A high-filled plant fiber reinforced epoxy plant oil-based glass-like polymer composite material and a preparation method thereof

Abstract

The application discloses a kind of high filling plant fiber reinforced epoxy vegetable oil-based glass-like high molecular composite material and preparation method thereof, and is prepared according to the following steps: (1) the synthesis of aldehyde group-containing intermediate: epoxidized vegetable oil is reacted with aldehyde group-containing compound in the presence of catalyst to obtain aldehyde group-containing intermediate; (2) melt premixing: aldehyde group-containing intermediate obtained in step (1) is melt mixed with dry plant fiber at 140~180 °C; (3) prepolymer formation: diamine compound is added to the mixture of step (2), wherein the molar ratio of amino group to aldehyde group is (1.1~1.6):1, and the mixture is continuously reacted to form a prepolymer; (4) curing forming: the prepolymer obtained in step (3) is subjected to mold forming and curing treatment to obtain a composite material. The application significantly improves the comprehensive performance of epoxy vegetable oil-based composite material, and the raw material source is extensive, and the process is green and environmentally friendly, which has wide application prospect in the field of recyclable high-performance structural materials.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material and its preparation method. Background Technology

[0002] Epoxy thermosetting resins are widely used in coatings, adhesives, and high-performance composites due to their excellent mechanical properties, dimensional stability, and chemical resistance. However, the production of traditional epoxy resins mainly relies on petroleum-based raw materials, and their permanently cross-linked structure makes the materials difficult to recycle and reuse after use, posing a serious challenge to sustainable development.

[0003] Synthesizing bio-based epoxy thermosetting materials using renewable resources (such as vegetable oils, lignin, and natural polyphenols) is an important way to reduce dependence on fossil resources. Among them, epoxidized vegetable oils (such as epoxidized soybean oil and epoxidized linseed oil) have attracted much attention due to their commercial availability, cost competitiveness, and environmental friendliness. However, the flexible aliphatic long-chain structure of vegetable oils leads to insufficient inherent mechanical strength and heat resistance, limiting their application in the field of high-performance materials.

[0004] Introducing dynamic covalent bonds into polymer networks is an effective strategy for addressing the recyclability issues of thermosetting materials. Crosslinked networks containing dynamic covalent bonds are called covalent adaptive networks, which can undergo network topological rearrangement under external stimuli (such as heat, light, or chemical action), endowing materials with reprocessing and recyclability. Among these, glass-like polymers based on imine bond exchange have attracted widespread attention due to their thermally driven rearrangement characteristics. However, existing epoxy-based vegetable oil glass-like polymers still face problems such as low mechanical properties, poor heat resistance, and a significant decrease in recyclability under high-filling conditions.

[0005] Composites of natural plant fibers with bio-based thermosetting resins are an effective way to improve mechanical properties and reduce costs. However, the restriction of matrix molecular chain movement by the fiber network under high fiber filler content significantly inhibits dynamic bond exchange efficiency, resulting in severely compromised recyclability of the composite material. Maintaining good recyclability while ensuring high fiber filler content and excellent mechanical properties is a pressing technical challenge in this field. Summary of the Invention

[0006] To address the aforementioned technical problems, the first objective of this invention is to provide a method for preparing a highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material, and the second objective is to provide the resulting highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material. By introducing excess amino groups into the dynamic imine network, hydrogen bonding with the plant fiber surface is promoted to enhance interfacial adhesion, and the transamination reaction accelerates dynamic bond exchange, thereby achieving a synergistic improvement in mechanical properties, fiber filling amount, and recyclability.

[0007] To achieve the first objective mentioned above, the present invention provides the following technical solution: a method for preparing a highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material, characterized by the following steps:

[0008] (1) Synthesis of aldehyde-containing intermediates: epoxidized vegetable oil and aldehyde-containing compounds were subjected to ring-opening reaction in the presence of a catalyst to obtain aldehyde-containing intermediates;

[0009] (2) Melt premixing: The aldehyde-containing intermediate obtained in step (1) is melt-mixed with dry plant fibers at 140~180 °C;

[0010] (3) Prepolymer formation: Add a diamine compound to the mixture in step (2), wherein the molar ratio of amino to aldehyde groups is (1.1~1.6):1, and continue the mixing reaction to form a prepolymer;

[0011] (4) Curing and molding: The prepolymer obtained in step (3) is subjected to compression molding and curing treatment to obtain the composite material.

