octane were added to tetrahydrofuran and stirred at 40-50℃ for 24 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The precipitate was collected, washed three times with anhydrous acetone, and dried under vacuum at 60℃ for 1 h to obtain the intermediate. The molecule of 4,4'-dihydroxy-3,3'-dimethoxybenzophenone contains two phenolic hydroxyl groups, which can be used as reaction sites to react with dicyclohexylmethane-4,4'-diisocyanate to generate an isocyanate-terminated intermediate. Step A2: The intermediate is completely dissolved in N,N-dimethylacetamide, then isopropanol and acetic acid are added. The mixture is irradiated under a nitrogen atmosphere and UV lamp for 7 days. After the reaction is complete, the mixture is poured into anhydrous n-hexane to form a precipitate. The precipitate is collected by filtration and dried under vacuum at 60°C to obtain a dynamic crosslinking agent. Under UV irradiation, the benzophenone unit in the intermediate undergoes a photo-coupling reaction to generate a dynamic crosslinking agent with an isocyanate group-terminated aromatic pinacol structure. The dynamic crosslinking agent molecule contains two methoxy groups, which can provide additional hydrogen bonding sites to enhance the interfacial bonding with carbon fibers. At the same time, the dynamic phenol-carbamate bonds generated in the reaction can undergo reversible dissociation and reconstruction under thermal stimulation, giving the material additional self-healing properties.

[0009] Further, the ratio of 4,4'-dihydroxy-3,3'-dimethoxybenzophenone, dicyclohexylmethane-4,4'-diisocyanate, 1,4-diazabicyclo[2.2.2]octane and tetrahydrofuran is 34.7 mmol: 111-166.8 mmol: 0.07-0.11 mmol: 80 mL.

[0010] Furthermore, the ratio of the intermediate, N,N-dimethylacetamide, isopropanol, and acetic acid is 18-22 g: 100 mL: 50 mL: 0.15 mL.

[0011] Furthermore, the recyclable carbon fiber fishing rod is manufactured by the following method: A single layer of carbon fiber cloth was impregnated in reversibly cross-linked polyurethane at a mass ratio of 1:3.6 for 30 minutes, and then vacuum dried at 60°C for 2 hours to obtain a prepreg. The prepreg layer was then laid and wound onto a steel mandrel with a total thickness controlled at 1.2 mm. The prepreg was then transferred to an autoclave and heated from room temperature to 80°C for 1 hour under a pressure of 0.5 MPa, then heated to 120°C for 2 hours, and then heated to 140-160°C for 4 hours to complete the curing. Finally, the prepreg was cooled and demolded to obtain a recyclable carbon fiber fishing rod.

[0012] Secondly, the present invention provides a method for recycling the aforementioned carbon fiber fishing rod, comprising the following steps: S1. Place the waste carbon fiber fishing rod in a polar aprotic solvent and heat it at 100-110℃ for 3 hours. The aromatic pinacol bonds in the matrix resin undergo thermally reversible cleavage, and the dynamic phenol-carbamate bonds undergo reversible dissociation. The resin network dissociates and dissolves in the solvent. The carbon fiber cloth separates from the dissociated resin. After washing and drying, the recycled carbon fiber cloth is obtained. S2. After concentrating the solution of the dissociated resin, hot-press it to obtain a recycled high-performance elastomer material. The dynamic phenol-carbamate bonds in the elastomer material give it repairable and reprocessable properties.

[0013] Furthermore, the polar aprotic solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, or dimethyl sulfoxide.

[0014] Beneficial effects: The reversible crosslinked polyurethane matrix resin used in this invention endows the composite material with excellent mechanical properties through the synergistic effect of aromatic pinacol covalent crosslinking and hydrogen bond physical crosslinking. At the same time, the methoxy group introduced in the reversible crosslinking agent can form stronger hydrogen bond interactions with the oxygen-containing functional groups on the carbon fiber surface, significantly improving the interfacial bonding strength. This invention utilizes the reversible breaking characteristics of aromatic pinacol bonds under heating conditions to achieve the conversion of a three-dimensional cross-linked resin network into a linear polymer in a conventional solvent at 100°C. Compared with traditional pyrolysis or strong acid / alkali treatment, this process is extremely mild, consumes little energy, and does not cause any damage to the carbon fiber cloth. The recycled carbon fiber cloth has no resin residue on its surface, has an intact microstructure, and retains ≥98% of its tensile strength, making it directly usable for remanufacturing high-performance fishing rods. This invention not only enables the non-destructive recycling of high-value carbon fiber cloth, allowing it to be directly used for remanufacturing and achieving closed-loop recycling of carbon fiber; but also allows the linear polymer dissolved in the solvent to be transformed into a high-performance thermoplastic elastomer through simple solution thermopressing. This elastomer, containing dynamic phenol-carbamate bonds, exhibits high tensile strength, high toughness, excellent elasticity and tear resistance, as well as excellent self-healing properties and reprocessability, successfully achieving the recycling of the matrix resin. The recycled elastomer material can self-repair through thermal stimulation when damaged, further extending the material's service life and reducing resource consumption. In summary, this invention, through the innovation of reversible crosslinking agents, constructs a reversible crosslinked polyurethane system, realizing the high performance, recyclability, and self-healing of carbon fiber fishing rods. It completely solves the industry pain point of traditional CFRP waste downgrading and recycling or direct disposal, and provides a new and efficient solution for the green and sustainable development of the polymer composite materials industry. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0016] Example 1

