A method for high-value utilization of polyurethane foam degradation solid products

Abstract

The invention discloses a kind of high value utilization method of polyurethane foam degradation solid product, including:The solid product produced after degradation is crushed and pulverized;Powdered solid is mixed with composite polyether polyol, and is added to ball mill after mixing;Epoxy surface modifier is added into ball mill;Ball mill is placed in ball mill and ball milled, and ball milling obtains dispersion liquid;Dispersion liquid is placed in sand mill, and triethylamine is added, sand milled, and after sand milling, a dispersion liquid with a particle diameter of 20 100 microns is obtained, for the preparation of sponge.PUSR can be effectively processed into a sponge reinforcing agent to replace the effect of polymer polyol (POP, commonly known as white oil) by the inventive method, while possessing good dispersibility and compatibility, and can be used to prepare polyurethane foam, to achieve the full utilization of polyurethane degradation product.

Description

Technical Field

[0001] The present invention relates to a method for resource utilization of bulk waste polymer materials, in particular to a method for high-value utilization of solid products obtained by chemical degradation of waste polyurethane soft foam. Background Art

[0002] Polyurethane flexible foam (commonly known as sponge) is widely used in applications ranging from home furnishings to transportation due to its excellent resilience and fatigue resistance. With economic development and growing consumer demand, the use of polyurethane flexible foam is increasing, and with it, waste. However, since waste cannot be naturally degraded, it can only be disposed of through incineration or landfill, posing a significant environmental challenge. Against this backdrop, developing technologies to degrade waste polyurethane and achieve high-value utilization throughout its lifecycle has become a research hotspot.

[0003] At present, the degradation methods of waste polyurethane include alcoholysis, acidolysis, etc., the essence of which is that small molecule diols or organic acids depolymerize polyurethane and convert it into smaller molecular weight chemicals such as polyols, thereby realizing the degradation and recycling of resources. However, both acidolysis and alcoholysis methods are prone to produce solid components that are incompatible with polyols, which come from the non-degradable polyurethane hard segment (polyurea generated by the reaction of isocyanate and water). The solid product is usually difficult to further reuse at a high value. Studies have shown that although there are reports that a large amount of solid products will exist after polyurethane degradation, effective utilization methods are often not proposed. For example, Chemical Engineering Journal 395(2020)125102 only introduces the structural formula of the solid product, but does not discuss its reuse.

[0004] Typically, after polyurethane degradation, its incompletely depolymerized urea-containing fragments are dispersed in the polyol as a solid state and can be used directly. However, if the polyols in the recovered components are fully separated, the actual value of the depolymerization product will be greatly improved. The applicant has successfully achieved phase separation of polyols and urea-containing fragments by utilizing innovations in degradation methods and catalysts, greatly improving the reuse value of the recovered polyols. However, there is still the problem that the solid products need to be further processed and reused. Therefore, it is necessary to develop a method for high-value utilization of solid products produced by polyurethane degradation. Chinese invention patent CN113717434B discloses a method for degrading polyurethane soft foam using acidic ionic liquids. The recovered polyether polyol containing solid products obtained by degradation through this method can be used in the production of regenerated polyurethane soft foam, further improving the commercial value of polyurethane foam degradation. However, the invention does not specify the method for treating the solid products in the degradation products. Chinese invention patent CN114106281A discloses a modification method for recovering and regenerating polyols and its recycling in the polyurethane industry. The method achieves the recycling of polyurethane foam materials through alcoholysis technology. Although this technology realizes the recycling of polyurethane foam, it also does not provide a detailed description of the treatment method of the solid products in the degradation products. Summary of the Invention

[0005] In order to overcome the problem that the solid products (PUSR) generated after the degradation of waste polyurethane cannot be reused and the solid products cannot be well dispersed in PPG to achieve high-value utilization, the present invention provides a method for high-value utilization of solid products of polyurethane foam degradation. This method can effectively process PUSR into a sponge reinforcing agent to replace the function of polymer polyol (POP, commonly known as white oil), while having good dispersibility and compatibility, and can be used to prepare polyurethane foam to achieve full utilization of polyurethane degradation products.