[0012] In the above scheme: in step (1), the epoxidized vegetable oil is selected from one or more of epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil, epoxidized palm oil, epoxidized rapeseed oil, and epoxidized cottonseed oil; the aldehyde-containing compound is selected from one or more of hydroxybenzaldehyde and / or carboxybenzaldehyde compounds; specifically, it can be one or more of vanillin, 4-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 2-hydroxybenzaldehyde, 3-aldehyde benzoic acid, and 2-aldehyde benzoic acid.

[0013] The catalyst is one of 4-dimethylaminopyridine, 2-methylimidazole, 2-ethylimidazole or 2-ethyl-4-methylimidazole.

[0014] In the above scheme: In step (1), the aldehyde-containing compound and the epoxidized vegetable oil are fed at a molar ratio of hydroxyl or carboxyl groups / epoxy groups of 0.6-1:1. The ring-opening reaction temperature under nitrogen protection is 100-180 °C, the reaction time is 1-12 hours, and the amount of catalyst added is 0.5%-5% of the mass of the epoxidized soybean oil. Preferably, the reaction is carried out at 120-140 °C for 3-10 hours.

[0015] In the above scheme: in step (2), the plant fiber is selected from one or more of wood fiber, bamboo fiber, hemp fiber, jute fiber, sisal fiber, sugarcane fiber, and straw fiber, and the fiber form is one or more of powder, short fiber or long fiber; the mass fraction of plant fiber is 30 to 80% of the total mass of the composite material.

[0016] In the above scheme: in step (3), the diamine compound is selected from one or more of alicyclic diamines and / or aromatic diamines.

[0017] In the above scheme: the alicyclic diamine is selected from one or more of 4,4'-diaminodicyclohexylmethane, isophorone diamine, 1,3-diaminocyclohexane, and 1,4-diaminocyclohexane; the aromatic diamine is selected from one or more of 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, m-phenylenediamine, and p-phenylenediamine.

[0018] In the above scheme: in step (3), the mixing reaction is carried out at 140~180 °C for 5~20 minutes.

[0019] In the above scheme: the molding temperature in step (4) is 140~180 °C, the pressure is 10~30 MPa, and the time is 5~20 minutes.

[0020] In the above scheme, the curing temperature is 140~180 °C and the time is 1~4 hours.

[0021] The high-filled plant fiber reinforced epoxy plant oil-based glass polymer composite material prepared by the method described above contains an epoxy plant oil-based dynamic imine network and plant fibers dispersed therein.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention regulates the exchange reaction kinetics of dynamic imine network through an excess amino strategy: the excess amino not only accelerates the dynamic bond exchange rate through transamine reaction (the stress relaxation time can reach 6.6 s at 120 °C), but also reduces the crosslinking density to enhance the molecular chain mobility, so that the composite material still maintains good thermal recyclability under high fiber filling.

[0024] (2) The present invention achieves a synergistic improvement in mechanical properties and recyclability: the tensile strength of the obtained composite material can reach 67 MPa, and the strength retention rate can reach 86.0% after three hot pressing cycles.

[0025] (3) This invention breaks through the technical bottleneck of high fiber filling: by adopting an excessive amino strategy, the composite material still maintains good recyclability (69.4% strength retention rate after three cycles) with a wood fiber filling of 60 wt%, and even with a filling of 80 wt%, the strength retention rate can still reach 52.7% after three cycles.

[0026] (4) The present invention adopts a solvent-free process, which is green and environmentally friendly: the entire preparation process does not require organic solvents, avoiding solvent recycling and environmental pollution problems, and is suitable for industrial production.

[0027] (5) The raw materials of this invention are widely available and inexpensive: both epoxidized vegetable oil and plant fiber are renewable biomass resources, which helps to reduce dependence on fossil resources and meets the requirements of sustainable development. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments.

