Bio-based 3D printing resin and preparation method thereof

Abstract

The invention discloses bio-based 3D printing resin and a preparation method thereof, and belongs to the technical field of resin preparation. The bio-based 3D printing resin is prepared from the following components in parts by weight: 46 to 62 parts of castor oil, 24 to 32 parts of bio-based polyethylene, 8 to 12 parts of 2-hydroxy-2-methyl-1-phenyl-1-acetone, 2 to 5 parts of hydroxyethyl methylacrylate, 3 to 7 parts of pentaerythritol, 1 to 1.5 parts of p-toluenesulfonic acid, 2 to 2.8 parts of glycerol, 0.8 to 1.4 parts of a composite heat stabilizer and 0.3 to 0.6 part of a modified accelerant. The bio-based 3D printing resin prepared from the substances has excellent thermal stability, mechanical properties and light curing rate.

Description

Technical Field

[0001] This invention belongs to the field of resin preparation technology, specifically relating to a bio-based 3D printing resin and its preparation method. Background Technology

[0002] Bio-based 3D printing resins, as innovative materials in the field of green manufacturing, are being developed due to the environmental pressures and sustainable development needs of traditional petroleum-based resins. Petroleum-based resins have long dominated the 3D printing market, but their non-degradability has led to increasingly serious white pollution problems, and their production process generates high carbon emissions, contradicting global "dual carbon" goals. Against this backdrop, bio-based resins have become a research hotspot due to their renewable, degradable, and low-carbon emission characteristics. Their raw materials mainly come from plant oils (such as soybean oil and castor oil), lignin, starch, and other biomass resources. Through chemical modification, acrylate groups or photosensitive groups are introduced to achieve second-level curing under ultraviolet light, balancing the high-precision molding requirements of 3D printing with environmental performance.

[0003] Patent CN113583165B discloses a 3D printing resin and its preparation method. The preparation method includes: (1) synthesizing a bio-based acrylate monomer using biomass and bio-based glycidyl methacrylate as raw materials; (2) mixing the bio-based acrylate monomer and a photoinitiator, and performing photocuring 3D printing to obtain a bio-based 3D printing resin. The bio-based 3D printing resin prepared by this invention has a green preparation method, a simple preparation process, and is easy to industrialize. The resulting resin has excellent comprehensive properties and can be directly applied to 3D printing. It also pioneers a method for preparing high-performance 3D printing resin using aliphatic biomass. Although the 3D printing resin prepared by the above patent using biomass and bio-based glycidyl methacrylate has advantages in green process and raw material renewability, it still has problems with insufficient thermal stability and toughness in practical applications. This is mainly due to the complexity of biomass raw materials, which limits the uniformity of the polymerization reaction. Some unreacted active groups or small molecule impurities are easily decomposed at high temperatures, weakening the thermal stability of the material. At the same time, the molecular chain structure of bio-based monomers is relatively simple and the cross-linking density is insufficient, making it difficult for the resin to effectively disperse stress when subjected to force, resulting in low toughness. Summary of the Invention

[0004] The purpose of this invention is to provide a bio-based 3D printing resin and its preparation method, which solves the technical problems of poor thermal stability and mechanical properties of printing resins in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a bio-based 3D printing resin, which is composed of the following components by weight: 46-62 parts castor oil, 24-32 parts bio-based polyethylene, 8-12 parts 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-5 parts hydroxyethyl methacrylate, 3-7 parts pentaerythritol, 1-1.5 parts p-toluenesulfonic acid, 2-2.8 parts glycerol, 0.8-1.4 parts composite heat stabilizer, and 0.3-0.6 parts modified accelerator.

[0006] Preferably, the preparation method of the composite heat stabilizer includes the following steps: Q1: Bisphenol AF and N,N-dimethylformamide were added to a container and stirred to dissolve. Anhydrous potassium carbonate and toluene were added, and the mixture was heated to reflux. Then the temperature was lowered, and a mixed solution of 2-chloro-3,5-dinitrotrifluorotoluene and N,N-dimethylformamide was added. After the addition was complete, the reaction was continued. The mixture was filtered while hot, evaporated by rotary evaporation, added to ethanol, and stirred until crystals appeared. The mixture was washed, dried, and recrystallized to obtain organic compound a. Q2: Add organic compound a, ethanol and N,N-dimethylformamide to a container, then add Pd / C, purge with nitrogen, heat up, purge with hydrogen to maintain the pressure inside the container, and let the reaction proceed. After the reaction is complete, filter while hot, pour the solution into distilled water, precipitate out, dry, recrystallize to obtain organic compound b. Q3: Add organic compound b, maleic anhydride and N,N-dimethylformamide to a container, stir to dissolve, heat to react, add distilled water after the reaction is complete, filter, wash and dry, then add to toluene containing p-toluenesulfonic acid, dehydrate, cool, precipitate solid, wash and dry to obtain organic compound c; Q4: Polycaprolactone diol was dehydrated under vacuum, cooled, and added to a container. Then, diphenylmethane diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide were added in sequence and heated to react. Then, furfuryl alcohol was added and the reaction continued. After the reaction was completed, the temperature was lowered to obtain organic compound d. Then, organic compound c was added to organic compound d and reacted to obtain a composite heat stabilizer.

