Plant oil-based multifunctional amine curing agent, full-bio-based antibacterial thermosetting resin, and preparation method and application thereof

Abstract

The application discloses a plant oil-based multifunctional amine curing agent, a full-biological antibacterial thermosetting resin and a preparation method and application thereof, and belongs to the technical field of thermosetting resins.The full-biological antibacterial thermosetting resin is obtained by curing a resin composition of components including a plant oil-based multifunctional amine curing agent and an itaconic acid-based epoxy resin precursor, wherein the plant oil-based multifunctional amine curing agent is obtained by a thiol-double bond click reaction of 2-amino-5-mercapto-1,3,4-thiadiazole and a plant oil-based unsaturated fatty acid glyceride.The full-biological antibacterial thermosetting resin has excellent thermodynamic properties, antibacterial and antiviral functions, and a simple and controllable preparation process, is convenient to apply, is suitable for large-scale industrial production, and has a very good application prospect in the fields of protective coatings and antibacterial coatings.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of thermosetting resin, and particularly relates to a plant oil-based multifunctional amine curing agent, a full-bio-based antibacterial thermosetting resin and a preparation method and application thereof. BACKGROUND

[0002] Itaconic acid is a bio-based platform compound produced by biological fermentation of cheap agricultural and sideline products such as starch and sucrose, and is widely used in chemical fibers, synthetic resins, medicines, surfactants, ion exchange resins and food additives. Among them, itaconic acid-based epoxy resin as a typical bio-based epoxy resin has been widely reported and gradually developed and applied due to its sustainability and excellent mechanical properties, corrosion resistance, adhesion and other advantages; the Chinese patent document with publication number CN103965046A prepares itaconic acid-based triepoxy compound by the method of double bond oxidation, and the monomer type epoxy monomer is prepared by this method; the Chinese patent document with publication number CN102382079A discloses itaconic acid glycidyl ester with low viscosity and high epoxy value with an average degree of polymerization of 0-10, and the pre-polymer type itaconic acid-based epoxy resin precursor is prepared by this method.

[0003] Unsaturated fatty acid glyceride refers to plant oil containing unsaturated carbon chain, which has the characteristics of wide source, large yield, sustainability and low price, and there are chemically modified unsaturated double bonds in its structure, and is widely used in the synthesis and preparation of high polymers. Generally, the modification method is to prepare plant oil-based epoxy resin precursor by epoxidation, for example, the unsaturated double bond on the soybean oil segment is epoxidized to prepare epoxy soybean oil (ESO), which further expands the application field of plant oil-based thermosetting resin. In the field of epoxy resin, compounds containing flexible segments are usually used as toughening components, but due to the presence of many flexible fatty segments, the mechanical strength and thermodynamic properties of the epoxy resin will be greatly reduced, for example, the Chinese patent document with publication number CN104356358A discloses a preparation method of itaconic acid epoxy resin modified by dimer acid, the non-polar alkyl of dimer acid is introduced into the structure of the modified epoxy system, which improves the flexibility, but this will lead to a decrease in the crosslinking degree of the resin cured product. The Chinese patent document with publication number CN105440252A also discloses a water-based polyurethane modified epoxy itaconic acid resin, which uses -NCO terminated polyurethane to react with -OH in epoxy itaconic acid resin, thereby modifying the epoxy itaconic acid resin to increase the flexibility of the cured film, but the curing of the modified epoxy itaconic acid resin requires the action of ultraviolet light and photoinitiator and other auxiliaries. SUMMARY

[0004] The present application provides a plant oil-based multifunctional amine curing agent, which, after curing with an itaconic acid-based epoxy resin precursor, can produce a resin with excellent thermodynamic properties, high toughness, antibacterial and antiviral functions.

[0005] The specific technical solutions are as follows:

[0006] A plant oil-based multifunctional amine curing agent, the structural formula is shown as formula (I):

[0007]

[0008] The structural formula of R1, R2 and R3 is -COR, wherein R is A substituted or unsubstituted C11-C24 fatty carbon chain (the fatty carbon chain can be a saturated fatty carbon chain or an unsaturated fatty carbon chain); R1, R2 and R3 are the same or different, and * represents the connection position.