[0006] The technical solutions of the present invention are as follows:

[0007] A method for high-value utilization of a solid product of polyurethane foam degradation comprises the following steps:

[0008] Step 1: crushing and grinding the solid product produced after degradation to obtain a powdery solid;

[0009] Step 2: Mix the powdered solid and the composite polyether polyol in a mass ratio of 20-50:80-50, and add the mixed mixture into a ball mill;

[0010] Step 3: Adding epoxy surface modifier to the ball mill;

[0011] Step 4: placing the ball mill jar in a ball mill for ball milling to obtain a dispersion;

[0012] Step 5: Place the dispersion obtained in step 4 in a sand mill, use zirconium oxide balls as sand milling media, add triethylamine, and sand mill to obtain a dispersion with a particle size of 20-100 microns. Prepare a sponge using the dispersion with a particle size of 20-100 microns.

[0013] Further preferably, a method for high-value utilization of a solid product of polyurethane foam degradation comprises the following steps:

[0014] Step 1: The solid PUSR produced after degradation is separated from the polyol and then mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10-1000 mesh.

[0015] Step 2: Powdered PUSR is mixed with two or more composite polyether polyols with a molecular weight of 500-3000 g / mol and a hydroxyl value of 50-100 mgKOH / g in a mass ratio of 20-50:80-50, and the mixture is added to a ball mill jar, in which ball mill beads of appropriate proportion are placed.

[0016] Step 3: Add epoxy surface modifiers such as 1,2-epoxyhexane, ethylene oxide-PEG-ethylene oxide (Mw = 1000-10000Da, CAS: 72207-80-8), 1,2-epoxyoctane, 1,2-epoxyheptane, 1,2-epoxydecane, epoxypropyl phenyl ether, epoxypropyl methyl ether, 1,2-epoxy-5-hexene, propylene oxide, glycidyl ether, trimethylolpropane triglycidyl ether and allyl alcohol glycidyl ether, etc., to the ball mill jar. The modifier is one or more of them, and the mass ratio of the surface modifier to PUSR is 0.01-0.1:1.

[0017] Step 4: Place the ball mill in a ball mill and mill at 100-800 rpm / min for 8-24 hours to obtain a dispersion with a particle size of 50-1000 μm.

[0018] Step 5: The dispersion obtained in Step 4 is sand-milled at room temperature using 1.5 mm diameter zirconium oxide balls. The sand-milling time is 1-3 hours, during which 0.01-1 ml of triethylamine is added at a speed of 2000-6000 rpm (3000 rpm is most preferred). After sand-milling, a dispersion with a particle size of 20-100 μm is obtained, which is used to prepare the sponge.

[0019] This treatment process not only achieves the effective recovery and reuse of solid products in waste polyurethane soft foam, but also enhances the application value of the solid product PUSR through a combination of physical and chemical means, which helps to improve the overall resource utilization rate of polyurethane waste.

[0020] The ball milling treatment time is 8 to 24 hours, and the optimal time is 12 hours.

[0021] The sizes of the ball mill beads are 3mm, 5mm, and 10mm, and the ratio is 3:2:1.

[0022] The composite polyether polyol is a mixture of a polyol containing double bonds and a polyether polyol, with a mass ratio of 30-50:70-50.

[0023] The polyol containing double bonds is allyl alcohol random polyether methyl end capping (CAS: 52232-27-6), polyether F-6, and the like.

[0024] The polyether polyol generally has a hydroxyl value of 50-100 mgKOH / g and a molecular weight of 500-4000 g / mol, and preferably has a hydroxyl value of 56 mgKOH / g and a molecular weight of 3500.

[0025] The polyether polyol can be any one of polypropylene glycol PPG2000, polyether polyol 5623, polyether polyol 5602, etc.

[0026] Most preferably, the composite polyether polyol is a mixture of allyl alcohol random polyether methyl terminated purchased from Zhejiang Huangma Science and Technology Co., Ltd. and polyether polyol PPG5623 purchased from Zhejiang Hengfeng New Materials Co., Ltd. in a mass ratio of 3:7.

[0027] The ball mill and the tank body are both made of zirconium oxide.

