Bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing hexahydro-s-triazine structure and preparation method thereof

Abstract

The invention discloses a preparation method of bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure. The preparation process comprises the following steps: (1) carrying out chemical reaction synthesis on an aldehyde compound, a bio-based hydroxylamine compound and mercaptoalkyl acid to obtain mercaptohexahydro-s-triazine; (2) carrying out chemical reaction on maleic anhydride, an aniline compound, 2, 5-furan dimethylamine and alkyl mercaptan to synthesize a bio-based maleimide monomer; (3) carrying out click reaction on the mercapto-terminated hexahydro-s-triazine, a bio-based maleimide monomer and an alkenyl epoxy compound to obtain bio-based hyperbranched epoxy resin; and (4) uniformly stirring the bio-based hyperbranched epoxy resin, bisphenol A epoxy resin and a curing agent, and carrying out thermocuring to obtain the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin. The process is simple, and the composite resin has remarkable advantages in the aspects of green preparation, high performance, environmental pollution reduction and the like.

Description

Technical Field

[0001] The invention relates to the technical field of degradable hyperbranched epoxy resins, and specifically to a bio-based hyperbranched epoxy resin-bisphenol A type epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof. Background Art

[0002] Epoxy resin has excellent physical and mechanical properties, electrical insulation properties, heat resistance and adhesion to various materials, so it is widely used in coatings, adhesives, electronic appliances, aerospace, automobiles and medical fields. However, the common epoxy resin has poor crack resistance, low toughness, easy decomposition at high temperature to produce toxic gases, and the use of toxic curing agents during the curing process, which limits the application of epoxy resin in many fields. As a thermosetting material, a three-dimensional irreversible cross-linked network structure will be formed during the curing process, and the processing raw materials are highly dependent on non-renewable substances, which leads to waste of resources and environmental pollution.

[0003] As a thermosetting hyperbranched polymer, hyperbranched epoxy resin can enhance and toughen traditional bisphenol A epoxy resin due to its unique topological structure, multiple active end groups, high reactivity and good compatibility. The prepared hyperbranched epoxy resin is blended with ordinary bisphenol A epoxy resin, which is not only beneficial to the enhancement and toughening of bisphenol A epoxy resin, but also helps to realize the functionalization of epoxy resin composite resin by regulating the structure of hyperbranched epoxy resin. To this end, the inventor of this application (Zhang Daohong) introduced the hexahydrotriazine structure to invent a degradable hyperbranched epoxy resin (ZL201810386063.3; Nature Sustainability, 2020, 3, 29-34; Composites Part B, 2020, 196, 108109), and studied the influence of topological structure on the mechanical properties of renewable bio-based hyperbranched epoxy / carbon fiber composites (Chemical Engineering Journal 471 (2023): 144329.) process technology.

[0004] However, thermosetting hyperbranched epoxy resin composites are usually prepared from non-biobased raw materials. The production process of non-biobased materials is usually accompanied by a large amount of greenhouse gas emissions, which has a negative impact on the environment, is unsustainable in resources, and exacerbates global climate change. Therefore, the development of a preparation technology for hyperbranched epoxy resin / bisphenol A epoxy resin composites with simple processes, good biocompatibility, and renewable raw materials is a fundamental way to solve the current problems in this field, thereby reducing carbon emissions and reducing environmental load. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof.

[0006] The present invention solves the above technical problems with the following technical solutions:

[0007] Technical solution 1: A bio-based hyperbranched epoxy resin containing a hexahydrotriazine structure, the structural formula of which is the following general formula (1):

[0008]

[0009] Wherein, R', R", and R'" are the same or different, and are independently represented by the structure shown in general formula (2), general formula (3) or general formula (4):

[0010]

[0011] Wherein, X is one or more of the following structures:

[0012]

[0013] The structure of R is as follows:

[0014]

[0015] R 2 One or more of the following structures:

[0016]

[0017] Among them, mercaptoalkyl acid and alcohol are esterified to make -CO- in the structure and -R 4 The -CO- in the structure is connected to form -COO-, and the other end of the structure is connected to the -N in the structure R to form -CN-;

[0018] R 1 The structure is as follows:

[0019]

[0020] Among them, R 3 One or more of the following structures:

[0021]

[0022] Among them, R 4 For the following structure:

[0023] n is a natural number from 1 to 5

[0024] Among them, mercaptoalkyl acid and alcohol are esterified to make -CO- in the structure and -R 2 The -CO- in the structure is connected to form -COO-, and the thiol and olefin compounds react through the thiol-olefin click reaction to make the -CS- in the structure connect to R 1 The C in the molecule connects to form -CSC-;

[0025] Among them, R 5 A fatty alkane group having 5 to 18 carbon atoms 5 H 11 ~-C 18 H 37 ;

[0026] The number average molecular weight of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure is 11000-36000 g / mol, and the epoxy value is 0.06-0.10 mol / 100 g.

