A method for high-value recycling of waste nylon

Abstract

The present invention belongs to the field of polymer materials and provides a method for the high-value recycling of waste nylon. Specifically, nylon recovered from products such as waste fishing nets, textiles, oil pipes, and oil cups is depolymerized by small molecule acids containing ether oxygen bond structures to obtain carboxyl-terminated oligomeric nylon chain segments, which are then further reacted with polyether components to prepare polyetheramide elastomers. The present invention not only broadens the recycling and treatment ideas for waste nylon, reduces environmental pollution caused by nylon waste, but also transforms waste nylon into high-value polyetheramide elastomers. Compared with the current nylon recycling routes and polyetheramide synthesis routes, it has the advantages of simple process flow and equipment, short reaction cycle, and low energy consumption, and the obtained products have excellent comprehensive properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and particularly relates to a method for the high-value recycling of waste nylon. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the overall understanding of the present invention, and it is not necessarily to be regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Nylon materials have characteristics such as good wear resistance, chemical resistance, good mechanical properties, high melting point, and good biocompatibility. They are polymer materials with excellent comprehensive properties and are widely used in fields such as automotive, electronics, transportation, textiles, and medical. Nylon materials represented by PA66 and PA6 are one of the engineering plastic products with the largest global production and market demand. With the development of social economy, people's demand for nylon materials is increasing. However, a large amount of waste that is difficult to degrade naturally is generated during consumption. If these waste products are not properly treated, it will cause irreparable damage to the environment. For example, the waste fishing nets in the ocean not only pollute the environment but also have a fatal impact on marine life. Therefore, it is necessary to guide fishery participants to bring the waste nylon fishing nets in the deep sea back to land. In other aspects, the nylon materials on products such as engine filter oil cups and oil pipes cannot be degraded naturally after being discarded and need to be given a new life cycle.

[0004] Therefore, the recycling technology of nylon waste has attracted extensive attention. The main recycling methods of nylon waste include energy recovery, physical recovery, and chemical recovery. Among them, energy recovery and physical recovery mainly refer to landfill incineration or melting and remanufacturing, which have disadvantages such as secondary pollution and poor properties of recycled materials. Chemical recovery refers to degrading waste into corresponding monomers or chemical raw materials with higher added value through chemical reactions, thereby realizing the recycling of resources, which is a more thorough recovery method that conforms to atom economy. However, the current methods of nylon chemical recovery mainly use alcoholysis, ammonolysis, hydrolysis and other means to depolymerize nylon into diacids or diamines, and then the monomers are applied to nylon polymerization. These routes generally require high temperature and high pressure or supercritical conditions, and have low monomer recovery rate, large energy consumption, and high requirements for reaction equipment.

[0005] Polyetheramide elastomer is a block polymer composed of high-melting polyamide hard segments and polyether soft segments. Their chemical composition, block length, and the ratio between components determine the physical and chemical properties of this material. Polyetheramide elastomer has high strength, high toughness, good elasticity, low specific gravity, good flexural fatigue resistance, wear resistance, and good low-temperature resistance, and can be widely used in fields such as automobiles, sports goods, medical supplies, sealing components, and mechanical parts. Currently, commercially available polyetheramide elastomers generally adopt nylon 11 or nylon 12 systems, with high costs and poor domestic production capabilities. Some domestic researchers use conventional nylon segments to prepare oligomeric nylon by salification and then polymerization, and then add polyether for branching. Although polyetheramide elastomers can also be synthesized, the process route is complex, the reaction pressure is high during the synthesis process of nylon segments, and a large amount of wastewater containing amine compounds is generated, which is extremely environmentally unfriendly.