[0028] In the present invention, the resulting product can be directly used to foam polyurethane foam (using polyurethane foam preparation methods known in the art), replacing the role played by POP. The addition ratio can be as high as 30 wt%, solving the problem of solid products being unable to achieve high-value utilization. Furthermore, the present invention conducts in-depth research on the recycling and reuse of waste polyurethane foam, optimizing the utilization rate of degradation products from chemical degradation methods, thereby ensuring that the commercial properties of the resulting polyurethane foam meet market demand.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The present invention deepens the technical route for high-value utilization of solid products from the degradation of waste polyurethane foam, further solves the problem that solid products cannot be highly valued and are wasted, and provides a more efficient and lower-cost approach for large-scale industrial degradation of polyurethane foam.

[0031] The composite polyol of the present invention is easy to prepare, easy to operate, low in cost, and convenient for industrial mass use.

[0032] The method of the present invention utilizes methods such as physical crushing and chemical surface modification to improve the compatibility and dispersibility of the solid product of waste polyurethane foam degradation in a composite polyol. First, ball milling technology is used to further crush the crushed waste polyurethane foam, breaking it into smaller particles to increase its surface area and improve its surface activity, providing favorable conditions for subsequent chemical treatment. Next, by adding an epoxy surface modifier that can react with the -COOH or -OH groups on the surface of the solid product, the epoxy groups are selectively opened in the ball milling environment and react with the carboxyl / hydroxyl groups on the solid product, resulting in the grafting of polar segments with good compatibility with the polyol on the particle surface, thereby improving the dispersibility and stability of the particles in the polyol. At the same time, the addition of triethylamine during the sand milling process helps the system reach an alkaline environment, which is beneficial for the reaction of the hydroxyl groups on the particle surface with the double bonds in the double-bond polyol, resulting in the grafting of long polyol chains on the particle surface, further improving the dispersibility of the solid product in the polyol. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the recovery process in Example 1.

[0034] Figure 2 The simplified chemical structure formula of the acid hydrolysis solid product obtained in Preparation Example 1.

[0035] Figure 3 The simplified chemical structure formula of the alcoholysis solid product obtained in Preparation Example 2.

[0036] Figure 4 Diagram of the reaction process of the functional groups of the acidolysis solid product PUSR with surfactants and polyols containing double bonds.

[0037] Figure 5 Diagram of the reaction process of alcoholysis solid product and polyol containing double bond components.

[0038] Figure 6 Figure 1 shows the recycled polyurethane sponge prepared in Example 1.

[0039] Figure 7 Figure 2 shows the recycled polyurethane sponge prepared in Example 2.

[0040] Figure 8 Figure 3 shows the recycled polyurethane sponge prepared in Example 3.

[0041] Figure 9 Figure 4 shows the regenerated polyurethane sponge prepared in Example 4.

[0042] Figure 10 Figure 2 shows the recycled polyurethane sponge prepared in Comparative Example 2.

[0043] Figure 11 Figure 3 shows the recycled polyurethane sponge prepared in comparative example 3.

[0044] Figure 12 Figure 4 shows the recycled polyurethane sponge prepared in comparative example 4.

[0045] Figure 13 Figure 5 shows the recycled polyurethane sponge prepared in Comparative Example 5.

[0046] Figure 14 Figure 9 shows the recycled polyurethane sponge prepared in comparative example 9. DETAILED DESCRIPTION

[0047] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in the present invention, it is readily apparent to those skilled in the art that various modifications are possible without departing substantially from the teachings of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Other replacements, modifications, variations, and deletions may be made to the designs, operating conditions, and parameters of the following embodiments without departing from the gist of the present invention.

[0048] The present invention is further described in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0049] Unless otherwise specified in the present invention, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the embodiments, unless otherwise specified, are all conventional methods in the art.

[0050] Preparation Example 1 (acid hydrolysis method)

[0051] A method for preparing a polyurethane foam acid decomposition solid product comprises the following steps:

[0052] Take 500g of succinic acid, 1000g of PPG (polyether polyol PPG5623, purchased from Zhejiang Hengfeng New Materials Co., Ltd.), and 20g of zinc acetate and add them to a 20L glass reactor equipped with a pressure reducing device, a heating device, a condensing reflux device and a mechanical stirring device. Set the temperature to 200°C and the stirring speed to 60r / min. After the temperature is heated to 200°C, 2000g of waste polyether polyurethane foam fragments with a diameter of 2-3cm are added to the reactor at a feeding rate of 40g / min. After the polyurethane foam fragments are fed, the speed is adjusted to 150r / min. After the continuous pressure reduction reaction for 4h, the reaction can be stopped and the product can be discharged. The discharged product is treated by centrifugation to separate the solid and liquid components. The solid product PUSR is then obtained. The structure of the solid product is shown in the figure Figure 2 shown.