[0007] In the above process, reversible covalent Diels-Alder bonds are formed between organic compound c and organic compound d, thereby obtaining a composite heat stabilizer. The synthesis reaction formula of organic compound c is as follows:

[0008] The mass spectrometry analysis results of organic compound a were: m / z: 804.04 (100.0%), 805.04 (31.9%), 806.04 (7.4%), 805.03 (1.5%); the mass spectrometry analysis results of organic compound b were: m / z: 684.14 (100.0%), 685.14 (32.9%), 686.15 (4.8%); the mass spectrometry analysis results of organic compound c were: m / z: 1004.10 (100.0%), 1005.10 (50.5%), 1006.11 (11.9%), 1007.11 (2.9%), 1006.10 (2.8%). The synthesis reaction formula for organic compound d is as follows:

[0009] Preferably, in Q1, the ratio of bisphenol AF, anhydrous potassium carbonate, toluene, and 2-chloro-3,5-dinitrotrifluorotoluene is (33.12-34.02) g : (13.12-14.28) g : (90-110) mL : (55.12-55.82) g. The mixture is heated to 130-140℃ and refluxed for 90-100 min, then cooled to 100-102℃ and reacted for another 3-5 h. The mixture is then rotary evaporated at 110-120℃ and added to a mixed solution of N,N-dimethylformamide and ethanol in a volume ratio of 1:1 for recrystallization.

[0010] Preferably, in Q2, the ratio of organic compound a, ethanol, N,N-dimethylformamide, and Pd / C is (62-68) g : (180-220) mL : (380-430) mL : (9.2-10.3) g, the temperature is raised to 70-72℃, the pressure inside the container is maintained at 0.4-0.6 MPa, the reaction is carried out for 4-6 h, and recrystallization is performed with ethanol; in Q3, the ratio of organic compound b, maleic anhydride, N,N-dimethylformamide, p-toluenesulfonic acid, and toluene is (3.12-3.45) g : (7.22-8.23) g : (38-42) mL : (0.21-0.28) g : (30-45) mL, the reaction temperature is heated to 50-60℃, the time is 1-2 h, and the dehydration reaction time is 2-4 h.

[0011] Preferably, in Q4, the ratio of polycaprolactone diol, diphenylmethane diisocyanate, dibutyltin dilaurate, N,N-dimethylformamide, furfuryl alcohol, and organic compound c is (19.88-21.21) g : (4.12-4.68) g : (0.01-0.03) g : (50-65) mL : (1.92-2.14) g : (3.12-4.23) g, the average molecular weight of polycaprolactone diol is 2000, the vacuum dehydration temperature is 100-104℃, the time is 1-2 h, the temperature is cooled to 72-75℃, the reaction temperature is heated to 72-78℃, the time is 2-4 h, the reaction time is continued for 2-3 h, the temperature is lowered to 60-65℃, and the reaction time is 42-48 h.

[0012] Preferably, the preparation method of the modified accelerator includes the following steps: S1: Add 2-chloro-6-nitrobenzoic acid, sodium sulfide and an aqueous ethanol solution to a container, heat and stir to react. After the reaction is complete, add dichloromethane, filter, and distill under reduced pressure to obtain intermediate 1; add intermediate 1 and formamide to a container, heat to react, then add ice water, precipitate solid, filter, dry, recrystallize to obtain intermediate 2. S2: Intermediate 2, 4-vinylpyridine, scandium trifluoromethanesulfonate and toluene were added to a container and the reaction was carried out under nitrogen atmosphere. After the reaction was completed, the mixture was distilled under reduced pressure, dichloromethane was added, filtered, dried, concentrated under reduced pressure, and recrystallized to obtain intermediate 3. S3: 1,8-Dihydroxyanthraquinone, anhydrous potassium carbonate and N,N-dimethylformamide were added to a container, stirred and mixed, and then intermediate 3 was added. The mixture was heated under nitrogen atmosphere. After the reaction was completed, the mixture was cooled, poured into ice water, pH was adjusted, filtered, washed, dried, rotary evaporated and purified to obtain the modified accelerator.

[0013] The synthesis reaction formula for the modification accelerator in the above process is as follows:

[0014] The mass spectrometry analysis results of intermediate 1 were: m / z: 171.01 (100.0%), 173.01 (32.4%), 172.01 (8.1%), 174.01 (2.5%); the mass spectrometry analysis results of intermediate 2 were: m / z: 180.01 (100.0%), 182.01 (32.2%), 181.01 (9.4%), 183.01 (2.8%); the mass spectrometry analysis results of intermediate 3 were: m / z: 285.07 (100.0%), 287.06 (32.0%), 286.07 (16.4%), 288.07 (5.3%), 287.07 (1.6%), 286.06 (1.1%); The mass spectrometry analysis results of the modified accelerator were as follows: m / z: 738.22 (100.0%), 739.23 (48.2%), 740.23 (12.6%), 741.23 (2.5%), 739.22 (2.2%), 740.22 (1.1%).