[0006] All of the above problems will affect the popularization of nylon materials and polyetheramide materials. It is necessary to provide a high-value solution for the environmental pollution problem of waste nylon, that is, to provide a technical route for preparing polyetheramide elastomer based on the recycling of waste nylon. Summary of the Invention

[0007] Aiming at the above technical problems and the deficiencies in this field, the present invention is based on the recycling of waste nylon, and uses chemical recycling of nylon components to prepare polyetheramide elastomer, which not only solves the problem of treating nylon waste, but also the synthesized polyetheramide elastomer belongs to a high-value product with excellent comprehensive properties and wide applications.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In the first aspect of the present invention, a method for high-value recycling of waste nylon is provided, including:

[0010] Mix nylon component A, nylon component B, component C, and catalyst E evenly, and carry out a depolymerization reaction to obtain a carboxyl-terminated nylon oligomer;

[0011] Add polyether component D, catalyst F, and antioxidant to the carboxyl-terminated nylon oligomer, and carry out reduced-pressure polycondensation to obtain a nylon elastomer product;

[0012] Based on the above polyetheramide elastomer and nylon components, the present invention also explored the components such as nylon component A, nylon component B, component C, and component D in the raw materials and their dosages. After verification, the ratio of nylon component A and nylon component B provided by the present invention is 7:3 to 2:8; the proportion of nylon component A, nylon component B, and component C in the total amount of all components is 25-60%; when the molar ratio of component C and component D is 1:1, the obtained polyetheramide elastomer has normal viscosity, high strength, good flexibility, and excellent comprehensive mechanical properties.

[0013] In the second aspect of the present invention, there is provided a polyetheramide elastomer prepared by the above method.

[0014] In the third aspect of the present invention, there is provided the application of the above polyetheramide elastomer in the manufacture of automobiles, sports goods, medical supplies, sealing components, and mechanical parts.

[0015] Advantages of the present invention

[0016] (1) In the present invention, a carboxyl compound containing an ether oxygen bond is used to acidolyze the recycled waste nylon. Different from the currently commonly used alcoholysis, ammonolysis, and hydrolysis routes, the depolymerization degree of the recycled nylon can be controlled by the addition amount of the carboxyl compound containing an ether oxygen bond. Without going through separation and purification and the continuous polymerization of monomers, it can be directly used for the subsequent copolymerization with polyether components to prepare polyetheramide elastomers. The process route is simple. Compared with the conventional monomer polymerization route, the reaction period is short and no large amount of amine-containing wastewater is generated.

[0017] (2) In the present invention, by regulating the components of the recycled waste nylon and using a carboxyl compound containing an ether oxygen bond to participate in the depolymerization as the hard segment part of the polyetheramide elastomer, it has good flexibility, excellent elasticity, and can reduce the melting point, facilitating processing and application in fields such as foaming.

[0018] (3) The present invention provides a method for recycling nylon waste, which can relieve the plastic pollution pressure caused by the non-biodegradability of nylon waste after disposal. At the same time, a polyetheramide elastomer material with excellent performance is prepared using nylon waste, without the problem of performance attenuation when nylon waste is used as a nylon material again. Moreover, compared with commercially available polyetheramide elastomer materials, the cost is low, significantly improving the recycling value of nylon waste. Brief description of the drawings

[0019] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0020] Figure 1 It is the infrared spectrum of the product prepared in Example 2 of the present invention;

[0021] Figure 2 It is the DSC curve of the product prepared in Example 2 of the present invention. Detailed description of the specific embodiments

[0022] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanations of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0023] A method for high-value recycling of waste nylon, comprising the steps of:

[0024] Add nylon component A, nylon component B, component C, and catalyst E into a reaction kettle in a certain proportion, displace the air in the reaction kettle with high-purity nitrogen, heat up to 200-250 °C for a pressure-holding depolymerization reaction, keep the temperature constant for 3-5 h to obtain a carboxyl-terminated nylon oligomer, then add polyether component D, catalyst F, and antioxidant into the system for reduced-pressure polycondensation, react at a pressure ≤ 200 Pa for 4-6 h, take a sample to detect that the carboxyl content ≤ 30 mol / t, and then discharge under normal pressure nitrogen protection to obtain a nylon elastomer product.

[0025] In some embodiments, the nylon component A is a short carbon chain nylon product such as nylon 66 or nylon 6 recovered from waste fishing nets, carpets, textiles, etc.;

[0026] In some embodiments, the nylon component B is a long carbon chain nylon product such as nylon 12 or nylon 1010 recovered from waste filter oil cups, oil pipes, etc.;

[0027] In some embodiments, the component C is a small molecule compound with a carboxyl end and containing an ether oxygen group;

[0028] In some embodiments, the polyether component D is one of polytetramethylene ether glycol, polyethylene glycol, and polypropylene glycol;

[0029] In some embodiments, for the method for high-value recycling of waste nylon, the ratio of nylon component A to nylon component B is 7:3 to 2:8.

