阅读说明：本技术 一种高性能环氧树脂固化剂及其制备方法 (High-performance epoxy resin curing agent and preparation method thereof ) 是由 不公告发明人 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种高性能环氧树脂固化剂,包括以下重量份原料：腰果酚10-20份、二乙烯三胺5-10份、多聚甲醛5-8份、乙二醇30-40份、偏苯三酸酐5-10份、促进剂1份、助剂2份、催化剂0.1份；本发明还公开了该高性能环氧树脂固化剂的制备方法,第一步、将腰果酚、二乙烯三胺和催化剂加入反应釜中,升温至90-100℃,加入多聚甲醛,搅拌反应1h后,得到第一组合物；第二步、向第一组合物中加入乙二醇,搅拌10min后,向反应釜中加入偏苯三酸酐、促进剂和助剂,继续搅拌30-60min；本发明提高的环氧树脂固化剂不仅能够提高环氧树脂固化后的韧性和固化速率,还赋予其阻燃性能、抗菌性。(The invention discloses a high-performance epoxy resin curing agent which comprises the following raw materials in parts by weight: 10-20 parts of cardanol, 5-10 parts of diethylenetriamine, 5-8 parts of paraformaldehyde, 30-40 parts of ethylene glycol, 5-10 parts of trimellitic anhydride, 1 part of accelerator, 2 parts of auxiliary agent and 0.1 part of catalyst; the invention also discloses a preparation method of the high-performance epoxy resin curing agent, which comprises the steps of firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, heating to 90-100 ℃, adding paraformaldehyde, and stirring for reacting for 1 hour to obtain a first composition; secondly, adding ethylene glycol into the first composition, stirring for 10min, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 30-60 min; the epoxy resin curing agent provided by the invention can improve the toughness and curing rate of the cured epoxy resin, and endows the cured epoxy resin with flame retardant property and antibacterial property.)

1. The high-performance epoxy resin curing agent is characterized by comprising the following raw materials in parts by weight: 10-20 parts of cardanol, 5-10 parts of diethylenetriamine, 5-8 parts of paraformaldehyde, 30-40 parts of ethylene glycol, 5-10 parts of trimellitic anhydride, 1 part of accelerator, 2 parts of auxiliary agent and 0.1 part of catalyst;

the high-performance epoxy resin curing agent is prepared by the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring for 10min at the rotating speed of 60-100r/min, heating to 90-100 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 100-200r/min, keeping the temperature unchanged, and stirring for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 30-60min to obtain the high-performance epoxy resin curing agent.

2. The curing agent for high-performance epoxy resin according to claim 1, wherein the catalyst is a 17% by mass hydrochloric acid solution, and the accelerator is N-N dimethylbenzylamine.

3. The high-performance epoxy resin curing agent according to claim 1, wherein the auxiliary agent is prepared by the following steps:

step A1, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tetrahydrofuran into a three-neck flask, controlling the reaction temperature to be 50 ℃, stirring and reacting at the rotating speed of 30-60r/min under the nitrogen atmosphere, adding maleic anhydride into the three-neck flask while stirring, increasing the rotating speed to 200-300r/min, stirring and reacting for 6 hours, naturally cooling to room temperature, filtering, collecting filtrate, performing rotary evaporation for 1-2 hours at the temperature of 65-70 ℃ in a rotary evaporator, and performing rotary evaporation on a product, ethyl acetate and deionized water according to the weight ratio of 1 g: 5mL of: adding 5mL of the mixture into a reactor for extraction, and finally performing rotary evaporation to remove ethyl acetate to obtain an intermediate 1;

step A2, adding 1, 2-dichloroethane and o-methoxyphenol which are dried by anhydrous calcium chloride into a dried three-neck round-bottom flask, stirring at the rotating speed of 60-120r/min for 10min at room temperature, placing the three-neck round-bottom flask into a low-temperature constant-temperature tank, controlling the temperature to be 0 ℃, adding anhydrous aluminum chloride, continuously stirring at the constant rotating speed for 30min, adding an intermediate 1 into the three-neck round-bottom flask, continuously stirring for 20min, heating to 30 ℃, reacting at the rotating speed of 100-200r/min for 8h, pouring a reaction solution into ice water with the volume being 2 times that of the reaction solution after the reaction is finished, adding concentrated hydrochloric acid into the ice water, stirring at the rotating speed of 60-100r/min for 20min, filtering, collecting solids, recrystallizing by ethyl acetate, and finally drying in a 50 ℃ oven to constant weight to obtain an intermediate 2;

step A3, adding 2-amino-5-chloropyridine and methanol into a round-bottom flask, stirring for 10min at the rotating speed of 60-100r/min, adding N, N-dimethylformamide dimethyl acetal into the round-bottom flask, heating to 65-70 ℃, carrying out reflux reaction for 3h, cooling to-5 ℃, carrying out suction filtration, recrystallizing a filter cake with N-hexane, and drying in a vacuum drying oven at 50 ℃ for 5-10h to obtain an intermediate 3;