[0029] Example 1

[0030] (1) Synthesis of aldehyde-containing intermediate: Epoxidized soybean oil and vanillin were fed at a hydroxyl / epoxy molar ratio of 0.7:1. 1.0 wt% of 4-dimethylaminopyridine was added as a catalyst and the reaction was carried out at 130 °C for 10 hours under nitrogen protection to obtain an intermediate containing three aldehyde groups.

[0031] (2) Preparation of the composite material: The intermediate containing three aldehyde groups was melt-mixed with dry wood fibers in a torque rheometer at 160 °C and 80 rpm for 5 minutes in the required ratio. Then, 4,4'-diaminodicyclohexylmethane was added, with an amino / aldehyde molar ratio of 1.3:1. The mixture was stirred at 160 °C and 80 rpm for another 10 minutes to form a prepolymer. The prepolymer was molded at 160 °C and 20 MPa for 10 minutes, and then cured in an oven at 160 °C for 2 hours. The wood fiber content of the composite material was 50 wt%.

[0032] The resulting composite material has a tensile strength of 57.69 MPa, a tensile modulus of 4.09 GPa, and an impact strength of 6.32 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 85.0%.

[0033] Example 2

[0034] Same as Example 1, except that the catalyst is 0.5 wt% 2-ethylimidazole, the reaction time is 12 hours at 130°C under nitrogen protection, and the lignocellulose content is 60 wt%.

[0035] The resulting composite material has a tensile strength of 62.37 MPa, a tensile modulus of 4.52 GPa, and an impact strength of 6.55 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 69.4%.

[0036] Example 3

[0037] Same as Example 1, except that the catalyst is 2 wt% 2-methylimidazole, the reaction time is 8 hours at 130°C under nitrogen protection, and the lignocellulose content is 70 wt%.

[0038] The resulting composite material has a tensile strength of 60.19 MPa, a tensile modulus of 4.85 GPa, and an impact strength of 6.12 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 58.1%.

[0039] Example 4

[0040] Same as Example 1, except that the catalyst is 4 wt% 2-methylimidazole, the reaction time is 6 hours at 120°C under nitrogen protection, and the molar ratio of amino to aldehyde is 1.1:1.

[0041] The resulting composite material has a tensile strength of 48.30 MPa, a tensile modulus of 3.51 GPa, and an impact strength of 5.87 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 81.2%.

[0042] Example 5

[0043] Same as Example 1, except that the catalyst is 5 wt% 4-dimethylaminopyridine, the reaction time is 3 hours at 140°C under nitrogen protection, and the molar ratio of amino to aldehyde is 1.6:1.

[0044] The resulting composite material has a tensile strength of 53.44 MPa, a tensile modulus of 3.88 GPa, and an impact strength of 6.05 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 86.7%.

[0045] Example 6

[0046] Same as Example 1, except that vanillin is replaced with 4-hydroxybenzaldehyde, 1,3-diaminocyclohexane is selected as the diamine compound, and the lignocellulose content is 30 wt%.

[0047] The resulting composite material has a tensile strength of 43.82 MPa, a tensile modulus of 3.22 GPa, and an impact strength of 5.73 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 87.5%.

[0048] Example 7

[0049] Same as Example 1, except that vanillin is replaced with 3-hydroxybenzaldehyde, 1,4-diaminocyclohexane is selected as the diamine compound, the amino / aldehyde molar ratio is 1.6:1, and the wood fiber content is 80 wt%.

[0050] The resulting composite material has a tensile strength of 51.66 MPa, a tensile modulus of 4.98 GPa, and an impact strength of 4.98 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 52.7%.

[0051] Example 8

[0052] Same as Example 1, except that vanillin is obtained using 2-hydroxybenzaldehyde, the diamine compound is 4,4'-diaminodiphenylmethane, and the molar ratio of amino to aldehyde is 1.2:1.

[0053] The resulting composite material has a tensile strength of 52.83 MPa, a tensile modulus of 3.79 GPa, and an impact strength of 6.14 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 83.8%.

[0054] Example 9

[0055] Same as Example 1, except that vanillin is replaced with 3-aldehyde benzoic acid, and m-phenylenediamine is used as the diamine compound. The reaction is carried out at 180 °C for 4 hours under nitrogen protection, and the molar ratio of amino to aldehyde is 1.4:1.

