Preparation and application of polydisulfide reinforced bio-based epoxy thermosetting material

Abstract

The invention discloses preparation and application of a polydisulfide reinforced bio-based epoxy thermosetting material. The invention designs a dual dynamic covalent cross-linked network system of an epoxy monomer and a curing agent based on a bio-based source through a molecular editing means, and aims to solve the problems of difficult recovery, insufficient mechanical property, poor green sustainability and the like of the traditional epoxy resin material in fan blade application. The system not only realizes the renewability of the raw materials and the recoverability of the materials, but also remarkably improves the comprehensive mechanical properties of the materials through structural regulation and control and dynamic key design, and provides technical support for green manufacturing and cyclic utilization of materials such as fan blades and the like.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials, and in particular relates to the preparation and application of a polydisulfide-reinforced bio-based epoxy thermosetting material. Background Art

[0002] As an important part of the global renewable energy sector, the wind power industry has developed rapidly in recent years. As the core component of the wind power generation system, the material properties of wind turbine blades directly affect the efficiency and life of the wind turbine. At present, epoxy resin composites have been widely used in wind turbine blades due to their excellent mechanical properties, heat resistance and corrosion resistance. However, traditional epoxy resin materials (such as epoxy-amine cross-linking systems) are difficult to recycle after their service. Their dense three-dimensional network structure and chemical inertness lead to high recycling costs and complex processes. In addition, harmful substances may be produced during the recycling process, which is not in line with the concept of green and sustainable development. In addition, the potential reproductive toxicity of bisphenol A (BPA) epoxy resins further limits their application in the field of environmental protection.

[0003] In order to solve the above problems, materials based on dynamic covalent adaptive networks (CANs) came into being. This type of material introduces dynamic covalent bonds (such as ester bonds, disulfide bonds, siloxane bonds, etc.) into the polymer network to give the material the characteristics of recyclability, reprocessability and self-healing. In 2011, French scholar Leibler proposed the concept of vitrimer, an epoxy resin glass trimer material based on dynamic covalent bonds. This material has the stability and heat resistance of thermosetting polymers at room temperature, and can rearrange the network topology structure through thermal triggering or catalytic action at high temperatures, thereby realizing the reprocessing and recycling of the material. Despite this, existing vitrimers materials still face challenges: one is the balance between recyclability and mechanical properties, and the other is that it is difficult to balance the toughness and strength of the material. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a preparation and application of a polydisulfide-reinforced bio-based epoxy thermosetting material. The present invention designs a dual dynamic covalent cross-linked network system based on a bio-based epoxy monomer and a curing agent by molecular editing, aiming to solve the problems of recycling, insufficient mechanical properties, and poor green sustainability faced by traditional epoxy resin materials in the application of wind turbine blades. This system not only realizes the renewability of raw materials and the recyclability of materials, but also significantly improves the comprehensive mechanical properties of materials through structural regulation and dynamic bond design, providing technical support for the green manufacturing and recycling of materials such as wind turbine blades.

[0005] The polydisulfide-reinforced bio-based epoxy thermosetting material of the present invention is prepared and processed from the following raw materials in parts by weight:

[0006] 20 - 80 parts of epoxy monomer, 20 - 80 parts of lipoic acid, and 0 - 5 parts of catalyst.

[0007] More preferably: 65 parts of epoxy monomer, 30 parts of lipoic acid, and 5 parts of catalyst.

[0008] The epoxy monomer is selected from one or more of the following glycidyl ethers, glycidyl esters, and glycidyl amine structure compounds:

[0009]

[0010] Wherein: R1, R2, and R3 are each independently selected from -CH 2 OCH 2 -, -(CH 2 ) n -, n = 1 - 5.

[0011] The epoxy monomer of the present invention includes glycidyl ethers, glycidyl esters, and glycidyl amines, and preferably two of them are compounded.

[0012] Furthermore, the epoxy monomer is composed of a compound of glycidyl ester and glycidyl amine, and the mass ratio of the two is 1:2 to 2:1.

[0013] Among them, glycidyl ether and glycidyl amine epoxy monomers are obtained by the following method:

[0014] In the first step, furfuryl alcohol or furfurylamine is mixed with epichlorohydrin and reacted overnight (8 - 12 h);

[0015] In the second step, 50 wt% NaOH solution is added to the system, and the reaction is carried out at 25 - 70 °C for 2 - 12 hours to obtain the target product.