[0009] Preferably, R1, R2 and R3 are each independently selected from any one of the following formulas:

[0010]

[0011] * represents the connection position.

[0012] The plant oil-based multifunctional amine curing agent is obtained by thiol-double bond click reaction of 2-amino-5-thiol-1,3,4-thiadiazole and plant oil-based unsaturated fatty acid glyceride; the plant oil-based unsaturated fatty acid glyceride includes but is not limited to at least one of tridecenoic acid glyceride, dodecenoic acid glyceride, tetradecenoic acid glyceride, pentadecenoic acid glyceride, hexadecenoic acid glyceride, heptadecenoic acid glyceride, octadec-9-enoic acid glyceride (oleic acid glyceride), octadec-6-enoic acid glyceride (petroselinic acid glyceride), octadecadienoic acid glyceride (linoleic acid glyceride), octadecatrienoic acid glyceride (linolenic acid glyceride), 12-hydroxy-9-octadecenoic acid glyceride (ricinoleic acid glyceride), nonadecenoic acid glyceride, nonadecadienoic acid glyceride, eicosenoic acid glyceride, eicosadienoic acid glyceride, eicosatrienoic acid glyceride, eicosatetraenoic acid glyceride (arachidonic acid glyceride), eicosapentaenoic acid glyceride, heneicosenoic acid glyceride, docosenoic acid glyceride (erucic acid glyceride), docosadienoic acid glyceride, docosahexaenoic acid glyceride, tetracosenoic acid glyceride.

[0013] The plant oil-based unsaturated fatty acid glyceride can be further preferably any one of glyceryl tridecenoate, glyceryl octadeca-9-enoate (glyceryl trioleate), glyceryl octadeca-6-enoate (glyceryl trierucate), glyceryl octadecadienoate (glyceryl trilinoleate), glyceryl octadecatrienoate (glyceryl trilinolenate), glyceryl 12-hydroxy-9-octadecenoate (glyceryl triricinoleate), glyceryl docoseneate (glyceryl trerapeate), or a combination of two or more thereof.

[0014] Specifically, the preparation method of the plant oil-based multifunctional amine curing agent comprises the following steps: adding 2-amino-5-thiol-1, 3, 4-thiadiazole and plant oil-based unsaturated fatty acid glyceride into an organic solvent, then adding a photoinitiator or a thermal initiator and mixing uniformly, and then performing ultraviolet light irradiation or heating treatment, and finally performing post-treatment to obtain the plant oil-based multifunctional amine curing agent.

[0015] The organic solvent comprises methanol, ethanol, tetrahydrofuran, dioxane, toluene, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, or N-methyl pyrrolidone.

[0016] The photoinitiator comprises, but is not limited to, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl phenyl ketone, methyl o-benzoylformate, methyl o-benzoylbenzoate, 2, 4, 6-trimethylbenzoyl phenyl phosphonic acid ethyl ester, phenyl bis (2, 4, 6-trimethylbenzoyl) phosphine oxide, 2, 4, 6-trimethylbenzoyl diphenyl phosphine oxide, 2-dimethylamino-2-benzyl-1-[4-(4-morpholinyl) phenyl]-1-butanone, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy) phenyl]-1-propanone, 1, 1'-(methylenebis-4, 1-phenylene) bis[2-hydroxy-2-methyl-1-propanone], 2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone, benzoin dimethyl ether, benzophenone, isopropyl thioxanthone, 2, 2-dimethyl-ɑ-hydroxyacetophenone, ɑ, ɑ'-ethoxyacetophenone, 4-(N, N-dimethylamino) benzoic acid ethyl ester, or 4-isobutylphenyl-4'-methylphenyl iodine hexafluorophosphate.