[0027] Technical solution 2: A method for preparing a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, comprising the following steps:

[0028] (1) adding an aldehyde compound, a bio-based hydroxylamine compound and an organic solvent to a reaction flask, stirring and reacting at 40-100° C. for 5-15 hours, then cooling to 10-30° C., adding a mercaptoalkyl acid and a catalyst, stirring and reacting for 12-18 hours to obtain a terminal mercapto hexahydro-s-triazine monomer (A) 3 );

[0029] (2) adding maleic anhydride, aniline compounds and an organic solvent into a reaction flask, stirring and reacting at 2-10° C. for 1-7 hours, then heating to 50-80° C., stirring and reacting for 5-15 hours to obtain a maleimide monomer;

[0030] (3) adding maleimide monomer, 2,5-furandimethylamine, alkylthiol, maleic anhydride and organic solvent into a reaction flask, stirring and reacting at 45-160° C. for 15-20 hours to obtain bio-based maleimide monomer (B 2 );

[0031] (4) the terminal mercapto hexahydro-s-triazine monomer (A) obtained in step (1) 3 ), the bio-based maleimide monomer (B 2 ), an olefin epoxy compound, an organic solvent and a photoinitiator are added to a reaction bottle and irradiated with ultraviolet light of a power of 400 to 800 W for 10 to 60 minutes to carry out a thiol-olefin click reaction to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, with a number average molecular weight of 11000 to 36000 g / mol and an epoxide value of 0.06 to 0.10 mol / 100 g.

[0032] Furthermore, the bio-based hydroxylamine compound is 1-amino-2-indanol 4-Hydroxybutylamine and L-phenylglycinol One or more of .

[0033] Further, the aldehyde compound is one or more of triformaldehyde, paraformaldehyde and formaldehyde solution;

[0034] Furthermore, the catalyst is one or more of p-toluenesulfonic acid, trifluoromethanesulfonic acid, and 4-dimethylaminopyridine;

[0035] Further, the mercaptoalkyl acid is

[0036]

[0037] Furthermore, the aniline compound is one or more of aniline, β-naphthylamine and 1-aminopyrene.

[0038] Furthermore, the carbon number of the alkyl group in the alkylthiol RSH is C 5 ~C 18 One of them.

[0039] Furthermore, the alkenyl epoxy compound is one or more of allyl glycidyl ether, 2,3-epoxypropyl acrylate, and 1,2-epoxy-5-hexene.

[0040] Furthermore, the photoinitiator is one or more of 1,1-dimethoxy-1-phenylacetophenone (Light 651), 1-hydroxycyclohexylphenyl ketone (Light 184), 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone (Light 907) and 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone (Light 369).

[0041] Furthermore, the organic solvents in steps (1) to (4) are the same or different, and are independently one or more of tetrahydrofuran, 1,4-dioxane, ethyl acetate, acetone, anhydrous ethanol, chloroform, N,N-dimethylformamide and dichloromethane, and the mass of the added organic solvent is 1-10 times the total mass of the monomers added in the step.

[0042] Furthermore, in the step (1), the molar ratio of the bio-based hydroxylamine compound, the aldehyde compound, and the mercaptoalkyl acid is 1:(1-1.2):(1-1.2);

[0043] Furthermore, in the step (1), the mass ratio of the bio-based hydroxylamine compound to the catalyst is 1:(0.01-0.1);

[0044] Furthermore, in the step (2), the molar ratio of maleic anhydride to aniline compound is 1:(1-1.2);

[0045] Furthermore, in the step (3), the molar ratio of maleimide monomer, 2,5-furandimethylamine, alkyl mercaptan, and maleic anhydride is 1: (1-1.2): (1-1.3): (2-2.2);

[0046] Furthermore, in the step (4), the terminal mercapto hexahydro-s-triazine monomer (A 3 ), bio-based maleimide monomer (B 2 ) and the alkenyl epoxy compound in a molar ratio of 1:(0.75-0.95):(1.09-1.2); the mass ratio of the terminal mercapto hexahydro-s-triazine monomer and the photoinitiator is 1:(0.01-0.02).

[0047] Technical solution three: A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure, the composite resin comprising the above-mentioned bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure or the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure prepared by the above-mentioned method. The preparation steps of the composite resin include: fully mixing the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, bisphenol A epoxy resin and a curing agent, pouring them into a mold for thermal curing to obtain the composite resin; the thermal curing temperature is 50-180°C, and the thermal curing time is 3-15 hours; the curing agent is one or more of 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, and metaphenylenediamine.

[0048] Furthermore, the bisphenol A epoxy resin model is E51.

[0049] Furthermore, the mass ratio of the bio-based hyperbranched epoxy resin, the bisphenol A epoxy resin and the curing agent is 1:(4-9):(1-3).

[0050] Technical solution 4: Application of bio-based hyperbranched epoxy resin containing hexahydrotriazine structure in the reinforcement and toughening of linear epoxy resin.

[0051] Compared with the prior art, the technical solution of the present invention has the following advantages and beneficial effects:

[0052] 1. The present invention utilizes a thiol-olefin click reaction to prepare a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, thereby obtaining a hyperbranched epoxy resin with an efficient and environmentally friendly preparation method;

[0053] 2. The preparation process of the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin of the present invention is simple, the reaction conditions are relatively mild, the reaction time is short, and the raw material cost is low;

[0054] 3. The bio-based hyperbranched epoxy resin of the present invention not only has the unique advantages of hyperbranched polymers themselves, but also exhibits extremely significant strengthening and toughening performance when interacting with linear epoxy resins, which can effectively improve the comprehensive performance of the material, expand its application scope and potential, and is expected to be widely used in the field of strengthening and toughening epoxy resins;

[0055] 4. The bio-based hyperbranched epoxy resin of the present invention can be greenly degraded under relatively mild conditions because it contains a hexahydro-s-triazine structure;

[0056] 5. The preparation process of the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure of the present invention is simple, the reaction conditions are mild, the reaction time is short, and the reaction process has little environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is the FT-IR spectrum of the bio-based hyperbranched epoxy resin containing hexahydrotriazine structure synthesized in Example 1. As shown in the figure, 2572 cm -1 The vibration absorption peaks at 1640 cm-1 and 1640 cm-2 are attributed to -SH. -1 The absorption peak at 912 cm-1, which is attributed to the C=C double bond of AGE, disappears and the absorption peak at 912 cm-1 appears. -1 The peak at is attributed to the absorption peak of the epoxy group, indicating the successful synthesis of bio-based hyperbranched epoxy resin. DETAILED DESCRIPTION

[0058] The method of the present invention is further described below in conjunction with specific examples, but these examples should not limit the scope of protection of the present invention in any way.