[0016] In the first step of the reaction, the addition amount of epichlorohydrin is 5 - 20 equivalents, more preferably 15 equivalents; the reaction temperature is 25 - 70 °C, more preferably 30 °C.

[0017] In the second step of the reaction, the reaction temperature is preferably 40 °C, and the reaction time is preferably 5 hours.

[0018] The structure of furfurylamine is shown in Table 1, and the structure of furfuryl alcohol is shown in Table 2.

[0019] Among them, glycidyl ester epoxy monomers are obtained by the following method:

[0020] Under ice bath conditions, glycidyl, triethylamine, and the solvent dichloromethane are added, and diacyl chloride monomer is dropped into the mixture. After the dropping is completed, the mixture is raised to room temperature and stirred for reaction; after the reaction is completed, it is treated by rotary evaporation to obtain the target product.

[0021] During the reaction, the addition amount of glycidyl is 1 - 8 equivalents, preferably 4 equivalents; the addition amount of triethylamine is 1 - 8 equivalents, preferably 2 equivalents; the reaction time is 1 - 12 hours, preferably 4 hours.

[0022] The structure of the diacyl chloride monomer is shown in Table 4.

[0023] The catalyst is one or a mixture of metal acetylacetonates, metal acetates, and the organic base 1,5,7 - triazabicyclo[4.4.0]dodec - 5 - ene (TBD).

[0024] The preparation method of the polydisulfide - enhanced bio - based epoxy thermosetting material of the present invention includes the following steps:

[0025] Step 1: Mix lipoic acid with the catalyst and then raise the temperature to carry out a ring - opening polymerization reaction, and then quickly mix with the epoxy monomer and pour it into a mold; the ring - opening polymerization product of lipoic acid, polydisulfide, is the curing agent.

[0026] Step 2: First carry out pre - curing, and then raise the temperature for curing. After curing is completed, the target epoxy thermosetting material is obtained.

[0027] In Step 1, the temperature for the ring - opening polymerization reaction is 80 - 160 °C, and the time is 0.5 - 4 h. Further preferably, the temperature is 140 °C and the time is 0.5 h.

[0028] In Step 2, the pre - curing temperature is 60 - 120 °C, further preferably 80 °C; the pre - curing time is 0.5 - 8 hours, further preferably 4 hours. The curing temperature is 120 - 180 °C, further preferably 160 °C; the curing time is 0.5 - 4 hours, further preferably 2 hours.

[0029] The bio - based epoxy thermosetting material prepared by the present invention is constructed by a dual dynamic covalent cross - linking network system based on bio - based epoxy monomers and curing agents, and has the advantages of renewable raw materials, low toxicity, environmental friendliness, structural tunability, functional diversity, recyclability, etc., providing technical support for the green manufacturing and recycling of wind turbine blades, and can be widely applied in fields such as wind power, coatings, adhesives, composite materials, electronic packaging materials, biomedical materials, etc.

[0030] In addition, the preparation method of the present invention is convenient to operate, simple and easy to implement, and the raw material price is low, which is of great significance for improving the comprehensive performance of new bio - based epoxy resins and reducing production costs.

[0031] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0032] 1. Renewable raw materials: Furan-based bio-based epoxy resins are derived from non-grain bio-based raw materials, featuring renewability and low carbon emissions, and conforming to the concept of green and sustainable development.

[0033] 2. Low toxicity and environmental friendliness: Bio-based epoxy resins avoid the reproductive toxicity problems of bisphenol A-based epoxy resins, and their degradation products are harmless to the environment.

[0034] 3. Structural tunability and functional diversity: The structures of bio-compounds are easy to modify. Intrinsic toughening of epoxy resins can be achieved by introducing flexible structures such as ether bonds and carbon chains. Meanwhile, by regulating the crosslinking density and the types of dynamic bonds, the mechanical properties and recyclability of the materials can be optimized.

[0035] 4. Dual roles of dynamic covalent bonds: In this invention, dual dynamic covalent bonds (such as ester bonds and disulfide bonds) are introduced into the bio-based epoxy resin network, which not only provides the material with high-efficient recycling ability, but also realizes the balance between toughness and strength of the material through the synergistic effect of strong and weak dynamic bonds.