[0017] This embodiment provides a dynamic crosslinking agent, which is prepared by the following method: Step A1: 34.7 mmol of 4,4'-dihydroxy-3,3'-dimethoxybenzophenone, 111 mmol of dicyclohexylmethane-4,4'-diisocyanate and 0.07 mmol of 1,4-diazabicyclo[2.2.2]octane were added to 80 mL of tetrahydrofuran and stirred at 40 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The precipitate was collected, washed three times with anhydrous acetone, and dried under vacuum at 60 °C for 1 h to obtain the intermediate. Step A2: Dissolve 18g of the intermediate completely in 100mL of N,N-dimethylacetamide, then add 50mL of isopropanol and 0.15mL of acetic acid. Dissolve under a nitrogen atmosphere and a 395nm UV lamp (6mW / cm²). 2 Irradiated for 7 days, and after the reaction was completed, the precipitate was poured into 800 mL of anhydrous n-hexane to form a precipitate. The precipitate was collected by filtration and dried under vacuum at 60 °C to obtain the dynamic crosslinking agent.

[0018] Example 2

[0019] This embodiment provides a dynamic crosslinking agent, which is prepared by the following method: Step A1: 34.7 mmol of 4,4'-dihydroxy-3,3'-dimethoxybenzophenone, 139 mmol of dicyclohexylmethane-4,4'-diisocyanate and 0.09 mmol of 1,4-diazabicyclo[2.2.2]octane were added to 80 mL of tetrahydrofuran and stirred at 45 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The precipitate was collected, washed three times with anhydrous acetone, and dried under vacuum at 60 °C for 1 h to obtain the intermediate. Step A2: Dissolve 20g of the intermediate completely in 100mL of N,N-dimethylacetamide, then add 50mL of isopropanol and 0.15mL of acetic acid. Proceed under a nitrogen atmosphere and with a 395nm UV lamp (6mW / cm²). 2 Irradiated for 7 days, and after the reaction was completed, the precipitate was poured into 800 mL of anhydrous n-hexane to form a precipitate. The precipitate was collected by filtration and dried under vacuum at 60 °C to obtain the dynamic crosslinking agent.

[0020] Example 3

[0021] This embodiment provides a dynamic crosslinking agent, which is prepared by the following method: Step A1: 34.7 mmol of 4,4'-dihydroxy-3,3'-dimethoxybenzophenone, 166.8 mmol of dicyclohexylmethane-4,4'-diisocyanate and 0.11 mmol of 1,4-diazabicyclo[2.2.2]octane were added to 80 mL of tetrahydrofuran and stirred at 50 °C for 24 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The precipitate was collected, washed three times with anhydrous acetone, and dried under vacuum at 60 °C for 1 h to obtain the intermediate. Step A2: Dissolve 22g of the intermediate completely in 100mL of N,N-dimethylacetamide, then add 50mL of isopropanol and 0.15mL of acetic acid. Dissolve under a nitrogen atmosphere and a 395nm UV lamp (6mW / cm²). 2 Irradiated for 7 days, and after the reaction was completed, the precipitate was poured into 800 mL of anhydrous n-hexane to form a precipitate. The precipitate was collected by filtration and dried under vacuum at 60 °C to obtain the dynamic crosslinking agent.

[0022] Comparative Example 1 The difference between this comparative example and Example 2 is that 4,4'-dihydroxybenzophenone is used to replace 4,4'-dihydroxy-3,3'-dimethoxybenzophenone in an equal amount, while all other conditions are the same.

