Simple high-selectivity polyurethane degradation method
By combining ethanolamine and sodium methoxide in a specific proportion of composite as degradation agents, the polyurethane material is efficiently decomposed, and the problem of difficult degradation of polyurethane in the prior art is solved, and the efficient, environmentally friendly and low-cost degradation effect is achieved.
Patent Information
- Application Number
- CN202510178392.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2025-05-23
AI Technical Summary
The existing technology is difficult to effectively degrade polyurethane materials. Traditional landfill and incineration treatments have problems of environmental pollution and health hazards. The existing catalyst degradation methods have harsh reaction conditions and low conversion rates.
The polyurethane material is efficiently decomposed into the amine corresponding to the isocyanate monomer by a specific proportion of ethanolamine and sodium methoxide as the degradation agent. The degradation agent and product are easily separated and recovered by heating and stirring reaction.
It realizes efficient degradation of polyurethane materials, with a degradation rate of up to 99.7%, reducing treatment costs and environmental pollution, and simplifying the process flow.
Smart Images
Figure CN120025249A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polymer material degradation, in particular to a simple and highly selective polyurethane degradation method. Background Art
[0002] In today's era of highly developed material science and industrial production, polyurethane, as an important type of high molecular polymer, has shown its indispensable application value in many fields with its excellent wear resistance, flexibility, chemical corrosion resistance and good mechanical properties. From furniture, mattresses, soles, clothing fabrics in daily life to key industries such as automobile manufacturing, building insulation, electronic equipment packaging and aerospace in the industrial field, polyurethane materials can be seen everywhere. Its wide range of applications and huge usage fully demonstrate its important position in modern society.
[0003] However, with the large-scale production and wide application of polyurethane products, the treatment of its waste has gradually become a severe environmental challenge and social problem. Polyurethane materials have a highly stable chemical structure, which makes it difficult to effectively degrade them through conventional physical, chemical or biological processes in the natural environment. Traditional waste treatment methods, such as landfill and incineration, have many disadvantages for polyurethane waste. Landfill treatment not only occupies a large amount of valuable land resources, but also due to the difficulty of degradation of polyurethane materials, in the long-term landfill process, it may slowly release harmful substances, gradually pollute the soil and groundwater environment, and pose a potential threat to the balance and stability of the ecosystem. Although incineration treatment can reduce the volume of waste to a certain extent, polyurethane will produce a large amount of harmful gases during the incineration process, including highly toxic substances such as nitrogen oxides, sulfur oxides, polycyclic aromatic hydrocarbons and dioxins. These harmful gases are discharged into the atmosphere, which will cause serious pollution to air quality, thereby endangering human health and the sustainable development of the ecological environment. The existing method of using catalysts to degrade it cannot completely degrade it due to harsh reaction conditions, low conversion rate, and difficult control of degradation products.
[0004] In summary, it is urgent to develop a new technical solution to solve the problems existing in the prior art. Summary of the invention
[0005] Based on this, the present invention has developed an efficient, green, simple and highly selective polyurethane degradation method. The present invention uses a specific ratio of ethanolamine and sodium methoxide compound as a degradation agent, which can efficiently decompose the polyurethane material, and the obtained degradation product is the amine corresponding to the isocyanate monomer. The degradation agent and the product are easy to separate and recover, which greatly reduces the processing cost and the pollution to the environment, overcomes the defects of existing products, and has good application prospects.
[0006] One object of the present invention is to provide a simple and highly selective polyurethane degradation method, which comprises the following steps:
[0007] The polyurethane material is crushed and added to the degradation agent, heated and stirred for reaction, and the degradation product is separated;
[0008] in,
[0009] The degradation agent is a mixed solution of ethanolamine and sodium methoxide.
[0010] Furthermore, the raw material of the polyurethane material includes isocyanate, and the structural formula of the isocyanate is R-(NCO) n ;
[0011] Wherein, the R is selected from C1-C20 alkyl, alkylene or aryl and their derivatives;
[0012] The n is 1-3.
[0013] Furthermore, the degradation product includes the amine corresponding to the isocyanate, and the structural formula of the amine corresponding to the isocyanate is R-NH 2 or H 2 NR-NH 2 .
[0014] Furthermore, the preparation method of the degradation agent is: mixing ethanolamine and sodium methoxide, stirring for 0.5-2h, to obtain the degradation agent.
[0015] Furthermore, the particle size of the crushed material is 5-7 mm.
