A waste polyimide upgrading material, a preparation method and application thereof
By preparing polyimide materials modified with sulfur-containing heterocyclic rings, the problems of high-value utilization of waste polyimide and insufficient selectivity in precious metal recycling have been solved, realizing the resource utilization of waste polyimide and the efficient recycling of precious metals, which is in line with the scientific concept of "treating waste with waste".
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHONGQING UNIVERSITY OF SCIENCE AND TECHNOLOGY
- Filing Date
- 2026-04-10
- Publication Date
- 2026-06-09
AI Technical Summary
In existing technologies, waste polyimide is difficult to utilize at high value, and the selectivity and tolerance of adsorbents to complex environments are insufficient during the precious metal recycling process. There is a lack of effective means to simultaneously achieve resource utilization and precious metal recycling.
By reacting sulfur-containing heterocyclic compounds with waste polyimide in an organic solvent, a sulfur-containing heterocyclic modified polyimide-based adsorbent material is prepared. Targeted extraction is achieved by utilizing its high affinity for noble metal ions such as gold and palladium.
The preparation method is simple and low-cost. The material has high adsorption capacity and selectivity for Au(III) and Pd(II), realizing the upgrading and utilization of waste polyimide and the efficient recycling of precious metals, which is in line with the concept of sustainable development.
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Figure CN122167736A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic polymer materials technology, and in particular to an upgraded material for waste polyimide, its preparation method, and its application. Background Technology
[0002] Polyimide (PI) is a class of organic polymer materials with excellent comprehensive properties and wide applications. With its increasing use in electronics, aerospace, and other fields, the proper disposal of large quantities of polyimide waste has become a major challenge. Currently, traditional treatment methods mainly include landfilling, incineration, and hydrolysis. However, these methods often fail to effectively dispose of waste polyimide and have significant limitations such as occupying land resources, wasting raw materials, high energy consumption, and the potential for secondary pollution. Therefore, there is an urgent need to develop a green and efficient new approach for upgrading and utilizing waste polyimide.
[0003] On the other hand, precious metals such as gold and palladium have wide applications in the industrial sector. However, their natural ore mining faces problems such as insufficient resource supply and severe ecological damage, making the recovery of precious metals from secondary resources (such as electronic waste) a current research hotspot. The content of precious metals in secondary resources is usually much higher than in natural ores, but they are difficult to separate effectively from other impurities. Adsorption methods have attracted much attention due to their safe and simple operation and relatively low cost. However, in practical applications, the adsorption and recovery of precious metals places high demands on the selective adsorption capacity of the adsorbent and its tolerance to complex environments.
[0004] In summary, existing technologies lack both effective means for upgrading and utilizing waste polyimide to higher value and adsorption materials capable of efficiently and selectively recovering precious metals from complex secondary resources. How to simultaneously achieve the resource utilization of waste polyimide and the efficient recovery of precious metals has become a pressing technical problem to be solved in this field. Summary of the Invention
[0005] The purpose of this invention is to provide an upgraded material for waste polyimide, its preparation method, and its application, which solves the problems of difficulty in utilizing waste polyimide at high value and insufficient selectivity and tolerance to complex environments of adsorbents in the process of precious metal recycling.
[0006] To achieve the above objectives, the present invention provides a method for preparing upgraded waste polyimide materials, comprising the following steps: The sulfur-containing heterocyclic compound was dissolved in an organic solvent, and waste polyimide was added. The mixture was stirred and reacted at 20-40°C for 4-8 hours. After the reaction was completed, the product was collected by vacuum filtration and washed with deionized water. The washed solid was then vacuum dried at 110°C for 8 hours to obtain a sulfur-containing heterocyclic modified waste polyimide upgraded material.
[0007] The process involves dissolving sulfur-containing heterocyclic compounds in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The sulfur-containing heterocyclic compound is at least one of thiophene-2-methylamine, thiophene-3-methylamine, thiozol-2-methylamine, thiozol-4-methylamine, thiozol-5-methylamine, isothiazol-3-methylamine, isothiazol-4-methylamine, and 1,3,4-thiadiazole-2-methylamine.