[0036] 5. High-efficient chemical recycling and value-added utilization: Through innovative chemical recycling means and green degradants, this invention realizes the high-efficient depolymerization of epoxy resins, providing a brand-new solution for the recycling of retired wind turbine blades. Description of the Drawings

[0037] Figure 1 1H NMR (DMSO-d6) of glycidyl ether.

[0038] Figure 2 Infrared structural characterization of the sample after depolymerization of epoxy thermosetting materials. Detailed Description of the Invention

[0039] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] The preparation method of a furan-based bio-based epoxy monomer in the present invention consists of the following steps: The preparation methods of glycidyl ether and amine are as follows: In the first step, furan-based diol and diamine are respectively mixed with epichlorohydrin and reacted overnight at a certain temperature; in the second step, 50 wt% NaOH solution is added to the mixture and reacted at a certain temperature for a certain time to obtain the target product.

[0041] The preparation method of glycidyl ester is as follows: Under ice bath conditions, glycidyl, triethylamine and the solvent dichloromethane are added, and diacyl chloride monomer is dropped into the mixture. After the dropping is completed, the mixture is raised to room temperature and stirred for a certain time. After the reaction is completed, rotary evaporation post-treatment is carried out to obtain the target product.

[0042] A polydisulfide - enhanced bio - based epoxy thermosetting material in the present invention is composed of the following steps: In the first step, lipoic acid and a catalyst are mixed and then heated to undergo a ring - opening polymerization reaction to prepare a curing agent, polydisulfide. Subsequently, it is rapidly mixed with a single epoxy monomer or an epoxy mixture and poured into a mold. In the second step, the mixture is first pre - cured for a certain time, and then heated for curing for a certain time. After the curing is completed, the target epoxy thermosetting material is obtained.

[0043] Example 1: Preparation of furan - based bio - based epoxy glycidyl ether monomers

[0044] First, a furan - based diol and 5 - 20 equivalents of epichlorohydrin are reacted overnight at 30°C. Subsequently, 50 wt% NaOH solution is added to the mixture, and the reaction is carried out at 40°C for 5 h. After the reaction is completed, the reaction solution is extracted with ethyl acetate and water, and after rotary evaporation and post - treatment, a yellow viscous oily product is obtained.

[0045] Example 2: Preparation of furan - based bio - based epoxy glycidyl ether monomers

[0046] First, a furan - based diol and 15 equivalents of epichlorohydrin are reacted overnight at 25 - 70°C. Subsequently, 50 wt% NaOH solution is added to the mixture, and the reaction is carried out at 40°C for 5 h. After the reaction is completed, the reaction solution is extracted with ethyl acetate and water, and after rotary evaporation and post - treatment, a yellow viscous oily product is obtained.

[0047] Example 3: Preparation of furan - based bio - based epoxy glycidyl ether monomers

[0048] First, a furan - based diol and 15 equivalents of epichlorohydrin are reacted overnight at 30°C. Subsequently, 50 wt% NaOH solution is added to the mixture, and the reaction is carried out at 25 - 70°C for 5 h. After the reaction is completed, the reaction solution is extracted with ethyl acetate and water, and after rotary evaporation and post - treatment, a yellow viscous oily product is obtained.

[0049] Example 4: Preparation of furan - based bio - based epoxy glycidyl ether monomers

[0050] First, a furan - based diol and 15 equivalents of epichlorohydrin are reacted overnight at 30°C. Subsequently, 50 wt% NaOH solution is added to the mixture, and the reaction is carried out at 40°C for 2 - 12 hours. After the reaction is completed, the reaction solution is extracted with ethyl acetate and water, and after rotary evaporation and post - treatment, a yellow viscous oily product is obtained.

[0051] Example 5: Preparation of furan - based bio - based epoxy glycidyl ether monomers

[0052] First, react different furan diols B1 - B7 with 15 equivalents of epichlorohydrin at 30 °C overnight. Subsequently, add 50 wt% NaOH solution to the mixture and react at 40 °C for 5 hours. After the reaction, extract the reaction solution with ethyl acetate and water, and obtain a yellow viscous oily product after rotary evaporation and post-treatment.

[0053] Example 6: Preparation of Furan-based Bio-based Epoxy Glycidyl Amine Monomers

[0054] First, react furan diamine with 5 - 20 equivalents of epichlorohydrin at 30 °C overnight. Subsequently, add 50 wt% NaOH solution to the mixture and react at 40 °C for 5 h. After the reaction, extract the reaction solution with ethyl acetate and water, and obtain a yellow viscous oily product after rotary evaporation and post-treatment.