step A4, adding the intermediate 3 and N, N-dimethylformamide into a reaction kettle, then adding sodium bicarbonate into the reaction kettle, stirring at the room temperature and the rotation speed of 80r/min for 5-10min, dropwise adding methyl bromoacetate into the reaction kettle, heating to 90 ℃ after dropwise adding, stirring at the rotation speed of 100r/min for 5h, cooling to 10 ℃ after the reaction is finished, adding deionized water into the reaction kettle, stirring for 30min, separating out solids, performing suction filtration, washing a filter cake with distilled water for 3-5 times, recrystallizing with methanol, and finally drying at 50 ℃ to constant weight to obtain an intermediate 4;

step A5, adding the intermediate 4 and dimethyl sulfoxide into a three-neck flask, stirring and reacting at the rotation speed of 100 plus 200r/min, introducing ammonia gas for 30min, heating to reflux, continuing to introduce ammonia gas until solid begins to be separated out, continuing to introduce ammonia gas, stopping introducing ammonia gas after the rotation speed is unchanged and continuing to react for 30-60min, filtering, washing a filter cake with absolute ethyl alcohol for 2 times, transferring to deionized water to dilute and stir for 30min, filtering, washing the filter cake with distilled water for 2 times, and finally vacuum-drying at 55 ℃ to constant weight to obtain an intermediate 5;

and A6, adding the intermediate 2 and dimethyl sulfoxide into a reaction kettle, stirring for 10min at the rotation speed of 50-80r/min, adding potassium carbonate, tetrabutyl ammonium bromide and potassium iodide into the reaction kettle, continuously stirring for 5min, adding the intermediate 5 into the reaction kettle, heating to reflux for reaction for 12h, transferring the mixture into deionized water when the mixture is hot after the reaction is finished, stirring for 5min, standing for 5-10h, filtering, washing precipitates twice with the deionized water, and finally drying in an oven at 50 ℃ to constant weight to obtain the auxiliary agent.

4. The curing agent for high performance epoxy resin as claimed in claim 3, wherein the ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tetrahydrofuran and the eleostearic anhydride in step A1 is 0.1 mol: 30-60 mL: 0.1mol, and the dosage ratio of the 1, 2-dichloroethane, the o-methoxyphenol, the anhydrous aluminum chloride and the intermediate 1 in the step A2 is 250-300 mL: 31 g: 83.34 g: 40g of concentrated hydrochloric acid, wherein the dosage of the concentrated hydrochloric acid is 1/5 of the volume of the ice water, and the mass fraction of the concentrated hydrochloric acid is 37%.

5. The curing agent for high performance epoxy resin according to claim 3, wherein the ratio of the amount of 2-amino-5-chloropyridine, methanol and N, N-dimethylformamide dimethyl acetal used in step A3 is 100 mmol: 100-150 mL: 100mmol, the ratio of the intermediate 3, N-dimethylformamide, sodium bicarbonate, methyl bromoacetate and deionized water in step A4 is 100 mmol: 100mL of: 19 g: 33-35 g: 200-250mL, the ratio of the amount of the intermediate 4 to the amount of the dimethyl sulfoxide in the step A5 is 50 mmol: 400mL, wherein the dosage ratio of the intermediate 2, the dimethyl sulfoxide, the potassium carbonate, the tetrabutylammonium bromide, the potassium iodide and the intermediate 5 in the step A6 is 10-20 g: 250mL of: 10 g: 0.2 g: 0.2 g: 15 g.

6. The preparation method of the high-performance epoxy resin curing agent according to claim 1, comprising the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring for 10min at the rotating speed of 60-100r/min, heating to 90-100 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 100-200r/min, keeping the temperature unchanged, and stirring for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 30-60min to obtain the high-performance epoxy resin curing agent.

Technical Field

The invention belongs to the technical field of curing agent preparation, and particularly relates to a high-performance epoxy resin curing agent and a preparation method thereof.

Background

Epoxy resins are well known for their excellent mechanical, electrical, thermal stability, chemical resistance and adhesive properties, and cured epoxy resin systems have found wide application, including coatings, adhesives, composites, specific examples including epoxy resin composites using carbon fiber and glass fiber reinforcement, protective coatings for metal surfaces, building products for concrete, cement or ceramic substrates; the fields of electronics and electricity, aerospace, ship transportation and the like.

The epoxy resin is a thermoplastic linear structure, cannot be directly used, and can be used only after a second component is added into the resin and is subjected to addition polymerization reaction or catalytic polymerization reaction with an epoxy group of the epoxy resin under the conditions of certain temperature, humidity and the like to generate a cured product with a three-dimensional network structure (a three-dimensional network structure). Epoxy resins are substances or mixtures containing epoxy resin groups, curing agents include compounds reactive with the epoxy groups of the epoxy resin, such as amines, carboxylic acids and thiols, and epoxy resins can be crosslinked or cured by a curing agent, which is a chemical reaction of the epoxy groups in the epoxy resin with the reactive groups in the curing agent, and curing converts epoxy resins having relatively low molecular weights into relatively high molecular weight materials by chemical addition of the curing agent to the epoxy resin.