[0053] Preparation Example 2 (alcoholysis method)

[0054] A method for preparing a polyurethane foam acid decomposition solid product comprises the following steps:

[0055] 1) Weigh 300 g of ethylene glycol and 1000 g of PPG (polyether polyol PPG5623, purchased from Zhejiang Hengfeng New Materials Co., Ltd.) and add them to a 20 L glass reactor equipped with a pressure reducing device, a heating device, a condensing reflux device, and a mechanical stirring device.

[0056] 2) Reaction Step: Heat the reactor to 160°C, set the stirring speed to 60 rpm, and add 3000 g of discarded polyether PUF fragments with a diameter of 2-3 cm to the reactor at a feeding rate of approximately 40 g / min. After the PUF is completely added, adjust the speed to 150 rpm. After continuous decompression reaction for 5 hours, the reaction can be stopped and the product discharged. The discharged product is processed by centrifugation to separate the solid and liquid components. The solid product PUSR is then obtained. The structure of the solid product is shown in the figure below. Figure 3 shown.

[0057] Example 1

[0058] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0059] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0060] Step 3: Add 200 g of ethylene oxide-PEG-ethylene oxide (Beijing Bailingwei Technology Co., Ltd., product number: 1685134, average molecular weight 1,000) into the ball mill, with the mass ratio of ethylene oxide-PEG-ethylene oxide to PUSR being 0.1:1.

[0061] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0062] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 2 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 6Its mechanical properties are shown in Table 2.

[0063] Example 2

[0064] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0065] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0066] Step 3: Add 200g of propylene oxide to the ball mill, with a mass ratio of propylene oxide to PUSR of 0.1:1.

[0067] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0068] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 2 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 7 Its mechanical properties are shown in Table 2.

[0069] Example 3

[0070] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0071] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0072] Step 3: Add 200 g of 1,2-epoxydecane to the ball mill, with a mass ratio of 1,2-epoxydecane to PUSR of 0.1:1.

[0073] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0074] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 8 Its mechanical properties are shown in Table 2.

[0075] Example 4

[0076] Step 1: The solid PUSR produced after degradation in Preparation Example 2 was mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0077] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0078] Step 3: Add 200 g of 1,2-epoxydecane to the ball mill, with a mass ratio of 1,2-epoxydecane to PUSR of 0.1:1.

[0079] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0080] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 9 Its mechanical properties are shown in Table 2.

[0081] Application Examples

[0082] 30g of the dispersion, 70g of PPG (polyether polyol PPG5623, purchased from Zhejiang Hengfeng New Materials Co., Ltd.), 3.2g of H2O, 0.8g of silicone oil, 0.05g of triethylamine, 0.2g of diethanolamine, and 0.14g of stannous octoate were placed in a plastic beaker and stirred at 2000rpm for 60 seconds until a uniform dispersion was formed. 46g of TDI (toluene diisocyanate, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) was added to the dispersion and stirred at 2000rpm for 10 seconds. The mixture was then quickly poured into a mold for molding. After the foaming height stopped changing, the mixture was placed in a 70°C oven for 7 hours and removed to obtain a sponge product.

[0083] Comparative Example 1

[0084] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0085] Step 2: 3 kg of powdered PUSR solid was mixed with 7 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0086] Step 3: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0087] Step 4: At room temperature of 25°C, place the dispersion obtained in step 4 in a sand mill and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 2 hours, and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponge. The viscosity data of the dispersion are shown in Table 1, and the mechanical properties of the regenerated soft polyurethane foam are shown in Table 2. Compared with Examples 1, 2, and 3, the viscosity can be significantly reduced and the mechanical properties of the regenerated soft polyurethane foam are significantly improved through the modification method of the present invention.

[0088] Comparative Example 2

[0089] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0090] Step 2: 3 kg of powdered PUSR solid was mixed with 7 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0091] Step 3: Add 300 g of ethylene oxide-PEG-ethylene oxide (Beijing Bailingwei Technology Co., Ltd., product number: 1685134, average molecular weight 1,000) into the ball mill, with the mass ratio of ethylene oxide-PEG-ethylene oxide to PUSR being 0.1:1.