[0059] The raw materials used in the following examples are as follows:

[0060] The model of bisphenol A epoxy resin is E51;

[0061] The mass concentration of the formaldehyde aqueous solution is 37wt%;

[0062] The degree of polymerization n of paraformaldehyde is 2.

[0063] Example 1 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0064] (1) 2.35 g (0.029 mol) of formaldehyde aqueous solution, 3.97 g (0.029 mol) of L-phenylglycine and 50 ml of anhydrous ethanol were added to a reaction flask, stirred and reacted at 85° C. for 15 hours, then cooled to 10° C., 3.07 g (0.029 mol) of mercaptopropionic acid and 0.08 g of p-toluenesulfonic acid were added, and the stirring reaction was continued for 18 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0065] (2) 4.11 g (0.042 mol) of maleic anhydride, 6.00 g (0.042 mol) of β-naphthylamine and 50 ml of N,N-dimethylformamide were added to a reaction bottle, stirred and reacted at 2° C. for 7 hours, then heated to 50° C., stirred and reacted for 15 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0066] (3) 12.05 g (0.05 mol) of maleimide monomer, 6.3 g (0.05 mol) of 2,5-furandimethylamine, 5.2 g (0.05 mol) of pentamethylenemercaptan, 9.8 g (0.1 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45° C. for 8 hours, and then the temperature was raised to 100° C. and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0067] (4) 5.54 g (0.0078 mol) of A 3 4.30 g (0.0070 mol) B 2 , 1.03g

[0068] (0.009 mol) allyl glycidyl ether, 0.06 g 1-hydroxycyclohexyl phenyl ketone (Light 184) and 50 ml ethyl acetate were added to a reaction bottle, irradiated with ultraviolet light at a power of 400 W for 30 min for click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (HBEP-12) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0069] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.77 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0070] Example 2 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0071] (1) 4.86 g (0.054 mol) of trioxymethylene, 4.00 g (0.045 mol) of 4-hydroxybutylamine and 50 ml of 1,4-dioxane were added to a reaction flask, stirred and reacted at 100° C. for 5 hours, then cooled to 15° C., 5.72 g (0.054 mol) of mercaptopropionic acid and 0.4 g of 4-dimethylaminopyridine were added, stirred and reacted for 12 hours, and the solvent was removed by rotary evaporation to obtain terminal mercapto hexahydro-s-triazine (A) 3 );

[0072] (2) 4.21 g (0.043 mol) of maleic anhydride, 6.15 g (0.043 mol) of β-naphthylamine and 50 ml of ethyl acetate were added to a reaction bottle, stirred and reacted at 5° C. for 5 hours, then heated to 70° C., stirred and reacted for 5 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0073] (3) 12.05 g (0.05 mol) of maleimide monomer, 6.30 g (0.05 mol) of 2,5-furandimethylamine, 9.32 g (0.05 mol) of octadecanethiol, 9.8 g (0.1 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 60° C. for 10 hours, and then the temperature was raised to 160° C. and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0074] (4) 5.82 g (0.0078 mol) of A 3 5.62g (0.0070mol) B 2 , 1.06g

[0075] (0.0093 mol) allyl glycidyl ether, 0.06 g 1-hydroxycyclohexyl phenyl ketone (Light 184) and 50 ml tetrahydrofuran were added to a reaction bottle, irradiated with ultraviolet light with a power of 800 W for 10 min for click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (DBEP-12) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0076] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.76 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0077] Example 3 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0078] (1) 3.0 g (0.05 mol) of paraformaldehyde, 7.45 g (0.05 mol) of 1-amino-2-indanol and 50 ml of tetrahydrofuran were added to a reaction flask, stirred and reacted at 40° C. for 7 hours, then cooled to 20° C., 4.6 g (0.05 mol) of thioglycolic acid and 0.3 g of trifluoromethanesulfonic acid were added, and the stirring reaction was continued for 15 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0079] (2) 6.86 g (0.07 mol) of maleic anhydride, 15.19 g (0.07 mol) of 1-aminopyrene and 50 ml of ethyl acetate were added to a reaction bottle, stirred and reacted at 10° C. for 1 hour, then heated to 55° C., stirred and reacted for 5 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0080] (3) 14.85 g (0.05 mol) of maleimide monomer, 6.3 g (0.05 mol) of 2,5-furandimethylamine, 5.2 g (0.05 mol) of pentamethylenemercaptan, 9.8 g (0.1 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45° C. for 8 hours, and then the temperature was raised to 100° C. and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0081] (4) 6.21 g (0.0080 mol) of A 3 5.60 g (0.0076 mol) B 2 , 0.99g