[0030] In some embodiments, for the method for high-value recycling of waste nylon, the proportion of nylon component A, nylon component B, and component C in the total amount of all components is 25-60%.

[0031] In some embodiments, for the method for high-value recycling of waste nylon, the molar ratio of component C to component D is 1:1.

[0032] In some embodiments, for the method for high-value recycling of waste nylon, the component C is the reaction product of diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and acid anhydride or diglycolic acid;

[0033] In some embodiments, the acid anhydride is at least one of succinic anhydride, maleic anhydride, glutaric anhydride, adipic anhydride, pimelic anhydride, and phthalic anhydride.

[0034] In some embodiments, the preparation method of the small molecule compound of component C, which is carboxyl-terminated and contains ether oxygen groups, includes: dehydrating one of diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol at 100 - 120 °C under vacuum (1000 Pa) (the dehydration time can be 1 - 2 h) until the water content is less than 100 ppm, and then adding an acid anhydride for reaction at atmospheric pressure. The molar ratio of the acid anhydride to the diol is 2.05 - 2.2:1. After reacting for 2 - 4 h, vacuum is applied to remove low boilers, obtaining the carboxyl-terminated compound of component C that contains ether oxygen groups.

[0035] In some embodiments, the molecular weight of component D is 600 - 3000 g / mol;

[0036] In some embodiments, the catalyst E is a tin-based catalyst, which can be at least one of stannous octanoate, stannous oxalate, monobutyltin oxide, dibutyltin dilaurate, and methyltin neodecanoate, and the addition amount is 0.02 - 0.05% of the total amount of component A and component B.

[0037] In some embodiments, the catalyst F is a titanate-based catalyst, which can be at least one of tetrabutyl titanate, tetraisopropyl titanate, tetraethyl titanate, and tetrapropyl titanate, and the addition amount is 0.03 - 0.08% of the mass of component D;

[0038] In some embodiments, the antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants, and the addition amount is 0.05% - 0.5% of the mass of component D.

[0039] The following combines specific embodiments to further elaborate on the present invention. It should be noted that the specific embodiments are explanations rather than limitations of the present invention.

[0040] Example 1

[0041] 60 kg of PA66 (nylon component A) recycled from waste fishing nets, 40 kg of PA12 (nylon component B) recycled from filter oil cups, 55.08 kg of the product prepared by the reaction of diethylene glycol and succinic anhydride (component C), and 25 g of stannous oxalate catalyst were added to the reaction kettle. The air in the reaction kettle was replaced with high-purity nitrogen. After replacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 240 °C for a pressure-holding depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to viscous liquid state. After reacting at a constant temperature for 4 h, a carboxyl-terminated nylon oligomer was obtained. Then, 180 kg of polytetramethylene ether glycol with a molecular weight of 1000 g / mol (component D), 90 g of tetrabutyl titanate catalyst, and 0.8 kg of antioxidant 1010 were added to the system. The pressure was reduced to 150 Pa under vacuum at 240 °C for a compression polymerization reaction for 4 h. The carboxyl group content of the sample was detected to be 21 mol / t. After returning to normal pressure and protecting with nitrogen, the material was discharged, and a nylon elastomer product was obtained through water cooling and pelletizing. The obtained product was used to prepare specimens by injection molding for mechanical property test and evaluation. The specific data are shown in Table 1.