[0056] The resulting composite material has a tensile strength of 56.12 MPa, a tensile modulus of 3.96 GPa, and an impact strength of 6.23 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 84.3%.

[0057] Example 10

[0058] Same as Example 1, except that vanillin is replaced with 2-aldehyde benzoic acid, and the reaction is carried out at 120 °C for 10 hours under nitrogen protection with an amino / aldehyde molar ratio of 1.5:1.

[0059] The resulting composite material has a tensile strength of 54.78 MPa, a tensile modulus of 3.92 GPa, and an impact strength of 6.15 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 85.9%.

[0060] Example 11

[0061] Same as Example 1, except that epoxidized soybean oil was replaced with epoxidized linseed oil, the catalyst was 3 wt% 2-ethylimidazolium, and the reaction was carried out at 130°C for 7 hours under nitrogen protection.

[0062] The resulting composite material has a tensile strength of 59.10 MPa, a tensile modulus of 4.18 GPa, and an impact strength of 6.41 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 84.2%.

[0063] Example 12

[0064] Same as Example 1, except that epoxidized soybean oil is replaced with epoxidized castor oil, aldehyde-containing compounds are replaced with 3-aldehyde benzoic acid, the catalyst is 3 wt% 2-ethyl-4-methylimidazole, and the reaction is carried out at 180°C for 1 hour under nitrogen protection.

[0065] The resulting composite material has a tensile strength of 50.80 MPa, a tensile modulus of 3.92 GPa, and an impact strength of 5.96 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 83.1%.

[0066] Example 13

[0067] Same as Example 1, except that the diamine compound is replaced with isophorone diamine, and the amino / aldehyde molar ratio is 1.5:1.

[0068] The resulting composite material has a tensile strength of 54.20 MPa, a tensile modulus of 3.87 GPa, and an impact strength of 6.08 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 80.5%.

[0069] Example 14

[0070] Same as Example 1, except that the diamine compound is replaced with 4,4'-diaminodiphenyl ether.

[0071] The resulting composite material has a tensile strength of 51.30 MPa, a tensile modulus of 4.02 GPa, and an impact strength of 5.74 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 79.6%.

[0072] Example 15

[0073] Same as Example 1, except that the molar ratio of vanillin to epoxy group is 0.6:1 and the molar ratio of amino to aldehyde group is 1.1:1.

[0074] The resulting composite material has a tensile strength of 52.40 MPa, a tensile modulus of 3.78 GPa, and an impact strength of 6.01 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 83.5%.

[0075] Example 16

[0076] Same as Example 1, except that the molar ratio of vanillin to epoxy group is 0.8:1, the lignocellulose content is 60wt%, and the amino / aldehyde molar ratio is 1.4:1.

[0077] The resulting composite material has a tensile strength of 63.74 MPa, a tensile modulus of 4.63 GPa, and an impact strength of 6.60 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 71.8%.

[0078] Example 17

[0079] Same as Example 1, except that the molar ratio of vanillin to epoxy group is 1:1, the lignocellulose content is 30wt%, and the molar ratio of amino to aldehyde group is 1.6:1.

[0080] The resulting composite material has a tensile strength of 45.43 MPa, a tensile modulus of 3.30 GPa, and an impact strength of 5.82 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 88.2%.

[0081] Example 18

[0082] Same as Example 1, except that the molar ratio of vanillin to epoxy group is 0.9:1, the lignocellulose content is 70wt%, and the amino / aldehyde molar ratio is 1.2:1.

[0083] The resulting composite material has a tensile strength of 61.50 MPa, a tensile modulus of 4.93 GPa, and an impact strength of 6.21 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 60.3%.

[0084] Example 19

[0085] Same as Example 1, except that wood fiber is replaced with bamboo fiber, and the bamboo fiber content is 50 wt%.

[0086] The resulting composite material has a tensile strength of 62.31 MPa, a tensile modulus of 4.42 GPa, and an impact strength of 6.83 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 83.7%.