[0017] The thermal initiator is selected from peroxide, azo initiator or redox system initiator; the peroxide includes but is not limited to lauroyl peroxide, dibenzoyl peroxide, tert-butyl perbenzoate, tert-butyl peroxy-2-ethylhexanoate; the azo initiator includes but is not limited to azobis isobutyronitrile, azobis isohexylnitrile, azobis isobutyryl hydrazine hydrochloride, azobis isobutylimidazole hydrochloride, azoisobutyryl cyanamide; the redox system initiator includes but is not limited to benzoyl peroxide / sucrose, tert-butyl hydroperoxide / ascorbic acid, tert-butyl hydroperoxide / sodium metabisulfite, benzoyl peroxide / N, N-dimethylaniline, ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydrogen peroxide / tartaric acid, hydrogen peroxide / ascorbic acid, ammonium persulfate / ferrous sulfate, hydrogen peroxide / ferrous sulfate, benzoyl peroxide / N, N-diethylaniline, benzoyl peroxide / ferrous pyrophosphate, potassium persulfate / silver nitrate, persulfate / thiol, cumene hydroperoxide / ferrous chloride, potassium persulfate / ferrous chloride, hydrogen peroxide / ferrous chloride or cumene hydroperoxide / tetraethylenepentamine.

[0018] The present application also provides a resin composition, components including the plant oil-based multifunctional amine curing agent and itaconic acid-based epoxy resin precursor, the molar ratio of epoxy functional group in the itaconic acid-based epoxy resin precursor to amine functional group in the plant oil-based multifunctional amine curing agent is 1:0.5-1.5.

[0019] The itaconic acid-based epoxy resin precursor is selected from the first component or the second component.

[0020] The first component is synthesized by oxidizing itaconic acid, and includes at least one of the compounds shown in formula (II).

[0021]

[0022] In formula (II), X is * = CH2 or * represents the connection position;

[0023] The second component is synthesized by alkaline epichlorohydrin method of itaconic acid, and includes at least one of the compounds shown in formula (III).

[0024]

[0025] In formula (III), Y is H or * represents the connection position; 10≥n≥1, n is an integer.

[0026] Preferably, the epoxy value of the itaconic acid-based epoxy resin precursor is 0.10-1.16 mol / 100g.

[0027] The plant oil-based multifunctional amine curing agent in the application is a bio-based monomer derived from a bulk bio-based raw material and is easy to prepare; the itaconic acid-based epoxy resin precursor is prepared using a bio-based raw material, which can reduce the consumption of petrochemical products by the plastic industry, and also reduces the environmental pollution in the production process of petroleum-based raw materials, and has the dual effects of saving petroleum resources and protecting the environment; the plant oil-based multifunctional amine curing agent with flexible aliphatic chains and rigid 1,3,4-thiadiazole ring structure is introduced into the epoxy resin system, which can greatly improve the strength and toughness of the bio-based thermosetting resin material, solve the problem of poor mechanical properties of antibacterial polymers, and endow the bio-based thermosetting resin material with good antibacterial and bacteriostatic effects.

[0028] The application further provides a full bio-based antibacterial thermosetting resin obtained by curing the resin composition.

[0029] Preferably, the resin composition is pre-cured at 50-100 DEG C for 0.5-10 hours to obtain a pre-cured product, and the pre-cured product is heated and cured at 100-200 DEG C for 0.5-10 hours to obtain the full bio-based antibacterial thermosetting resin.

[0030] Preferably, the full bio-based antibacterial thermosetting resin has a glass transition temperature of 55-156 DEG C, a tensile strength of 40-130 MPa, and an impact strength of 30-88 kJ / m 2 Meanwhile, the application shows excellent broad-spectrum antibacterial properties: the killing rate of gram-positive bacteria and gram-negative bacteria is more than 100% and 94.0%, respectively.

[0031] The application further provides a use of the resin composition or the full bio-based antibacterial thermosetting resin in the field of protective coatings of rail transportation, indoor and outdoor building facilities or aerospace materials.

[0032] The application further provides an antibacterial coating, wherein the resin composition is fully mixed and applied to a substrate surface or a mold, and the antibacterial coating is obtained after curing treatment.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] (1) The application utilizes the high-efficiency and high-selectivity "sulfhydryl-double bond" click reaction between the sulfhydryl functional group in the structure of 2-amino-5-sulfhydryl-1, 3, 4-thiadiazole and the unsaturated double bond in the structure of plant oil-based unsaturated fatty acid glyceride to obtain a plant oil-based multifunctional amine curing agent, which has antibacterial and toughening effects and belongs to renewable resources.

