A photocurable bio-based flame retardant resin and a method for preparing the same

Abstract

The application provides a photocurable bio-based flame-retardant resin and a preparation method thereof, and belongs to the technical field of bio-based polymer flame-retardant materials. Palm oil and phytic acid are used as raw materials to prepare palm oil-based methacrylate and phytic acid-based methacrylate monomers, respectively. The palm oil-based methacrylate and the phytic acid-based methacrylate are mixed with a photoinitiator through one-pot blending. The preparation method is simple and fast, the obtained bio-based resin is environment-friendly, and a three-dimensional structure material of the environment-friendly bio-based flame-retardant resin can be prepared through ultraviolet light curing by using ultraviolet light 3D printing technology. The bio-based flame-retardant resin has excellent mechanical strength, good deformability and high efficient flame retardancy, is also suitable for photocuring 3D printing, and can solve the technical bottlenecks of insufficient mechanical properties, low anti-deformation capacity and flammability of traditional vegetable oil-based resins.

Description

Technical Field

[0001] This invention relates to the field of bio-based polymer flame retardant materials technology, and in particular to a photocurable bio-based flame retardant resin made from biomass resources such as palm oil and phytic acid, and its preparation method. Background Technology

[0002] With increasing environmental awareness and the demands for sustainable development, the application of bio-based materials in photopolymer 3D printing is gradually growing. Plant oil bio-based resources are highly renewable, with a continuous and widely available supply, reducing dependence on finite fossil resources. Their production process typically consumes little energy, and they are biodegradable after use, making them environmentally friendly and helping to reduce carbon emissions and pollution. Furthermore, plant oils possess excellent properties such as low volatility, high flash point, and good lubricity. Their chemical structure contains unique triglyceride structures and various functional groups, making them widely used in construction, biofuels, bioplastics, and lubricating oils, driving the green transformation of multiple industries. Palm oil is one of the world's largest-produced, consumed, and internationally traded plant oils, characterized by its renewable nature, abundant resources, and low cost. However, the palm oil molecule contains a variable number of unsaturated double bonds, which often leads to insufficient mechanical strength in the resulting resin when directly chemically crosslinked, exhibiting lower mechanical properties and poor resistance to deformation. Additionally, the alkyl carbon chains in palm oil are flammable and easily decompose when heated. Phytic acid (PA) has emerged as an environmentally friendly phosphorus-based flame retardant. Derived from natural plants, it is a sustainable resource that helps reduce negative environmental impacts. Phytic acid carries approximately 80%-85% of the total phosphorus in plants, making it a major phosphorus reservoir. With a phosphorus content of 28 wt%, it is a promising alternative phosphorus source. Phytic acid decomposes at around 200°C, promoting the dehydration of carbon sources and forming a stable protective layer. This creates a barrier between the flame and combustible materials, making it an important material for promoting sustainable development in the construction industry.

[0003] 3D printing technology, as a rapid prototyping technology, has been widely used in construction, medical, aerospace and other fields in recent years. However, traditional 3D printing materials are prone to deformation or combustion in high-temperature environments, limiting their application in scenarios with high flame retardancy requirements. Flame-retardant resins not only need to meet the high precision, rapid prototyping and mechanical performance requirements of 3D printing, but also need to possess good flame-retardant properties to meet the safety challenges in high-temperature environments. Therefore, developing 3D printing resins with excellent flame-retardant properties has become a research hotspot. Ultraviolet (UV) curing 3D printing technology, due to its high efficiency, environmental friendliness and high precision, has become an ideal method for preparing flame-retardant resins with complex structures. How to rapidly prepare environmentally friendly materials with excellent plasticity, flame retardant properties and mechanical strength using photocurable bio-based flame-retardant resins is a problem that urgently needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a photocurable bio-based flame-retardant resin and its preparation method. This preparation method is simple and rapid, yielding an environmentally friendly bio-based resin with excellent mechanical strength, good deformability, and high flame retardancy. It is also suitable for photocurable 3D printing, overcoming the technical bottlenecks of insufficient mechanical properties, low deformation resistance, and flammability of traditional plant oil-based resins.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A photocurable bio-based flame retardant resin, the raw material components by mass parts include: 0-50 parts of palm oil-based methacrylate, 50-100 parts of phytic acid-based methacrylate and 2 parts of initiator.