[0015] Preferably, in S1, the ratio of 2-chloro-6-nitrobenzoic acid, sodium sulfide, aqueous ethanol solution, and dichloromethane is (0.81-0.88) g : (0.71-0.78) g : (12-15) mL : (20-25) mL, the volume fraction of the aqueous ethanol solution is 10 vt%, the temperature is raised to 80-82℃, and the reaction time is stirred for 2-4 h; the ratio of intermediate 1 to formamide is (0.63-0.72) g : (1.08-1.25) g, and the reaction is carried out at 120-135℃ for 5-7 h.

[0016] Preferably, in step S2, the ratio of intermediate 2, 4-vinylpyridine, scandium trifluoromethanesulfonate, and toluene is (0.31-0.42) g : (0.41-0.48) g : (0.08-0.12) g : (18-22) mL, and the reaction is carried out at 105-110℃ for 5-7 h; in step S3, the molar ratio of 1,8-dihydroxyanthraquinone and intermediate 3 is (0.8-1.2) : (1.5-2.5), and the reaction is carried out at 100-120℃ for 6-12 h, with the pH adjusted to 6-7 using 1 mol / L hydrochloric acid.

[0017] Preferably, the method for preparing a bio-based 3D printing resin includes the following steps: Step 1: After vacuum dehydration of castor oil, add it to a container, followed by the sequential addition of bio-based polyethylene, pentaerythritol, and p-toluenesulfonic acid. Under nitrogen protection, heat the mixture to obtain a mixture. Step 2: Cool the mixture, then add hydroxyethyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone. After heating and stirring to react, add the composite heat stabilizer, heat and melt to blend, then add the modifier accelerator and glycerol, stir to react, cool, and dry to obtain the bio-based 3D printing resin.

[0018] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This invention first prepares a composite heat stabilizer using bisphenol AF, 2-chloro-3,5-dinitrotrifluorotoluene, maleic anhydride, polycaprolactone diol, diphenylmethane diisocyanate, and furfuryl alcohol as raw materials. Then, a modification accelerator is prepared using 2-chloro-6-nitrobenzoic acid, 4-vinylpyridine, and 1,8-dihydroxyanthraquinone as raw materials. The prepared composite heat stabilizer and modification accelerator are then applied to the preparation process of printing resin, which can effectively improve its thermal stability, mechanical properties, and photocuring rate.

[0019] 2. This invention applies the prepared composite heat stabilizer to the preparation process of bio-based 3D printing resin, which can effectively improve its thermal stability and mechanical properties. The maleimide ring contained in the composite stabilizer can capture free radicals and interrupt the chain reaction. The benzene ring structure contained therein can disperse energy through conjugation stability, and the formed hydrogen bond network can restrict molecular chain movement and improve the thermal stability of the printing resin. The soft-hard segment material formed by polycaprolactone diol soft segment and diphenylmethane diisocyanate can effectively improve its mechanical properties.

[0020] 3. This invention applies the prepared modified accelerator to the preparation process of bio-based 3D printing resin, which can effectively improve its photocuring rate, thermal stability and mechanical properties. The anthraquinone group contained in the modified accelerator acts as a photosensitizer to absorb ultraviolet light, and the introduced pyridine group can act as a co-catalyst to accelerate network formation. The anthraquinone, quinazolinone and pyridine contained in the modified accelerator are aromatic heterocycles with a large π-conjugated system, which can effectively disperse thermal vibration energy and increase the thermal decomposition temperature. The rigid aromatic rings are embedded in the resin network, restricting the movement of polymer chain segments, so that the resin can still maintain shape stability at high temperature. In addition, anthraquinone and quinazolinone are rigid planar structures, which can act as physical crosslinking points in the resin network, effectively bearing stress, thereby improving its mechanical properties. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: This example discloses a method for preparing a composite heat stabilizer, including the following steps: Q1: Add 33.57g of bisphenol AF and 100mL of N,N-dimethylformamide to a container, stir to dissolve, then add 13.65g of anhydrous potassium carbonate and 100mL of toluene, heat to 135℃ and reflux for 90min, then cool to 100℃, add 55.46g of a mixed solution of 2-chloro-3,5-dinitrotrifluorotoluene and 100mL of N,N-dimethylformamide, continue to react for 4h after the addition is complete, filter while hot, rotary evaporate at 110℃, add to ethanol, stir until crystals appear, wash, dry, add to a mixed solution of N,N-dimethylformamide and ethanol in a volume ratio of 1:1 for recrystallization to obtain organic compound a; Q2: Add 65g of organic compound a, 200mL of ethanol and 405mL of N,N-dimethylformamide to a container, then add 9.8g of Pd / C, purge with nitrogen, heat to 70℃, then purge with hydrogen, maintain the pressure in the container at 0.5MPa, and react for 6h. After the reaction is complete, filter while hot, pour the solution into distilled water, precipitate out, dry, and recrystallize with ethanol to obtain organic compound b. Q3: Add 3.28g of organic compound b, 7.71g of maleic anhydride and 40mL of N,N-dimethylformamide to a container, stir to dissolve, heat at 55℃ for 2h, after the reaction is complete, add distilled water, filter, wash and dry, then add to 37.5mL of toluene containing 0.25g of p-toluenesulfonic acid, dehydrate for 4h, cool, precipitate solid, wash and dry to obtain organic compound c; Q4: 20.52g of polycaprolactone diol with an average molecular weight of 2000 was dehydrated under vacuum at 100℃ for 2h, cooled to 72℃, and added to a container. Then, 4.4g of diphenylmethane diisocyanate, 0.02g of dibutyltin dilaurate, and 57.5mL of N,N-dimethylformamide were added sequentially. The mixture was heated at 75℃ for 4h, followed by the addition of 2.03g of furfuryl alcohol, and the reaction was continued for 3h. After the reaction was completed, the temperature was lowered to 60℃ to obtain organic compound d. Then, 3.72g of organic compound c was added to organic compound d, and the reaction was carried out for 48h to obtain a composite heat stabilizer.