[0042] Example 2

[0043] 50 kg of PA66 (nylon component A) recycled from waste fishing nets, 50 kg of PA12 (nylon component B) recycled from filter oil cups, 33.52 kg of diglycolic acid (component C), and 35 g of stannous octoate catalyst were added to the reaction kettle. The air in the reaction kettle was replaced with high-purity nitrogen. After replacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 245 °C for a pressure-holding depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to viscous liquid state. After reacting at a constant temperature for 3.5 h, a carboxyl-terminated nylon oligomer was obtained. Then, 250 kg of polytetramethylene ether glycol with a molecular weight of 1000 g / mol (component D), 160 g of tetrabutyl titanate catalyst, and 1.2 kg of antioxidant 1010 were added to the system. The pressure was reduced to 100 Pa under vacuum at 245 °C for a compression polymerization reaction for 5 h. The carboxyl group content of the sample was detected to be 19.8 mol / t. After returning to normal pressure and protecting with nitrogen, the material was discharged, and a nylon elastomer product was obtained through water cooling and pelletizing. The obtained product was used to prepare specimens by injection molding for mechanical property test and evaluation. The specific data are shown in Table 1. The DSC and infrared spectrum test spectra are shown in Figure 1 、 Figure 2 。

[0044] Example 3

[0045] 70 kg of PA66 (nylon component A) recycled from waste carpets, 30 kg of PA1010 (nylon component B) recycled from oil pipes, 77.85 kg of the product prepared by reacting triethylene glycol with succinic anhydride (component C), and 20 g of the catalyst monobutyltin oxide were added to the reaction kettle. The air in the reaction kettle was displaced with high-purity nitrogen. After displacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 235 °C for a pressure-retaining depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to viscous liquid. After reacting at a constant temperature for 5 h, a carboxyl-terminated nylon oligomer was obtained. Then, 400 kg of polytetramethylene ether glycol with a molecular weight of 1800 g / mol (component D), 280 g of the catalyst tetraethyl titanate, 0.7 kg of antioxidant 1010, and 0.7 kg of antioxidant 168 were added to the system. The pressure was reduced to 100 Pa under vacuum at 235 °C for a condensation polymerization reaction for 5 h. The carboxyl group content of the sample was detected to be 23 mol / t. After returning to normal pressure and protecting with nitrogen, the material was discharged, and a nylon elastomer product was obtained through water cooling and pelletizing. The obtained product was used to prepare specimens by injection molding for mechanical property testing and evaluation. The specific data are shown in Table 1.

[0046] Example 4

[0047] 40 kg of PA6 (nylon component A) recycled from waste textiles, 60 kg of PA12 (nylon component B) recycled from filter oil cups, 63.06 kg of the product prepared by reacting tripropylene glycol with glutaric anhydride (component C), and 40 g of the catalyst dibutyltin dilaurate were added to the reaction kettle. The air in the reaction kettle was displaced with high-purity nitrogen. After displacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 240 °C for a pressure-retaining depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to viscous liquid. After reacting at a constant temperature for 6 h, a carboxyl-terminated nylon oligomer was obtained. Then, 180 kg of polytetramethylene ether glycol with a molecular weight of 1200 g / mol (component D), 95 g of the catalyst tetraisopropyl titanate, and 0.65 kg of antioxidant 1076 were added to the system. The pressure was reduced to 90 Pa under vacuum at 240 °C for a condensation polymerization reaction for 4.5 h. The carboxyl group content of the sample was detected to be 16 mol / t. After returning to normal pressure and protecting with nitrogen, the material was discharged, and a nylon elastomer product was obtained through water cooling and pelletizing. The obtained product was used to prepare specimens by injection molding for mechanical property testing and evaluation. The specific data are shown in Table 1.

[0048] Example 5

[0049] 30 kg of PA6 (nylon component A) recycled from waste textiles, 70 kg of PA1010 (nylon component B) recycled from oil pipes, 54.05 kg of the product prepared by reacting dipropylene glycol with adipic anhydride (component C), and 45 g of the catalyst methyltin neodecanoate were added to a reaction kettle. The air in the reaction kettle was replaced with high-purity nitrogen. After replacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 245 °C for a pressure-maintaining depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to viscous liquid. After a constant-temperature reaction for 4 h, a carboxyl-terminated nylon oligomer was obtained. Then, 120 kg of polyethylene glycol with a molecular weight of 1000 g / mol (component D), 65 g of the catalyst tetrapropyl titanate, 0.35 kg of antioxidant 1010, and 0.1 kg of antioxidant 168 were added to the system. The pressure was reduced and polymerized under vacuum at 245 °C to 120 Pa for 6 h. The carboxyl-terminal content was sampled and detected to be 20 mol / t. After returning to normal pressure and protecting with nitrogen, the product was discharged, and a nylon elastomer product was obtained by water cooling and pelletizing. The obtained product was used to prepare specimens by injection molding for mechanical property test and evaluation. The specific data are shown in Table 1.