[0007] Furthermore, the palm oil-based methacrylate is synthesized from palm oil, diethanolamine, and methacrylic anhydride through amidation and esterification reactions.

[0008] The phytic acid-based methacrylate is synthesized from phytic acid and glycidyl methacrylate via an epoxy ring-opening reaction.

[0009] The initiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0010] Furthermore, the structural formula of the palm oil-based methacrylate is as follows:

[0011] ;

[0012] R1, R2, and R3 are saturated or unsaturated fatty acids, and R1, R2, and R3 are long-chain fatty acids. The flexibility of long-chain fatty acids can improve the impact resistance and ductility of materials, reduce the risk of brittle fracture, enhance the overall strength of materials, and form a three-dimensional network structure with the binding sites of carbonyl and nitrogen groups, thereby improving the heat resistance and chemical stability of materials.

[0013] Furthermore, the structural formula of the phytic acid methacrylate is as follows:

[0014] ;

[0015] R represents -H or glycidyl methacrylate grafted segments. The multifunctional structure forms a denser network, improving the material's hardness and wear resistance.

[0016] Furthermore, this includes the following steps:

[0017] S1: Palm oil-based methacrylate is synthesized from palm oil, diethanolamine, and methacrylic anhydride through amidation and esterification reactions.

[0018] S2: Phytic acid-based methacrylate is synthesized from phytic acid and glycidyl methacrylate through an epoxy ring-opening reaction; methacrylate groups (double bonds) are precisely introduced into the surface of phytic acid to give it photocurability.

[0019] S3: A photocurable bio-based flame retardant resin prepared by blending palm oil-based methacrylate, phytic acid-based methacrylate and a photoinitiator until uniformly mixed.

[0020] Furthermore, step S1 specifically includes:

[0021] S11: Amide reaction to synthesize palm oil diethanolamide;

[0022] 35–40 parts by weight of diethanolamine and 0.004–0.005 parts by weight of sodium methoxide were mixed and stirred at 80–85°C for 30–35 min under nitrogen atmosphere. Then, 60–65 parts by weight of palm oil were added and stirred at 120–130°C for 4–5 h. After cooling to room temperature, the mixture was mixed with ethyl acetate and purified repeatedly with saturated sodium chloride solution 5–8 times. Finally, the mixture was purified by rotary evaporation for 2–3 h to obtain palm oil diethanolamide. The introduction of polar groups such as hydroxyl and amino groups through amidation reaction enhances the active sites of subsequent esterification reactions, providing an efficient and flexible preparation route for palm oil-based methacrylates.

[0023] S12: Esterification reaction to synthesize palm oil-based methacrylate;

[0024] Palm oil diethanolamide, methacrylic anhydride, hydroquinone, and 4-dimethylaminopyridine were stirred at 60–65 °C for 5–6 h, cooled to room temperature, and purified 5–8 times with saturated sodium bicarbonate solution, followed by rotary evaporation for 1–2 h to obtain palm oil-based methacrylate. The palm oil-based methacrylate generated by the esterification reaction forms a three-dimensional network structure through free radical polymerization, significantly improving the material's hardness, heat resistance, and impact strength.

[0025] Furthermore, the mass ratio of palm oil diethanolamide, methacrylic anhydride, hydroquinone, and 4-dimethylaminopyridine is 10:15:0.052:0.20.

[0026] Furthermore, step S2 specifically includes:

[0027] Phytic acid, glycidyl methacrylate, polymerization inhibitor, and catalyst were stirred and reacted at 85±5℃ for 1-2 h. The mixture was extracted with ethyl acetate and then rotary evaporated to obtain phytic acid-based methacrylate. The mass ratio of phytic acid, glycidyl methacrylate, polymerization inhibitor, and catalyst was 1:1.94:0.0029:0.029.