[0023] Example 4

[0024] This embodiment provides a reversible crosslinked polyurethane, which is prepared by the following method: Nine mmol of polytetrahydrofuran ether glycol was stirred under vacuum at 120°C for 2 hours. After cooling to 80°C, 6 mmol of dicyclohexylmethane-4,4'-diisocyanate and 0.08 g of dibutyltin dilaurate were added. The mixture was stirred for 2 hours under a nitrogen atmosphere to obtain a hydroxyl-terminated prepolymer. After cooling to 60°C, 30 mL of anhydrous N,N-dimethylacetamide and 4.5 mmol of the dynamic crosslinking agent prepared in Example 1 were added. The mixture was stirred for another 2 hours. Then, 6.8 mmol of butanediamine was added, and the mixture was stirred for another 24 hours at 45°C to obtain a reversibly crosslinked polyurethane.

[0025] Example 5

[0026] This embodiment provides a reversible crosslinked polyurethane, which is prepared by the following method: 9 mmol of polytetrahydrofuran ether diol was stirred under vacuum at 120 °C for 2 h. After cooling to 80 °C, 6 mmol of dicyclohexylmethane-4,4'-diisocyanate and 0.08 g of dibutyltin dilaurate were added. The mixture was stirred and reacted under a nitrogen atmosphere for 2 h to obtain a hydroxyl-terminated prepolymer. After cooling to 60 °C, 30 mL of anhydrous N,N-dimethylacetamide and 6 mmol of the dynamic crosslinking agent prepared in Example 2 were added. The mixture was stirred and reacted for another 2 h. Then, 9 mmol of butanediamine was added, and the mixture was stirred and reacted at 45 °C for another 24 h to obtain a reversibly crosslinked polyurethane.

[0027] Example 6

[0028] This embodiment provides a reversible crosslinked polyurethane, which is prepared by the following method: 6.9 mmol of polytetrahydrofuran ether diol was stirred under vacuum at 120 °C for 2 h. After cooling to 80 °C, 6.9 mmol of dicyclohexylmethane-4,4'-diisocyanate and 0.06 g of dibutyltin dilaurate were added. The mixture was stirred and reacted under a nitrogen atmosphere for 2 h to obtain a hydroxyl-terminated prepolymer. After cooling to 60 °C, 30 mL of anhydrous N,N-dimethylacetamide and 5.2 mmol of the dynamic crosslinking agent prepared in Example 3 were added. The mixture was stirred and reacted for another 2 h. Then, 6.8-10.4 mmol of butanediamine was added, and the mixture was stirred and reacted at 45 °C for another 24 h to obtain a reversibly crosslinked polyurethane.

[0029] Comparative Example 2 The difference between this comparative example and Example 5 is that the dynamic crosslinking agent prepared in Comparative Example 1 is used to replace the dynamic crosslinking agent prepared in Example 2 in an equal amount, while the other raw materials and conditions are the same.

[0030] Comparative Example 3 The difference between this comparative example and Example 5 is that a commercially available trifunctional isocyanate crosslinking agent (Covestro Desmodur N 3300) was used to replace the dynamic crosslinking agent prepared in Example 2 in an equal amount, while all other raw materials and conditions were the same.

[0031] Example 7

[0032] This embodiment provides a recyclable carbon fiber fishing rod, which is manufactured by the following method: A single layer of carbon fiber cloth was impregnated in the reversible crosslinked polyurethane prepared in Example 4 at a mass ratio of 1:3.6 for 30 min, and then vacuum dried at 60°C for 2 h to obtain a prepreg. The prepreg layer was laid and wound onto a steel mandrel with a total thickness controlled at 1.2 mm. It was then transferred to an autoclave and heated from room temperature to 80°C for 1 h at a pressure of 0.5 MPa, then heated to 120°C for 2 h, and then heated to 140°C for 4 h to complete the curing. Finally, it was cooled and demolded to obtain a recyclable carbon fiber fishing rod.

[0033] Example 8

[0034] This embodiment provides a recyclable carbon fiber fishing rod, which is manufactured by the following method: A single layer of carbon fiber cloth was impregnated in the reversible crosslinked polyurethane prepared in Example 5 at a mass ratio of 1:3.6 for 30 min, and then vacuum dried at 60°C for 2 h to obtain a prepreg. The prepreg layer was laid and wound onto a steel mandrel with a total thickness controlled at 1.2 mm. It was then transferred to an autoclave and heated from room temperature to 80°C for 1 h under a pressure of 0.5 MPa, then heated to 120°C for 2 h, and then heated to 150°C for 4 h to complete the curing. Finally, it was cooled and demolded to obtain a recyclable carbon fiber fishing rod.