[0023] This embodiment discloses a method for preparing a modified accelerator, including the following steps: S1: 0.84 g of 2-chloro-6-nitrobenzoic acid, 0.75 g of sodium sulfide, and 13.5 mL of 10 wt% ethanol aqueous solution were added to a container, heated to 80 °C, and stirred for 4 h. After the reaction was completed, 22.5 mL of dichloromethane was added, filtered, and distilled under reduced pressure to obtain intermediate 1. 0.68 g of intermediate 1 and 1.15 g of formamide were added to a container, heated to 120 °C, and reacted for 6 h. Ice water was then added, and a solid precipitated. The solid was filtered, dried, and recrystallized to obtain intermediate 2. S2: Add 0.36g of intermediate 2, 0.44g of 4-vinylpyridine, 0.1g of scandium trifluoromethanesulfonate and 20mL of toluene to a container, and heat to 110℃ for 6h under nitrogen atmosphere. After the reaction is completed, distill under reduced pressure, add dichloromethane, filter, dry, concentrate under reduced pressure, and recrystallize to obtain intermediate 3. S3: Add 0.48g of 1,8-dihydroxyanthraquinone, 0.12g of anhydrous potassium carbonate and 10mL of N,N-dimethylformamide to a container, stir and mix, then add 1.14g of intermediate 3. Under nitrogen atmosphere, heat at 110℃ for 8h. After the reaction is complete, cool and pour into ice water. Adjust the pH to 7 with 1mol / L hydrochloric acid, filter, wash, dry, rotary evaporate, and purify to obtain the modification accelerator.

[0024] This embodiment discloses a bio-based 3D printing resin, which is composed of the following components by weight: 54 parts castor oil, 29 parts bio-based polyethylene, 10 parts 2-hydroxy-2-methyl-1-phenyl-1-propanone, 3.5 parts hydroxyethyl methacrylate, 5 parts pentaerythritol, 1.25 parts p-toluenesulfonic acid, 2.4 parts glycerol, 1.1 parts composite heat stabilizer and 0.45 parts modification accelerator.

[0025] This embodiment discloses a method for preparing a bio-based 3D printing resin, including the following steps: Step 1: After vacuum dehydration of castor oil, add it to a container, followed by the sequential addition of bio-based polyethylene, pentaerythritol, and p-toluenesulfonic acid. Under nitrogen protection, heat the mixture to obtain a mixture. Step 2: Cool the mixture, then add hydroxyethyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone. After heating and stirring, add a composite heat stabilizer, heat and melt blend, then add a modifier accelerator and glycerol, stir and react, cool, and dry to obtain a bio-based 3D printing resin.

[0026] Example 2: This example discloses a method for preparing a composite heat stabilizer, including the following steps: Q1: Add 33.12g of bisphenol AF and 100mL of N,N-dimethylformamide to a container, stir to dissolve, then add 13.12g of anhydrous potassium carbonate and 90mL of toluene, heat to 135℃ and reflux for 90min, then cool to 100℃, add a mixed solution of 55.12g of 2-chloro-3,5-dinitrotrifluorotoluene and 100mL of N,N-dimethylformamide, and continue to react for 4h after the addition is complete. Filter while hot, evaporate at 110℃, add to ethanol, stir until crystals appear, wash, dry, and recrystallize in a mixed solution of N,N-dimethylformamide and ethanol at a volume ratio of 1:1 to obtain organic compound a; Q2: Add 62g of organic compound a, 220mL of ethanol and 430mL of N,N-dimethylformamide to a container, then add 9.2g of Pd / C, purge with nitrogen, heat to 70℃, then purge with hydrogen, maintain the pressure in the container at 0.5MPa, and react for 6h. After the reaction is complete, filter while hot, pour the solution into distilled water, precipitate out, dry, and recrystallize with ethanol to obtain organic compound b; Q3: Add 3.12g of organic compound b, 7.22g of maleic anhydride and 42mL of N,N-dimethylformamide to a container, stir to dissolve, heat at 55℃ for 2h, after the reaction is complete, add distilled water, filter, wash and dry, then add to 30mL of toluene containing 0.21g of p-toluenesulfonic acid, dehydrate for 4h, cool, precipitate solid, wash and dry to obtain organic compound c; Q4: 21.22g of polycaprolactone diol with an average molecular weight of 2000 was dehydrated under vacuum at 100℃ for 2h, cooled to 72℃, and added to a container. Then, 4.12g of diphenylmethane diisocyanate, 0.01g of dibutyltin dilaurate, and 50mL of N,N-dimethylformamide were added sequentially. The mixture was heated at 75℃ for 4h, followed by the addition of 1.92g of furfuryl alcohol, and the reaction was continued for 3h. After the reaction was completed, the temperature was lowered to 60℃ to obtain organic compound d. Then, 3.12g of organic compound c was added to organic compound d, and the reaction was carried out for 48h to obtain a composite heat stabilizer.