[0028] Furthermore, the polymerization inhibitor is hydroquinone; the catalyst is tetrabutylammonium bromide. The high catalytic rate shortens the reaction time to within 4.5 hours, enabling rapid preparation. Hydroquinone effectively inhibits the self-polymerization tendency of glycidyl methacrylate at high temperatures by capturing free radicals, avoiding excessively high local crosslinking density and resulting in a more uniform distribution of crosslinking points. This leads to a more uniform molecular weight distribution of the product, reducing stress concentration points caused by differences in chain segment length, thereby improving flexibility. It also ensures the integrity of the C=C double bonds. The complete preservation of double bonds allows the cured material to achieve a balance between crosslinking density and chain segment mobility. During subsequent photocuring, the double bonds fully participate, forming a three-dimensional network that combines strength and flexibility.

[0029] Furthermore, the mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate is 3:7 to 4:6; the amount of initiator is 2% of the total resin mass.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The bio-based photocurable resin prepared by the present invention uses palm oil and phytic acid, which are abundant, inexpensive and green and harmless, as raw materials, and is an environmentally friendly material; the bio-based photocurable resin not only has excellent plasticity, flame retardant properties and mechanical strength, but also achieves flame retardancy through the synergistic effect of palm oil and phytic acid, thus creating a new method for preparing flame retardant photocurable polymers.

[0031] (2) This invention optimizes the combination of process parameters to form a blend of phytic acid-based methacrylate, palm oil-based methacrylate, and a photoinitiator. This blend is then cured using 365 nm ultraviolet light in a 3D printer at a printing speed of 20 mm / h, successfully producing a bio-based photocurable resin with excellent comprehensive performance. It is evident that the bio-based photocurable resin of this invention is suitable for photocurable 3D printing, enabling the rapid production of three-dimensional structural materials with excellent mechanical strength, good deformability, and efficient flame retardancy. By combining the bio-based resin with a photoinitiator and utilizing ultraviolet curing technology, three-dimensional structural materials with high mechanical properties and excellent flame retardancy can be rapidly produced. This material not only meets the high-precision requirements of architectural models and customized components but can also be used in the manufacture of functional components for high-temperature environments such as fire-fighting equipment, providing a new solution for the construction industry and the fire protection field. Attached Figure Description

[0032] Figure 1This is a schematic diagram of the synthetic reaction route for palm oil-based methacrylates according to the present invention;

[0033] Figure 2 This is a schematic diagram of the synthetic reaction route for phytic acid-based methacrylate of the present invention.

[0034] Figure 3 The bending stress-deflection curve of the bio-based photocurable flame retardant resin in this embodiment of the invention;

[0035] Figure 4 This is a diagram illustrating the vertical combustion process of the bio-based photocurable flame retardant resin in an embodiment of the present invention.

[0036] Among them, M 50 G 50 This indicates a light-cured resin with a mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate of 5:5; M 40 G 60 This indicates a light-cured resin with a mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate of 4:6; M 30 G 70 This indicates a light-cured resin with a mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate of 3:7; M 20 G 80 This indicates a light-cured resin with a mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate of 2:8; M 10 G 90 This indicates a light-curing resin with a mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate of 1:9; MOG 100 This refers to a light-curable resin prepared from phytic acid methacrylate. Detailed Implementation

[0037] To provide a further understanding of the purpose, structure, features, and functions of this invention, the accompanying drawings are provided. Figure 1-4 The technical solution of the present invention will be clearly and completely described in detail with specific 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. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0038] Raw materials: 18° palm oil was purchased from Shanghai Dingfen Chemical Technology Co., Ltd., China; diethanolamine, methacrylic anhydride, tetrabutylammonium bromide, 4-dimethylaminopyridine and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were purchased from Shanghai Jingchun (Aladdin) Industrial Co., Ltd.; sodium chloride, ethyl acetate, hydroquinone, sodium methoxide and sodium bicarbonate were purchased from Shanghai Guoyao Group Chemical Reagent Co., Ltd.; phytic acid and glycidyl methacrylate were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0039] Synthetic process of palm oil-based methacrylate:

[0040] 249.8 g of diethanolamine and 3.24 g of sodium methoxide were added to a flask and nitrogen gas was introduced. The oil bath was set to 80°C and mechanically stirred (250 r / min) for 30 min. Then, 400 g of palm oil was added and the oil bath was heated to 120°C. Stirring was continued (250 r / min) for 4 h, and then cooled to room temperature. The mixture was thoroughly mixed with 500 mL of ethyl acetate and purified repeatedly with 2 L of saturated sodium chloride solution for 5-8 times. The mixture was then purified by rotary evaporation for 2 h to obtain palm oil diethanolamide. 100 g of palm oil diethanolamide, 150 g of methacrylic anhydride, 0.52 g of hydroquinone, and 1.99 g of 4-dimethylaminopyridine were added to flasks respectively. The oil bath temperature was set to 60°C and mechanically stirred (250 r / min) for 5 h. After stirring, the mixture was cooled to room temperature and purified 5-8 times with 2 L of saturated sodium bicarbonate solution. The mixture was then purified by rotary evaporation for 1 h to obtain palm oil-based methacrylate. Synthetic reaction route as follows Figure 1 As shown.

[0041] Synthesis of phytic acid-based methacrylate, synthesis process:

[0042] A 500 mL three-necked flask equipped with a condenser was preheated in an 85°C oil bath. Then, 66 g of phytic acid, 128 g of glycidyl methacrylate, 0.19 g of hydroquinone (polymer inhibitor), and 1.9 g of tetrabutylammonium bromide (catalyst) were added sequentially to the flask. The mixture was mechanically stirred at 250 r / min for 1 h, cooled to room temperature, extracted with 200 mL of ethyl acetate, and then rotary evaporated to obtain phytic acid-based methacrylate. The synthetic route is as follows: Figure 2 As shown. Example 1

[0043] Preparation of photocurable bio-based flame retardant resin:

[0044] 25 g of palm oil-based methacrylate, 25 g of phytic acid-based methacrylate, and 1 g of photoinitiator were uniformly mixed to obtain a photocurable bio-based flame-retardant resin. In the preparation process of this embodiment, the ratio of palm oil-based methacrylate to phytic acid-based methacrylate by mass was 5:5; the amount of initiator was 2% of the total resin mass.

[0045] Photocurable resin for 3D printing: The photocurable bio-based flame retardant resin prepared in this embodiment is poured into a UV-treated 3D printer and printed at a speed of 20 mm / h under UV light irradiation at a wavelength of 365 nm according to the set program. Example 2

[0046] Preparation of photocurable bio-based flame retardant resin:

[0047] 20 g of palm oil-based methacrylate, 30 g of phytic acid-based methacrylate, and 1 g of photoinitiator were uniformly mixed to obtain a photocurable bio-based flame-retardant resin. In the preparation process of this embodiment, the ratio of palm oil-based methacrylate to phytic acid-based methacrylate by mass was 4:6; the amount of initiator was 2% of the total resin mass.

[0048] Photocurable resin for 3D printing: The photocurable bio-based flame retardant resin prepared in this embodiment is poured into a UV-treated 3D printer and printed at a speed of 20 mm / h under UV light irradiation at a wavelength of 365 nm according to the set program. Example 3

[0049] Preparation of photocurable bio-based flame retardant resin:

[0050] 15 g of palm oil-based methacrylate, 35 g of phytic acid-based methacrylate, and 1 g of photoinitiator were uniformly mixed to obtain a photocurable bio-based flame-retardant resin. In the preparation process of this embodiment, the ratio of palm oil-based methacrylate to phytic acid-based methacrylate by mass was 3:7; the amount of initiator was 2% of the total resin mass.