[0082] (0.0087 mol) allyl glycidyl ether, 0.12 g 1,1-dimethoxy-1-phenylacetophenone (Light 651) and 50 ml N,N-dimethylformamide were added to a reaction bottle, irradiated with ultraviolet light at a power of 400 W for 60 minutes, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (BBEP-24) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0083] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.76 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0084] Example 4 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0085] (1) 4.05 g (0.05 mol) of formaldehyde aqueous solution, 6.85 g (0.05 mol) of L-phenylglycinol and 50 ml of anhydrous ethanol were added to a reaction flask, stirred and reacted at 85° C. for 5 hours, then cooled to 10° C., 4.6 g (0.05 mol) of thioglycolic acid and 0.13 g of p-toluenesulfonic acid were added, and the stirring reaction was continued for 12 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0086] (2) 4.2 g (0.05 mol) of maleic anhydride, 7.16 g (0.05 mol) of β-naphthylamine and 50 ml of N,N-dimethylformamide were added to a reaction bottle, stirred and reacted at 5° C. for 2 hours, then heated to 80° C., stirred and reacted for 6 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0087] (3) 5 g (0.05 mol) of maleimide monomer, 7.56 g (0.06 mol) of 2,5-furandimethylamine, 5.20 g (0.05 mol) of pentamethylenemercaptan, 10.78 g (0.11 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45° C. for 8 hours, and then the temperature was raised to 100° C. and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0088] (4) 5.35 g (0.008 mol) of A 34.42 g (0.0072 mol) B 2 , 1.09g

[0089] (0.0096 mol) allyl glycidyl ether, 0.11 g 1,1-dimethoxy-1-phenylacetophenone (Light 651) and 50 ml acetone were added to a reaction bottle, irradiated with ultraviolet light at a power of 400 W for 30 min for a click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (LBEP-12) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0090] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.77 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 60°C for 1 hour, 80°C for 3 hours, 120°C for 3 hours and 160°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0091] Example 5 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0092] (1) 2.43 g (0.03 mol) of formaldehyde aqueous solution, 2.67 g (0.03 mol) of 4-hydroxybutylamine and 50 ml of 1,4-dioxane were added to a reaction flask, stirred and reacted at 75° C. for 5 hours, then cooled to 15° C., 3.39 g (0.03 mol) of mercaptopropionic acid and 0.05 g of 4-dimethylaminopyridine were added, stirred and reacted for 12 hours, and the solvent was removed by rotary evaporation to obtain terminal mercapto hexahydro-s-triazine (A) 3 );

[0093] (2) 5.88 g (0.06 mol) of maleic anhydride, 5.58 g (0.06 mol) of aniline and 50 ml of ethyl acetate were added to a reaction bottle, stirred and reacted at 5° C. for 2 hours, then heated to 55° C., stirred and reacted for 5 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0094] (3) 8.5 g (0.05 mol) of maleimide monomer, 6.3 g (0.05 mol) of 2,5-furandimethylamine, 5.2 g (0.05 mol) of pentamethylenemercaptan, 9.8 g (0.1 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45° C. for 8 hours, and then the temperature was raised to 100° C. for reaction, and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2);

[0095] (4) 5.67 g (0.01 mol) of A 3 4.94 g (0.009 mol) B 2 , 1.37 g (0.012 mol) of allyl glycidyl ether, 0.11 g of 1,1-dimethoxy-1-phenylacetophenone (Light 651) and 50 ml of chloroform were added to a reaction bottle, irradiated with ultraviolet light at a power of 400 W for 30 min to perform a click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (SBEP-12) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0096] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.78 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 60°C for 1 hour, 80°C for 3 hours, 120°C for 3 hours, and 160°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0097] Example 6 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0098] (1) 0.97 g (0.012 mol) of formaldehyde aqueous solution, 1.79 g (0.012 mol) of 1-amino-2-indanol and 50 ml of anhydrous ethanol were added to a reaction flask, stirred and reacted at 90° C. for 6 hours, then cooled to 8° C., 1.77 g (0.012 mol) of mercaptohexanoic acid and 0.11 g of p-toluenesulfonic acid were added, and the stirring reaction was continued for 15 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0099] (2) 4.2 g (0.021 mol) of maleic anhydride, 3.0 g (0.021 mol) of β-naphthylamine and 50 ml of ethyl acetate were added to a reaction bottle, stirred and reacted at 5° C. for 2 hours, then heated to 55° C., stirred and reacted for 5 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0100] (3) 11.15 g (0.05 mol) of maleimide monomer, 5.92 g (0.05 mol) of 2,5-furandimethylamine, 11.5 g (0.05 mol) of tetradecanethiol, 9.8 g (0.1 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45° C. for 8 hours, and then the temperature was raised to 100° C. and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0101] (4) 5.97 g (0.008 mol) of A 3 5.10 g (0.0072 mol) B 2 , 1.23g

[0102] (0.0096 mol) 2,3-epoxypropyl acrylate, 0.11 g 1,1-dimethoxy-1-phenylacetophenone (Light 651) and 50 ml N,N-dimethylformamide were added to a reaction bottle, irradiated with ultraviolet light at a power of 400 W for 30 min for click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (YBEP-12) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0103] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.76 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 60°C for 1 hour, 80°C for 3 hours, 120°C for 3 hours, and 160°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0104] Example 7 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0105] 5.97 g (0.008 mol) of the mercapto-terminated hexahydro-s-triazine (A) prepared in step (1) of Example 1 was added. 3 ), 4.67 g (0.0076 mol) of bio-based maleimide monomer (B 2 ), 0.99 g (0.0087 mol) of allyl glycidyl ether, 0.06 g of 1-hydroxycyclohexyl phenyl ketone (Light 184) and 50 ml of ethyl acetate were added to a reaction bottle, irradiated with ultraviolet light with a power of 400 W for 30 min to perform a click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (HBEP-24) containing a hexahydro-s-triazine structure, and its number average molecular weight and epoxide value are shown in Table 1;