[0035] Example 9

[0036] This embodiment provides a recyclable carbon fiber fishing rod, which is manufactured by the following method: A single layer of carbon fiber cloth was impregnated in the reversible crosslinked polyurethane prepared in Example 6 for 30 minutes at a mass ratio of 1:3.6, and then vacuum dried at 60°C for 2 hours to obtain a prepreg. The prepreg layer was laid and wound onto a steel mandrel with a total thickness of 1.2 mm. It was then transferred to an autoclave and heated from room temperature to 80°C for 1 hour under a pressure of 0.5 MPa, then heated to 120°C for 2 hours, and then heated to 160°C for 4 hours to complete the curing. Finally, it was cooled and demolded to obtain a recyclable carbon fiber fishing rod.

[0037] Comparative Example 4 The difference between this comparative example and Example 8 is that the reversible crosslinked polyurethane prepared in Comparative Example 3 is used to replace the reversible crosslinked polyurethane prepared in Example 5 in an equal amount, while the other raw materials and conditions are the same.

[0038] Comparative Example 5 The difference between this comparative example and Example 8 is that the polyurethane prepared in Comparative Example 4 is used to replace the reversible crosslinked polyurethane prepared in Example 5 in an equal amount, while the other raw materials and conditions are the same.

[0039] Comparative Example 6 The difference between this comparative example and Example 8 is that commercially available epoxy resin was used to replace the reversible crosslinked polyurethane prepared in Example 5 in an equal amount, while all other raw materials and conditions were the same.

[0040] The carbon fiber fishing rods prepared in Examples 7-9 and Comparative Examples 4-6 were subjected to performance tests, and the test methods are as follows: Mechanical property testing: Tensile tests were conducted using a universal testing machine (INSTRON 5900). The tensile rate of the composite material was 5 mm / min, and the tensile rate of the elastomer was 100 mm / min. Interlaminar shear strength (ILSS): Short beam shear test according to ASTM D2344 standard; The test results are shown in Table 1: Table 1 As shown in Table 1, the carbon fiber fishing rods prepared in Examples 7-9 of this invention exhibit excellent mechanical properties, with tensile strengths ranging from 875 to 968 MPa and interlaminar shear strengths ranging from 45.6 to 52.8 MPa. Example 9 (high crosslinking density) shows the highest strength, while Example 7 (low crosslinking density) demonstrates superior toughness. Compared to Comparative Example 1, the interlaminar shear strength of Example 7 is increased by approximately 25%, proving that the introduction of methoxy groups significantly enhances interfacial bonding. The mechanical properties of Comparative Example 2 are significantly lower than those of the embodiments of this invention.

[0041] The carbon fiber fishing rods prepared in Examples 7-9 and Comparative Examples 4-6 were recycled according to the following method: S1. Place each group of carbon fiber fishing rods in N,N-dimethylacetamide and heat them at 100°C for 3 hours. Remove the carbon fiber cloth, wash and dry it to obtain the recycled carbon fiber cloth. S2. After concentrating the solution of the dissociated resin, hot-press it at 100℃ and 10MPa to obtain the recycled elastomer material.

[0042] The recycled carbon fiber cloth and elastomer materials were subjected to performance tests, and the test methods are as follows: Carbon fiber recycling rate: The percentage of recovered carbon fiber monofilament tensile strength retained relative to the original filament; Mechanical property testing: Tensile tests were conducted using a universal testing machine (INSTRON 5900). The tensile rate of the composite material was 5 mm / min, and the tensile rate of the elastomer was 100 mm / min. Self-healing efficiency: After the elastomer sample is cut open, it is contacted for repair at 100℃ for 24 hours, and the ratio of the fracture strength before and after repair is used for calculation. The test results are shown in Table 2: Table 2 Note: Comparative Example 2 only swelled but did not dissolve; it still did not dissolve after being heated to 150℃; when the temperature was further increased to above 250℃, the resin underwent thermal decomposition, leaving char residue on the surface of the carbon fiber cloth, and the tensile strength of the single filaments decreased by more than 40%; Comparative Example 3 was completely insoluble, and the resin decomposed when heated to above 250℃, resulting in severe damage to the carbon fiber.

[0043] As shown in Table 2, the carbon fiber recovery rate of Examples 7-9 is ≥98%, and the recovered carbon fiber cloth can be directly reused in fishing rod manufacturing. The tensile strength of the recovered elastomer is ≥72.5MPa, and the self-healing efficiency is ≥89%, achieving high-value upgrading and recycling of the matrix resin. In contrast, the self-healing efficiency of the elastomer recovered in Comparative Example 1 is only 82%, while Comparative Examples 2 and 3 cannot be recycled under mild conditions at all.