[0027] This embodiment discloses a method for preparing a modified accelerator, including the following steps: S1: 0.81 g of 2-chloro-6-nitrobenzoic acid, 0.71 g of sodium sulfide, and 12 mL of 10 wt% ethanol aqueous solution were added to a container. The mixture was heated to 80 °C and stirred for 4 h. After the reaction was completed, 25 mL of dichloromethane was added, filtered, and distilled under reduced pressure to obtain intermediate 1. 0.63 g of intermediate 1 and 1.25 g of formamide were added to a container. The mixture was heated to 120 °C and reacted for 6 h. Ice water was then added, and a solid precipitated. The solid was filtered, dried, and recrystallized to obtain intermediate 2. S2: 0.31 g of intermediate 2, 0.41 g of 4-vinylpyridine, 0.08 g of scandium trifluoromethanesulfonate and 18 mL of toluene were added to a container. Under nitrogen atmosphere, the temperature was raised to 110 °C and reacted for 6 h. After the reaction was completed, the mixture was distilled under reduced pressure, dichloromethane was added, filtered, dried, concentrated under reduced pressure, and recrystallized to obtain intermediate 3. S3: Add 0.38g of 1,8-dihydroxyanthraquinone, 0.12g of anhydrous potassium carbonate and 10mL of N,N-dimethylformamide to a container, stir and mix, then add 0.86g of intermediate 3. Under nitrogen atmosphere, heat at 110℃ for 8h. After the reaction is complete, cool and pour into ice water. Adjust the pH to 7 with 1mol / L hydrochloric acid, filter, wash, dry, rotary evaporate, and purify to obtain the modification accelerator.

[0028] This embodiment discloses a bio-based 3D printing resin, which is composed of the following components by weight: 46 parts castor oil, 24 parts bio-based polyethylene, 8 parts 2-hydroxy-2-methyl-1-phenyl-1-propanone, 5 parts hydroxyethyl methacrylate, 7 parts pentaerythritol, 1.5 parts p-toluenesulfonic acid, 2 parts glycerol, 0.8 parts composite heat stabilizer and 0.3 parts modification accelerator.

[0029] This embodiment discloses a method for preparing a bio-based 3D printing resin, including the following steps: Step 1: After vacuum dehydration of castor oil, add it to a container, followed by the sequential addition of bio-based polyethylene, pentaerythritol, and p-toluenesulfonic acid. Under nitrogen protection, heat the mixture to obtain a mixture. Step 2: Cool the mixture, then add hydroxyethyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone. After heating and stirring, add a composite heat stabilizer, heat and melt blend, then add a modifier accelerator and glycerol, stir and react, cool, and dry to obtain a bio-based 3D printing resin.

[0030] Example 3: This example discloses a method for preparing a composite heat stabilizer, including the following steps: Q1: 34.02g of bisphenol AF and 100mL of N,N-dimethylformamide were added to a container and stirred to dissolve. Then, 14.28g of anhydrous potassium carbonate and 110mL of toluene were added. The mixture was heated to 135℃ and refluxed for 90min. Then, the temperature was lowered to 100℃ and a mixed solution of 55.82g of 2-chloro-3,5-dinitrotrifluorotoluene and 100mL of N,N-dimethylformamide was added. After the addition was complete, the reaction was continued for 4h. The mixture was filtered while hot and evaporated at 110℃. The solution was added to ethanol and stirred until crystals appeared. The crystals were washed, dried, and recrystallized in a mixed solution of N,N-dimethylformamide and ethanol at a volume ratio of 1:1 to obtain organic compound a. Q2: Add 68g of organic compound a, 180mL of ethanol and 380mL of N,N-dimethylformamide to a container, then add 10.3g of Pd / C, purge with nitrogen, heat to 70℃, then purge with hydrogen, maintain the pressure in the container at 0.5MPa, and react for 6h. After the reaction is complete, filter while hot, pour the solution into distilled water, precipitate out, dry, and recrystallize with ethanol to obtain organic compound b. Q3: Add 3.45g of organic compound b, 8.23g of maleic anhydride and 38mL of N,N-dimethylformamide to a container, stir to dissolve, heat at 55℃ for 2h, after the reaction is complete, add distilled water, filter, wash and dry, then add to 45mL of toluene containing 0.28g of p-toluenesulfonic acid, dehydrate for 4h, cool, precipitate solid, wash and dry to obtain organic compound c; Q4: 19.88g of polycaprolactone diol with an average molecular weight of 2000 was dehydrated under vacuum at 100℃ for 2h, cooled to 72℃, and added to a container. Then, 4.68g of diphenylmethane diisocyanate, 0.03g of dibutyltin dilaurate, and 65mL of N,N-dimethylformamide were added sequentially. The mixture was heated at 75℃ for 4h, followed by the addition of 2.14g of furfuryl alcohol, and the reaction was continued for 3h. After the reaction was completed, the temperature was lowered to 60℃ to obtain organic compound d. Then, 4.23g of organic compound c was added to organic compound d, and the reaction was carried out for 48h to obtain a composite heat stabilizer.