At present, the polyamine curing agent with the most usage amount of the curing agent typically represents 4, 4 '-diaminodiphenylmethane and 4, 4' -diaminodiphenyl ether, but has the disadvantages of high toxicity, liver damage and strong volatility, and a homogeneous system is difficult to form with epoxy resin at normal temperature, so that the technical problem to be solved at present is to provide a high-performance environment-friendly epoxy resin curing agent.

Disclosure of Invention

The invention aims to provide a high-performance epoxy resin curing agent and a preparation method thereof.

The technical problems to be solved by the invention are as follows:

in the prior art, the curing agent has low curing activity, single performance and strong volatility, and can not effectively solve the problems of large brittleness, no high temperature resistance and other poor mechanical properties of the cured epoxy resin.

The purpose of the invention can be realized by the following technical scheme:

a high-performance epoxy resin curing agent comprises the following raw materials in parts by weight: 10-20 parts of cardanol, 5-10 parts of diethylenetriamine, 5-8 parts of paraformaldehyde, 30-40 parts of ethylene glycol, 5-10 parts of trimellitic anhydride, 1 part of accelerator, 2 parts of auxiliary agent and 0.1 part of catalyst;

the high-performance epoxy resin curing agent is prepared by the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring for 10min at the rotating speed of 60-100r/min, heating to 90-100 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 100-200r/min, keeping the temperature unchanged, and stirring for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 30-60min to obtain the high-performance epoxy resin curing agent.

Further, the catalyst is a hydrochloric acid solution with the mass fraction of 17%, and the accelerator is N-N dimethylbenzylamine.

Further, the auxiliary agent is prepared by the following steps:

step A1, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tetrahydrofuran into a three-neck flask, controlling the reaction temperature to be 50 ℃, stirring and reacting at the rotating speed of 30-60r/min under the nitrogen atmosphere, adding maleic anhydride into the three-neck flask while stirring, increasing the rotating speed to 200-300r/min, stirring and reacting for 6 hours, naturally cooling to room temperature, filtering, collecting filtrate, performing rotary evaporation for 1-2 hours at the temperature of 65-70 ℃ in a rotary evaporator, and performing rotary evaporation on a product, ethyl acetate and deionized water according to the weight ratio of 1 g: 5mL of: adding 5mL of the mixture into a reactor for extraction, and finally performing rotary evaporation to remove ethyl acetate to obtain an intermediate 1;

the reaction process is as follows:

step A2, adding 1, 2-dichloroethane and o-methoxyphenol which are dried by anhydrous calcium chloride into a dried three-neck round-bottom flask, stirring at the rotating speed of 60-120r/min for 10min at room temperature, placing the three-neck round-bottom flask into a low-temperature constant-temperature tank, controlling the temperature to be 0 ℃, adding anhydrous aluminum chloride, continuously stirring at the constant rotating speed for 30min, adding an intermediate 1 into the three-neck round-bottom flask, continuously stirring for 20min, heating to 30 ℃, reacting at the rotating speed of 100-200r/min for 8h, pouring a reaction solution into ice water with the volume being 2 times that of the reaction solution after the reaction is finished, adding concentrated hydrochloric acid into the ice water, stirring at the rotating speed of 60-100r/min for 20min, filtering, collecting solids, recrystallizing by ethyl acetate, and finally drying in a 50 ℃ oven to constant weight to obtain an intermediate 2;

the reaction process is as follows:

step A3, adding 2-amino-5-chloropyridine and methanol into a round-bottom flask, stirring for 10min at the rotating speed of 60-100r/min, adding N, N-dimethylformamide dimethyl acetal into the round-bottom flask, heating to 65-70 ℃, carrying out reflux reaction for 3h, cooling to-5 ℃, carrying out suction filtration, recrystallizing a filter cake with N-hexane, and drying in a vacuum drying oven at 50 ℃ for 5-10h to obtain an intermediate 3;

the reaction process is as follows:

step A4, adding the intermediate 3 and N, N-dimethylformamide into a reaction kettle, then adding sodium bicarbonate into the reaction kettle, stirring at the room temperature and the rotation speed of 80r/min for 5-10min, dropwise adding methyl bromoacetate into the reaction kettle, heating to 90 ℃ after dropwise adding, stirring at the rotation speed of 100r/min for 5h, cooling to 10 ℃ after the reaction is finished, adding deionized water into the reaction kettle, stirring for 30min, separating out solids, performing suction filtration, washing a filter cake with distilled water for 3-5 times, recrystallizing with methanol, and finally drying at 50 ℃ to constant weight to obtain an intermediate 4;

the reaction process is as follows:

step A5, adding the intermediate 4 and dimethyl sulfoxide into a three-neck flask, stirring and reacting at the rotation speed of 100 plus 200r/min, introducing ammonia gas for 30min, heating to reflux, continuing to introduce ammonia gas until solid begins to be separated out, continuing to introduce ammonia gas, stopping introducing ammonia gas after the rotation speed is unchanged and continuing to react for 30-60min, filtering, washing a filter cake with absolute ethyl alcohol for 2 times, transferring to deionized water to dilute and stir for 30min, filtering, washing the filter cake with distilled water for 2 times, and finally vacuum-drying at 55 ℃ to constant weight to obtain an intermediate 5;

the reaction process is as follows:

and A6, adding the intermediate 2 and dimethyl sulfoxide into a reaction kettle, stirring for 10min at the rotation speed of 50-80r/min, adding potassium carbonate, tetrabutyl ammonium bromide and potassium iodide into the reaction kettle, continuously stirring for 5min, adding the intermediate 5 into the reaction kettle, heating to reflux for reaction for 12h, transferring the mixture into deionized water when the mixture is hot after the reaction is finished, stirring for 5min, standing for 5-10h, filtering, washing precipitates twice with the deionized water, and finally drying in an oven at 50 ℃ to constant weight to obtain the auxiliary agent.