[0008] The process involves dissolving sulfur-containing heterocyclic compounds in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The organic solvent is at least one of ethanol, N,N-dimethylformamide, and dimethyl sulfoxide.
[0009] The process involves dissolving sulfur-containing heterocyclic compounds in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The mass ratio of the waste polyimide to the sulfur-containing heterocyclic compound is 1:0.5~5.
[0010] After the reaction, the product was collected by vacuum filtration and washed with deionized water. The washed solid was then vacuum dried at 110°C for 8 hours to obtain sulfur-containing heterocyclic modified waste polyimide upgraded material, which specifically includes: The waste polyimide upgrade material is in the form of at least one of foam, fiber, membrane, resin particles, and powder.
[0011] The process involves dissolving sulfur-containing heterocyclic compounds in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The general structural formula of the waste polyimide is:
[0012] Wherein, Ar is at least one of the following groups:
[0013] An upgraded material for waste polyimide is prepared using the aforementioned preparation method.
[0014] Among them, the application of the waste polyimide upgrade material in the recycling of precious metals.
[0015] This invention discloses an upgraded waste polyimide material, its preparation method, and its application. Waste polyimide is mixed with a sulfur-containing heterocyclic compound containing an aminomethyl side chain, followed by an ammonolytic ring-opening reaction to obtain a type of sulfur-containing heterocyclic modified polyimide-based adsorbent material, namely, the upgraded waste polyimide material. Introducing sulfur-containing heterocyclic functional groups into the polyimide backbone significantly improves its affinity for noble metal ions such as gold and palladium, enabling the targeted extraction of gold and palladium from waste materials such as electronic waste. The material preparation method is simple, mild, and low-cost, facilitating large-scale production. The resulting product retains its acid resistance and high-temperature resistance properties, and exhibits high recovery efficiency for target ions. The upgraded waste polyimide material obtained by this invention originates from industrial waste, contains abundant sulfur-containing heterocyclic functional groups, and possesses high adsorption capacity and selectivity for Au(III) and Pd(II), allowing for direct adsorption and recovery of noble metals from secondary resources, resulting in high efficiency and environmental friendliness. This invention simultaneously realizes the upgrading and utilization of waste polyimide and the recycling of precious metal resources, embodying the scientific idea of "treating waste with waste" and the concept of sustainable development. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.
[0017] Figure 1 This is a schematic diagram illustrating the synthesis of PI-1, an upgraded material from waste polyimide, in Example 1 of the present invention.
[0018] Figure 2 This is the infrared spectrum of PI-1, the waste polyimide upgrade material in Example 1 of the present invention.
[0019] Figure 3 This is a flowchart of the preparation method of the waste polyimide upgraded material of the present invention. Detailed Implementation
[0020] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.
[0021] Please refer to Figures 1 to 3 This invention provides a method for preparing upgraded waste polyimide materials, comprising the following steps: S101: Dissolve the sulfur-containing heterocyclic compound in an organic solvent, add waste polyimide, and stir the reaction at 20~40℃ for 4~8 hours; S102: After the reaction is complete, the product is collected by vacuum filtration and washed with deionized water. The washed solid is then vacuum dried at 110°C for 8 hours to obtain sulfur-containing heterocyclic modified waste polyimide upgraded material.
[0022] Specifically, waste polyimide is reacted with a specific sulfur-containing heterocyclic compound in an organic solvent at 20-40°C for 4-8 hours to induce an ammonolytic ring-opening reaction. The mixture is then subjected to vacuum filtration, water washing, and vacuum drying to obtain a sulfur-containing heterocyclic modified waste polyimide upgrade material. The sulfur-containing heterocyclic compound is thiophene-2-methylamine, thiophene-3-methylamine, thiazole-2-methylamine, thiazole-4-methylamine, thiazole-5-methylamine, isothiazole-3-methylamine, isothiazole-4-methylamine, 1, At least one of 3,4-thiadiazole-2-methylamine; the organic solvent is at least one of ethanol, N,N-dimethylformamide, and dimethyl sulfoxide; the mass ratio of the waste polyimide to the sulfur-containing heterocyclic compound is 1:0.5~5; the waste polyimide upgrade material can be in the form of foam, fiber, membrane, resin particles or powder; the waste polyimide upgrade material can be used to recycle precious metals, especially gold and palladium, thereby simultaneously realizing the upgrading and utilization of waste polyimide and the recycling of precious metal resources.