[0050] Example 6

[0051] 20 kg of PA66 (nylon component A) recycled from waste fishing nets, 80 kg of PA1010 (nylon component B) recycled from oil pipes, 18.37 kg of the product prepared by reacting diethylene glycol with succinic anhydride (component C), and 38 g of the catalyst stannous oxalate were added to a reaction kettle. The air in the reaction kettle was replaced with high-purity nitrogen. After replacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 240 °C for a pressure-maintaining depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to viscous liquid. After a constant-temperature reaction for 4 h, a carboxyl-terminated nylon oligomer was obtained. Then, 120 kg of polypropylene glycol with a molecular weight of 2000 g / mol (component D), 80 g of the catalyst tetrabutyl titanate, 0.3 kg of antioxidant 1010, and 0.15 kg of antioxidant 168 were added to the system. The pressure was reduced and polymerized under vacuum at 240 °C to 150 Pa for 4 h. The carboxyl-terminal content was sampled and detected to be 24 mol / t. After returning to normal pressure and protecting with nitrogen, the product was discharged, and a nylon elastomer product was obtained by water cooling and pelletizing. The obtained product was used to prepare specimens by injection molding for mechanical property test and evaluation. The specific data are shown in Table 1.

[0052] Comparative Example 1

[0053] 60 kg of PA66 (nylon component A) recycled from waste fishing nets, 40 kg of PA12 (nylon component B) recycled from filter oil cups, 55.08 kg of diethylene glycol, and 25 g of stannous oxalate catalyst were added to a reaction kettle. High-purity nitrogen was used to displace the air in the reaction kettle. After displacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 240 °C for depolymerization reaction. It could be observed that the materials in the kettle gradually changed from granular to a liquid state with lower viscosity. After reacting at a constant temperature for 4 h, a state quite different from that of the above-mentioned examples was obtained, with a significant ammonia smell. It should be that diethylene glycol depolymerized the nylon components into small-molecule amines. Then, 180 kg of polytetramethylene ether glycol (component D) with a molecular weight of 1000 g / mol, 90 g of tetrabutyl titanate catalyst, and 0.8 kg of antioxidant 1010 were added to the system. Under the condition of maintaining 240 °C, the pressure was reduced to 150 Pa under vacuum for polycondensation reaction for 6 h. The viscosity of the system did not increase, and it gradually turned black. After discharging under the protection of normal-pressure nitrogen, the product was a low-viscosity liquid, and it became slag-like after cooling and forming, without mechanical properties.

[0054] Comparative Example 2

[0055] PA66 salt and PA1010 salt were pre-prepared in a salt-forming reaction kettle. Then, 70 kg of PA66 salt, 30 kg of PA1010 salt, 26.22 kg of succinic acid, and 20 g of monobutyltin oxide catalyst were added to the reaction kettle. High-purity nitrogen was used to displace the air in the reaction kettle. After displacing 3 times, high-purity nitrogen was introduced into the kettle, and the temperature was raised to 250 °C for pressure-maintaining polymerization. After reacting under pressure for 4 h, the exhaust valve of the reaction kettle was slowly opened to cool down, and the pressure in the kettle was released to normal pressure within 3 h to obtain a carboxyl-terminated nylon oligomer. Then, 400 kg of polytetramethylene ether glycol (component D) with a molecular weight of 1800 g / mol, 280 g of tetraethyl titanate catalyst, 0.7 kg of antioxidant 1010, and 0.7 kg of antioxidant 168 were added to the system. Under the condition of maintaining 250 °C, the pressure was reduced to 100 Pa under vacuum for polycondensation reaction for 5 h. After discharging under the protection of normal-pressure nitrogen, the product was obtained by water-cooling and pelletizing to obtain a nylon elastomer product, which was significantly yellowish compared with the materials obtained in the above-mentioned examples. The obtained product was used to prepare specimens by injection molding for mechanical property test and evaluation. The specific data are shown in Table 1.

