Recyclable all-bio-based glassy polymer material and preparation method, recycling method and application thereof

Abstract

The application discloses a kind of full bio-based glass polymer materials of closed loop recycling and preparation method, recycling method and application thereof, the method comprises the following steps: lignin small molecule acid alcohol diglycidyl ether is reacted with glycerol, dimer acid under the condition of no catalyst, to obtain the full bio-based glass polymer material of closed loop recycling.The application effectively solves the catalyst toxicity problem and the problem of poor mechanical properties of epoxy resin glass polymer material.The raw materials used in the application are all derived from biomass, and the closed loop recycling capability enables the waste and damaged materials to be reused, greatly improving the green sustainability of the material, and has a broad application prospect in the field of replacing traditional epoxy resin materials.

Description

Technical Field

[0001] This invention relates to a fully bio-based glass polymer material that can be recycled in a closed loop, as well as its preparation method, recycling method, and application, belonging to the field of bio-based polymer material technology. Background Technology

[0002] Epoxy resins possess excellent mechanical properties, solvent resistance, heat resistance, chemical stability, and low curing shrinkage, making them widely used in coatings, adhesives, and composite materials. However, their permanently cross-linked network structure after curing makes them difficult to degrade and recycle. Industrially, most waste epoxy resins are disposed of through landfill or incineration, which not only wastes resources but also pollutes the environment. Therefore, the development of a green, recyclable polymer material that retains the properties of traditional epoxy resins has attracted widespread attention and research.

[0003] In 2011, Leibler's research team embedded reversibly cross-linked dynamic ester bonds into the cross-linked network of thermosetting polymers, preparing recyclable epoxy resins. These resins exhibited glass-like rheological behavior at high temperatures, hence the name "glass-like polymers," also known as glass-like materials. Currently, researchers have constructed various epoxy resin glass-like polymers based on β-hydroxy ester bonds, achieving self-healing and recyclability of epoxy resins. However, due to the low bond energy of the dynamic covalent bonds of β-hydroxy esters, their introduction into epoxy resins reduces their mechanical strength, cross-linking density, and modulus. Furthermore, current reports on epoxy resins based on β-hydroxy ester bonds typically require catalysts such as tin salts, zinc salts, tertiary amines, organic protic acids, and triphenylphosphine to accelerate the transesterification reaction rate. These catalysts not only reduce the thermal stability and mechanical properties of the materials but also pose safety hazards to human health and environmental pollution. Therefore, there is an urgent need to find a method to prepare high-strength epoxy resin glass-like polymers based on β-hydroxy ester bonds without the need for external catalysts.

[0004] Hyperbranched polymers possess highly branched network structures, numerous modifiable active end groups within their branches, and unique microporous structures, exhibiting characteristics such as low molecular chain entanglement, good solubility, low viscosity, and high chemical reactivity. Furthermore, the toughening and reinforcement of epoxy resins with hyperbranched polymers has been a research hotspot in recent years. Therefore, utilizing hyperbranched epoxy resin-based glass polymer materials holds promise for solving the problem of difficult recycling of high-performance epoxy resins. Summary of the Invention

[0005] In view of this, the main objective of this invention is to provide a fully bio-based glass polymer material that is recyclable in a closed loop, as well as its preparation method, recycling method, and applications. The technical problem to be solved is to prepare a fully bio-based epoxy resin glass polymer material using renewable biomass resources as raw materials under catalyst-free conditions. By constructing a hyperbranched network structure, the numerous branches contain abundant terminal hydroxyl groups, which catalyze transesterification reactions under catalyst-free conditions, thereby endowing the material with excellent mechanical properties, shape memory, and closed-loop recyclability.

[0006] The objective of this invention and the technical problem it solves are achieved through the following technical solution. This invention proposes a method for preparing a closed-loop recyclable, fully bio-based glass polymer material, comprising the following steps:

[0007] The lignin small molecule acid alcohol diglycidyl ether reacts with glycerol and dimer acid under catalyst-free conditions to obtain the fully bio-based glass polymer material that can be closed-loop recycled.

[0008] The objectives of this invention and the technical problems solved can be further achieved by the following technical measures.

[0009] Preferably, the aforementioned method for preparing a closed-loop recyclable, fully bio-based glass polymer material includes the following steps:

[0010] Step 1: Mix lignin small molecule acid alcohol, epichlorohydrin and catalyst evenly, control the reaction temperature at 90-120℃, stir for 1-3 hours, cool to 0-20℃ in an ice bath, add sodium hydroxide aqueous solution, and continue to react at 0-20℃ for 3 hours; after the reaction is completed, extract, wash with water, separate, dry, distill under reduced pressure and recrystallize to obtain lignin small molecule acid alcohol diglycidyl ether.