[0051] Photocurable resin for 3D printing: The photocurable bio-based flame retardant resin prepared in this embodiment is poured into a UV-treated 3D printer and printed at a speed of 20 mm / h under UV light irradiation at a wavelength of 365 nm according to the set program. Example 4

[0052] Preparation of photocurable bio-based flame retardant resin:

[0053] 10 g of palm oil-based methacrylate, 40 g of phytic acid-based methacrylate, and 1 g of photoinitiator were uniformly mixed to obtain a photocurable bio-based flame-retardant resin. In the preparation process of this embodiment, the ratio of palm oil-based methacrylate to phytic acid-based methacrylate by mass was 2:8; the amount of initiator was 2% of the total resin mass.

[0054] Photocurable resin for 3D printing: The photocurable bio-based flame retardant resin prepared in this embodiment is poured into a UV-treated 3D printer and printed at a speed of 20 mm / h under UV light irradiation at a wavelength of 365 nm according to the set program. Example 5

[0055] Preparation of photocurable bio-based flame retardant resin:

[0056] 5 g of palm oil-based methacrylate, 45 g of phytic acid-based methacrylate, and 1 g of photoinitiator were uniformly mixed to obtain a photocurable bio-based flame-retardant resin. In the preparation process of this embodiment, the ratio of palm oil-based methacrylate to phytic acid-based methacrylate by mass was 1:9; the amount of initiator was 2% of the total resin mass.

[0057] Photocurable resin for 3D printing: The photocurable bio-based flame retardant resin prepared in this embodiment is poured into a UV-treated 3D printer and printed at a speed of 20 mm / h under UV light irradiation at a wavelength of 365 nm according to the set program. Example 6

[0058] 50 g of phytic acid-based methacrylate and 1 g of photoinitiator were uniformly mixed to obtain a photocurable bio-based flame retardant resin. In the preparation process of this embodiment, the ratio of palm oil-based methacrylate to phytic acid-based methacrylate by mass was 0:10; the amount of initiator was 2% of the total resin mass.

[0059] Photocurable resin for 3D printing: The photocurable bio-based flame retardant resin prepared in this embodiment is poured into a UV-treated 3D printer and printed at a speed of 20 mm / h under UV light irradiation at a wavelength of 365 nm according to the set program.

[0060] Product performance testing:

[0061] 1. Mechanical property testing of resin:

[0062] Dumbbell-shaped resin specimens (75 mm total length, 12.5 mm width at both ends, 4 mm width in the middle, 25 mm length in the middle, and 3 mm thickness) were prepared for tensile property testing, which was performed according to ASTM D638-10 standard. Resin rectangular specimens (80 mm long, 10 mm wide, and 3 mm thick) were prepared for flexural property testing. Both tensile and flexural property tests were performed on a computer-controlled electronic universal testing machine. Specific data are shown in Table 1 and... Figure 3 As shown in Table 1, the tensile and flexural properties of the bio-based photocurable flame retardant resins prepared in Examples 1-6 are as follows:

[0063]

[0064] As shown in Table 1, for the photocurable polymer copolymerized from palm oil-based methacrylate and phytic acid-based methacrylate, the tensile strength, tensile modulus, flexural strength, and flexural modulus all gradually decrease with the increase of phytic acid-based methacrylate content, while the elongation at break gradually increases with the increase of phytic acid-based methacrylate content.

[0065] Figure 3 The bending stress-deflection curves of the bio-based photocurable flame retardant resins prepared in Examples 1-6 are shown. Figure 3 It is known that the flexural strength of photocurable flame-retardant resin increases with increasing palm oil-based methacrylate content, but the flexural deflection at break first decreases and then increases with increasing palm oil-based methacrylate content, and M... 50 G 50 The bending strength is the greatest, M 30 G 70 The maximum bending fracture deflection indicates that the resin has excellent resistance to deformation.

[0066] 2. Resin gelation amount test:

[0067] The gel content was determined according to the solvent extraction method in GB / T 37498-2019, with toluene as the solvent.