[0056] In addition, commercially available Pebax products were selected for performance testing as a comparative reference.

[0057] Table 1

[0058]

[0059]

[0060] As can be seen from the data in Table 1, the nylon elastomer material synthesized from recycled waste nylon in the present invention has mechanical properties such as tensile strength, elongation at break, and tear strength that are close to those of the conventional salification route and currently commercially available Pebax products. The melt index is also within the normal range, indicating normal viscosity and normal usability, significantly improving the application value of waste nylon. Moreover, the melting point of the nylon elastomer prepared by this technical solution can be slightly lower than that of commercially available products, which is more conducive to injection molding and applications in fields such as foaming.

[0061] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for high-value recycling of waste nylon, characterized in that, Including: Mix nylon component A, nylon component B, component C, and catalyst E evenly and carry out a depolymerization reaction to obtain a carboxyl-terminated nylon oligomer; Add polyether component D, catalyst F, and antioxidant to the carboxyl-terminated nylon oligomer and carry out a reduced-pressure polycondensation to obtain a nylon elastomer product; Among them, the ratio of nylon component A to nylon component B is 7:3 to 2:8; The proportion of nylon component A, nylon component B, and component C in the total amount of all components is 25-60%; The molar ratio of component C to component D is 1:1; Nylon component A is a short carbon chain nylon product recovered from waste fishing nets, carpets, and textiles; Nylon component B is a long carbon chain nylon product recovered from waste filter oil cups and oil pipes; Component C is a carboxyl-terminated small molecule compound containing an ether oxygen group, and component C is the reaction product of diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and an acid anhydride or diglycolic acid; The acid anhydride is at least one of succinic anhydride, maleic anhydride, glutaric anhydride, adipic anhydride, pimelic anhydride, and phthalic anhydride.

2. The method for high-value recycling of waste nylon according to claim 1, characterized in that, The short carbon chain nylon product is nylon 66 or nylon 6.

3. The method for high-value recycling of waste nylon according to claim 1, characterized in that, The long carbon chain nylon product is nylon 12 or nylon 1010.

4. The method for high-value recycling of waste nylon according to claim 1, characterized in that, Polyether component D is at least one of polytetramethylene ether glycol, polyethylene glycol, and polypropylene glycol.

5. The method for high-value recycling of waste nylon according to claim 4, characterized in that, The molecular weight of polyether component D is 600-3000 g / mol.

6. The method for high-value recycling of waste nylon according to claim 1, characterized in that, Catalyst E is a tin-based catalyst.

7. The method for high-value recycling of waste nylon according to claim 6, characterized in that, The tin-based catalyst is at least one of stannous octoate, stannous oxalate, monobutyltin oxide, dibutyltin dilaurate, and methyltin neodecanoate.

8. The method for high-value recycling of waste nylon according to claim 1, characterized in that, The addition amount of catalyst E is 0.02-0.05% of the total amount of component A and component B.

9. The method for high-value recycling of waste nylon according to claim 1, characterized in that, Catalyst F is a titanate-based catalyst.

10. The method for high-value recycling of waste nylon according to claim 9, characterized in that, The titanate-based catalyst is at least one of tetrabutyl titanate, tetraisopropyl titanate, tetraethyl titanate, and tetrapropyl titanate.

11. The method for high-value recycling of waste nylon according to claim 1, characterized in that, The addition amount of catalyst F is 0.03-0.08% of the mass of component D.

12. The method for high-value recycling of waste nylon according to claim 1, characterized in that, The antioxidant is at least one of hindered phenol antioxidants and phosphite antioxidants.

13. The method for high-value recycling of waste nylon according to claim 1, characterized in that, The addition amount of the antioxidant is 0.05% to 0.5% of the mass of component D.

14. A polyetheramide elastomer prepared by the method according to any one of claims 1 to 13.

15. Use of the polyetheramide elastomer according to claim 14 in the manufacture of motor vehicles, sports articles, medical articles, sealing components, and machine components.

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