[0031] This embodiment discloses a method for preparing a modified accelerator, including the following steps: S1: 0.88 g of 2-chloro-6-nitrobenzoic acid, 0.78 g of sodium sulfide, and 15 mL of 10 wt% ethanol aqueous solution were added to a container. The mixture was heated to 80 °C and stirred for 4 h. After the reaction was completed, 20 mL of dichloromethane was added, filtered, and distilled under reduced pressure to obtain intermediate 1. 0.72 g of intermediate 1 and 1.08 g of formamide were added to a container. The mixture was heated to 120 °C and reacted for 6 h. Ice water was then added, and a solid precipitated. The solid was filtered, dried, and recrystallized to obtain intermediate 2. S2: 0.42 g of intermediate 2, 0.48 g of 4-vinylpyridine, 0.12 g of scandium trifluoromethanesulfonate and 22 mL of toluene were added to a container and the mixture was heated to 110 °C for 6 h under nitrogen atmosphere. After the reaction was completed, the mixture was distilled under reduced pressure, dichloromethane was added, filtered, dried, concentrated under reduced pressure, and recrystallized to obtain intermediate 3. S3: Add 0.58g of 1,8-dihydroxyanthraquinone, 0.12g of anhydrous potassium carbonate and 10mL of N,N-dimethylformamide to a container, stir and mix, then add 1.43g of intermediate 3. Under nitrogen atmosphere, heat at 110℃ for 8h. After the reaction is complete, cool and pour into ice water. Adjust the pH to 7 with 1mol / L hydrochloric acid, filter, wash, dry, rotary evaporate, and purify to obtain the modification accelerator.

[0032] This embodiment discloses a bio-based 3D printing resin, which is composed of the following components by weight: 62 parts castor oil, 32 parts bio-based polyethylene, 12 parts 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2 parts hydroxyethyl methacrylate, 3 parts pentaerythritol, 1 part p-toluenesulfonic acid, 2.8 parts glycerol, 1.4 parts composite heat stabilizer and 0.6 parts modification accelerator.

[0033] This embodiment discloses a method for preparing a bio-based 3D printing resin, including the following steps: Step 1: After vacuum dehydration of castor oil, add it to a container, followed by the sequential addition of bio-based polyethylene, pentaerythritol, and p-toluenesulfonic acid. Under nitrogen protection, heat the mixture to obtain a mixture. Step 2: Cool the mixture, then add hydroxyethyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone. After heating and stirring, add a composite heat stabilizer, heat and melt blend, then add a modifier accelerator and glycerol, stir and react, cool, and dry to obtain a bio-based 3D printing resin.

[0034] Example 4: This example discloses a method for preparing a composite heat stabilizer, including the following steps: Q1: 33.34 g of bisphenol AF and 100 mL of N,N-dimethylformamide were added to a container and stirred until dissolved. Then, 13.37 g of anhydrous potassium carbonate and 95 mL of toluene were added. The mixture was heated to 135 °C and refluxed for 90 min. Then, the mixture was cooled to 100 °C and a mixed solution of 55.31 g of 2-chloro-3,5-dinitrotrifluorotoluene and 100 mL of N,N-dimethylformamide was added. After the addition was complete, the mixture was reacted for 4 h. The mixture was filtered while hot and evaporated at 110 °C. The solution was added to ethanol and stirred until crystals appeared. The crystals were washed, dried, and recrystallized in a mixed solution of N,N-dimethylformamide and ethanol at a volume ratio of 1:1 to obtain organic compound a. Q2: Add 63g of organic compound a, 190mL of ethanol and 390mL of N,N-dimethylformamide to a container, then add 9.5g of Pd / C, purge with nitrogen, heat to 70℃, then purge with hydrogen, maintain the pressure in the container at 0.5MPa, and react for 6h. After the reaction is complete, filter while hot, pour the solution into distilled water, precipitate out, dry, and recrystallize with ethanol to obtain organic compound b; Q3: Add 3.16g of organic compound b, 7.48g of maleic anhydride and 39mL of N,N-dimethylformamide to a container, stir to dissolve, heat at 55℃ for 2h, after the reaction is complete, add distilled water, filter, wash and dry, then add to 35mL of toluene containing 0.24g of p-toluenesulfonic acid, dehydrate for 4h, cool, precipitate solid, wash and dry to obtain organic compound c; Q4: 20.12g of polycaprolactone diol with an average molecular weight of 2000 was dehydrated under vacuum at 100℃ for 2h, cooled to 72℃, and added to a container. Then, 4.31g of diphenylmethane diisocyanate, 0.015g of dibutyltin dilaurate, and 55mL of N,N-dimethylformamide were added sequentially. The mixture was heated at 75℃ for 4h, followed by the addition of 1.98g of furfuryl alcohol, and the reaction was continued for 3h. After the reaction was completed, the temperature was lowered to 60℃ to obtain organic compound d. Then, 3.61g of organic compound c was added to organic compound d, and the reaction was carried out for 48h to obtain a composite heat stabilizer.