[0068] 3. Glass transition temperature test of resin:

[0069] Resin rectangular samples (30 mm in length, 10 mm in width, and 2 mm in thickness) were tested on a Q800 dynamic mechanical analyzer (TA Instruments, USA) under alternating stress at a fixed frequency and at a certain heating rate. The test was conducted in a single cantilever mode in an air atmosphere, with a frequency of 1 Hz, a temperature range of -50℃ to 150℃, and a heating rate of 5℃ / min.

[0070] 4. Limiting Oxygen Index (LOI) Test of Resin:

[0071] The Limiting Oxygen Index (LOI) test was conducted according to ASTM D 2863-97, using an FTT0077 limiting oxygen index instrument (UK). The sample size was 100 × 12.5 × 3 mm. 3 When the oxygen index is below 22%, it is classified as a flammable material; when the oxygen index is between 22% and 27%, it is classified as a combustible material; and when the oxygen index is above 27%, it is classified as a flame-retardant material.

[0072] 5. Vertical burning test of resin (UL-94):

[0073] The vertical burning test was conducted according to the UL-94 test method on a Suzhou Yangyi Volch VOUCH 5402 instrument. The burning process was recorded using a digital camera. The sample size was 125 × 10 × 3 mm. 3 UL-94 is mainly divided into V0, V1, and V2 levels, with V0 level corresponding to the highest flame retardant rating.

[0074] The specific vertical combustion process is as follows: Figure 4 As shown, by Figure 4 The vertical combustion process of bio-based photocurable flame retardant resin can be observed in polymer M. 50 G 50 During the vertical combustion test, the sample ignited on the first ignition extinguished instantly, but failed to self-extinguish on the second ignition; in polymer M 40 G 60 During the vertical burning test, the flame retardant properties of the polymer were instantly extinguished within 10 seconds in both the first and second tests, meeting the UL-94 V0 rating. The flame retardant properties of the polymer were further enhanced with increasing amounts of phytic acid-based methacrylate.

[0075] The gel content, glass transition temperature, limiting oxygen index, and UL-94 rating of bio-based photocurable flame retardant resins are shown in Table 2 below:

[0076]

[0077] Table 2 shows that the photocurable flame retardant resin M 50 G 50 M 40 G 60 and M 30 G 70 The glass transition temperatures of the polymers were 107.4℃, 101.6℃, and 81.0℃, respectively, and the gel contents were 98.3%, 98.1%, and 96.9%, respectively. With increasing amounts of palm oil-based methacrylate, both the glass transition temperature and gel content of the polymers showed an increasing trend. Photocurable polymer M... 50 G 50 M 40 G 60 and M30 G 70 The limiting oxygen indices were 25.8%, 30.44%, and 31.4%, respectively, and the UL-94 ratings were NR, V0, and V0, respectively. With the increase of phytic acid methacrylate content, the limiting oxygen index of the polymer showed an increasing trend, and the flame retardant effect also became better and better.

[0078] In summary, this invention uses biomass palm oil and phytic acid as raw materials, and synthesizes highly reactive monomers that can participate in free radical polymerization through amidation and esterification reactions of palm oil and ring-opening reactions of phytic acid. The two highly reactive photosensitive monomers are copolymerized in a one-pot process. The mechanical strength, glass transition temperature and flame retardant performance test results show that the resin has good mechanical properties and flame retardant effect, which can solve the technical bottlenecks of insufficient mechanical properties, low deformation resistance and flammability of traditional vegetable oil-based resins.

[0079] Therefore, the bio-based resin prepared in this invention is environmentally friendly and suitable for photopolymerization 3D printing, while also possessing excellent mechanical strength, good deformability, and high flame retardancy. Its suitability for photopolymerization 3D printing overcomes the technical bottlenecks of traditional plant oil-based resins, such as insufficient mechanical properties, low resistance to deformation, and flammability. Furthermore, the preparation of this resin fully utilizes bio-based raw materials, greatly expanding the efficient utilization of palm oil and phytic acid in the field of flame retardancy. This not only reduces dependence on fossil fuels but also promotes the development of a low-carbon economy in China.