[0092] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0093] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 2 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. Recycled soft polyurethane foam such as Figure 10 Its mechanical properties are shown in Table 2. Compared with Example 1, the modification method of the present invention, with an increased PUSR mass ratio, achieved a viscosity of 1290 mPa·s, only slightly higher than that of Example 1 and significantly lower than the 7820 mPa·s viscosity of Comparative Example 1, demonstrating a significant reduction in viscosity. Furthermore, the mechanical properties of the regenerated flexible polyurethane foam produced from the dispersion, including 40% indentation hardness and 75% permanent compression set, showed only a modest increase compared to Example 1, still meeting the mechanical performance requirements for commercial foams.

[0094] Comparative Example 3

[0095] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0096] Step 2: 3 kg of powdered PUSR solid was mixed with 7 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0097] Step 3: Add 300g of propylene oxide to the ball mill, with a mass ratio of propylene oxide to PUSR of 0.1:1.

[0098] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0099] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 2 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 11 Its mechanical properties are shown in Table 2. Compared with Example 2, despite the increased PUSR mass ratio, the viscosity remained at 1320 mPa·s, only slightly higher than the 1010 mPa·s in Example 2, maintaining good viscosity performance. Furthermore, the mechanical properties of the recycled flexible polyurethane foam produced from the dispersion showed minimal changes in rebound rate (39.2%), 40% indentation hardness (144 N), and 75% permanent compression set (2.31%) compared to Example 2, still meeting the mechanical performance requirements for commercial foams.

[0100] Comparative Example 4

[0101] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0102] Step 2: 3 kg of powdered PUSR solid was mixed with 7 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0103] Step 3: Add 300 g of 1,2-epoxydecane to the ball mill, with a mass ratio of 1,2-epoxydecane to PUSR of 0.1:1.

[0104] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0105] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 12 Its mechanical properties are shown in Table 2. Compared with Example 3, despite the increased PUSR mass ratio, the viscosity remained at 1320 mPa·s, only slightly higher than the 1010 mPa·s in Example 2, maintaining good viscosity performance. Furthermore, the mechanical properties of the recycled flexible polyurethane foam produced from the dispersion, including a rebound rate of 39.2%, a 40% indentation hardness of 144 N, and a 75% permanent compression set of 2.31%, showed minimal changes compared to Example 2, and still met the mechanical performance requirements for commercial foams.

[0106] Comparative Example 5

[0107] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0108] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0109] Step 3: Add 100 g of 1,2-epoxydecane and 100 g of ethylene oxide-PEG-ethylene oxide (Beijing Bailingwei Technology Co., Ltd., product number: 1685134, average molecular weight 1,000) to the ball mill, with the total mass ratio of the two to the mass ratio of PUSR being 0.1:1.

[0110] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0111] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 13 Its mechanical properties are shown in Table 2. Compared with Examples 1 and 3, the combination of the two surface modifiers maintains a dispersion viscosity of 820 mPa·s, which is lower than the viscosity of the dispersions produced in Examples 1 and 3, maintaining good viscosity performance. Furthermore, the mechanical properties of the recycled flexible polyurethane foam produced from the dispersion, including a rebound rate of 39.2%, a 40% indentation hardness of 144 N, and a 75% permanent compression set of 2.31%, show little change compared to Example 2, meeting the mechanical performance requirements for commercial foams.

[0112] Comparative Example 6

[0113] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0114] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0115] Step 3: Add 100 g of propylene oxide and 100 g of ethylene oxide-PEG-ethylene oxide (Beijing Bailingwei Technology Co., Ltd., product number: 1685134, average molecular weight 1,000) into the ball mill, with the total mass ratio of the two to the mass ratio of PUSR being 0.1:1.

[0116] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0117] Step 5: At room temperature of 25°C, place the dispersion obtained in step 4 in a sand mill and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours, during which 1ml of triethylamine is added, and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponge. The viscosity data of the dispersion are shown in Table 1, and the mechanical properties of the regenerated soft polyurethane foam are shown in Table 2. Compared with Examples 1 and 2, the combination of the two surface modifiers can keep the viscosity data of the dispersion at 960mPa·s, maintaining good viscosity performance. At the same time, the rebound rate, 40% indentation hardness and 75% permanent compression deformation of the mechanical properties of the regenerated soft polyurethane foam prepared from the dispersion have little change compared with Examples 1 and 2, and still meet the mechanical properties requirements of commercial foams.