[0087] Example 20

[0088] Same as Example 1, except that wood fiber is replaced with bamboo fiber, the bamboo fiber content is 60 wt%, and the amino / aldehyde molar ratio is 1.4:1.

[0089] The resulting composite material has a tensile strength of 67.36 MPa, a tensile modulus of 4.88 GPa, and an impact strength of 7.05 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 72.5%.

[0090] Example 21

[0091] Same as Example 1, except that the wood fiber is replaced with hemp fiber, the hemp fiber content is 40 wt%, and the amino / aldehyde molar ratio is 1.2:1.

[0092] The resulting composite material has a tensile strength of 53.42 MPa, a tensile modulus of 3.84 GPa, and an impact strength of 6.53 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 83.8%.

[0093] Example 22

[0094] Same as Example 1, except that the wood fiber is replaced with hemp fiber, the hemp fiber content is 30 wt%, and the amino / aldehyde molar ratio is 1.6:1.

[0095] The resulting composite material has a tensile strength of 48.20 MPa, a tensile modulus of 3.54 GPa, and an impact strength of 6.26 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 86.5%.

[0096] Example 23

[0097] Same as Example 1, except that the wood fiber is replaced with jute fiber, and the jute fiber content is 50 wt%.

[0098] The resulting composite material has a tensile strength of 60.57 MPa, a tensile modulus of 4.29 GPa, and an impact strength of 6.58 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 84.1%.

[0099] Example 24

[0100] Same as Example 1, except that epoxidized soybean oil is replaced with epoxidized palm oil, wood fiber is replaced with sisal fiber, the sisal fiber content is 60 wt%, and the amino / aldehyde molar ratio is 1.4:1.

[0101] The resulting composite material has a tensile strength of 71.73 MPa, a tensile modulus of 5.20 GPa, and an impact strength of 6.92 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 70.8%.

[0102] Example 25

[0103] Same as Example 1, except that epoxidized soybean oil is replaced with epoxidized rapeseed oil, and lignocellulose is replaced with sugarcane fiber, with a sugarcane fiber content of 40 wt% and an amino / aldehyde molar ratio of 1.2:1.

[0104] The resulting composite material has a tensile strength of 44.68 MPa, a tensile modulus of 3.33 GPa, and an impact strength of 5.76 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 82.9%.

[0105] Example 26

[0106] Same as Example 1, except that epoxidized soybean oil is replaced with epoxidized cottonseed oil, and lignocellulose is replaced with straw fiber, with a straw fiber content of 70 wt% and an amino / aldehyde molar ratio of 1.5:1.

[0107] An intermediate containing three aldehyde groups was melt-mixed with dried wood fibers in a torque rheometer at 180 °C and 80 rpm for 5 minutes in the desired ratio. Then, 4,4'-diaminodicyclohexylmethane was added, with an amino / aldehyde molar ratio of 1.3:1, and mixing continued for 8 minutes at 180 °C and 80 rpm to form a prepolymer. The prepolymer was then molded at 180 °C and 30 MPa for 5 minutes, and then cured in an oven at 180 °C for 1.5 hours.

[0108] The resulting composite material has a tensile strength of 52.97 MPa, a tensile modulus of 4.27 GPa, and an impact strength of 5.58 kJ / m². After three hot-pressing cycles, the tensile strength retention rate is 59.6%.

[0109] Comparative Example 1

[0110] Same as Example 1, except that the molar ratio of amino to aldehyde is 1:1.

[0111] The resulting composite material has a tensile strength of 43.77 MPa and a tensile modulus of 3.23 GPa. After three hot-pressing cycles, the tensile strength retention rate is 76.2%.

[0112] This comparative example shows that when the amino / aldehyde molar ratio is 1:1, the performance retention rate of the highly cross-linked glass-like polymer network decreases significantly after repeated processing with high fiber content. Compared with the amino-excessive glass-like polymer composite material with the same fiber content, the performance retention rate is even lower, demonstrating the beneficial effect of the amino excess strategy in improving the reprocessing performance of composite materials.

[0113] Comparative Example 2

[0114] Same as Example 1, except that the amino / aldehyde molar ratio is adjusted to 1.7:1 and the wood fiber content is 50 wt%.