[0035] (2) The plant oil-based multifunctional amine curing agent is prepared by introducing 1, 3, 4-thiadiazole derivatives with the activities of killing bacteria, fungi, killing insects, killing weeds and resisting viruses into the structure of plant oil-based unsaturated fatty acid glyceride, and the rigid 1, 3, 4-thiadiazole ring can be enhanced; the plant oil-based multifunctional amine curing agent with flexible fatty chains and rigid 1, 3, 4-thiadiazole ring structures is introduced into the epoxy resin system, which can greatly improve the strength and toughness of the material and solve the problem of poor mechanical properties of antibacterial polymers. At the same time, the high-density 1, 3, 4-thiadiazole ring structure can also endow the product with excellent antibacterial, antibacterial and antiviral properties.

[0036] (3) The full-biological antibacterial thermosetting resin provided by the application has excellent thermodynamic properties, antibacterial and antiviral functions, and the preparation process is simple and controllable, easy to use, suitable for large-scale industrial production, and has a very good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The infrared spectrum of the plant oil-based multifunctional amine curing agent synthesized in Example 2.

[0038] Figure 2 The antibacterial ability characterization diagram of the full-biological antibacterial thermosetting resin in Example 1 on Escherichia coli; wherein a is the characterization diagram of Escherichia coli before adding the full-biological antibacterial thermosetting resin; b is the characterization diagram of Escherichia coli after adding the full-biological antibacterial thermosetting resin.

[0039] Figure 3 The antibacterial ability characterization diagram of the full-biological antibacterial thermosetting resin in Example 1 on Staphylococcus aureus; wherein a is the characterization diagram of Staphylococcus aureus before adding the full-biological antibacterial thermosetting resin; b is the characterization diagram of Staphylococcus aureus after adding the full-biological antibacterial thermosetting resin.

[0040] Figure 4is the antibacterial ability characterization graph of the full-bio-based antibacterial thermosetting resin in Example 2 on Escherichia coli; wherein a is the characterization graph of Escherichia coli before the full-bio-based antibacterial thermosetting resin is added; b is the characterization graph of Escherichia coli after the full-bio-based antibacterial thermosetting resin is added;

[0041] Figure 5 is the antibacterial ability characterization graph of the full-bio-based antibacterial thermosetting resin in Example 2 on Staphylococcus aureus; wherein a is the characterization graph of Staphylococcus aureus before the full-bio-based antibacterial thermosetting resin is added; b is the characterization graph of Staphylococcus aureus after the full-bio-based antibacterial thermosetting resin is added. DETAILED DESCRIPTION

[0042] The application will be further illustrated below in conjunction with the embodiments and the accompanying drawings. It should be understood that these embodiments are only used to illustrate the application, and are not used to limit the scope of the application.

[0043] In the following examples, the source part structure of component A is a commercialized plant oil-based unsaturated fatty acid glyceride; component B can be prepared according to the method in the literature (Chinese patent documents: CN103965046A, CN102382079A, CN102718945A and Bio-based epoxy resin from itaconic acid and its thermosets cured with anhydride and comonomers, Green Chemistry, 2013, 15(1): 245-254, DOI: 10.1039 / C2GC36715G).

[0044] Example 1

[0045]

[0046] 1 mol of octadec-9-enoic acid glycerol triester (oleic acid glycerol triester) and 3.5 mol of 2-amino-5-mercapto-1,3,4-thiadiazole were placed in a round-bottom flask, tetrahydrofuran was added for sufficient stirring to dissolve, 0.03 wt.% of a thermal initiator, dibenzoyl peroxide, was added and mixed uniformly, the reaction system was heated and stirred at 60°C for 24 h, after the reaction was completed, the reaction liquid was rotary evaporated and dried at 60°C, and washed with methanol for three times to remove the unreacted 2-amino-5-mercapto-1,3,4-thiadiazole monomer, and then vacuum dried for 48 h to constant weight, to obtain a plant oil-based multifunctional amine curing agent (component A);

[0047] The plant oil-based multifunctional amine curing agent (component A) was mixed with an itaconic acid-based epoxy resin precursor (component B, which was synthesized by using itaconic acid by an alkaline method of epoxy chloropropane, wherein Y is H or

[0048] 10≥n≥1, n is an integer) to obtain a resin composition, wherein the molar ratio of the epoxy functional groups in the itaconic acid based epoxy resin precursor to the amine functional groups in the vegetable oil based multifunctional amine curing agent is 1:1; then the resin composition system is pre-cured at 100°C for 0.5 hours, and the obtained pre-cured product is heated and cured at 100°C for 10 hours to obtain the full-bio-based antibacterial thermosetting resin.