[0044] In summary, this invention successfully achieves high performance, recyclability, and self-healing properties of carbon fiber fishing rods by using 4,4'-dihydroxy-3,3'-dimethoxybenzophenone to prepare a dynamic crosslinking agent and constructing a reversible crosslinked polyurethane system, demonstrating significant inventiveness and industrial application value.

[0045] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0046] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A recyclable carbon fiber fishing rod, comprising carbon fiber cloth and a matrix resin, characterized in that, The matrix resin is a reversibly crosslinked polyurethane, which is prepared by the following method: The polytetrahydrofuran ether diol was dehydrated under vacuum at 120°C, cooled to 80°C, and then dicyclohexylmethane-4,4'-diisocyanate and dibutyltin dilaurate were added. The mixture was stirred for 2 hours under a nitrogen atmosphere to obtain a hydroxyl-terminated prepolymer. After cooling to 60°C, anhydrous N,N-dimethylacetamide and a dynamic crosslinking agent were added, and the mixture was stirred for another 2 hours. Then, butanediamine was added, and the mixture was stirred for another 24 hours at 45°C to obtain a reversibly crosslinked polyurethane.

2. The recyclable carbon fiber fishing rod according to claim 1, characterized in that, The ratio of polytetrahydrofuran ether diol, dicyclohexylmethane-4,4'-diisocyanate, dibutyltin dilaurate, N,N-dimethylacetamide, dynamic crosslinking agent and butanediamine is 6.9-9 mmol: 6-6.9 mmol: 0.06-0.08 g: 30 mL: 4.5-6 mmol: 6.8-10.4 mmol.

3. The recyclable carbon fiber fishing rod according to claim 1, characterized in that, The dynamic crosslinking agent is prepared by the following method: Step A1: 4,4'-dihydroxy-3,3'-dimethoxybenzophenone, dicyclohexylmethane-4,4'-diisocyanate and 1,4-diazabicyclo[2.2.2]octane were added to tetrahydrofuran and stirred at 40-50℃ for 24 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The precipitate was collected, washed, and dried under vacuum to obtain the intermediate. Step A2: Dissolve the intermediate completely in N,N-dimethylacetamide, then add isopropanol and acetic acid. Under nitrogen atmosphere and UV light, irradiate for 7 days. After the reaction is complete, pour into anhydrous n-hexane to form a precipitate. Filter and collect the precipitate, then vacuum dry to obtain the dynamic crosslinking agent.

4. A recyclable carbon fiber fishing rod according to claim 3, characterized in that, The ratio of 4,4'-dihydroxy-3,3'-dimethoxybenzophenone, dicyclohexylmethane-4,4'-diisocyanate, 1,4-diazabicyclo[2.2.2]octane and tetrahydrofuran is 34.7 mmol: 111-166.8 mmol: 0.07-0.11 mmol: 80 mL.

5. A recyclable carbon fiber fishing rod according to claim 3, characterized in that, The ratio of the intermediate, N,N-dimethylacetamide, isopropanol and acetic acid is 18-22g:100mL:50mL:0.15mL.

6. A recyclable carbon fiber fishing rod according to claim 1, characterized in that, The recyclable carbon fiber fishing rod is manufactured by the following method: A single layer of carbon fiber cloth was impregnated in reversibly cross-linked polyurethane at a mass ratio of 1:3.6 for 30 minutes, and then vacuum dried at 60°C for 2 hours to obtain a prepreg. The prepreg layer was then laid and wound onto a steel mandrel, and then transferred to an autoclave. Under a pressure of 0.5 MPa, the temperature was raised from room temperature to 80°C and held for 1 hour, then raised to 120°C and held for 2 hours, and then raised to 140-160°C and held for 4 hours to complete the curing. Finally, the material was cooled and demolded to obtain a recyclable carbon fiber fishing rod.

7. The recycling method for a recyclable carbon fiber fishing rod according to claim 1, characterized in that, Includes the following steps: S1. Place the waste carbon fiber fishing rod in a polar aprotic solvent and heat it at 100-110℃ for 3 hours. The carbon fiber cloth separates from the dissociation resin. Take out the carbon fiber cloth, wash it, and dry it to obtain the recycled carbon fiber cloth. S2. After concentrating the solution of the dissociated resin, hot-press it to obtain the recycled high-performance elastomer material.

8. The recycling method for a recyclable carbon fiber fishing rod according to claim 7, characterized in that, The polar aprotic solvent is at least one of N,N-dimethylformamide, N,N-dimethylacetamide, or dimethyl sulfoxide.

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