[0106] (2) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.77 g of 4,4'-diaminodiphenylmethane in step (1) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0107] Example 8-1 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0108] A mixture of 1 g of the bio-based hyperbranched epoxy resin HBEP-12 containing a hexahydro-s-triazine structure prepared in Example 1, 9 g of bisphenol A epoxy resin and 2.89 g of 4,4'-diaminodiphenyl sulfone was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0109] Example 8-2 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0110] A mixture of 1 g of the bio-based hyperbranched epoxy resin HBEP-12 containing a hexahydro-s-triazine structure prepared in Example 1, 9 g of bisphenol A epoxy resin and 2.68 g of polyetheramine was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0111] Example 8-3 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0112] A mixture of 1 g of the bio-based hyperbranched epoxy resin HBEP-12 containing a hexahydro-s-triazine structure prepared in Example 1, 9 g of bisphenol A epoxy resin and 1.20 g of diethylenetriamine was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0113] Example 8-4 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0114] A mixture of 1 g of the bio-based hyperbranched epoxy resin HBEP-12 containing a hexahydro-s-triazine structure prepared in Example 1, 9 g of bisphenol A epoxy resin and 1.26 g of m-phenylenediamine was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0115] Example 9 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0116] A mixture of 2 g of the bio-based hyperbranched epoxy resin HBEP-12 containing a hexahydro-s-triazine structure prepared in Example 1, 8 g of bisphenol A epoxy resin and 2.77 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0117] Example 10 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0118] (1) 2.35 g (0.029 mol) of formaldehyde aqueous solution, 4.32 g (0.029 mol) of 1-amino-2-indanol and 50 ml of anhydrous ethanol were added to a reaction flask, stirred and reacted at 85° C. for 15 hours, then cooled to 10° C., 3.07 g (0.029 mol) of mercaptopropionic acid and 0.08 g of p-toluenesulfonic acid were added, and the stirring reaction was continued for 18 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0119] (2) 4.11 g (0.042 mol) of maleic anhydride, 6.00 g (0.042 mol) of β-naphthylamine and 50 ml of N,N-dimethylformamide were added to a reaction bottle, stirred and reacted at 2° C. for 7 hours, then heated to 50° C., stirred and reacted for 15 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0120] (3) 12.05 g (0.05 mol) of maleimide monomer and 6.3 g (0.05 mol) of

[0121] 2,5-furandimethylamine, 5.2g (0.05mol) pentamethylenethiol, 9.8g (0.1mol) maleic anhydride and 50ml N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45°C for 8 hours, then the temperature was raised to 100°C, and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0122] (4) 5.83 g (0.0078 mol) of A 3 4.30 g (0.0070 mol) B 2 , 1.03 g (0.009 mol) of allyl glycidyl ether, 0.06 g of 1-hydroxycyclohexyl phenyl ketone (Light 184) and 50 ml of ethyl acetate were added to a reaction bottle, irradiated with ultraviolet light with a power of 400 W for 30 min to carry out a click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (ABEP-12) containing a hexahydro-s-triazine structure, and its number average molecular weight and epoxide value are shown in Table 1;

[0123] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.77 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0124] Example 11 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0125] (1) 2.35 g (0.029 mol) of formaldehyde aqueous solution, 2.58 g (0.029 mol) of 4-hydroxybutylamine and 50 ml of anhydrous ethanol were added to a reaction flask, stirred and reacted at 85° C. for 15 hours, then cooled to 10° C., 3.07 g (0.029 mol) of mercaptopropionic acid and 0.08 g of p-toluenesulfonic acid were added, and the stirring reaction was continued for 18 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0126] (2) 4.11 g (0.042 mol) of maleic anhydride, 6.00 g (0.042 mol) of β-naphthylamine and 50 ml of N,N-dimethylformamide were added to a reaction bottle, stirred and reacted at 2° C. for 7 hours, then heated to 50° C., stirred and reacted for 15 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0127] (3) 12.05 g (0.05 mol) of maleimide monomer and 6.3 g (0.05 mol) of

[0128] 2,5-furandimethylamine, 5.2g (0.05mol) pentamethylenethiol, 9.8g (0.1mol) maleic anhydride and 50ml N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45°C for 8 hours, then the temperature was raised to 100°C, and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0129] (4) 4.42 g (0.0078 mol) of A 3 4.30 g (0.0070 mol) B 2 , 1.03 g (0.009 mol) of allyl glycidyl ether, 0.06 g of 1-hydroxycyclohexyl phenyl ketone (Light 184) and 50 ml of ethyl acetate were added to a reaction bottle, irradiated with ultraviolet light with a power of 400 W for 30 min to carry out a click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (IBEP-12) containing a hexahydro-s-triazine structure, and its number average molecular weight and epoxide value are shown in Table 1;

[0130] (5) A mixture of 1 g of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, 9 g of bisphenol A epoxy resin and 2.78 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0131] Example 12 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0132] (1) 0.97 g (0.012 mol) of formaldehyde aqueous solution, 1.79 g (0.012 mol) of 1-amino-2-indanol and 50 ml of anhydrous ethanol were added to a reaction flask, stirred and reacted at 90° C. for 6 hours, then cooled to 8° C., 1.77 g (0.012 mol) of mercaptohexanoic acid and 0.11 g of p-toluenesulfonic acid were added, and the stirring reaction was continued for 15 hours. The solvent was removed by rotary evaporation to obtain a terminal mercapto hexahydro-s-triazine (A) 3 );