[0049] The performance test results show that the glass transition temperature of the full-bio-based antibacterial thermosetting resin is 122°C, the tensile strength is 114 MPa, and the impact strength is 48 kJ / m 2 .

[0050] Representative and typical test strains are selected: Escherichia coli (gram-negative bacteria) and Staphylococcus aureus (gram-positive bacteria). The agar diffusion method is used for the antibacterial experiment. Under sterile conditions, the strains are inoculated on the slant medium, activated twice at 37°C, then inoculated into a suitable amount of nutrient broth, and cultured for 24 h for standby. The original bacterial solution is diluted to 10 7 copies / mL by 10-fold dilution method, then added dropwise to all the cured resin sheets wiped with ethanol, and the ethanol-wiped quartz glass plate is used as a blank test. After covering the fresh-keeping film and leveling, the antibacterial effect is determined, and the results are shown as a and b in Figure 2 and Figure 3 . The killing rate of the full-bio-based antibacterial thermosetting resin cured product prepared in this embodiment to gram-positive bacteria is 100%, and the killing rate to gram-negative bacteria is above 94%.

[0051] Example 2

[0052]

[0053] 1 mol of octadecadienoic acid triglyceride (linoleic acid triglyceride) and 3.1 mol of 2-amino-5-mercapto-1,3,4-thiadiazole are placed in a round-bottom flask, N,N-dimethylformamide is added for stirring to dissolution, 0.03 wt.% of a photoinitiator 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester is added and uniformly mixed, the reaction system is wrapped with tin foil paper and irradiated with 365 nm ultraviolet light under argon protection, and stirred for 48 h. After the reaction is completed, the reaction solution is poured into a large amount of methanol solution to remove the unreacted 2-amino-5-mercapto-1,3,4-thiadiazole monomer, and then vacuum dried for 48 h to constant weight to obtain the vegetable oil based multifunctional amine curing agent (component A). The infrared spectrum of the vegetable oil based multifunctional amine curing agent is shown in Figure 1 .

[0054] The plant oil based multifunctional amine curing agent (component A) is mixed with the itaconic acid based epoxy resin precursor (component B, synthesized by using itaconic acid via the base method of epichlorohydrin, wherein Y is H or 10≥n≥1, n is an integer) to obtain a resin composition, wherein the molar ratio of the epoxy functional groups in the itaconic acid based epoxy resin precursor to the amine functional groups in the plant oil based multifunctional amine curing agent is 1:1; then the resin composition system is pre-cured at 50°C for 10 hours, and the obtained pre-cured product is heated and cured at 140°C for 6 hours to obtain the full-bio-based antibacterial thermosetting resin.

[0055] The performance test results show that the glass transition temperature of the full-bio-based antibacterial thermosetting resin is 134°C, the tensile strength is 86 MPa, and the impact strength is 44 kJ / m 2 .

[0056] The antibacterial test experiment steps are the same as those of Example 1, and the bacteriostatic effect diagram of the full-bio-based antibacterial thermosetting resin prepared in this example is shown in FIGS. a and b in Figure 4 and Figure 5 , wherein the killing rate of gram-positive bacteria is 100%, and the killing rate of gram-negative bacteria is more than 97%.

[0057] Example 3

[0058]

[0059]

[0060] 1 mol of octadecatrienoic acid glyceride (linolenic acid glyceride) and 3.1 mol of 2-amino-5-mercapto-1,3,4-thiadiazole are placed in a round-bottom flask, toluene is added for stirring and heating to dissolution, 0.03 wt.% of a photoinitiator phenyl bis(2,4,6-trimethylbenzoyl) phosphine oxide is added and uniformly mixed, the reaction system is wrapped with tin foil paper and irradiated with 365 nm ultraviolet light under argon protection, and stirring reaction is carried out for 48 h. After the reaction is completed, the reaction liquid is poured into a large amount of methanol solution to remove the unreacted 2-amino-5-mercapto-1,3,4-thiadiazole monomer, and then vacuum drying is carried out for 48 h to constant weight to obtain the plant oil based multifunctional amine curing agent (component A).