[0055] Example 7: Preparation of Furan-based Bio-based Epoxy Glycidyl Amine Monomers

[0056] First, react furan diamine with 15 equivalents of epichlorohydrin at 25 - 70 °C overnight. Subsequently, add 50 wt% NaOH solution to the mixture and react at 40 °C for 5 h. After the reaction, extract the reaction solution with ethyl acetate and water, and obtain a yellow viscous oily product after rotary evaporation and post-treatment.

[0057] Example 8: Preparation of Furan-based Bio-based Epoxy Glycidyl Amine Monomers

[0058] First, react furan diamine with 15 equivalents of epichlorohydrin at 30 °C overnight. Subsequently, add 50 wt% NaOH solution to the mixture and react at 25 - 70 °C for 5 h. After the reaction, extract the reaction solution with ethyl acetate and water, and obtain a yellow viscous oily product after rotary evaporation and post-treatment.

[0059] Example 9: Preparation of Furan-based Bio-based Epoxy Glycidyl Amine Monomers

[0060] First, react furan diamine with 15 equivalents of epichlorohydrin at 30 °C overnight. Subsequently, add 50 wt% NaOH solution to the mixture and react at 40 °C for 2 - 12 hours. After the reaction, extract the reaction solution with ethyl acetate and water, and obtain a yellow viscous oily product after rotary evaporation and post-treatment.

[0061] Example 10: Preparation of Furan-based Bio-based Epoxy Glycidyl Amine Monomers

[0062] First, react different furan diamines A1 - A6 with 15 equivalents of epichlorohydrin at 30 °C overnight. Subsequently, add 50 wt% NaOH solution to the mixture and react at 40 °C for 5 hours. After the reaction, extract the reaction solution with ethyl acetate and water, and obtain a yellow viscous oily product after rotary evaporation and post-treatment.

[0063] Table 1: Furan-based Bio-based Glycidyl Amine Monomers and Raw Materials

[0064]

[0065]

[0066] Table 2: Furan-based Bio-based Glycidyl Ether Monomers and Raw Materials

[0067]

[0068]

[0069] Table 3 Reaction Conditions of Examples 1-10

[0070]

[0071]

[0072] Example 11: Preparation of Furan-based Bio-based Epoxy Glycidyl Ester Monomers

[0073] Under ice bath conditions, add 1-8 equivalents of glycidol, 2 equivalents of triethylamine and 50 mL of solvent dichloromethane, and slowly dropwise add the diacyl chloride monomer to the mixture. After the addition is complete, raise the mixture to room temperature and stir for 4 hours. After the reaction is completed, perform rotary evaporation post-treatment to obtain the target product.

[0074] Example 12: Preparation of Furan-based Bio-based Epoxy Glycidyl Ester Monomers

[0075] Under ice bath conditions, add 4 equivalents of glycidol, 1-8 equivalents of triethylamine and 50 mL of solvent dichloromethane, and slowly dropwise add the diacyl chloride monomer to the mixture. After the addition is complete, raise the mixture to room temperature and stir for 4 hours. After the reaction is completed, perform rotary evaporation post-treatment to obtain the target product.

[0076] Example 13: Preparation of Furan-based Bio-based Epoxy Glycidyl Ester Monomers

[0077] Under ice bath conditions, add 4 equivalents of glycidol, 2 equivalents of triethylamine and 50 mL of solvent dichloromethane, and slowly dropwise add the diacyl chloride monomer to the mixture. After the addition is complete, raise the mixture to room temperature and stir for 1-12 hours. After the reaction is completed, perform rotary evaporation post-treatment to obtain the target product.

[0078] Example 14: Preparation of Furan-based Bio-based Epoxy Glycidyl Ester Monomers

[0079] Under ice bath conditions, 4 equivalents of glycidol, 2 equivalents of triethylamine and 50 mL of the solvent dichloromethane were added, and the diacyl chloride monomer was slowly added dropwise to the mixture. After the addition was complete, the mixture was warmed to room temperature and stirred for 1 to 12 hours. After the reaction was completed, the target product was obtained after rotary evaporation workup.