[0011] Step 2: Dissolve the lignin small molecule acid alcohol diglycidyl ether obtained in Step 1 in a solvent, stir it evenly with glycerol at room temperature, and then react at 70-120℃ for 1-2 hours. Then add dimer acid and continue to react for 1-2 hours. After curing at 60-160℃ for 3-48 hours, a fully bio-based glass polymer material that can be closed-loop recycled is obtained.

[0012] The objectives of this invention and the technical problems solved can be further achieved by the following technical measures.

[0013] Preferably, in the aforementioned method for preparing the closed-loop recyclable fully bio-based glass polymer material, in step one, the concentration of the sodium hydroxide aqueous solution is 20wt%-50wt%.

[0014] Preferably, in the aforementioned method for preparing a closed-loop recyclable fully bio-based glass polymer material, in step one, the catalyst is selected from one of tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, and benzyltriethylammonium chloride, and the molar amount of the catalyst is 1-5% of the total molar number of hydroxyl and carboxyl groups in the lignin small molecule acid alcohol.

[0015] Preferably, in the aforementioned method for preparing a closed-loop recyclable fully bio-based glass polymer material, the lignin small molecule acid alcohol is selected from at least one of coumaric acid, ferulic acid, sinapic acid, tetrahydrocurcumin, p-coumarol, coniferol, and sinapol.

[0016] Preferably, in the aforementioned method for preparing a fully bio-based glass polymer material that can be recycled in a closed loop, the reaction temperature before ice bath cooling in step one is 90-110°C, and the reaction time is 1-2 hours.

[0017] Preferably, in the aforementioned method for preparing a closed-loop recyclable fully bio-based glass polymer material, in step two, the solvent is selected from ethyl acetate, anhydrous ethanol, and N,N-dimethylformamide.

[0018] Preferably, in the aforementioned method for preparing a closed-loop recyclable fully bio-based glass polymer material, in step two, the lignin small molecule acid alcohol diglycidyl ether is mixed uniformly with glycerol and dimer acid in a molar ratio of epoxy group / hydroxyl group / carboxyl group of (0.6-1):0.5:0.5.

[0019] Preferably, in the aforementioned method for preparing a closed-loop recyclable fully bio-based glass polymer material, in step two, the dimer acid is selected from one of Pripol 1004, Pripol 1006, Pripol 1025, and Pripol 1022VEG.

[0020] Preferably, in the aforementioned method for preparing the fully bio-based glass polymer material that can be recycled in a closed loop, the curing temperature in step two is 120-160℃ and the curing time is 8-12h.

[0021] Preferably, in the aforementioned method for preparing a closed-loop recyclable, fully bio-based glass polymer material, wherein...

[0022] The objective of this invention and the technical problem it solves are achieved through the following technical solution. This invention proposes a closed-loop recyclable, fully bio-based glass polymer material. This closed-loop recyclable, fully bio-based glass polymer material has a hyperbranched network structure, a tensile strength of 34.8–72.5 MPa, and an elongation at break of 51.6%–108%. This closed-loop recyclable, fully bio-based glass polymer material is prepared by the method described above.

[0023] The objective of this invention and the technical problem it solves are achieved through the following technical solution. This invention proposes a triboelectric nanogenerator, comprising a positive electrode composed of a recyclable, fully bio-based glass-like polymer material; the recyclable, fully bio-based glass-like polymer material has a hyperbranched network structure, with a tensile strength of 34.8–72.5 MPa and an elongation at break of 51.6%–108%.

[0024] The objective of this invention and the technical problem it solves are achieved by the following technical solution. This invention proposes a closed-loop recyclable fully bio-based glass polymer material recycling method, comprising the following steps: adding the aforementioned closed-loop recyclable fully bio-based glass polymer material and a solvent together into a high-pressure reactor; the alcohol hydroxyl groups in the solvent undergo a bond exchange reaction with the ester groups in the β-hydroxy ester bonds, degrading the cross-linked network structure into small molecules; after solvent removal, the material is re-cured to obtain regenerated fully bio-based glass polymer material.

[0025] The objectives of this invention and the technical problems solved can be further achieved by the following technical measures.

[0026] Preferably, in the aforementioned method for recycling fully bio-based glass polymer materials that can be closed-loop recycled, the solvent is selected from ethanol and methanol, the reaction temperature is 140-180℃, and the degradation reaction time is 6-10h.