The reaction process is as follows:

further, in the step A1, the dosage ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the tetrahydrofuran to the eleostearic anhydride is 0.1 mol: 30-60 mL: 0.1 mol.

Further, the amount ratio of the 1, 2-dichloroethane, o-methoxyphenol, anhydrous aluminum chloride and intermediate 1 in step A2 was 250-300 mL: 31 g: 83.34 g: 40g of concentrated hydrochloric acid, wherein the dosage of the concentrated hydrochloric acid is 1/5 of the volume of the ice water, and the mass fraction of the concentrated hydrochloric acid is 37%.

Further, the amount ratio of the 2-amino-5-chloropyridine, methanol and N, N-dimethylformamide dimethyl acetal in step A3 was 100 mmol: 100-150 mL: 100 mmol.

Further, in step a4, the amount ratio of the intermediate 3, N-dimethylformamide, sodium bicarbonate, methyl bromoacetate and deionized water is 100 mmol: 100mL of: 19 g: 33-35 g: 200 and 250 mL.

Further, the amount ratio of the intermediate 4 to the dimethyl sulfoxide in the step A5 is 50 mmol: 400 mL.

Further, in the step A6, the dosage ratio of the intermediate 2, dimethyl sulfoxide, potassium carbonate, tetrabutylammonium bromide, potassium iodide and the intermediate 5 is 10-20 g: 250mL of: 10 g: 0.2 g: 0.2 g: 15 g.

Further, the preparation method of the high-performance epoxy resin curing agent comprises the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring for 10min at the rotating speed of 60-100r/min, heating to 90-100 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 100-200r/min, keeping the temperature unchanged, and stirring for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 30-60min to obtain the high-performance epoxy resin curing agent.

The invention has the beneficial effects that:

the invention takes cardanol, diethylenetriamine, paraformaldehyde, glycol, trimellitic anhydride, an accelerant part, an auxiliary agent part and a catalyst as raw materials to prepare a high-performance epoxy resin curing agent, wherein trimellitic anhydride contains carboxyl and anhydride groups, can perform ring-opening reaction with epoxy groups, cardanol contains phenolic hydroxyl groups, can maintain the reaction activity of the curing agent, and contains unsaturated long carbon chains, and can improve the toughness of epoxy resin, paraformaldehyde and diethylenetriamine in the first component perform aldehyde-amine condensation reaction, and then grafting is performed on para-position of the long carbon chains of the cardanol, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and the chimonane anhydride are taken as raw materials to enable 9, 10-dicarballyl to be 9, 10-dicarballyl oxidePerforming addition reaction on P-H of hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide and unsaturated double bonds in an alkyl long chain of the eleostearic anhydride to obtain an intermediate 1, further performing Friedel-crafts reaction on the intermediate 1 and o-methoxyphenol under the action of a catalyst to obtain an intermediate 2 containing carboxyl and phenolic hydroxyl, synthesizing an intermediate 3 containing an N ═ C double bond in a methanol solution by using 2-amino-5-chloropyridine as a raw material, further performing ring-closing reaction on the intermediate 3 and methyl bromoacetate in an N, N-dimethylformamide solvent to obtain an intermediate 4 containing a conjugated imidazole ring and a pyridine ring, reducing the intermediate 4 in the methanol solvent by ammonia gas to obtain an intermediate 5 containing amino, and finally performing elimination reaction on chlorine atoms of the intermediate 5 and hydrogen atoms on the phenolic hydroxyl of the intermediate 2, the auxiliary agent is obtained, the auxiliary agent contains an alkyl flexible long chain of the eleostearic anhydride and is used as one of raw materials of the curing agent, the alkyl long chain can increase the flexibility of the epoxy resin, improve the mechanical property of the epoxy resin and improve the brittleness of the epoxy resin, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide can improve the flame retardant property of the epoxy resin, an imidazole structure and a pyridine structure have certain antibacterial property, imidazole is a five-membered ring containing two nitrogen atoms, contains a tertiary nitrogen atom and can be used as an anionic polymer type curing agent to cure the epoxy resin, the curing activity of the auxiliary agent is improved, and-NH contained in the auxiliary agent₂and-COOH can participate in the curing of the epoxy resin, so that the improved epoxy resin curing agent disclosed by the invention can improve the toughness and the curing rate of the cured epoxy resin and endow the cured epoxy resin with flame retardant performance and antibacterial property.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

A high-performance epoxy resin curing agent comprises the following raw materials in parts by weight: 10 parts of cardanol, 5 parts of diethylenetriamine, 5 parts of paraformaldehyde, 30 parts of ethylene glycol, 5 parts of trimellitic anhydride, 1 part of accelerator, 2 parts of assistant and 0.1 part of catalyst;

the high-performance epoxy resin curing agent is prepared by the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring for 10min at a rotating speed of 60r/min, heating to 90 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 100r/min, keeping the temperature unchanged, and stirring for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 30min to obtain the high-performance epoxy resin curing agent.