[0080] Table 4: Furan-based bio-based glycidyl ester monomers and raw materials

[0081]

[0082]

[0083] Table 5 Reaction conditions for Examples 11 - 14

[0084]

[0085]

[0086] Example 15: Preparation of bio-based epoxy thermosetting materials

[0087] In the first step, 20 - 80 parts of lipoic acid and 0 - 5 parts of the catalyst TBD were mixed and heated to 140 °C for a ring-opening polymerization reaction for 0.5 hours, and then quickly mixed with 20 - 80 parts of glycidyl ether monomer and 20 - 80 parts of glycidyl ester monomer and poured into a mold. In the second step, the mixture was first pre-cured at 80 °C for 4 hours, and then heated to 160 °C for curing for 2 hours. After curing was completed, the target epoxy thermosetting material was obtained.

[0088] Example 16: Preparation of bio-based epoxy thermosetting materials

[0089] In the first step, 30 parts of lipoic acid and 5 parts of different catalysts were mixed and heated to 140 °C for a ring-opening polymerization reaction for 0.5 hours, and then quickly mixed with 65 parts of glycidyl ether monomer and poured into a mold. In the second step, the mixture was first pre-cured at 80 °C for 4 hours, and then heated to 160 °C for curing for 2 hours. After curing was completed, the target epoxy thermosetting material was obtained.

[0090] Example 17: Preparation of bio-based epoxy thermosetting materials

[0091] In the first step, 30 parts of lipoic acid and 5 parts of the catalyst TBD were mixed and heated to 80 - 160 °C for a ring-opening polymerization reaction for 0.5 hours, and then quickly mixed with 65 parts of glycidyl ether monomer and poured into a mold. In the second step, the mixture was first pre-cured at 80 °C for 4 hours, and then heated to 160 °C for curing for 2 hours. After curing was completed, the target epoxy thermosetting material was obtained.

[0092] Example 18: Preparation of bio-based epoxy thermosetting materials

[0093] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for ring-opening polymerization reaction for 0.5 - 4 hours, and then quickly mix with 65 parts of glycidyl ether monomer and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 4 hours, then heated up to 160 °C for curing for 2 hours, and after the curing is completed, the target epoxy thermosetting material is obtained.

[0094] Example 19: Preparation of bio-based epoxy thermosetting material

[0095] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for ring-opening polymerization reaction for 0.5 hour, and then quickly mix with 65 parts of glycidyl ether monomer and pour into a mold. Second step: The mixture is first pre-cured at 60 - 120 °C for 4 hours, then heated up to 160 °C for curing for 2 hours, and after the curing is completed, the target epoxy thermosetting material is obtained.

[0096] Example 20: Preparation of bio-based epoxy thermosetting material

[0097] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for ring-opening polymerization reaction for 0.5 hour, and then quickly mix with 65 parts of glycidyl ether monomer and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 0.5 - 8 hours, then heated up to 160 °C for curing for 2 hours, and after the curing is completed, the target epoxy thermosetting material is obtained.

[0098] Example 21: Preparation of bio-based epoxy thermosetting material

[0099] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for ring-opening polymerization reaction for 0.5 hour, and then quickly mix with 65 parts of glycidyl ether monomer and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 4 hours, then heated up to 120 - 180 °C for curing for 2 hours, and after the curing is completed, the target epoxy thermosetting material is obtained.

[0100] Example 22: Preparation of bio-based epoxy thermosetting material

[0101] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for ring-opening polymerization reaction for 0.5 hour, and then quickly mix with 65 parts of glycidyl ether monomer and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 4 hours, then heated up to 160 °C for curing for 0.5 - 4 hours, and after the curing is completed, the target epoxy thermosetting material is obtained.

[0102] Example 23: Preparation of bio-based epoxy thermosetting material

[0103] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for a ring-opening polymerization reaction for 0.5 hours. Subsequently, quickly mix with 65 parts of different epoxy resin monomers (glycidyl ester or glycidyl amine) and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 4 hours, then heated up to 160 °C for curing for 2 hours. After curing is completed, the target epoxy thermosetting material is obtained.

[0104] Table 6 Reaction conditions and performance data of Examples 15 - 23

[0105]

[0106]

[0107] Example 24: Preparation of bio-based epoxy thermosetting material

[0108] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for a ring-opening polymerization reaction for 0.5 hours. Subsequently, quickly mix with 65 parts of glycidyl ester CC2 and 65 parts of glycidyl amine and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 4 hours, then heated up to 160 °C for curing for 2 hours. After curing is completed, the target epoxy thermosetting material is obtained.