[0027] Compared with existing technologies, the fully bio-based glass polymer material with closed-loop recyclability described in this invention, as well as its preparation method, recycling method, and application, have the following beneficial effects:

[0028] This invention provides a closed-loop recyclable, fully bio-based glass polymer material prepared by the above method. Its hyperbranched network structure contains abundant hydroxyl groups, endowing the material with transesterification capabilities. This allows the epoxy resin-based glass polymer material to exhibit closed-loop recyclability, shape memory, and self-healing abilities. It effectively solves the problems of difficult recycling of traditional epoxy resin materials and poor mechanical properties and catalyst toxicity in epoxy resin-based glass polymer materials. Furthermore, the fully bio-based glass polymer material obtained by this method is entirely derived from non-toxic, biocompatible biomass raw materials, conforming to the concept of green and sustainable development.

[0029] The bio-based glass polymer material prepared by this invention has a hyperbranched network structure, a tensile strength of 34.8–72.5 MPa, and an elongation at break of 51.6%–108%.

[0030] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating the preparation route of ferulic acid diglycidyl ether and epoxy resin in Example 1 of the present invention.

[0032] Figure 2 The infrared spectra of ferulic acid and ferulic acid diglycidyl ether in Example 1 of this invention;

[0033] Figure 3 This is a stress-strain curve of the fully bio-based glass polymer material in Example 1 of the present invention;

[0034] Figure 4 This is a diagram showing a 10kg weight of the all-biobased glass polymer material used in Example 1 of this invention.

[0035] Figure 5 This is a diagram illustrating the self-healing properties of the fully bio-based glass polymer material in Example 1 of this invention.

[0036] Figure 6 This is a diagram illustrating the shape memory process of the fully bio-based glass polymer material in Example 1 of the present invention.

[0037] Figure 7 This is a schematic diagram of the chemical degradation and reprocessing of the fully bio-based glass polymer material in Example 1 of the present invention. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following detailed description, in conjunction with preferred embodiments, details a closed-loop recyclable fully bio-based glass polymer material proposed by the present invention, its preparation method, recycling method, and application, as well as its specific implementation methods, structures, features, and effects. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable manner.

[0039] Unless otherwise specified, all materials and reagents mentioned below are commercially available products well-known to those skilled in the art; unless otherwise specified, all methods described are methods known in the art. Unless otherwise defined, the technical or scientific terms used should have the ordinary meaning understood by those skilled in the art. Where specific experimental steps or conditions are not specified below, they can be performed according to the conventional experimental steps or conditions described in the literature in this field.

[0040] Some embodiments of the present invention provide a method for preparing a closed-loop recyclable, fully bio-based glass-like polymer material (Vitrimer), comprising the following steps:

[0041] (1) Add lignin small molecule acid alcohol, epichlorohydrin and catalyst in a molar ratio of 1:10:0.02 to 1:14:0.05 to a flask and mix well. If the molar ratio of lignin small molecule acid alcohol, epichlorohydrin and catalyst is lower than 1:14:0.05, the reaction of lignin small molecule acid alcohol will be incomplete; if the molar ratio of lignin small molecule acid alcohol, epichlorohydrin and catalyst is higher than 1:10:0.02, the concentration of lignin small molecule acid alcohol and catalyst in the reaction system will decrease, resulting in a decrease in the reaction rate. The reaction temperature should be controlled at 90-120℃. If it is lower than 90℃, the reaction of lignin acid alcohol will be incomplete; if it is higher than 120℃, some ferulic acid raw material will be decarboxylated. Stir the reaction for 1-3 hours. If it is lower than 1 hour, the reaction of ferulic acid will be insufficient; if it is higher than 3 hours, more by-products will be generated due to decarboxylation. Cool the reaction in an ice bath. The reaction temperature should be maintained between 0-20℃. Temperatures below 0℃ will cause the subsequently added hydroxide aqueous solution to clump, resulting in incomplete ring-closure. Adding alkali metal hydroxides to the reaction system is exothermic, causing the solution temperature to rise. Under high-temperature alkaline conditions, the ester bonds in the ferulic acid diglycidyl ether intermediate are easily hydrolyzed and broken. Temperatures above 20℃ will make the reaction more vigorous, generating a large amount of heat, further raising the solution temperature and leading to the formation of byproducts. Adding 20wt%-50wt% sodium hydroxide aqueous solution and continuing the reaction at 0-20℃ for 1-3 hours will also cause the hydroxide aqueous solution to clump, resulting in incomplete ring-closure. This reaction is exothermic; temperatures above 20℃ will lead to excessively high temperatures and the formation of byproducts. Reacting for less than 1 hour will result in incomplete ring closure of the intermediate, leading to a low yield of the target product. Within 3 hours, the intermediate will be almost completely ring-closed, indicating the reaction is complete. Reactions exceeding 3 hours will result in resource waste. After the reaction, the product is extracted, washed with water, separated, dried, distilled under reduced pressure, and recrystallized to obtain lignin small molecule acid alcohol diglycidyl ether, which is a white solid. The preferred reaction temperature is 90-110℃. Within this reaction temperature range, the conversion rate of raw materials is high and the product yield is high. The reaction time is 1-2 hours. Within this reaction time range, the raw materials can be completely converted into the target product, and there are few by-products.