[0035] This embodiment discloses a method for preparing a modified accelerator, including the following steps: S1: 0.82 g of 2-chloro-6-nitrobenzoic acid, 0.72 g of sodium sulfide, and 14 mL of 10 wt% ethanol aqueous solution were added to a container. The mixture was heated to 80 °C and stirred for 4 h. After the reaction was completed, 21 mL of dichloromethane was added, filtered, and distilled under reduced pressure to obtain intermediate 1. 0.65 g of intermediate 1 and 1.11 g of formamide were added to a container. The mixture was heated to 120 °C and reacted for 6 h. Ice water was then added, and a solid precipitated. The solid was filtered, dried, and recrystallized to obtain intermediate 2. S2: 0.33 g of intermediate 2, 0.42 g of 4-vinylpyridine, 0.09 g of scandium trifluoromethanesulfonate and 19 mL of toluene were added to a container. Under nitrogen atmosphere, the mixture was heated to 110 °C and reacted for 6 h. After the reaction was completed, the mixture was distilled under reduced pressure, dichloromethane was added, filtered, dried, concentrated under reduced pressure, and recrystallized to obtain intermediate 3. S3: Add 0.42g of 1,8-dihydroxyanthraquinone, 0.12g of anhydrous potassium carbonate and 10mL of N,N-dimethylformamide to a container, stir and mix, then add 0.98g of intermediate 3. Under nitrogen atmosphere, heat at 110℃ for 8h. After the reaction is complete, cool and pour into ice water. Adjust the pH to 7 with 1mol / L hydrochloric acid, filter, wash, dry, rotary evaporate, and purify to obtain the modification accelerator.

[0036] This embodiment discloses a bio-based 3D printing resin, which is composed of the following components by weight: 48 parts castor oil, 26 parts bio-based polyethylene, 9 parts 2-hydroxy-2-methyl-1-phenyl-1-propanone, 3 parts hydroxyethyl methacrylate, 4 parts pentaerythritol, 1.1 parts p-toluenesulfonic acid, 2.2 parts glycerol, 0.9 parts composite heat stabilizer and 0.4 parts modification accelerator.

[0037] This embodiment discloses a method for preparing a bio-based 3D printing resin, including the following steps: Step 1: After vacuum dehydration of castor oil, add it to a container, followed by the sequential addition of bio-based polyethylene, pentaerythritol, and p-toluenesulfonic acid. Under nitrogen protection, heat the mixture to obtain a mixture. Step 2: Cool the mixture, then add hydroxyethyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone. After heating and stirring, add a composite heat stabilizer, heat and melt blend, then add a modifier accelerator and glycerol, stir and react, cool, and dry to obtain a bio-based 3D printing resin.

[0038] Comparative Example 1: Compared with Example 1, Comparative Example 1 did not add a composite heat stabilizer during the preparation of bio-based 3D printing resin, and all other conditions remained unchanged.

[0039] Comparative Example 2: Compared with Example 1, Comparative Example 2 did not add any modifying accelerator during the preparation of bio-based 3D printing resin, and all other conditions remained unchanged.

[0040] Performance testing: The bio-based 3D printing resins prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests. The load deformation temperature of the samples was tested according to GB / T1634.2-2019, the tensile properties were tested according to GB / T 1040.2-2022, the impact resistance was tested according to ASTM D256, and the photocuring rate was tested according to ASTM D1003. The test results are shown in Table 1. Table 1

[0041] As shown in Table 1, the test results indicate that the methods described in Examples 1-5 can effectively improve the thermal stability, mechanical properties, and curing rate of the printing resin. A comparison between Comparative Example 1 and Examples 1-4 reveals that adding a composite heat stabilizer can effectively improve the thermal stability and mechanical properties of the printing resin; a comparison between Comparative Example 2 and Examples 1-4 reveals that adding a modified accelerator can effectively improve the thermal stability, mechanical properties, and curing rate of the printing resin.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0043] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A bio-based 3D printing resin, characterized in that, The composition comprises the following components by weight: 46-62 parts of castor oil, 24-32 parts of bio-based polyethylene, 8-12 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-5 parts of hydroxyethyl methacrylate, 3-7 parts of pentaerythritol, 1-1.5 parts of p-toluenesulfonic acid, 2-2.8 parts of glycerol, 0.8-1.4 parts of a composite heat stabilizer, and 0.3-0.6 parts of a modified accelerator.

2. The bio-based 3D printing resin according to claim 1, characterized in that, The preparation method of the composite heat stabilizer comprises the following steps: Q1: Bisphenol AF and N,N-dimethylformamide are added to a container, after stirring and dissolving, anhydrous potassium carbonate and toluene are added, and the reaction is carried out under reflux, then the temperature is lowered, a mixed solution of 2-chloro-3,5-dinitrobenzotrifluoride and N,N-dimethylformamide is added, after the addition is completed, the reaction is continued, hot filtration is carried out, rotary evaporation is carried out, it is added to ethanol, stirring is carried out until crystals appear, washing and drying are carried out, recrystallization is carried out, and organic matter a is obtained; Q2: Organic matter a, ethanol and N,N-dimethylformamide are added to a container, then Pd / C is added, nitrogen replacement is carried out, after warming, hydrogen is used to replace nitrogen, the pressure in the container is maintained, and the reaction is carried out, after the reaction is completed, hot filtration is carried out, the solution is poured into distilled water, a precipitate is separated out, drying and recrystallization are carried out, and organic matter b is obtained; Q3: Organic matter b, maleic anhydride and N,N-dimethylformamide are added to a container, stirring and dissolving are carried out, and the reaction is carried out under heating, after the reaction is completed, distilled water is added, filtration is carried out, washing and drying are carried out, then it is added to toluene containing p-toluenesulfonic acid, dehydration reaction is carried out, cooling is carried out, a solid is separated out, washing and drying are carried out, and organic matter c is obtained; Q4: After vacuum dehydration of polycaprolactone diol, cooling is carried out, it is added to a container, then diphenylmethane diisocyanate, dibutyltin dilaurate and N,N-dimethylformamide are added in sequence, heating reaction is carried out, then furfuryl alcohol is added, and the reaction is continued, after the reaction is completed, the temperature is lowered, organic matter d is obtained, then organic matter c is added to organic matter d, and the reaction is carried out, and the composite heat stabilizer is obtained.