[0109] Example 25: Preparation of bio-based epoxy thermosetting material

[0110] First step: Mix 30 parts of lipoic acid with 5 parts of catalyst TBD, then heat up to 140 °C for a ring-opening polymerization reaction for 0.5 hours. Subsequently, quickly mix with 20 - 80 parts of glycidyl ester and 20 - 80 parts of glycidyl amine and pour into a mold. Second step: The mixture is first pre-cured at 80 °C for 4 hours, then heated up to 160 °C for curing for 2 hours. After curing is completed, the target epoxy thermosetting material is obtained.

[0111] Table 7 Reaction conditions and performance data of Examples 24 - 25

[0112] Serial number Epoxy monomer 1 Epoxy monomer 2 Mass ratio Tensile strength / MPa Elongation at break / % 1 AA1 CC2 1：1 44.29 2.08 2 AA2 CC2 1：1 39.17 1.42 3 AA3 CC2 1：1 42.29 2.90 4 AA4 CC2 1：1 58.09 3.93 5 AA5 CC2 1：1 45.82 3.05 6 AA6 CC2 1：1 66.78 8.20 7 AA6 CC2 2：1 54.01 7.36 8 AA6 CC2 1：2 23.99 3.90

[0113] Compared with the thermosetting material prepared from a single epoxy resin, the compounded epoxy resin has both the multi-branching degree of glycidyl amine and the high rigidity of glycidyl ester, thus forming an epoxy network with high strength, high thermal stability and high cross-linking degree. In addition, the structure contains double dynamic covalent bonds of ester bonds and disulfide bonds, which promotes the depolymerization of bio-based epoxy resin.

[0114] Example 26: Depolymerization and recycling of bio-based epoxy thermosetting material

[0115] Add 1 to 10 g of epoxy thermosetting material to 1 M aqueous sodium hydroxide solution and stir at room temperature for 2 to 12 hours until the material is completely depolymerized. Infrared structural characterization was performed on the depolymerized sample, as Figure 2 shown, indicating that the polymer material has been successfully depolymerized into polyol monomers.

[0116] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a polydisulfide-reinforced bio-based epoxy thermosetting material, characterized in that The steps include: Step 1: Mix lipoic acid and a catalyst, heat them up to cause a ring-opening polymerization reaction, and then quickly mix them with an epoxy monomer and pour them into a mold; Step 2: First, pre-curing is performed, and then the temperature is raised for curing, and after the curing is completed, the target epoxy thermosetting material is obtained; The epoxy monomer is selected from one or more of the following glycidyl ether, glycidyl ester, and glycidyl amine structural compounds: Wherein: R1, R2, R3 are independently selected from -CH2OCH2-, -(CH2) n -、 n=1-5.

2. The preparation method according to claim 1, characterized in that: The epoxy monomer is a composite of two of the structural compounds of glycidyl ether, glycidyl ester and glycidyl amine.

3. The preparation method according to claim 2, characterized in that: The epoxy monomer is a compound of glycidyl ester and glycidyl amine, and the mass ratio of the two is 1:2 to 2:

1.

4. The preparation method according to claim 1, characterized in that The composition of each raw material by mass is as follows: Epoxy monomer 20-80 parts, thioctic acid 20-80 parts, catalyst 0-5 parts.

5. The preparation method according to claim 1 or 4, characterized in that: The catalyst is one or a mixture of metal acetylacetonate, metal acetate, and organic base 1,5,7-triazacyclo[4.4.0]dodec-5-ene.

6. The preparation method according to claim 1, characterized in that: In step 1, the temperature for the ring-opening polymerization reaction is 80-160° C. and the time is 0.5-4 h.

7. The preparation method according to claim 1, characterized in that: In step 2, the pre-curing temperature is 60-120° C., and the pre-curing time is 0.5-8 hours.

8. The preparation method according to claim 1, characterized in that: In step 2, the curing temperature is 120-180° C., and the curing time is 0.5-4 hours.

9. Use of the bio-based epoxy thermosetting material prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The bio-based epoxy thermosetting material is completely depolymerized in an alkaline solution at room temperature.

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