[0042] (2) After dissolving the lignin small molecule acid alcohol diglycidyl ether obtained in step (1) in a solvent, stir it evenly with glycerol at room temperature, and then react at 70-120℃ for 1-2 hours. Below 70℃, the glycerol will not be completely consumed, while 70-120℃ can make the glycerol reaction complete, and above 120℃ will lead to resource waste; below 1 hour, the glycerol will not be completely consumed, while 1-2 hours can make the glycerol reaction complete, and above 2 hours will lead to resource waste; then add dimer acid, continue to react for 1-2 hours, and pour into a mold. Below 1 hour, the reaction will not be completely consumed, while 1-2 hours can make the glycerol reaction complete, and above 2 hours will lead to resource waste; then add dimer acid, continue to react for 1-2 hours, and pour into a mold. A curing time of 1-2 hours will result in uneven mixing of the dimer acid and prepolymer. A time exceeding 2 hours will lead to resource waste. Curing in an oven at 60-160℃ for 3-48 hours is also recommended. Temperatures below 60℃ will result in incomplete curing, while 60-160℃ will ensure complete curing. Temperatures above 160℃ will also lead to resource waste. Curing time below 3 hours will result in incomplete curing, while 3-48 hours will achieve complete curing and optimal performance. Temperatures exceeding 48 hours will also lead to resource waste. The result is a fully bio-based glass polymer material that can be recycled in a closed loop. Preferably, the curing reaction temperature is 120-160℃, as this temperature range ensures complete curing and the best performance. The reaction time is 8-12 hours, also preferably within this time range, to ensure complete curing and the best performance.

[0043] In some embodiments, to ensure reaction efficiency, the catalyst in step (1) above may be selected from one of tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride and benzyltriethylammonium chloride. The molar amount of the catalyst is 1-5% of the total number of molar amounts of hydroxyl and carboxyl groups in the lignin small molecule acid alcohol. Less than 1% will cause ferulic acid to react incompletely, 1-5% can make all ferulic acid react completely with epichlorohydrin, and more than 5% will lead to waste of resources.

[0044] In some embodiments, the lignin small molecule acid alcohol in step (1) above can be selected from at least one of coumaric acid, ferulic acid, sinapic acid, tetrahydrocurcumin, p-coumarol, coniferyl alcohol, and sinapyl alcohol. These monomers are biomass raw materials and can react with epichlorohydrin to obtain epoxy group-terminated lignin small molecule acid alcohol diglycidyl ether raw materials. Factors to consider: lignin biomass source, dual functionality, presence of a benzene ring, high reactivity, and reactivity with epichlorohydrin.

[0045] In some embodiments, in order to ensure product uniformity, the solvent in step (2) above may be selected from ethyl acetate, anhydrous ethanol and N,N-dimethylformamide.

[0046] In some embodiments, to improve product performance, the lignin small molecule acid alcohol diglycidyl ether in step (2) above is mixed uniformly with glycerol and dimer acid in a molar ratio of epoxy group / hydroxyl group / carboxyl group of (0.6-1):0.5:0.5. If the proportion of epoxy group is less than 0.6, the tensile strength of the material will be lower; if the proportion of epoxy group is greater than 1, the material will become brittle. The lignin small molecule acid alcohol diglycidyl ether is derived from lignin biomass, has two functionalities, has a benzene ring, and can react with epoxy group.

[0047] In some embodiments, the dimer acid in step (2) above may be selected from one of Pripol 1004, Pripol 1006, Pripol 1025 and Pripol 1022VEG; these are all dimer acids that can increase the flexibility of the target polymer.

[0048] In some embodiments, in step (2) above, the material used for the mold can be stainless steel or polytetrafluoroethylene, which can withstand high temperatures and can shape polymer materials at high temperatures.

[0049] In the above technical solution, the present invention prepares a fully bio-based glass polymer material that can be closed-loop recycled by reacting lignin small molecule acid alcohol diglycidyl ether with glycerol and dimer acid under catalyst-free conditions.