[0061] The plant oil based multifunctional amine curing agent (component A) is mixed with the itaconic acid based epoxy resin precursor (component B, synthesized by using itaconic acid via the base method of epichlorohydrin, wherein Y is H or ) and the plant oil based multifunctional amine curing agent (component A) to obtain a resin composition, wherein the molar ratio of the epoxy functional groups in the itaconic acid based epoxy resin precursor to the amine functional groups in the plant oil based multifunctional amine curing agent is 1:1; then the resin composition system is pre-cured at 60°C for 8 hours, and the obtained pre-cured product is heated and cured at 180°C for 4 hours to prepare the full-bio-based antibacterial thermosetting resin.

[0062] The performance test results show that the glass transition temperature of the full-bio-based antibacterial thermosetting resin is 146°C, the tensile strength is 126 MPa, and the impact strength is 42 kJ / m 2 .

[0063] The antibacterial test experiment steps are the same as those of Example 1, and the killing rate of the full-bio-based antibacterial thermosetting resin prepared in this example to gram-positive bacteria is more than 99%, and the killing rate to gram-negative bacteria is more than 95%.

[0064] Example 4

[0065]

[0066] The 1 mol of octadec-6-enoic acid triglyceride (glyceryl trilinolenate) and 4.0 mol of 2-amino-5-mercapto-1,3,4-thiadiazole are placed in a round-bottom flask, toluene is added, fully stirred and heated to dissolution, 0.03 wt.% of a photoinitiator (a mixture of 2,4,6-trimethylbenzoyl phenyl phosphinic acid ethyl ester and 1-hydroxycyclohexyl phenyl ketone at a weight ratio of 1:1) is added, mixed uniformly, the reaction system is wrapped with tin foil paper and irradiated with 365 nm ultraviolet light under argon protection, and stirred and reacted for 48 h. After the reaction is completed, the reaction solution is poured into a large amount of methanol solution to remove the unreacted 2-amino-5-mercapto-1,3,4-thiadiazole monomer, and then vacuum dried for 48 h to constant weight to obtain the plant oil based multifunctional amine curing agent (component A).

[0067] The plant oil based multifunctional amine curing agent (component A) and the itaconic acid based epoxy resin precursor (component B, synthesized by using itaconic acid by an oxidation method, X is *═CH2 or ) are mixed uniformly to obtain a resin composition, wherein the molar ratio of the epoxy functional groups in the itaconic acid based epoxy resin precursor to the amine functional groups in the plant oil based multifunctional amine curing agent is 1:1; then the resin composition system is pre-cured at 100°C for 5 hours, and the obtained pre-cured product is heated and cured at 200°C for 0.5 hours to prepare the full-bio-based antibacterial thermosetting resin.

[0068] The performance test results show that the glass transition temperature of the full-bio-based antibacterial thermosetting resin is 155°C, the tensile strength is 40 MPa, and the impact strength is 30 kJ / m 2 .

[0069] The antibacterial test experiment procedure is the same as that of Example 1. The killing rate of the full-bio-based antibacterial thermosetting resin prepared in this example on gram-positive bacteria is 100%, and the killing rate on gram-negative bacteria is above 96%.

[0070] Example 5

[0071]

[0072] 1 mol of erucic acid triglyceride (erucic acid triglyceride) and 5.0 mol of 2-amino-5-mercapto-1, 3, 4-thiadiazole were placed in a round-bottom flask, N-methylpyrrolidone was added, fully stirred and heated to dissolution, 0.01 wt.% of a redox system initiator, benzoyl peroxide / N, N-dimethylaniline, was added and uniformly mixed, the reaction system was heated and stirred at 80°C for 24h, after the reaction was completed, the reaction liquid was washed with ethanol three times to remove the unreacted 2-amino-5-mercapto-1, 3, 4-thiadiazole monomer, and then vacuum dried for 48h to constant weight to obtain a vegetable oil-based multifunctional amine curing agent (component A).