Wherein the catalyst is a hydrochloric acid solution with the mass fraction of 17%, and the accelerator is N-N dimethylbenzylamine.

Wherein the auxiliary agent is prepared by the following steps:

step A1, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tetrahydrofuran into a three-neck flask, controlling the reaction temperature to be 50 ℃, stirring and reacting at the rotation speed of 30r/min under the nitrogen atmosphere, adding eleostearic anhydride into the three-neck flask while stirring, increasing the rotation speed to 200r/min, stirring and reacting for 6 hours, then naturally cooling to the room temperature, filtering, collecting filtrate, performing rotary evaporation at the temperature of 65 ℃ for 1 hour in a rotary evaporator, and then performing rotary evaporation on a product, ethyl acetate and deionized water according to 1 g: 5mL of: adding 5mL of the mixture into a reactor for extraction, and finally performing rotary evaporation to remove ethyl acetate to obtain an intermediate 1;

step A2, adding 1, 2-dichloroethane and o-methoxyphenol which are dried by anhydrous calcium chloride into a dried three-neck round-bottom flask, stirring at the room temperature and the rotation speed of 60r/min for 10min, then placing the three-neck round-bottom flask into a low-temperature constant-temperature tank, controlling the temperature to be 0 ℃, adding anhydrous aluminum chloride, continuously stirring at the constant rotation speed for 30min, then adding the intermediate 1 into the three-neck round-bottom flask, continuously stirring for 20min, heating to 30 ℃, reacting at the rotation speed of 100r/min for 8h, after the reaction is finished, pouring the reaction liquid into ice water with the volume being 2 times of that of the reaction liquid, adding concentrated hydrochloric acid into the ice water, stirring at the rotation speed of 60r/min for 20min, filtering, collecting the solid, recrystallizing by ethyl acetate, and finally drying in a 50 ℃ oven to constant weight to obtain an intermediate 2;

step A3, adding 2-amino-5-chloropyridine and methanol into a round-bottom flask, stirring for 10min at a rotation speed of 60r/min, adding N, N-dimethylformamide dimethyl acetal into the round-bottom flask, heating to 65 ℃, carrying out reflux reaction for 3h, cooling to-5 ℃, carrying out suction filtration, recrystallizing a filter cake with N-hexane, and drying in a 50 ℃ vacuum drying oven for 5h to obtain an intermediate 3;

step A4, adding the intermediate 3 and N, N-dimethylformamide into a reaction kettle, then adding sodium bicarbonate into the reaction kettle, stirring at the room temperature and the rotation speed of 80r/min for 5min, dropwise adding methyl bromoacetate into the reaction kettle, heating to 90 ℃ after dropwise adding, stirring at the rotation speed of 100r/min for 5h, cooling to 10 ℃ after the reaction is finished, adding deionized water into the reaction kettle, stirring for 30min, separating out solids, performing suction filtration, washing a filter cake with distilled water for 3 times, recrystallizing with methanol, and finally drying at the temperature of 50 ℃ to constant weight to obtain an intermediate 4;

step A5, adding the intermediate 4 and dimethyl sulfoxide into a three-neck flask, stirring and reacting at the rotation speed of 100r/min, introducing ammonia gas for 30min, heating to reflux, continuously introducing ammonia gas until solid begins to be separated out, continuously introducing ammonia gas, continuously reacting for 30min at a constant rotation speed, stopping introducing ammonia gas, filtering, washing a filter cake with absolute ethyl alcohol for 2 times, transferring to deionized water for dilution and stirring for 30min, filtering, washing the filter cake with distilled water for 2 times, and finally vacuum-drying at 55 ℃ to constant weight to obtain an intermediate 5;

and A6, adding the intermediate 2 and dimethyl sulfoxide into a reaction kettle, stirring for 10min at the rotation speed of 50r/min, adding potassium carbonate, tetrabutyl ammonium bromide and potassium iodide into the reaction kettle, continuously stirring for 5min, adding the intermediate 5 into the reaction kettle, heating to reflux for 12h, transferring the mixture into deionized water while the mixture is hot after the reaction is finished, stirring for 5min, standing for 5h, filtering, washing precipitates with the deionized water twice, and finally drying in a 50 ℃ oven to constant weight to obtain the auxiliary agent.

Wherein, the dosage ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the tetrahydrofuran and the eleostearic anhydride in the step A1 is 0.1 mol: 30mL of: 0.1 mol.

Wherein, the dosage ratio of the 1, 2-dichloroethane, the o-methoxyphenol, the anhydrous aluminum chloride and the intermediate 1 in the step A2 is 250 mL: 31 g: 83.34 g: 40g of concentrated hydrochloric acid, wherein the dosage of the concentrated hydrochloric acid is 1/5 of the volume of the ice water, and the mass fraction of the concentrated hydrochloric acid is 37%.