[0050] The bio-based glass polymer material prepared by this invention, capable of closed-loop recycling, is added to a high-pressure reactor. The hydroxyl groups in the solvent undergo a bond exchange reaction with the ester groups in the β-hydroxy ester bonds, degrading the cross-linked network structure into smaller molecules. After solvent removal, the material is cured again to obtain a regenerated, fully bio-based glass polymer material. The hyperbranched network structure of this bio-based glass polymer material contains abundant hydroxyl groups, endowing it with ester exchange capabilities. This allows the epoxy resin-based glass polymer material to exhibit closed-loop recycling, shape memory, and self-healing abilities. This effectively solves the problems of difficult recycling of traditional epoxy resin materials and poor mechanical properties and catalyst toxicity in epoxy resin-based glass polymers. Furthermore, the material obtained by this method is entirely derived from non-toxic, biocompatible biomass raw materials, aligning with the concept of green and sustainable development.

[0051] Some embodiments of the present invention also provide a closed-loop recyclable fully bio-based glass polymer material, which is prepared by the above-described method, and the preparation process and structure are as follows. Figure 1As shown. The materials in Examples 1-3 all possess a hyperbranched network structure, exhibiting excellent mechanical properties (tensile strength reaching 34.8–72.5 MPa, elongation at break 51.6%–108%) and self-healing capabilities. Conversely, the material in Comparative Example 1 lacks a hyperbranched network structure, has a tensile stress of only 0.8 MPa, and does not possess self-healing capabilities. Furthermore, the material recovery efficiency obtained in Examples 3 and Comparative Example 1 can both reach over 90%.

[0052] Some embodiments of the present invention also provide a triboelectric nanogenerator, the triboelectric nanogenerator including a positive electrode, the positive electrode being composed of a fully bio-based glass polymer material that can be recycled in a closed loop; the fully bio-based glass polymer material that can be recycled in a closed loop has a hyperbranched network structure, and its tensile strength is 34.8 to 72.5 MPa, and its elongation at break is 51.6% to 108%.

[0053] Some embodiments of the present invention also provide a method for recycling a closed-loop recyclable fully bio-based glass polymer material, comprising the following steps: adding the aforementioned closed-loop recyclable fully bio-based glass polymer material and a solvent together into a high-pressure reactor; the hydroxyl groups in the solvent undergo a bond exchange reaction with the ester groups in the β-hydroxy ester bonds, degrading the cross-linked network structure into small molecules; after solvent removal, the material is re-cured to obtain regenerated fully bio-based glass polymer material. In this way, waste or broken materials can be degraded by solvent, re-cured, and reused, avoiding resource waste.

[0054] In some embodiments, to ensure degradation efficiency, the solvent in the above steps can be selected from ethanol and methanol, the reaction temperature is 140-180℃, and the degradation reaction time is 6-10h; below 140℃, the material cannot be completely degraded; above 180℃, it will lead to resource waste; below 6h, the material degradation is incomplete, and above 10h, the material can be completely degraded into small molecules. The preferred temperature is 160-180℃, within which the polymer material degrades more thoroughly and completely, and the reaction time is 8-10h, within which the polymer material depolymerizes completely.

[0055] The present invention will be further described below with reference to specific embodiments, but this should not be construed as a limitation on the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention.

[0056] Example 1

[0057] This embodiment provides a method for preparing a closed-loop recyclable, fully bio-based glass polymer material, including the following steps:

[0058] Ferulic acid (50g, Shanghai Aladdin Reagent Co., Ltd.), epichlorohydrin (330g), and tetrabutylammonium iodide (1.7g) were added to a flask and mixed thoroughly. The reaction temperature was controlled at 110℃, and the mixture was stirred for 3 hours. After stirring, the mixture was cooled to 20℃ in an ice bath, and 152g of 40wt% sodium hydroxide aqueous solution was added. The reaction was continued at 20℃ for another 3 hours. After the reaction was completed, 500ml of ethyl acetate was added for extraction, followed by washing three times with 100ml of deionized water. The organic phase was transferred to a beaker, dried with 10g of anhydrous magnesium sulfate, and then ethyl acetate and epichlorohydrin were removed using a rotary evaporator (80℃, -0.1MPa) to obtain the crude product ferulic acid diglycidyl ether. Subsequently, the crude product obtained in the above steps was dissolved in 100ml of ethyl acetate at 80℃. After cooling to room temperature, a white solid precipitated. The solution was filtered off, and the solid was dried to obtain the pure product ferulic acid diglycidyl ether. 1g of the obtained ferulic acid diglycidyl ether was dissolved in ethyl acetate (1g) and then stirred with 0.216g of glycerol at room temperature. The mixture was then reacted at 70℃ for 1 hour. Subsequently, 2g of Pripol 1006 was added, and the reaction continued for another hour. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum drying oven. Vacuum was applied at 60℃ under reduced pressure (-0.1MPa) to remove air bubbles. The temperature was then increased to 160℃ at a rate of 10℃ / min, and finally cured at 160℃ for 12 hours to obtain a yellow transparent film material, which is the closed-loop recyclable fully bio-based glass polymer material. This fully bio-based glass polymer material can be used in the preparation of positive electrode materials for triboelectric nanogenerators.