[0118] Comparative Example 7

[0119] Step 1: The solid PUSR produced after degradation in Preparation Example 1 is mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0120] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0121] Step 3: Add 100 g of propylene oxide and 100 g of ethylene oxide-PEG-ethylene oxide (Beijing Bailingwei Technology Co., Ltd., product number: 1685134, average molecular weight 1,000) into the ball mill, with the total mass ratio of the two to the mass ratio of PUSR being 0.1:1.

[0122] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0123] Step 5: At room temperature of 25°C, the dispersion obtained in step 4 was placed in a sand mill and sanded using 1.5mm diameter zirconium oxide balls as the sanding medium. The sanding time was 3 hours, during which 1ml of triethylamine was added, and the sanding speed was 3000 rpm. After sanding, a dispersion with a particle size of 20-100 microns was obtained, which was used to prepare the sponge. The viscosity data of the dispersion are shown in Table 1, and the mechanical properties of the regenerated soft polyurethane foam are shown in Table 2. Compared with Examples 1, 2, and 3, the combination of the three surface modifiers can keep the viscosity data of the dispersion at 750mPa·s, which is lower than the viscosity of the dispersions obtained in Examples 1, 2, and 3, maintaining good viscosity performance. At the same time, the 75% permanent compression set rate of the mechanical properties of the regenerated soft polyurethane foam prepared from the dispersion is significantly smaller than that of Examples 1, 2, and 3, and other indicators have not changed much, meeting the mechanical property requirements of commercial foams.

[0124] Comparative Example 8

[0125] Step 1: The solid PUSR produced after degradation in Preparation Example 2 was mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0126] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0127] Step 3: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0128] Step 4: At room temperature of 25°C, place the dispersion obtained in step 4 in a sand mill and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponge. The viscosity data of the dispersion are shown in Table 1, and the mechanical properties of the recycled soft polyurethane foam are shown in Table 2. Compared with Example 4, without surface modification treatment, the viscosity of the dispersion is 9180mPa·s, and the excessively high viscosity value affects the foaming process. The 75% permanent compression set rate in the mechanical properties of the recycled soft polyurethane foam prepared from the dispersion cannot be measured due to severe deformation of the foam, and does not meet the mechanical property requirements of commercial foam.

[0129] Comparative Example 9

[0130] Step 1: The solid PUSR produced after degradation in Preparation Example 2 was mechanically crushed and pulverized at high speed to obtain a powdery solid with a particle size controlled at 10 mesh.

[0131] Step 2: Mix 2 kg of powdered PUSR solid with 8 kg of a complex polyol (a mixture of allyl alcohol random polyether methyl-terminated from Zhejiang Huangma Technology Co., Ltd. and polyether polyol PPG5623 from Zhejiang Hengfeng New Materials Co., Ltd., in a mass ratio of 3:7). The mixed materials were added to a ball mill. The mill was filled with ball milling beads of different sizes (3 mm, 5 mm, and 10 mm in diameter) in a ratio of 3:2:1.

[0132] Step 3: Add 200 g of propylene oxide to the ball mill, with the total mass ratio of propylene oxide to PUSR being 0.1:1.

[0133] Step 4: Place the ball mill in a ball mill and mill at 400 rpm for 12 hours to obtain a dispersion with a particle size of 80 μm.

[0134] Step 5: Place the dispersion obtained in step 4 in a sand mill at room temperature (25°C) and use 1.5mm diameter zirconium oxide balls as sand milling media for sand milling. The sand milling time is 3 hours, during which 1ml of triethylamine is added and the sand milling speed is 3000 rpm. After sand milling, a dispersion with a particle size of 20-100 microns is obtained for the preparation of sponges. The viscosity data of the dispersion are shown in Table 1. The regenerated soft polyurethane foam is as follows: Figure 14 Its mechanical properties are shown in Table 2. Compared with Example 4, the modification method of the present invention, with an increased PUSR mass ratio, achieved a viscosity of 1540 mPa·s, only slightly higher than that of Example 4 and significantly lower than the 7820 mPa·s viscosity in Comparative Example 8. The mechanical properties of the regenerated flexible polyurethane foam produced from the dispersion were also compared to those in Example 4, with a slightly increased 75% permanent compression set, but still meeting the mechanical performance requirements for commercial foams.