3. The bio-based 3D printing resin according to claim 2, characterized in that, In Q1, the amount ratio of bisphenol AF, anhydrous potassium carbonate, toluene and 2-chloro-3,5-dinitrobenzotrifluoride is (33.12-34.02) g:(13.12-14.28) g:(90-110) mL:(55.12-55.82) g.

4. The bio-based 3D printing resin according to claim 2, characterized in that, In Q2, the amount ratio of organic matter a, ethanol, N,N-dimethylformamide and Pd / C is (62-68) g:(180-220) mL:(380-430) mL:(9.2-10.3) g; in Q3, the amount ratio of organic matter b, maleic anhydride, N,N-dimethylformamide, p-toluenesulfonic acid and toluene is (3.12-3.45) g:(7.22-8.23) g:(38-42) mL:(0.21-0.28) g:(30-45) mL.

5. The bio-based 3D printing resin according to claim 2, wherein, The use amount ratio of the polycaprolactone diol, diphenyl methane diisocyanate, dibutyl tin dilaurate, N,N-dimethyl formamide, furfuryl alcohol and organic matter c in the Q4 is (19.88-21.21) g:(4.12-4.68) g:(0.01-0.03) g:(50-65) mL:(1.92-2.14) g:(3.12-4.23) g.

6. The bio-based 3D printing resin according to claim 1, wherein, The preparation method of the modified accelerator comprises the following steps: S1: 2-chloro-6-nitrobenzoic acid, sodium sulfide and an ethanol aqueous solution are added into a container, and then the mixture is stirred and reacted at a high temperature; after the reaction is completed, dichloromethane is added, and then the mixture is filtered, distilled under reduced pressure, and then an intermediate 1 is obtained; the intermediate 1 and formamide are added into a container, and then the mixture is reacted at a high temperature; subsequently, ice water is added, and then a solid is precipitated; the solid is filtered, dried, recrystallized, and then an intermediate 2 is obtained; S2: the intermediate 2, 4-vinylpyridine, scandium trifluoromethanesulfonate and toluene are added into a container, and then the mixture is reacted at a high temperature in a nitrogen environment; after the reaction is completed, the mixture is distilled under reduced pressure, dichloromethane is added, and then the mixture is filtered, dried, concentrated under reduced pressure, and recrystallized, and then an intermediate 3 is obtained; S3: 1,8-dihydroxyanthraquinone, anhydrous potassium carbonate and N,N-dimethyl formamide are added into a container, and then the mixture is stirred and mixed; subsequently, the intermediate 3 is added, and then the mixture is heated and reacted in a nitrogen environment; after the reaction is completed, the mixture is cooled, poured into ice water, and then the pH value is adjusted; the mixture is filtered, washed, dried, rotary evaporated, and then the modified accelerator is obtained through purification.

7. The bio-based 3D printing resin according to claim 6, characterized in that, In the S1, the use amount ratio of the 2-chloro-6-nitrobenzoic acid, sodium sulfide, the ethanol aqueous solution and dichloromethane is (0.81-0.88) g:(0.71-0.78) g:(12-15) mL:(20-25) mL; and the use amount ratio of the intermediate 1 and formamide is (0.63-0.72) g:(1.08-1.25) g.

8. The bio-based 3D printing resin according to claim 6, characterized in that, In the S2, the use amount ratio of the intermediate 2, 4-vinylpyridine, scandium trifluoromethanesulfonate and toluene is (0.31-0.42) g:(0.41-0.48) g:(0.08-0.12) g:(18-22) mL; and in the S3, the molar ratio of the 1,8-dihydroxyanthraquinone and the intermediate 3 is (0.8-1.2):(1.5-2.5).

9. A process for the preparation of a bio-based 3D printing resin according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: Step one: castor oil is vacuum dehydrated and then added into a container; subsequently, bio-based polyethylene, pentaerythritol and p-toluenesulfonic acid are added into the container in sequence; the mixture is reacted at a high temperature under the protection of nitrogen, and then a mixture is obtained; Step two: the mixture is cooled, and then hydroxyethyl methacrylate and 2-hydroxy-2-methyl-1-phenyl-1-propanone are added into the mixture; after the mixture is heated and stirred, a composite heat stabilizer is added into the mixture; subsequently, the modified accelerator and glycerol are added into the mixture, and then the mixture is stirred and reacted; after the mixture is cooled and dried, a bio-based 3D printing resin is obtained.

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