[0073] The vegetable oil-based multifunctional amine curing agent (component A) was uniformly mixed with an itaconic acid-based epoxy resin precursor (component B, which was synthesized by an alkaline method using itaconic acid and epichlorohydrin, wherein Y is H or 10≥n≥1, n is an integer) to obtain a resin composition, wherein the molar ratio of the epoxy functional groups in the itaconic acid-based epoxy resin precursor to the amine functional groups in the vegetable oil-based multifunctional amine curing agent is 1:1; then the resin composition system was pre-cured at 80°C for 8h, and the obtained pre-cured product was heated and cured at 160°C for 6h to prepare the full-bio-based antibacterial thermosetting resin.

[0074] The performance test results show that the glass transition temperature of the full-bio-based antibacterial thermosetting resin is 145°C, the tensile strength is 130MPa, and the impact strength is 88kJ / m 2 .

[0075] The antibacterial test experiment procedure is the same as that of Example 1. The killing rate of the full-bio-based antibacterial thermosetting resin prepared in this example on gram-positive bacteria is 100%, and the killing rate on gram-negative bacteria is above 95%.

[0076] Example 6

[0077]

[0078] 1 mol of 12-hydroxy-9-octadecenoic acid triglyceride (ricinoleic acid triglyceride) and 6.0 mol of 2-amino-5-mercapto-1,3,4-thiadiazole were placed in a round-bottom flask. N,N-dimethylacetamide was added and stirred thoroughly and heated until dissolved. 0.02 wt.% of peroxide initiator benzoyl peroxide was added and mixed evenly. The reaction system was heated and stirred at 60 °C for 24 h. After the reaction was completed, the reaction solution was washed three times with ethanol to remove unreacted 2-amino-5-mercapto-1,3,4-thiadiazole monomer. The solution was then vacuum dried for 48 h to constant weight to obtain a vegetable oil-based multifunctional amine curing agent (component A).

[0079] The plant oil-based polyfunctional amine curing agent (component A) and itaconic acid-based epoxy resin precursor (component B, synthesized by oxidation of itaconic acid, where X is *═CH2 or ...) are used. The resin composition is obtained by mixing evenly, wherein the molar ratio of epoxy functional groups in the itaconic acid-based epoxy resin precursor to amine functional groups in the vegetable oil-based polyfunctional amine curing agent is 1:1; then the resin composition system is pre-cured at 80°C for 8 hours, and the obtained pre-cured material is heated and cured at 140°C for 8 hours to obtain the fully bio-based antibacterial thermosetting resin.

[0080] Performance test results show that the glass transition temperature of this fully bio-based antibacterial thermosetting resin is 133℃, the tensile strength is 110MPa, and the impact strength is 54kJ / m. 2 .

[0081] The antibacterial test procedure is the same as in Example 1. The all-bio-based antibacterial thermosetting resin prepared in this example has a 100% kill rate against Gram-positive bacteria and a kill rate of over 96% against Gram-negative bacteria.

[0082] Example 7

[0083]

[0084] 1 mol of undecenoic acid triglyceride and 3.0 mol of 2-amino-5-mercapto-1,3,4-thiadiazole were placed in a round-bottom flask. Toluene was added and stirred thoroughly and heated until dissolved. 0.03 wt.% of the photoinitiator 1-hydroxycyclohexylphenyl ketone was added and mixed evenly. The reaction system was wrapped with tin foil and irradiated with 365 nm ultraviolet light under argon protection and stirred for 48 h. After the reaction was completed, the reaction solution was concentrated by rotary evaporation at 90 °C and vacuum dried for 48 h to constant weight to obtain a vegetable oil-based multifunctional amine curing agent (component A).

[0085] The plant oil-based multifunctional amine curing agent (component A) and itaconic acid-based epoxy resin precursor (component B) were synthesized using itaconic acid via an epichlorohydrin alkaline method, wherein Y is H or 10≥n≥1, n is an integer, the resin composition is obtained by mixing uniformly, wherein the molar ratio of the epoxy functional groups in the itaconic acid-based epoxy resin precursor to the amine functional groups in the plant oil-based multifunctional amine curing agent is 1:1; then the resin composition system is pre-cured at 50°C for 10 hours, and the obtained pre-cured product is heated and cured at 100°C for 10 hours to obtain the full-bio-based antibacterial thermosetting resin.