[0133] (2) 4.2 g (0.021 mol) of maleic anhydride, 4.5 g (0.021 mol) of 1-aminopyrene and 50 ml of ethyl acetate were added to a reaction bottle, stirred at 5° C. for 2 hours, then heated to 55° C., stirred for 5 hours, and the solvent was removed by rotary evaporation to obtain a maleimide monomer;

[0134] (3) 14.85 g (0.05 mol) of maleimide monomer, 5.92 g (0.05 mol) of 2,5-furandimethylamine, 11.5 g (0.05 mol) of tetradecanethiol, 9.8 g (0.1 mol) of maleic anhydride and 50 ml of N,N-dimethylformamide were added to a reaction bottle, and the reaction was first carried out at 45° C. for 8 hours, and then the temperature was raised to 100° C. and the reaction was continued for 10 hours. The solvent was removed by rotary evaporation to obtain a bio-based maleimide monomer (B 2 );

[0135] (4) 5.97 g (0.008 mol) of A 3 5.85 g (0.0072 mol) B 2 , 1.23g

[0136] (0.0096 mol) 2,3-epoxypropyl acrylate, 0.12 g 1,1-dimethoxy-1-phenylacetophenone (Light 651) and 50 ml N,N-dimethylformamide were added to a reaction bottle, irradiated with ultraviolet light at a power of 400 W for 30 min for click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (FBEP-12) containing a hexahydro-s-triazine structure, the number average molecular weight and epoxy value of which are shown in Table 1;

[0137] (5) A mixture of 1 g of a bio-based hyperbranched epoxy resin containing a hexahydrotriazine structure, 9 g of a bisphenol A epoxy resin and 2.76 g of 4,4'-diaminodiphenylmethane in step (4) was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 60°C for 1 hour, 80°C for 3 hours, 120°C for 3 hours and 160°C for 2 hours to obtain a bio-based hyperbranched epoxy resin containing a hexahydrotriazine structure / bisphenol A epoxy resin composite resin, the mechanical strength of which is shown in Table 2.

[0138] Example 13 A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure and a preparation method thereof, wherein the steps are as follows:

[0139] (1) 6.21 g (0.0080 mol) of the terminal mercapto hexahydro-s-triazine (A) prepared in step (1) of Example 3 was added to 3 ), 5.31 g (0.0072 mol) of bio-based maleimide monomer (B 2 ), 1.03g (0.009mol) of allyl glycidyl ether, 0.12g of 1,1-dimethoxy-1-phenylacetophenone (Light 651) and 50ml of N,N-dimethylformamide were added to a reaction bottle, irradiated with ultraviolet light with a power of 400W for 60 minutes for a click reaction, and the solvent was removed by rotary evaporation to obtain a bio-based hyperbranched epoxy resin (BBEP-12) containing a hexahydro-s-triazine structure, and its number average molecular weight and epoxy value are shown in Table 1;

[0140] (2) A mixture of 1 g of the bio-based hyperbranched epoxy resin in step (1), 9 g of bisphenol A epoxy resin and 2.77 g of 4,4'-diaminodiphenylmethane was mixed and evenly placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin containing a hexahydrotriazine structure, the mechanical strength of which is shown in Table 2.

[0141] Comparative Example 1

[0142] A mixture of 10 g of the bio-based hyperbranched epoxy resin (HBEP-12) containing a hexahydrotriazine structure prepared in Example 1 and 3.96 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, whose mechanical strength is shown in Table 3.

[0143] Comparative Example 2

[0144] A mixture of 10 g of the bio-based hyperbranched epoxy resin (DBEP-12) containing a hexahydrotriazine structure prepared in Example 2 and 3.46 g of 4,4'-diaminodiphenylmethane was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0145] Comparative Example 3

[0146] A mixture of 10 g of the bio-based hyperbranched epoxy resin (BBEP-24) containing a hexahydrotriazine structure prepared in Example 3 and 2.97 g of 4,4'-diaminodiphenylmethane was stirred evenly and placed in a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0147] Comparative Example 4

[0148] A mixture of 10 g of the bio-based hyperbranched epoxy resin (LBEP-12) containing a hexahydrotriazine structure prepared in Example 4 and 4.46 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0149] Comparative Example 5

[0150] A mixture of 10 g of the bio-based hyperbranched epoxy resin (SBEP-12) containing a hexahydrotriazine structure prepared in Example 5 and 4.95 g of 4,4'-diaminodiphenylmethane was stirred evenly and placed in a mold. Thermal curing was performed according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0151] Comparative Example 6

[0152] A mixture of 10 g of the bio-based hyperbranched epoxy resin (YBEP-12) containing a hexahydrotriazine structure prepared in Example 6 and 3.47 g of 4,4'-diaminodiphenylmethane was stirred evenly and placed in a mold. Thermal curing was performed according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0153] Comparative Example 7

[0154] A mixture of 10 g of the bio-based hyperbranched epoxy resin (HBEP-24) containing a hexahydrotriazine structure prepared in Example 7 and 3.96 g of 4,4'-diaminodiphenylmethane was stirred evenly and placed in a mold. Thermal curing was performed according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0155] Comparative Example 10

[0156] A mixture of 10 g of the bio-based hyperbranched epoxy resin (ABEP-12) containing a hexahydrotriazine structure prepared in Example 10 and 3.96 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, whose mechanical strength is shown in Table 3.

[0157] Comparative Example 11

[0158] A mixture of 10 g of the bio-based hyperbranched epoxy resin (IBEP-12) containing a hexahydrotriazine structure prepared in Example 11 and 4.95 g of 4,4'-diaminodiphenylmethane was stirred evenly and placed in a mold. Thermal curing was performed according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, the mechanical strength of which is shown in Table 3.