[0059] like Figure 2 The infrared spectrum shows that the hydroxyl groups in ferulic acid are at 3432 cm⁻¹. -1 The characteristic absorption peak disappears at 910 cm⁻¹, and the epoxy group in ferulic acid diglycidyl ether reaches 910 cm⁻¹. -1 The appearance of a new characteristic absorption peak confirms the successful synthesis of ferulic acid diglycidyl ether. Mechanical properties were tested at an experimental speed of 10 mm / min according to GB / T1040.3-2006. The obtained recyclable, fully bio-based glass-like polymer material was subjected to tensile testing, and its tensile strength was 69.8 MPa. Figure 3 The elongation at break is 57.2%. A rectangular spline (5cm (length) × 1cm (width) × 0.1cm (thickness)) easily lifted a 10kg weight without breaking, demonstrating its excellent mechanical strength. Figure 4 After scratching the recyclable, fully bio-based glass polymer material (scratch width approximately 150 μm) and heating it in a 160°C oven for 180 min, the scratches almost completely healed. Figure 5 ).like Figure 6As shown, the bio-based glass polymer material that can be recycled in a closed loop achieves the conversion between permanent and temporary deformation at two temperatures: 95°C and 160°C.

[0060] Example 2

[0061] This embodiment provides a method for preparing a closed-loop recyclable, fully bio-based glass polymer material, including the following steps:

[0062] Ferulic acid (30g, Shanghai Aladdin Reagent Co., Ltd.), epichlorohydrin (198g), and tetrabutylammonium iodide (1.02g) were added to a flask and mixed thoroughly. The reaction temperature was controlled at 110℃, and the mixture was stirred for 3 hours. After stirring, the mixture was cooled to 20℃ in an ice bath, and 40wt% sodium hydroxide aqueous solution (91.2g) was added. The reaction was continued at 20℃ for another 3 hours. After the reaction was completed, 300ml of ethyl acetate was added for extraction, followed by washing three times with 60ml of deionized water. The organic phase was transferred to a beaker, dried with 6g of anhydrous magnesium sulfate, and then ethyl acetate and epichlorohydrin were removed using a rotary evaporator (80℃, -0.1MPa) to obtain the crude product ferulic acid diglycidyl ether. Subsequently, the crude product obtained in the above steps was dissolved in 60ml of ethyl acetate at 80℃. After cooling to room temperature, a white solid precipitated. The solution was filtered off, and the solid was dried to obtain the pure product ferulic acid diglycidyl ether. 1.6 g of the obtained ferulic acid diglycidyl ether was dissolved in ethyl acetate (1 g), and then stirred with 0.432 g of glycerol at room temperature. The mixture was then reacted at 70 °C for 1 h. Subsequently, 4 g of Pripol 1006 was added, and the reaction continued for another h. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum drying oven. Vacuum was applied at 60 °C under reduced pressure (-0.1 MPa) to remove air bubbles. The temperature was then increased to 150 °C at a rate of 5 °C / min, and finally cured at 150 °C for 12 h to obtain a yellow transparent film material, which is the closed-loop recyclable fully bio-based glass polymer material. This fully bio-based glass polymer material can be used in the preparation of positive electrode materials for triboelectric nanogenerators.

[0063] Mechanical properties were tested according to GB / T1040.3-2006 at an experimental speed of 10 mm / min. The obtained recyclable, fully bio-based glass polymer material was subjected to a tensile test, showing a tensile strength of 34.8 MPa and an elongation at break of 108%. Simultaneously, after scratching the recyclable, fully bio-based glass polymer material with a blade (scratches approximately 100 μm wide) and heating it in a 160°C oven for 180 min, the scratches almost completely healed. The recyclable, fully bio-based glass polymer material exhibited a transition between permanent and temporary deformation at two temperatures: 85°C and 150°C.