Wherein the dosage ratio of the 2-amino-5-chloropyridine, the methanol and the N, N-dimethylformamide dimethyl acetal in the step A3 is 100 mmol: 100mL of: 100 mmol.

Wherein, the dosage ratio of the intermediate 3, the N, N-dimethylformamide, the sodium bicarbonate, the methyl bromoacetate and the deionized water in the step A4 is 100 mmol: 100mL of: 19 g: 33 g: 200 mL.

Wherein, the dosage ratio of the intermediate 4 to the dimethyl sulfoxide in the step A5 is 50 mmol: 400 mL.

Wherein, the dosage ratio of the intermediate 2, dimethyl sulfoxide, potassium carbonate, tetrabutyl ammonium bromide, potassium iodide and the intermediate 5 in the step A6 is 10 g: 250mL of: 10 g: 0.2 g: 0.2 g: 15 g.

Example 2

A high-performance epoxy resin curing agent comprises the following raw materials in parts by weight: 15 parts of cardanol, 8 parts of diethylenetriamine, 7 parts of paraformaldehyde, 35 parts of ethylene glycol, 8 parts of trimellitic anhydride, 1 part of accelerator, 2 parts of assistant and 0.1 part of catalyst;

the high-performance epoxy resin curing agent is prepared by the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring for 10min at a rotating speed of 80r/min, heating to 95 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 150r/min, keeping the temperature unchanged, and stirring for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 40min to obtain the high-performance epoxy resin curing agent.

Wherein the catalyst is a hydrochloric acid solution with the mass fraction of 17%, and the accelerator is N-N dimethylbenzylamine.

Wherein the auxiliary agent is prepared by the following steps:

step A1, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tetrahydrofuran into a three-neck flask, controlling the reaction temperature to be 50 ℃, stirring and reacting at a rotating speed of 45r/min under a nitrogen atmosphere, adding eleostearic anhydride into the three-neck flask while stirring, increasing the rotating speed to 250r/min, stirring and reacting for 6 hours, naturally cooling to room temperature, filtering, collecting filtrate, performing rotary evaporation at a temperature of 68 ℃ in a rotary evaporator for 1.5 hours, and then performing rotary evaporation on a product, ethyl acetate and deionized water according to a proportion of 1 g: 5mL of: adding 5mL of the mixture into a reactor for extraction, and finally performing rotary evaporation to remove ethyl acetate to obtain an intermediate 1;

step A2, adding 1, 2-dichloroethane and o-methoxyphenol which are dried by anhydrous calcium chloride into a dried three-neck round-bottom flask, stirring at the room temperature and the rotation speed of 80r/min for 10min, then placing the three-neck round-bottom flask into a low-temperature constant-temperature tank, controlling the temperature to be 0 ℃, adding anhydrous aluminum chloride, continuously stirring at the constant rotation speed for 30min, then adding the intermediate 1 into the three-neck round-bottom flask, continuously stirring for 20min, heating to 30 ℃, reacting at the rotation speed of 150r/min for 8h, after the reaction is finished, pouring the reaction liquid into ice water with the volume being 2 times of that of the reaction liquid, adding concentrated hydrochloric acid into the ice water, stirring at the rotation speed of 80r/min for 20min, filtering, collecting the solid, recrystallizing by ethyl acetate, and finally drying in a 50 ℃ oven to constant weight to obtain an intermediate 2;

step A3, adding 2-amino-5-chloropyridine and methanol into a round-bottom flask, stirring for 10min at a rotating speed of 80r/min, adding N, N-dimethylformamide dimethyl acetal into the round-bottom flask, heating to 68 ℃, carrying out reflux reaction for 3h, cooling to-5 ℃, carrying out suction filtration, recrystallizing a filter cake with N-hexane, and drying in a 50 ℃ vacuum drying oven for 8h to obtain an intermediate 3;

step A4, adding the intermediate 3 and N, N-dimethylformamide into a reaction kettle, then adding sodium bicarbonate into the reaction kettle, stirring at the room temperature and the rotation speed of 80r/min for 8min, dropwise adding methyl bromoacetate into the reaction kettle, heating to 90 ℃ after dropwise adding, stirring at the rotation speed of 150r/min for 5h, cooling to 10 ℃ after the reaction is finished, adding deionized water into the reaction kettle, stirring for 30min, separating out solids, performing suction filtration, washing a filter cake with distilled water for 4 times, recrystallizing with methanol, and finally drying at the temperature of 50 ℃ to constant weight to obtain an intermediate 4;

step A5, adding the intermediate 4 and dimethyl sulfoxide into a three-neck flask, stirring and reacting at the rotation speed of 150r/min, introducing ammonia gas for 30min, heating to reflux, continuously introducing ammonia gas until solid begins to be separated out, continuously introducing ammonia gas, continuously reacting for 40min at a constant rotation speed, stopping introducing ammonia gas, filtering, washing a filter cake with absolute ethyl alcohol for 2 times, transferring to deionized water, diluting and stirring for 30min, filtering, washing the filter cake with distilled water for 2 times, and finally vacuum-drying at 55 ℃ to constant weight to obtain an intermediate 5;

and A6, adding the intermediate 2 and dimethyl sulfoxide into a reaction kettle, stirring for 10min at the rotation speed of 70r/min, adding potassium carbonate, tetrabutyl ammonium bromide and potassium iodide into the reaction kettle, continuously stirring for 5min, adding the intermediate 5 into the reaction kettle, heating to reflux for 12h, transferring the mixture into deionized water when the mixture is hot after the reaction is finished, stirring for 5min, standing for 5-10h, filtering, washing precipitates with the deionized water twice, and finally drying in a 50 ℃ oven to constant weight to obtain the auxiliary agent.