[0159] Comparative Example 12

[0160] A mixture of 10 g of the bio-based hyperbranched epoxy resin containing a hexahydrotriazine structure (FBEP-12) prepared in Example 12 and 3.47 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, whose mechanical strength is shown in Table 3.

[0161] Comparative Example 13

[0162] A mixture of 10 g of the bio-based hyperbranched epoxy resin (BBEP-12) containing a hexahydrotriazine structure prepared in Example 13 and 3.96 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold, and thermally cured according to a curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain a pure bio-based hyperbranched epoxy resin material, whose mechanical strength is shown in Table 3.

[0163] Comparative Example 14

[0164] A mixture of 10 g of bisphenol A epoxy resin and 3.03 g of 4,4'-diaminodiphenylmethane was stirred evenly and put into a mold. Thermal curing was performed according to the curing procedure of 50°C for 1 hour, 80°C for 2 hours, 100°C for 3 hours, and 140°C for 2 hours to obtain pure bisphenol A epoxy resin material. The mechanical strength of the material is shown in Table 3.

[0165] Table 1 Properties of bio-based hyperbranched epoxy resins containing hexahydrotriazine structures

[0166]

[0167]

[0168] Table 2 Mechanical properties of bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin containing hexahydrotriazine structure

[0169]

[0170] Table 3 Mechanical properties of pure bio-based hyperbranched epoxy resin or pure bisphenol A epoxy resin after curing

[0171]

[0172]

[0173] Note: The determination method of "tensile strength" in Table 2 and Table 3 is: using a universal material testing machine (Instron5943) to refer to ASTM standard ASTM D638-14 "Standard Test Method for Tensile Properties of Polymer-based Composite Resins" for testing; the determination method of "flexural strength" is: using a universal material testing machine (Instron5943) to refer to ASTM standard D790M-92 "Flexural Test Method" for testing, and the test temperature is 25°C.

[0174] 1. From the test results in Table 1, we can see that:

[0175] The number average molecular weight of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure obtained by the present invention gradually increases with the number of terminal epoxy groups. When the number of terminal epoxy groups is 24, the number average molecular weight reaches a maximum value of 35290 g / mol.

[0176] The bio-based hyperbranched epoxy resins containing hexahydro-s-triazine structures obtained in Examples 1-2 and Examples 4-6 of the present invention have different structures and different epoxy values. The larger the number average molecular weight, the smaller the epoxy value.

[0177] 2. From the test results in Table 2 and Table 3, we can see that:

[0178] The bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure obtained by the invention has an obvious reinforcing and toughening effect on a linear epoxy resin such as a bisphenol A type epoxy resin.

[0179] In Example 1, Examples 8-1, 8-2, 8-3, and 8-4 of the present invention, by changing the type of curing agent, the tensile strength and flexural strength of the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure will be different. Considering the applicable range of the curing temperature and the influence of the molecular structure of the curing agent on the mechanical properties of the composite resin, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone and m-phenylenediamine are more preferred curing agents, among which 4,4'-diaminodiphenylmethane is the best curing agent.

[0180] In Examples 1, 2, 3, 4, 5 and 6 of the present invention, by changing the structure of the terminal mercapto hexahydro-s-triazine monomer, the tensile strength and flexural strength of the composite resin will be different. A large number of holes reduce the crosslinking density and the mechanical properties. The smaller the volume of the cavity in the structure, the smaller the free volume of the molecule, and the greater the tensile strength and flexural strength.

[0181] In Examples 1, 7, 3 and 13 of the present invention, changing the number of terminal epoxy groups of the bio-based hyperbranched epoxy resin in the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure (by adjusting the ratio of the terminal thiol hexahydro-s-triazine monomer to the bio-based maleimide monomer) will result in different tensile strengths and flexural strengths of the composite resin. When the number of terminal epoxy groups of the bio-based hyperbranched epoxy resin is 12, the crosslinking density of the composite resin is the largest, so the tensile strength and flexural strength reach the maximum value; when the number of terminal epoxy groups of the bio-based hyperbranched epoxy resin is 24, a large number of vacancies reduces the crosslinking density, and the mechanical properties are therefore reduced.

[0182] In Examples 1, 10 and 11 of the present invention, by changing the bio-based hydroxylamine compound, the tensile strength and flexural strength of the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin will be different. When the rigid structure in the structure increases, the tensile strength and flexural strength will increase.

[0183] In Example 6 and Example 12 of the present invention, by changing the structure of the bio-based maleimide monomer, the tensile strength and flexural strength of the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin are different. The more benzene ring content, the stronger the rigidity of the composite resin and the stronger the mechanical properties. Therefore, Example 12 with more benzene ring structure has better performance.

[0184] In Example 1 and Example 9 of the present invention, by changing the mass fraction of the bio-based hyperbranched epoxy resin, the tensile strength and flexural strength of the bio-based hyperbranched epoxy resin / bisphenol A epoxy resin composite resin are different. When the mass fraction of the bio-based hyperbranched epoxy resin added is 10%, the tensile strength and flexural strength reach the maximum value, which are 96±5MPa and 178±6MPa, respectively; when the mass fraction of the bio-based hyperbranched epoxy resin added reaches 20%, the tensile strength and flexural strength are 88±5MPa and 165±7MPa, respectively. The proportion of the bio-based hyperbranched epoxy resin increases from 10% to 20%, the crosslinking density of the composite resin decreases, and the mechanical properties are also reduced.