[0064] Example 3

[0065] This embodiment provides a method for preparing a closed-loop recyclable, fully bio-based glass polymer material, including the following steps:

[0066] Sinic acid (10g, Shanghai Aladdin Reagent Co., Ltd.), epichlorohydrin (58g), and tetrabutylammonium iodide (0.3g) were added to a flask and mixed thoroughly. The reaction temperature was controlled at 110℃, and the mixture was stirred for 3 hours. After stirring, the mixture was cooled to 20℃ in an ice bath, and 30g of 40wt% sodium hydroxide aqueous solution was added. The reaction was continued at 20℃ for another 3 hours. After the reaction was completed, 100ml of ethyl acetate was added for extraction, followed by washing three times with 20ml of deionized water. The organic phase was transferred to a beaker, dried with 2g of anhydrous magnesium sulfate, and then ethyl acetate and epichlorohydrin were removed using a rotary evaporator (80℃, -0.1MPa) to obtain the crude product, sinic acid diglycidyl ether. Subsequently, the crude product obtained in the above steps was dissolved in 20ml of ethyl acetate at 80℃. After cooling to room temperature, a white solid precipitated. The solution was filtered off, and the solid was dried to obtain the pure product, sinic acid diglycidyl ether. 1g of the obtained sinapic acid diglycidyl ether was dissolved in ethyl acetate (1g), and then stirred with 0.09g of glycerol at room temperature. The mixture was then reacted at 70℃ for 1 hour. Subsequently, 0.84g of Pripol 1006 was added, and the reaction continued for another hour. The mixture was then poured into a polytetrafluoroethylene mold and placed in a vacuum drying oven. Vacuum was applied at 60℃ under reduced pressure (-0.1MPa) to remove air bubbles. The temperature was then increased to 160℃ at a rate of 10℃ / min, and finally cured at 160℃ for 12 hours to obtain a yellow transparent film material, which is the closed-loop recyclable fully bio-based glass polymer material. This fully bio-based glass polymer material can be used in the preparation of positive electrode materials for triboelectric nanogenerators.

[0067] Mechanical properties were tested according to GB / T1040.3-2006 at an experimental speed of 10 mm / min. The obtained recyclable, fully bio-based glass polymer material was subjected to tensile testing, showing a tensile strength of 72.5 MPa and an elongation at break of 51.6%. Simultaneously, the material was scratched with a blade (scratches approximately 150 μm wide), and after heating in an oven at 150°C for 180 min, the scratches on the material surface were almost completely healed. The recyclable, fully bio-based glass polymer material exhibited a transition between permanent and temporary deformation at two temperatures: 105°C and 170°C.

[0068] Comparative Example 1

[0069] This comparative example provides a method for preparing a fully bio-based glass polymer material, including the following steps:

[0070] Ferulic acid (50g, Shanghai Aladdin Reagent Co., Ltd.), epichlorohydrin (330g), and tetrabutylammonium iodide (1.7g) were added to a flask and mixed thoroughly. The reaction temperature was controlled at 110℃, and the mixture was stirred for 3 hours. After stirring, the mixture was cooled to 20℃ in an ice bath, and 152g of 40wt% sodium hydroxide aqueous solution was added. The reaction was continued at 20℃ for another 3 hours. After the reaction was completed, 500ml of ethyl acetate was added for extraction, followed by washing three times with 100ml of deionized water. The organic phase was transferred to a beaker, dried with 10g of anhydrous magnesium sulfate, and then ethyl acetate and epichlorohydrin were removed using a rotary evaporator (80℃, -0.1MPa) to obtain the crude product ferulic acid diglycidyl ether. Subsequently, the crude product obtained in the above steps was dissolved in 100ml of ethyl acetate at 80℃. After cooling to room temperature, a white solid precipitated. The solution was filtered off, and the solid was dried to obtain the pure product ferulic acid diglycidyl ether. 1g of the obtained ferulic acid diglycidyl ether was dissolved in ethyl acetate (1g), and then stirred with 2g of Pripol 1006 at room temperature. After reacting at 70℃ for 1h, the mixture was poured into a polytetrafluoroethylene mold, placed in a vacuum drying oven, and vacuumed at 60℃ (-0.1MPa) to remove air bubbles. The temperature was then increased to 160℃ at a rate of 10℃ / min, and then cured at 160℃ for 12h to obtain a yellow transparent film material.

[0071] Mechanical properties were tested according to GB / T1040.3-2006 at a test speed of 10 mm / min. The obtained material underwent a tensile test, and its tensile strength was only 0.8 MPa. Furthermore, after the material was scratched with a blade (scratches approximately 140 μm wide) and heated in an oven at 160℃ for 12 hours, the scratches were difficult to heal.