Wherein, the dosage ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the tetrahydrofuran and the eleostearic anhydride in the step A1 is 0.1 mol: 45mL of: 0.1 mol.

Wherein the dosage ratio of the 1, 2-dichloroethane, the o-methoxyphenol, the anhydrous aluminum chloride and the intermediate 1 in the step A2 is 280 mL: 31 g: 83.34 g: 40g of concentrated hydrochloric acid, wherein the dosage of the concentrated hydrochloric acid is 1/5 of the volume of the ice water, and the mass fraction of the concentrated hydrochloric acid is 37%.

Wherein the dosage ratio of the 2-amino-5-chloropyridine, the methanol and the N, N-dimethylformamide dimethyl acetal in the step A3 is 100 mmol: 120mL of: 100 mmol.

Wherein, the dosage ratio of the intermediate 3, the N, N-dimethylformamide, the sodium bicarbonate, the methyl bromoacetate and the deionized water in the step A4 is 100 mmol: 100mL of: 19 g: 34 g: 220 mL.

Wherein, the dosage ratio of the intermediate 4 to the dimethyl sulfoxide in the step A5 is 50 mmol: 400 mL.

Wherein the dosage ratio of the intermediate 2, dimethyl sulfoxide, potassium carbonate, tetrabutylammonium bromide, potassium iodide and the intermediate 5 in the step A6 is 15 g: 250mL of: 10 g: 0.2 g: 0.2 g: 15 g.

Example 3

A high-performance epoxy resin curing agent comprises the following raw materials in parts by weight: 20 parts of cardanol, 10 parts of diethylenetriamine, 8 parts of paraformaldehyde, 40 parts of ethylene glycol, 10 parts of trimellitic anhydride, 1 part of accelerator, 2 parts of assistant and 0.1 part of catalyst;

the high-performance epoxy resin curing agent is prepared by the following steps:

firstly, adding cardanol, diethylenetriamine and a catalyst into a reaction kettle, stirring at the rotating speed of 100r/min for 10min, heating to 100 ℃, adding polyformaldehyde into the reaction kettle, increasing the rotating speed to 200r/min, keeping the temperature unchanged, and stirring for reaction for 1h to obtain a first composition;

and secondly, adding ethylene glycol into the first composition, stirring for 10min at a constant rotating speed, adding trimellitic anhydride, an accelerator and an auxiliary agent into the reaction kettle, and continuously stirring for 60min to obtain the high-performance epoxy resin curing agent.

Wherein the catalyst is a hydrochloric acid solution with the mass fraction of 17%, and the accelerator is N-N dimethylbenzylamine.

Wherein the auxiliary agent is prepared by the following steps:

step A1, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and tetrahydrofuran into a three-neck flask, controlling the reaction temperature to be 50 ℃, stirring and reacting at a rotating speed of 60r/min under a nitrogen atmosphere, adding eleostearic anhydride into the three-neck flask while stirring, increasing the rotating speed to 300r/min, stirring and reacting for 6 hours, naturally cooling to room temperature, filtering, collecting filtrate, performing rotary evaporation for 2 hours at a temperature of 70 ℃ in a rotary evaporator, and then performing rotary evaporation on a product, ethyl acetate and deionized water according to 1 g: 5mL of: adding 5mL of the mixture into a reactor for extraction, and finally performing rotary evaporation to remove ethyl acetate to obtain an intermediate 1;

step A2, adding 1, 2-dichloroethane and o-methoxyphenol which are dried by anhydrous calcium chloride into a dried three-neck round-bottom flask, stirring at the room temperature and the rotation speed of 120r/min for 10min, then placing the three-neck round-bottom flask into a low-temperature constant-temperature tank, controlling the temperature to be 0 ℃, adding anhydrous aluminum chloride, continuously stirring at the constant rotation speed for 30min, then adding the intermediate 1 into the three-neck round-bottom flask, continuously stirring for 20min, heating to 30 ℃, reacting at the rotation speed of 200r/min for 8h, after the reaction is finished, pouring the reaction liquid into ice water with the volume being 2 times of that of the reaction liquid, adding concentrated hydrochloric acid into the ice water, stirring at the rotation speed of 100r/min for 20min, filtering, collecting the solid, recrystallizing by ethyl acetate, and finally drying in a 50 ℃ oven to constant weight to obtain an intermediate 2;