[0135] The dispersions prepared in the above-mentioned embodiments and comparative examples were subjected to basic physical property tests, and the results are shown in Table 1. Table 1 is a viscosity table of different samples, and Table 1 is a viscosity data table of the modified embodiments and comparative examples. Excessively high viscosity will greatly affect the mixing dispersibility and operability of the foaming process. The test results show that with the increase of PUSR solid content, the overall viscosity of the polyurethane foam increases, but through the modification method of the present invention, the viscosity data in all embodiments are lower than those in Comparative Example 1 and Comparative Example 8. Although the addition of PUSR will lead to a slight decrease in foam performance, the cost-effectiveness is significant in comparison, and the high-value utilization of the polyurethane foam solid product is achieved.

[0136] Table 1

[0137]

[0138] The polyurethane foams produced in the above examples and comparative examples were subjected to mechanical property testing. The results are shown in Table 2, which compares the mechanical properties of different foams. Table 2 also provides a table of mechanical properties of the recycled products produced in the examples and comparative examples. Resilience, a direct indicator of the structural integrity and uniformity of the PUF's three-dimensional cross-linked network, is easily affected by the quality of the raw materials, thus impacting commercial application requirements. Studies have shown that as the solids content of the solid product increases, the foam's resilience gradually decreases, while the 40% indentation hardness and 75% permanent compressibility change increase. Furthermore, if the solid product is directly dispersed in a polyol, the foam will not recover after being crushed, and its mechanical properties will not meet the required standards. The introduction of a surface modifier can improve the overall foam performance to meet commercial application requirements.

[0139] Table 2

[0140]

[0141] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of the technical contents disclosed above without departing from the scope of the technical solution of the invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for high-value utilization of polyurethane foam degradation solid products, characterized in that: The steps include: Step 1: crushing and grinding the solid product produced after degradation to obtain a powdery solid; Step 2: Mix the powdered solid and the composite polyether polyol in a mass ratio of 20-50:80-50, and add the mixed mixture into a ball mill; Step 3: Adding epoxy surface modifier to the ball mill; Step 4: placing the ball mill jar in a ball mill for ball milling to obtain a dispersion; Step 5: placing the dispersion obtained in step 4 in a sand mill, using a sand milling medium, adding triethylamine, and sand milling to obtain a dispersion with a particle size of 20-100 microns. The sponge is prepared from the dispersion with a particle size of 20-100 microns.

2. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 1, the solid product produced after the degradation is obtained by the following method: The polyurethane foam fragments are degraded by an acidolysis method or an alcoholysis method, and the solid products produced after degradation are obtained after separation.

3. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 1, the particle size of the powdered solid is controlled to be 10-1000 mesh.

4. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 2, the composite polyether polyol is a mixture of a polyether polyol and a polyol containing double bonds in a mass ratio of 30-50:70-50; The polyether polyol is one of polypropylene glycol PPG2000, polyether polyol 5623, and polyether polyol 5602; The double bond-containing polyol is allyl alcohol random polyether methyl terminated or polyether F-6.

5. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 2, ball milling beads are placed in a ball milling jar.

6. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step three, the epoxy surface modifier is one or more of 1,2-epoxyhexane, ethylene oxide-PEG-epoxyethane, 1,2-epoxyoctane, 1,2-epoxyheptane, 1,2-epoxydecane, glycidyl phenyl ether, glycidyl methyl ether, 1,2-epoxy-5-hexene, propylene oxide, and glycidyl ether.

7. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 3, the mass ratio of the surface modifier to the solid product produced after degradation is 0.01-0.1:

1.

8. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 4, the ball milling conditions are: ball milling at a speed of 100-800 rpm / min for 8-24 hours.

9. The method for high-value utilization of polyurethane foam degradation solid products according to claim 1, characterized in that: In step 5, the sanding conditions are: sanding time is 1-3 hours, and sanding speed is 2000-6000 rpm.

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