[0185] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, characterized in that: Its structural formula is the following general formula (1): Wherein, R', R", and R'" are the same or different, and are independently represented by the structure shown in general formula (2), general formula (3) or general formula (4): Wherein, X is one or more of the following structures: The structure of R is as follows: R2 is one or more of the following structures: The -CO- in the R2 structure is connected to the -CO- in the -R4 to form -COO-, and the other end of the R2 structure is connected to the -N in the structure R to form -CN-; The structure of R1 is as follows: Wherein, R3 is one or more of the following structures: Wherein, R4 is the following structure: n is a natural number from 1 to 5; Wherein, R5 is an aliphatic alkane group having 5 to 18 carbon atoms; The number average molecular weight of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure is 11000-36000 g / mol, and the epoxy value is 0.06-0.10 mol / 100 g.

2. The method for preparing the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure according to claim 1, characterized in that: The steps include: (1) Add an aldehyde compound, a bio-based hydroxylamine compound and an organic solvent to a reaction flask, stir and react at 40-100° C. for 5-15 hours, then cool to 10-30° C., add a mercaptoalkyl acid and a catalyst, and continue to stir and react for 12-18 hours. A mercapto-terminated hexahydro-s-triazine monomer is obtained; (2) Add maleic anhydride, aniline compounds and organic solvents to a reaction flask, stir and react at 2-10° C. for 1-7 hours, then heat to 50-80° C. Continue stirring and reacting for 5-15 hours to obtain a maleimide monomer; (3) adding maleimide monomer, 2,5-furandimethylamine, alkylthiol, maleic anhydride and organic solvent into a reaction bottle, stirring and reacting at 45-160° C. for 15-20 hours to obtain a bio-based maleimide monomer; (4) the terminal mercapto hexahydro-s-triazine monomer obtained in step (1) and step (3) The obtained bio-based maleimide monomer, alkenyl epoxy compound, organic solvent and photoinitiator are added to a reaction bottle, and ultraviolet light with a power of 400-800 W is used for 10-60 minutes to carry out a thiol-olefin click reaction to obtain a bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, with a number average molecular weight of 11000-36000 g / mol and an epoxide value of 0.06-0.1 mol / 100g.

3. The preparation method according to claim 2, characterized in that: The bio-based hydroxylamine compound is 1-amino-2-indanol 4-Hydroxybutylamine and L-phenylglycinol One or more of; The aniline compound is one or more of aniline, β-naphthylamine and 1-aminopyrene.

4. The preparation method according to claim 2, characterized in that: The aldehyde compound is one or more of trioxymethylene, polyformaldehyde and formaldehyde solution; the mercaptoalkyl acid is n＝1～5； The carbon number of the alkyl group in the alkyl mercaptan RSH is C5~C 18 One of; The alkenyl epoxy compound is one or more of allyl glycidyl ether, 2,3-epoxypropyl acrylate, and 1,2-epoxy-5-hexene.

5. The preparation method according to claim 2, characterized in that: The catalyst is one or more of p-toluenesulfonic acid, trifluoromethanesulfonic acid, and 4-dimethylaminopyridine; the photoinitiator is one or more of 1,1-dimethoxy-1-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, and 2-phenylbenzyl-2-dimethylamine-1-(4-morpholinobenzylphenyl)butanone; the organic solvents in steps (1) to (4) are the same or different, and are independently one or more of tetrahydrofuran, 1,4-dioxane, ethyl acetate, acetone, anhydrous ethanol, chloroform, N,N-dimethylformamide, and dichloromethane.

6. The preparation method according to claim 2, characterized in that: In the step (1), the molar ratio of the bio-based hydroxylamine compound, the aldehyde compound, and the mercaptoalkyl acid is 1:(1-1.2):(1-1.2), and the mass ratio of the bio-based hydroxylamine compound to the catalyst is 1:(0.01-0.1); In the step (2), the molar ratio of maleic anhydride to aniline compound is 1:(1-1.2); In the step (3), the molar ratio of maleimide monomer, 2,5-furandimethylamine, alkyl mercaptan, and maleic anhydride is 1: (1-1.2): (1-1.3): (2-2.2); In the step (4), the molar ratio of the terminal mercapto hexahydro triazine monomer, the bio-based maleimide monomer and the alkenyl epoxy compound is 1: (0.75-0.95): (1.09-1.2), and the mass ratio of the terminal mercapto hexahydro triazine monomer and the photoinitiator is 1: (0.01-0.02); In the steps (1) to (4), the mass of the organic solvent added is 1 to 10 times the total mass of the monomers added in the step.

7. A bio-based hyperbranched epoxy resin-bisphenol A epoxy resin composite resin containing a hexahydro-s-triazine structure, characterized in that: The composite resin comprises the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure according to claim 1 or the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure prepared by any one of the methods described in claims 2-6.

8. The bio-based hyperbranched epoxy resin-bisphenol A type epoxy resin composite resin according to claim 7, characterized in that: The bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure, bisphenol A epoxy resin and a curing agent are fully and evenly mixed and poured into a mold for thermal curing; the curing agent is one or more of 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone and m-phenylenediamine.

9. The bio-based hyperbranched epoxy resin-bisphenol A type epoxy resin composite resin according to claim 8, characterized in that: The mass ratio of bio-based hyperbranched epoxy resin, bisphenol A epoxy resin and curing agent is 1:(4-9):(1-3).

10. Use of the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure according to claim 1 or the bio-based hyperbranched epoxy resin containing a hexahydro-s-triazine structure prepared by any method according to claims 2 to 6 in strengthening and toughening linear epoxy resins.

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