[0086] The performance test results show that the glass transition temperature of the full-bio-based antibacterial thermosetting resin is 156°C, the tensile strength is 87 MPa, and the impact strength is 38 kJ / m 2 .

[0087] The antibacterial test experiment steps are the same as those in Example 1, and the killing rate of the full-bio-based antibacterial thermosetting resin prepared in this example on gram-positive bacteria is 100%, and the killing rate on gram-negative bacteria is more than 97%.

[0088] Comparative Example 1

[0089] The plant oil-based multifunctional amine curing agent (component A) in Example 1 is replaced by polyether amine D230, and other processes and raw materials are unchanged, and the glass transition temperature of the thermosetting resin prepared is 83°C, the tensile strength is 110 MPa, and the impact strength is 4 kJ / m 2 The killing rate of the thermosetting resin cured product prepared in this comparative example on gram-positive bacteria is 55%, and the killing rate on gram-negative bacteria is 48%, and the thermodynamic performance and antibacterial performance are obviously poorer than those of the full-bio-based antibacterial thermosetting resin in Example 1.

[0090] The above examples have described the technical solutions of the present application in detail, and it should be understood that the above description is only a specific embodiment of the present application and is not used to limit the present application. Any modification, supplement or similar substitution within the principle range of the present application should be included in the protection scope of the present application.

Claims

1. A vegetable oil based multifunctional amine curing agent, characterized by, The structural formula is shown as formula (I): R1, R2 and R3 are each independently selected from any one of the following formulae:

2. The process for the preparation of vegetable oil based multifunctional amine curing agent as claimed in claim 1, wherein, The plant oil-based multifunctional amine curing agent is obtained by a thiol-double bond click reaction of 2-amino-5-thiol-1,3,4-thiadiazole and a plant oil-based unsaturated fatty acid glyceride.

3. The process for the preparation of vegetable oil based multifunctional amine curing agent as claimed in claim 2, wherein, The plant oil-based unsaturated fatty acid glyceride is at least one of tricaprylin, triolein, trilinolein, trilinolenin, 12-hydroxy-9-octadecenoic acid glyceride, or docosatetraenoic acid glyceride.

4. The process for the preparation of vegetable oil based multifunctional amine curing agent as claimed in claim 2, wherein, The preparation method of the plant oil-based multifunctional amine curing agent comprises: adding 2-amino-5-thiol-1,3,4-thiadiazole and a plant oil-based unsaturated fatty acid glyceride into an organic solvent, adding a photo initiator or a thermal initiator and mixing uniformly, and then performing ultraviolet light irradiation or heating treatment, and finally obtaining the plant oil-based multifunctional amine curing agent after post-treatment.

5. A resin composition characterized by comprising: The components comprise the plant oil-based multifunctional amine curing agent of claim 1 and an itaconic acid-based epoxy resin precursor, and the molar ratio of the epoxy functional groups in the itaconic acid-based epoxy resin precursor to the amine functional groups in the plant oil-based multifunctional amine curing agent is 1:0.5-1.5; The itaconic acid-based epoxy resin precursor is selected from the first component or the second component; The first component is obtained by synthesizing itaconic acid by an oxidation method, and comprises at least one of the compounds shown in formula (II); In formula (II), X is * = CH2or The second component is obtained by synthesizing itaconic acid by an epichlorohydrin alkali method, and comprises at least one of the compounds shown in formula (III); In formula (III), Y is H or 10 > n > 1, n is an integer.

6. A fully bio-based antibacterial thermoset resin, characterized in that, The resin composition of claim 5 is cured.

7. The fully biobased antimicrobial thermosetting resin according to claim 6, characterized in that, The resin composition is pre-cured at 50-100 DEG C for 0.5-10 hours to obtain a pre-cured product, and then the pre-cured product is heated and cured at 100-200 DEG C for 0.5-10 hours to obtain the full-bio-based antibacterial thermosetting resin.

8. The fully biobased antimicrobial thermosetting resin according to claim 6, characterized in that, The full-bio-based antibacterial thermosetting resin has a glass transition temperature of 55-156 DEG C, a tensile strength of 40-130 MPa, and an impact strength of 30-88 kJ / m 2 .

9. Application of the resin composition of claim 5 or the full-bio-based antibacterial thermosetting resin of claim 6 in the field of protective coatings.

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