[0115] The system exhibits good fluidity during the melt premixing stage, and the molded samples have smooth surfaces and intact appearances. However, due to a severe excess of amino groups and the large number of terminal amines capping the aldehyde groups, the Schiff base crosslinking density is extremely low, making it impossible to form an effective glass-like polymer three-dimensional network structure.

[0116] The resulting composite material has a tensile strength of only 28.6 MPa, a tensile modulus of 2.52 GPa, and an impact strength of 4.14 kJ / m. 2 Although the tensile strength retention rate can reach 92.3% after three hot-pressing cycles (the retention rate seems high because the initial strength is extremely low), the absolute strength is low, and the heat resistance and solvent resistance are poor, limiting its application value.

[0117] The comparative example shows that when the amino / aldehyde molar ratio exceeds 1.6, the excess amino group destroys the structural integrity of the dynamic covalent network, and the composite material loses the core characteristics of glass-like polymer materials (the balance between thermally driven stress relaxation ability and mechanical properties), thus failing to achieve the technical objective of this invention.

[0118] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material, characterized in that, Prepare according to the following steps: (1) Synthesis of aldehyde-containing intermediates: epoxidized vegetable oil and aldehyde-containing compounds were subjected to ring-opening reaction in the presence of a catalyst to obtain aldehyde-containing intermediates; (2) Melt premixing: The aldehyde-containing intermediate obtained in step (1) is melt-mixed with dry plant fibers at 140~180 °C; (3) Prepolymer formation: Add a diamine compound to the mixture in step (2), wherein the molar ratio of amino to aldehyde groups is (1.1~1.6):1, and continue the mixing reaction to form a prepolymer; (4) Curing and molding: The prepolymer obtained in step (3) is subjected to compression molding and curing treatment to obtain the composite material.

2. The preparation method of the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 1, characterized in that: In step (1), the epoxidized vegetable oil is selected from one or more of epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil, epoxidized palm oil, epoxidized rapeseed oil, and epoxidized cottonseed oil; the aldehyde-containing compound is selected from one or more of hydroxybenzaldehyde and / or carboxybenzaldehyde compounds; and the catalyst is one of 4-dimethylaminopyridine, 2-methylimidazole, 2-ethylimidazole, or 2-ethyl-4-methylimidazole.

3. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 2, characterized in that: In step (1), the aldehyde-containing compound and the epoxidized vegetable oil are fed at a molar ratio of 0.6-1:1 for the active functional groups hydroxyl or carboxyl / epoxy groups. The ring-opening reaction temperature under nitrogen protection is 100-180 °C, the reaction time is 1-12 hours, and the amount of catalyst added is 0.5%-5% of the mass of the epoxidized soybean oil.

4. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to any one of claims 1-3, characterized in that: In step (2), the plant fiber is selected from one or more of wood fiber, bamboo fiber, hemp fiber, jute fiber, sisal fiber, sugarcane fiber, and straw fiber, and the fiber form is one or more of powder, short fiber or long fiber; the mass fraction of plant fiber is 30 to 80% of the total mass of the composite material.

5. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 4, characterized in that: In step (3), the diamine compound is selected from one or more alicyclic diamines and / or aromatic diamines.

6. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 5, characterized in that: The alicyclic diamine is selected from one or more of 4,4'-diaminodicyclohexylmethane, isophorone diamine, 1,3-diaminocyclohexane, and 1,4-diaminocyclohexane; the aromatic diamine is selected from one or more of 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, m-phenylenediamine, and p-phenylenediamine.

7. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 6, characterized in that: In step (3), the mixing reaction is carried out at 140~180 °C for 5~20 minutes.

8. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 7, characterized in that: The molding temperature in step (4) is 140~180 °C, the pressure is 10~30 MPa, and the time is 5~20 minutes.

9. The method for preparing the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to claim 8, characterized in that: The curing process is carried out at a temperature of 140~180 °C for 1~4 hours.

10. A method for preparing a highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material according to any one of claims 1-9, wherein the highly filled plant fiber reinforced epoxy plant oil-based glass polymer composite material comprises an epoxy plant oil-based dynamic imine network and plant fibers dispersed therein.