[0016] Furthermore, the mass ratio of the polyurethane material to the degradation agent is 1:(1-10).
[0017] Furthermore, the mass ratio of ethanolamine to sodium methoxide is (10-20):(0.01-0.15).
[0018] Preferably, the mass ratio of ethanolamine to sodium methoxide is 15:(0.015-0.06).
[0019] Furthermore, the temperature of the heating and stirring reaction is 120-180° C. and the time is 2-5 hours.
[0020] Furthermore, the separation method is distillation.
[0021] The present invention has the following beneficial effects:
[0022] The simple and highly selective polyurethane degradation method provided by the present invention adopts environmentally friendly organic solvent ethanolamine and trace sodium methoxide compounded in a specific ratio as a degradation agent, provides a suitable medium environment for the reaction, enhances the contact degree and reaction activity of each component, can also accelerate the reaction process, and reduce the reaction activation energy. In particular, we found that the degradation agent obtained by compounding ethanolamine and sodium methoxide can not only simply and efficiently reduce the polyurethane sponge to the amine form of the corresponding isocyanate monomer, but also significantly reduce the decomposition temperature, and can achieve the above results within 120-180°C, greatly reducing the difficulty and cost of the degradation process, thereby obtaining the technical effect of 1+1 greater than 2. Therefore, the degradation method of the present invention can fully degrade polyurethane, not only greatly reduces the reaction temperature, the reaction process is simple, and the material cost is extremely low; more importantly, the present invention can reduce the isocyanate monomer of the raw material to the corresponding amine form, the degradation rate is as high as 99.7%, and the product is easy to separate, and the degradation agent can also be recycled and reused, which significantly reduces the processing cost of waste polyurethane and avoids pollution to the environment. At the same time, it has high economic value and is of great significance to the development of waste material processing technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is the gas chromatography-mass spectrometry detection diagram of the decomposition product recovered in Example 1. DETAILED DESCRIPTION
[0024] In order to more clearly illustrate the technical solution of the present invention, the following examples are listed. Unless otherwise stated, the raw materials, reactions and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.
[0025] The words "preferred", "preferably", "more preferably", etc. in the present invention refer to embodiments of the present invention that can provide certain beneficial effects in certain circumstances. However, other embodiments may also be preferred under the same circumstances or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, nor is it intended to exclude other embodiments from the scope of the present invention.
[0026] It should be understood that, except in any operating examples, or where otherwise indicated, all numbers indicating, for example, the amounts of ingredients used in the specification and claims should be understood to be modified in all cases by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values that vary depending on the desired properties to be obtained by the present invention.
[0027] The waste polyurethane foam material in the embodiment of the present invention is TDI (toluene diisocyanate) foam material.
[0028] The sodium methoxide solution in the embodiment of the present invention is a sodium methoxide-methanol solution with a mass fraction of 30%.
[0029] Example 1
[0030] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0031] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0032] Take 15g of ethanolamine and 0.1g of sodium methoxide solution, add them into a 250mL three-necked flask, mix and stir for 0.5h to obtain a degradation agent, then add the pretreated polyurethane, stir and react at 180°C and normal pressure at 90rpm for 2h, observe no impurities at the bottom of the flask after the reaction, the polyurethane is completely dissolved, and then distill and separate to recover the degradation product and the degradation agent. The degradation product is toluenediamine, and the degradation rate is 99.7%.
[0033] Figure 1 This is the gas chromatography-mass spectrometry detection diagram of the decomposition product recovered in Example 1.
[0034] according to Figure 1 It can be seen that the retention time 11.169 is the characteristic peak of toluene diamine.
[0035] Example 2
[0036] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0037] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0038] Take 15g of ethanolamine and 0.1g of sodium methoxide solution, add them into a 250mL three-necked flask, mix and stir for 1h to obtain a degradation agent, then add the pretreated polyurethane, stir and react at 90rpm for 4h at 120°C and normal pressure, observe no impurities at the bottom of the flask after the reaction, the polyurethane has been completely dissolved, and then filter to recover the degradation product and the degradation agent. The degradation product is toluenediamine, and the degradation rate is 99.4%.
[0039] Example 3
[0040] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0041] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0042] Take 15g of ethanolamine and 0.2g of sodium methoxide solution, add them into a 250mL three-necked flask, mix and stir for 0.5h to obtain a degradation agent, then add the pretreated polyurethane, stir and react at 150°C and 0.5MPa at 90rpm for 4h, observe that no impurities are generated at the bottom of the flask after the reaction, and the polyurethane is completely dissolved, then distill and separate to recover the degradation product and the degradation agent. The degradation product is toluenediamine, and the degradation rate is 99.4%.