[0080] The present invention has been described in the above-described embodiments; however, these embodiments are merely examples for implementing the present invention. It must be noted that the disclosed embodiments do not limit the scope of the present invention. Conversely, any modifications and refinements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A photocurable bio-based flame-retardant resin, characterized in that: The raw material composition, by mass parts, includes: 0-50 parts palm oil-based methacrylate, 50-100 parts phytic acid-based methacrylate, and 2 parts initiator; the mass ratio of palm oil-based methacrylate to phytic acid-based methacrylate is 3:7-4:6; the amount of initiator is 2% of the total resin mass; The palm oil-based methacrylate is synthesized from palm oil, diethanolamine, and methacrylic anhydride through amidation and esterification reactions. The structural formula of the palm oil-based methacrylate is as follows: ； R1, R2, and R3 are saturated or unsaturated fatty acids; The phytic acid-based methacrylate is synthesized from phytic acid and glycidyl methacrylate via an epoxy ring-opening reaction. The initiator is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

2. The photocurable bio-based flame retardant resin as described in claim 1, characterized in that: The structural formula of the phytic acid-based methacrylate is: ； Where R is -H or glycidyl methacrylate graft segment.

3. A method for preparing a photocurable bio-based flame-retardant resin as described in any one of claims 1-2, characterized in that: Includes the following steps: S1: Palm oil-based methacrylate is synthesized from palm oil, diethanolamine, and methacrylic anhydride through amidation and esterification reactions. S2: Phytic acid-based methacrylate is synthesized from phytic acid and glycidyl methacrylate via an epoxy ring-opening reaction. S3: A photocurable bio-based flame retardant resin prepared by blending palm oil-based methacrylate, phytic acid-based methacrylate and a photoinitiator until uniformly mixed.

4. The method for preparing the photocurable bio-based flame retardant resin as described in claim 3, characterized in that: Step S1 specifically includes: S11: Amide reaction to synthesize palm oil diethanolamide; Mix 35-40 parts by weight of diethanolamine and 0.004-0.005 parts by weight of sodium methoxide, stir at 80-85°C for 30-35 min under nitrogen atmosphere, add 60-65 parts by weight of palm oil, stir at 120-130°C for 4-5 h, cool to room temperature, mix with ethyl acetate, add saturated sodium chloride solution and purify repeatedly 5-8 times, then purify by rotary evaporation for 2-3 h to obtain palm oil diethanolamide; S12: Esterification reaction to synthesize palm oil-based methacrylate; Palm oil diethanolamide, methacrylic anhydride, hydroquinone, and 4-dimethylaminopyridine were stirred at 60–65 °C for 5–6 h, cooled to room temperature, purified 5–8 times with saturated sodium bicarbonate solution, and then purified by rotary evaporation for 1–2 h to obtain palm oil-based methacrylate.

5. The method for preparing the photocurable bio-based flame retardant resin as described in claim 4, characterized in that: The mass ratio of palm oil diethanolamide, methacrylic anhydride, hydroquinone, and 4-dimethylaminopyridine is 10:15:0.052:0.

20.

6. The method for preparing the photocurable bio-based flame retardant resin as described in claim 3, characterized in that: Step S2 specifically includes: Phytic acid, glycidyl methacrylate, polymerization inhibitor, and catalyst were stirred and reacted at 85±5℃ for 1-2 h. The mixture was extracted with ethyl acetate and then rotary evaporated to obtain phytic acid-based methacrylate. The mass ratio of phytic acid, glycidyl methacrylate, polymerization inhibitor, and catalyst was 1:1.94:0.0029:0.

029.

7. The method for preparing the photocurable bio-based flame retardant resin as described in claim 6, characterized in that: The polymerization inhibitor is hydroquinone; the catalyst is tetrabutylammonium bromide.

Images