[0023] The waste polyimide upgrade material obtained by this invention comes from industrial waste, and the preparation method is simple, the conditions are mild, and it conforms to the concept of sustainable development.
[0024] The waste polyimide upgrading material prepared by this invention contains abundant sulfur-containing heterocyclic functional groups and has high adsorption capacity and high selectivity for Au(III) and Pd(II).
[0025] The waste polyimide upgrade material prepared by this invention can be directly used for the adsorption and recovery of precious metals in secondary resources. It is highly efficient and environmentally friendly, and conforms to the scientific concept of "treating waste with waste".
[0026] The structural formula of polyimide in the following examples is:
[0027] Example 1: In a 50 mL round-bottom flask, 1 g of thiophene-2-methylamine was dissolved in 20 mL of ethanol, then 1 g of polyimide foam was added, and the mixture was stirred at 30 °C for 6 hours. The reaction between polyimide and thiophene-2-methylamine is as follows: Figure 1 As shown in the figure. After the reaction was completed, the solid product was obtained by vacuum filtration and washed with a large amount of deionized water. Finally, the washed solid was dried under vacuum at 110 °C for 8 hours, and the final product was denoted as PI-1. PI-1 was characterized by Fourier transform infrared spectroscopy (FT-IR), and the results are shown in the figure. Figure 2 As shown. At 1020cm -1Characteristic peaks of the thiophene ring skeleton appeared nearby, at 620 cm⁻¹. -1 The presence of stretching vibration peaks of thioether bonds nearby further confirms the successful grafting of thiophene-2-methylamine. Example
[0028] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with thiophene-3-methylamine during the material preparation process, and the final product is denoted as PI-2. Example
[0029] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with thiazole-2-methylamine during the material preparation process, and the final product is denoted as PI-3. Example
[0030] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with thiazole-4-methylamine during the material preparation process, and the final product is denoted as PI-4. Example
[0031] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with thiazole-5-methylamine during the material preparation process, and the final product is denoted as PI-5. Example
[0032] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with isothiazol-3-methylamine during the material preparation process, and the final product is denoted as PI-6. Example
[0033] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with isothiazol-4-methylamine during the material preparation process, and the final product is denoted as PI-7. Example
[0034] The operation steps are the same as in Example 1, except that thiophene-2-methylamine is replaced with 1,3,4-thiadiazole-2-methylamine during the material preparation process, and the final product is denoted as PI-8.
[0035] Example 9: Gold Recycling 1. Experimental Procedure S1: Take 5 mg of each of the waste polyimide upgrade materials (PI-1~PI-8) prepared in Examples 1~8, and add them to 20 mL of Au(III) solution with a pH of 1. Stir magnetically at 25°C for 12 hours until adsorption equilibrium is reached. After the solution has stood for 5 minutes, take the supernatant, dilute and filter it, and determine the Au(III) concentration using inductively coupled plasma atomic emission spectrometry to calculate the adsorption capacity.
[0036] S2: The adsorbed material is placed in a muffle furnace and calcined at 1000℃ for 8 hours to obtain high-purity gold. The remaining solid is dissolved in 20 mL of aqua regia solution, the Au(III) concentration is determined, and the recovery rate is calculated.
[0037] 2. Experimental Results The gold recovery efficiency of PI-1 to PI-8 is shown in Table 1. All PI-1 to PI-8 can achieve efficient adsorption and recovery of gold, with PI-1 showing the best gold recovery efficiency.
[0038] Table 1 shows the gold recovery effect of the waste polyimide upgrading materials prepared in Examples 1-8.
[0039] Example 10: Palladium Recovery 1. Experimental Procedure S1: Take 5 mg of each of the waste polyimide upgrade materials (PI-1~PI-8) prepared in Examples 1~8, and add them to 20 mL of Pd(II) solution with a pH of 1. Stir magnetically at 25°C for 12 hours until adsorption equilibrium is reached. After the solution has stood for 5 minutes, take the supernatant, dilute and filter it, and determine the Pd(II) concentration using a graphite furnace atomic absorption spectrometer to calculate the adsorption capacity.