[0043] Example 4
[0044] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0045] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0046] Take 15g of ethanolamine and 0.05g of sodium methoxide solution, add them into a 250mL three-necked flask, mix and stir for 0.5h to obtain a degradation agent, then add the pretreated polyurethane, stir and react at 120°C and 0.5MPa at 90rpm for 4h, observe that no impurities are generated at the bottom of the flask after the reaction, and the polyurethane is completely dissolved, then distill and separate to recover the degradation product and the degradation agent. The degradation product is toluenediamine, and the degradation rate is 99.2%.
[0047] Example 5
[0048] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0049] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0050] Take 15g of ethanolamine and 0.01g of sodium methoxide solution, add them into a 250mL three-necked flask, mix and stir for 0.5h to obtain a degradation agent, then add the pretreated polyurethane, stir and react at 120°C and 0.5MPa at 90rpm for 4h, observe that no impurities are generated at the bottom of the flask after the reaction, and the polyurethane is completely dissolved, then distill and separate to recover the degradation product and the degradation agent. The degradation product is toluenediamine, and the degradation rate is 23.6%.
[0051] Comparative Example 1
[0052] A polyurethane degradation method, comprising the following steps:
[0053] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0054] 15 g of ethanolamine and 0.03 g of lithium hydroxide were added to a 250 mL three-necked flask, and then the pretreated polyurethane was added, and the reaction was stirred at 90 rpm for 4 hours at 180° C. and 0.5 MPa. After the reaction was completed, it was observed that there were obvious impurities remaining at the bottom of the flask, and the polyurethane was not completely dissolved, and then the degradation products and degradation agents were recovered by distillation separation. No small molecular weight substances were detected in the degradation products by GC-MS, the degradation rate was 1.0%, and no amine corresponding to the isocyanate was obtained.
[0055] Comparative Example 2
[0056] A polyurethane degradation method, comprising the following steps:
[0057] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0058] 15 g of ethanolamine and 0.03 g of aluminum chloride were added to a 250 mL three-necked flask, and then the pretreated polyurethane was added. The mixture was stirred at 90 rpm for 4 h at 180 ° C and 0.5 MPa. After the reaction was completed, it was observed that there were obvious impurities remaining at the bottom of the flask, and the polyurethane was not completely dissolved. Then, the degradation products and degradation agents were separated and recovered by distillation. No small molecular weight substances were detected in the degradation products by GC-MS, and the degradation rate was 1.3%, and no amine corresponding to the isocyanate was obtained.
[0059] Comparative Example 3
[0060] A polyurethane degradation method, comprising the following steps:
[0061] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0062] 15 g of ethanolamine and 0.03 g of zinc chloride were added to a 250 mL three-necked flask, and then the pretreated polyurethane was added. The mixture was stirred at 90 rpm for 4 h at 180 ° C and 0.5 MPa. After the reaction was completed, it was observed that there were obvious impurities remaining at the bottom of the flask, and the polyurethane was not completely dissolved. Then, the degradation products and degradation agents were separated and recovered by distillation. No small molecular weight substances were detected in the degradation products by GC-MS, the degradation rate was 1.5%, and no amine corresponding to the isocyanate was obtained.
[0063] Comparative Example 4
[0064] A polyurethane degradation method, comprising the following steps:
[0065] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0066] 15 g of ethanolamine and 0.083 g of hydrochloric acid with a mass fraction of 36% were added to a 250 mL three-necked flask, and then the pretreated polyurethane was added, and the reaction was stirred at 90 rpm for 4 hours at 180° C. and 0.5 MPa. After the reaction was completed, it was observed that there were obvious impurities remaining at the bottom of the flask, and the polyurethane was not completely dissolved, and then the degradation products and degradation agents were recovered by distillation separation. No small molecular weight substances were detected in the degradation products by GC-MS, the degradation rate was 0.9%, and no amine corresponding to the isocyanate was obtained.
[0067] Comparative Example 5
[0068] A polyurethane degradation method, comprising the following steps:
[0069] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0070] 15 g of ethanolamine and 0.031 g of sulfuric acid with a mass fraction of 98% were added to a 250 mL three-necked flask, and then the pretreated polyurethane was added, and the reaction was stirred at 90 rpm for 4 hours at 180° C. and 0.5 MPa. After the reaction was completed, impurities were observed to be generated at the bottom of the flask, and the polyurethane was not completely dissolved. Then, the degradation products and degradation agents were separated and recovered by distillation. No small molecular weight substances were detected in the degradation products by GC-MS, the degradation rate was 0.8%, and no amine corresponding to the isocyanate was obtained.