[0072] The bio-based glass polymer materials with closed-loop recyclability obtained in Examples 1-3 and the material obtained in Comparative Example 1 were respectively added to a high-pressure reactor. After adding ethanol, the temperature was raised to 180°C. After reacting for 10 hours, the network structure of the material was depolymerized into small molecules. Excess ethanol was removed by rotary evaporation (60°C, -0.1 MPa), and the mixture was poured into a polytetrafluoroethylene mold. After heating in a 160°C oven for 12 hours, it could be cured again to obtain a fully bio-based glass polymer material. The tensile strength of the bio-based glass polymer material with closed-loop recyclability in Example 1 could be restored to 96% of its original strength. The tensile strength of the bio-based glass polymer material with closed-loop recyclability in Example 2 could be restored to 97% of its original strength. The tensile strength of the bio-based glass polymer material with closed-loop recyclability in Example 3 could be restored to 93% of its original strength. The tensile strength of the material in Comparative Example 1 could be restored to 90% of its original strength. The process is as follows: Figure 7 As shown.

[0073] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some embodiments, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0075] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a closed-loop recyclable, fully bio-based glass polymer material, characterized in that, Includes the following steps: Step 1: Mix lignin small molecule acid alcohol, epichlorohydrin, and catalyst evenly. Control the reaction temperature at 90-120℃ and stir for 1-3 hours. Then cool to 0-20℃ in an ice bath, add sodium hydroxide aqueous solution, and continue the reaction at 0-20℃ for 3 hours. After the reaction is completed, extract, wash with water, separate, dry, distill under reduced pressure, and recrystallize to obtain lignin small molecule acid alcohol diglycidyl ether. The lignin small molecule acid alcohol is selected from at least one of coumaric acid, ferulic acid, sinapic acid, tetrahydrocurcumin, p-coumarol, coniferyl alcohol, and sinapyl alcohol. The catalyst is selected from one of tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, and benzyltriethylammonium chloride. The molar amount of the catalyst is 1-5% of the total molar number of hydroxyl and carboxyl groups in the lignin small molecule acid alcohol. Step 2: Dissolve the lignin small molecule acid alcohol diglycidyl ether obtained in Step 1 in a solvent, stir it evenly with glycerol at room temperature, and then react at 70-120℃ for 1-2 hours. Subsequently, add dimer acid, continue the reaction for 1-2 hours, and then cure at 60-160℃ for 3-48 hours to obtain a fully bio-based glass polymer material that can be closed-loop recycled. The lignin small molecule acid alcohol diglycidyl ether, glycerol, and dimer acid are mixed evenly according to the molar ratio of epoxy group / hydroxyl group / carboxyl group of (0.6-1):0.5:0.

5. The dimer acid is selected from Pripol 1004, Pripol 1006, Pripol 1025, and Pripol 1022 VEG.

2. The method for preparing the closed-loop recyclable, fully bio-based glass polymer material as described in claim 1, characterized in that, Step 1: The concentration of the sodium hydroxide aqueous solution is 20wt%-50wt%.

3. The method for preparing the closed-loop recyclable, fully bio-based glass polymer material as described in claim 1, characterized in that, In step one, the reaction temperature before ice bath cooling is 90-110℃, and the reaction time is 1-2 hours.

4. The method for preparing the closed-loop recyclable fully bio-based glass polymer material as described in claim 1, characterized in that, In step two, the solvent is selected from ethyl acetate, anhydrous ethanol, and N,N-dimethylformamide.

5. The method for preparing the closed-loop recyclable, fully bio-based glass polymer material as described in claim 1, characterized in that, In step two, the curing temperature is 120-160℃ and the curing time is 8-12h.

6. A fully bio-based glass polymer material that is recyclable in a closed loop, characterized in that, The recyclable, fully bio-based glass polymer material has a hyperbranched network structure, a tensile strength of 34.8~72.5 MPa, and an elongation at break of 51.6%~108%; the recyclable, fully bio-based glass polymer material is prepared by the method described in any one of claims 1-5.

7. A triboelectric nanogenerator, characterized in that, The triboelectric nanogenerator includes a positive electrode, which is composed of the fully bio-based glass polymer material that is recyclable in a closed loop as described in claim 6.

8. A closed-loop recyclable method for recovering fully bio-based glass polymer materials, characterized in that, The process includes the following steps: adding the recyclable bio-based glass polymer material as described in claim 6 and a solvent together into a high-pressure reactor; the alcohol hydroxyl groups in the solvent undergo a bond exchange reaction with the ester groups in the β-hydroxy ester bonds, degrading the cross-linked network structure into small molecules; after removing the solvent, the material is solidified again to obtain a regenerated bio-based glass polymer material.

9. The method for recycling the fully bio-based glass polymer material that can be recycled in a closed loop as described in claim 8, characterized in that, The solvent is selected from ethanol and methanol, the reaction temperature is 140-180℃, and the degradation reaction time is 6-10h.

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