step A3, adding 2-amino-5-chloropyridine and methanol into a round-bottom flask, stirring for 10min at the rotation speed of 100r/min, adding N, N-dimethylformamide dimethyl acetal into the round-bottom flask, heating to 70 ℃, carrying out reflux reaction for 3h, cooling to-5 ℃, carrying out suction filtration, recrystallizing a filter cake with N-hexane, and drying in a vacuum drying oven at 50 ℃ for 10h to obtain an intermediate 3;

step A4, adding the intermediate 3 and N, N-dimethylformamide into a reaction kettle, then adding sodium bicarbonate into the reaction kettle, stirring at the room temperature and the rotation speed of 80r/min for 10min, dropwise adding methyl bromoacetate into the reaction kettle, heating to 90 ℃ after dropwise adding, stirring at the rotation speed of 200r/min for 5h, cooling to 10 ℃ after the reaction is finished, adding deionized water into the reaction kettle, stirring for 30min, separating out solids, performing suction filtration, washing a filter cake with distilled water for 5 times, recrystallizing with methanol, and finally drying at the temperature of 50 ℃ to constant weight to obtain an intermediate 4;

step A5, adding the intermediate 4 and dimethyl sulfoxide into a three-neck flask, stirring and reacting at the rotation speed of 200r/min, introducing ammonia gas for 30min, heating to reflux, continuously introducing ammonia gas until solid begins to be separated out, continuously introducing ammonia gas, continuously reacting for 60min at a constant rotation speed, stopping introducing ammonia gas, filtering, washing a filter cake with absolute ethyl alcohol for 2 times, transferring to deionized water for dilution and stirring for 30min, filtering, washing the filter cake with distilled water for 2 times, and finally vacuum-drying at 55 ℃ to constant weight to obtain an intermediate 5;

step A6, adding the intermediate 2 and dimethyl sulfoxide into a reaction kettle, stirring for 10min under the condition of the rotation speed of 80r/min, adding potassium carbonate, tetrabutyl ammonium bromide and potassium iodide into the reaction kettle, continuously stirring for 5min, adding the intermediate 5 into the reaction kettle, heating to reflux reaction for 12h, transferring the mixture into deionized water when the mixture is hot after the reaction is finished, stirring for 5min, standing for 10h, filtering, washing precipitates with the deionized water twice, and finally drying in a 50 ℃ oven to constant weight to obtain the auxiliary agent.

Wherein, the dosage ratio of the 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the tetrahydrofuran and the eleostearic anhydride in the step A1 is 0.1 mol: 60mL of: 0.1 mol.

Wherein the dosage ratio of the 1, 2-dichloroethane, the o-methoxyphenol, the anhydrous aluminum chloride and the intermediate 1 in the step A2 is 300 mL: 31 g: 83.34 g: 40g of concentrated hydrochloric acid, wherein the dosage of the concentrated hydrochloric acid is 1/5 of the volume of the ice water, and the mass fraction of the concentrated hydrochloric acid is 37%.

Wherein the dosage ratio of the 2-amino-5-chloropyridine, the methanol and the N, N-dimethylformamide dimethyl acetal in the step A3 is 100 mmol: 150mL of: 100 mmol.

Wherein, the dosage ratio of the intermediate 3, the N, N-dimethylformamide, the sodium bicarbonate, the methyl bromoacetate and the deionized water in the step A4 is 100 mmol: 100mL of: 19 g: 35 g: 250 mL.

Wherein, the dosage ratio of the intermediate 4 to the dimethyl sulfoxide in the step A5 is 50 mmol: 400 mL.

Wherein the dosage ratio of the intermediate 2, dimethyl sulfoxide, potassium carbonate, tetrabutylammonium bromide, potassium iodide and the intermediate 5 in the step A6 is 20 g: 250mL of: 10 g: 0.2 g: 0.2 g: 15 g.

Comparative example

The comparative example is an amine curing agent which is commonly available on the market.

The curing agents of examples 1-3 and comparative example and epoxy resin are mixed according to the mass ratio of 1:3, placed in a mold for precuring for 4h at room temperature, cured for 2h at 120 ℃, then naturally cooled to room temperature, the impact strength is measured according to GB/T1732, the adhesion is tested according to GB/T5210-85 pull-open method, the abrasive steel plate is 150mm × 70mm × 3mm, the thickness of the epoxy coating is 3mm, the pencil hardness is tested according to GB/T76739-86, the flame retardant rating is tested according to UL94 horizontal vertical burning, the antibacterial performance is tested according to QB/T2591-2003, and the test results are shown in the following table:

item	Impact strength kg.cm	adhesion/MPa	Flame retardant rating	Inhibition of E.coli/%)
					Example 1	≥50	11.5	V-0	90％
Example 2	≥50	11.5	V-0	92％
					Example 3	≥50	11.3	V-0	91％
Comparative example	≥30	10.2	V-1	75％

As can be seen from the above table, the test results of examples 1-3 are superior to those of comparative examples in the test processes of mechanical property, adhesion, flame retardance and antibacterial property, and the improved epoxy resin curing agent disclosed by the invention not only can improve the toughness and curing rate of the cured epoxy resin, but also endows the cured epoxy resin with flame retardance and antibacterial property.

The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.