[0071] Comparative Example 6
[0072] A polyurethane degradation method, comprising the following steps:
[0073] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0074] 15 g of ethanolamine and 0.03 g of sodium hydroxide were added to a 250 mL three-necked flask, and then the pretreated polyurethane was added. The mixture was stirred at 90 rpm for 4 h at 120 ° C and 0.5 MPa. After the reaction was completed, impurities were observed to be generated at the bottom of the flask, and the polyurethane was not completely dissolved. Then, the degradation products and degradation agents were separated and recovered by distillation. No small molecular weight substances were detected in the degradation products by GC-MS, the degradation rate was 4.7%, and no amine corresponding to the isocyanate was obtained.
[0075] Comparative Example 7
[0076] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0077] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0078] Take 15g of ethanolamine and 0.1g of sodium methoxide solution, add them into a 250mL three-necked flask, then add the pretreated polyurethane, stir and react at 90rpm for 2h at 180°C and normal pressure, observe no impurities at the bottom of the flask after the reaction, the polyurethane is completely dissolved, and then distill and separate to recover the degradation product and degradation agent. The degradation product is toluenediamine, and the degradation rate is 83.7%.
[0079] Comparative Example 8
[0080] A simple and highly selective polyurethane degradation method, the simple and highly selective polyurethane degradation method comprising the following steps:
[0081] 3 g of waste polyurethane foam material was crushed to a particle size of 6 mm to obtain pretreated polyurethane;
[0082] 15g of isopropanol and 0.1g of sodium methoxide solution were added to a 250mL three-necked flask, mixed and stirred for 0.5h to obtain a degradation agent, and then the pretreated polyurethane was added, stirred at 180°C and normal pressure for 2h at 90rpm, and after the reaction was completed, no impurities were observed at the bottom of the flask, and the polyurethane was completely dissolved, and then the degradation product and the degradation agent were separated and recovered by distillation. The degradation product was toluenediamine, and the degradation rate was 80.6%.
[0083] The above results show that the simple and highly selective polyurethane degradation method of the embodiment of the present invention uses a specific ratio of ethanolamine and sodium methoxide as a degradation agent to efficiently degrade waste polyurethane foaming materials, and can reduce isocyanate monomers to corresponding amine forms, with a degradation rate of up to 99.7%. In contrast, the degradation agent is replaced with other substances in the comparative example, and the dissolution effect and degradation degree of polyurethane are significantly reduced, and the amine corresponding to the isocyanate cannot be obtained, and the degradation rate is not ideal. In summary, the present invention overcomes the shortcomings of the existing polyurethane degradation process, and provides an efficient, environmentally friendly, and low-cost polyurethane degradation and recovery method, which is of great significance to the further development and application of this field.
[0084] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.
[0085] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.
Claims
1. A simple and highly selective polyurethane degradation method, characterized in that: The simple and highly selective polyurethane degradation method comprises the following steps: The polyurethane material is crushed and added to the degradation agent, heated and stirred for reaction, and the degradation product is separated; in, The degradation agent is a mixed solution of ethanolamine and sodium methoxide.
2. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The raw material of the polyurethane material includes isocyanate, and the structural formula of the isocyanate is R-(NCO) n ; Wherein, the R is selected from C1-C20 alkyl, alkylene or aryl and their derivatives; The n is 1-3.
3. The simple and highly selective polyurethane degradation method according to claim 2, characterized in that: The degradation product includes the amine corresponding to the isocyanate, and the structural formula of the amine corresponding to the isocyanate is R-NH2 or H2N-R-NH2.
4. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The preparation method of the degradation agent is: mixing ethanolamine and sodium methoxide, and stirring for 0.5-2h to obtain the degradation agent.
5. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The particle size of the crushed material is 5-7 mm.
6. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The mass ratio of the polyurethane material to the degradation agent is 1:(1-10).
7. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The mass ratio of the ethanolamine to sodium methoxide is (10-20):(0.01-0.15).
8. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The temperature of the heating and stirring reaction is 120-180° C. and the time is 2-5 hours.
9. The simple and highly selective polyurethane degradation method according to claim 1, characterized in that: The separation method is distillation.