[0040] S2: The adsorption-saturated material was desorbed in a mixed eluent consisting of 1 mol / L hydrochloric acid and 1 mol / L thiourea solution. The eluent was heated to near boiling point, and 5 mg of ammonium chloride was added. After standing for 1 hour, the solution was filtered under reduced pressure to obtain a red powdery solid. The solid was washed with 1 mol / L hydrochloric acid, and then complexed with 10% ammonia solution. Hydrochloric acid was added dropwise to adjust the pH to 2-3, followed by further complexation with ammonia solution. Finally, an appropriate amount of hydrazine hydrate was added to obtain palladium powder. Samples were taken for purity analysis, and the recovery rate was calculated.
[0041] 2. Experimental Results The palladium recovery efficiency of PI-1 to PI-8 is shown in Table 2. All PI-1 to PI-8 can achieve efficient adsorption and recovery of palladium, with PI-1 showing the best palladium recovery efficiency.
[0042] Table 2 shows the palladium recovery effect of the waste polyimide upgrading materials prepared in Examples 1-8.
[0043] The waste polyimide upgrading material prepared by this invention contains abundant sulfur-containing heterocyclic functional groups, exhibiting high adsorption capacity and high selectivity for Au(III) and Pd(II). This upgraded waste polyimide material can be directly used for the adsorption and recovery of precious metals from secondary resources, demonstrating high efficiency and environmental friendliness, aligning with the scientific concept of "treating waste with waste."
[0044] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.
Claims
1. A method for preparing upgraded waste polyimide materials, characterized in that, Includes the following steps: The sulfur-containing heterocyclic compound was dissolved in an organic solvent, and waste polyimide was added. The mixture was stirred and reacted at 20-40°C for 4-8 hours. After the reaction was completed, the product was collected by vacuum filtration and washed with deionized water. The washed solid was then vacuum dried at 110°C for 8 hours to obtain a sulfur-containing heterocyclic modified waste polyimide upgraded material.
2. The method for preparing upgraded waste polyimide material as described in claim 1, characterized in that, The process involves dissolving a sulfur-containing heterocyclic compound in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The sulfur-containing heterocyclic compound is at least one of thiophene-2-methylamine, thiophene-3-methylamine, thiozol-2-methylamine, thiozol-4-methylamine, thiozol-5-methylamine, isothiazol-3-methylamine, isothiazol-4-methylamine, and 1,3,4-thiadiazole-2-methylamine.
3. The method for preparing upgraded waste polyimide materials as described in claim 1, characterized in that, The process involves dissolving a sulfur-containing heterocyclic compound in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The organic solvent is at least one of ethanol, N,N-dimethylformamide, and dimethyl sulfoxide.
4. The method for preparing upgraded waste polyimide material as described in claim 1, characterized in that, The process involves dissolving a sulfur-containing heterocyclic compound in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The mass ratio of the waste polyimide to the sulfur-containing heterocyclic compound is 1:0.5~5.
5. The method for preparing upgraded waste polyimide material as described in claim 1, characterized in that, After the reaction, the product was collected by vacuum filtration and washed with deionized water. The washed solid was then vacuum dried at 110°C for 8 hours to obtain a sulfur-containing heterocyclic modified waste polyimide upgrade material, specifically including: The waste polyimide upgrade material is in the form of at least one of foam, fiber, membrane, resin particles, and powder.
6. The method for preparing upgraded waste polyimide material as described in claim 1, characterized in that, The process involves dissolving a sulfur-containing heterocyclic compound in an organic solvent, adding waste polyimide, and stirring the mixture at 20-40°C for 4-8 hours. Specifically, this includes: The general structural formula of the waste polyimide is: , Wherein, Ar is at least one of the following groups: .
7. A waste polyimide upgrade material, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.
8. The application of the waste polyimide upgrade material as described in claim 1 in the recycling of precious metals.