阅读说明：本技术 一种含三嗪环结构的生物基环氧树脂及其制备方法 (Triazine ring structure-containing bio-based epoxy resin and preparation method thereof ) 是由 蹇锡高 翁志焕 王锦艳 张守海 刘程 戚裕 于 2020-01-07 设计创作，主要内容包括：本发明公开了一种含三嗪环结构的生物基环氧树脂及其制备方法,属于生物基高分子材料技术领域。以含醛基的生物基化合物为原料,首先使其中的醛基转换成氰基,随后在三氟甲磺酸的催化下,实现氰基三聚反应,制备成可用于聚合物合成的含三嗪环结构的全生物基碳源的三酚单体。该生物基单体可以与环氧氯丙烷反应,最终得到含三嗪环结构的生物基环氧树脂前驱体。所制备的含三嗪环结构生物基环氧树脂固化后,呈现出比石油基双酚A型环氧树脂更优异的热稳定性、力学性能、以及阻燃性能,具有替代现有石油基相关产品的可能。(The invention discloses a triazine ring structure-containing bio-based epoxy resin and a preparation method thereof, belonging to the technical field of bio-based high polymer materials. The method comprises the steps of taking a biology-based compound containing aldehyde group as a raw material, firstly converting the aldehyde group into cyano, and then realizing cyano trimerization reaction under the catalysis of trifluoromethanesulfonic acid to prepare the triphenol monomer of the all biology-based carbon source containing triazine ring structure, which can be used for polymer synthesis. The bio-based monomer can react with epoxy chloropropane to finally obtain a bio-based epoxy resin precursor containing a triazine ring structure. After being cured, the prepared triazine ring structure-containing bio-based epoxy resin shows more excellent thermal stability, mechanical property and flame retardant property than petroleum-based bisphenol A epoxy resin, and has the possibility of replacing the existing petroleum-based related products.)

1. The bio-based epoxy resin containing the triazine ring structure is characterized by having the following structure:

wherein the R groups are as follows:

wherein, is a substituent connected with oxygen, and is a substituent connected with triazine ring.

2. The preparation method of the triazine ring structure-containing bio-based epoxy resin is characterized by comprising the following steps:

(1) dissolving anhydrous ferric trichloride into anhydrous DMF, and adding an aldehyde group-containing bio-based compound and hydroxylamine hydrochloride into a reaction system, wherein the anhydrous DMF is prepared according to the weight ratio of 1g of anhydrous ferric trichloride: 5-80 ml of anhydrous DMF is added according to the molar ratio, and the reaction raw materials are anhydrous ferric trichloride according to the molar ratio: aldehyde group-containing bio-based compounds: adding hydroxylamine hydrochloride in a ratio of 1: 1-4: 2-6; then heating the system to 120-160 ℃, and reacting for 3-10 hours; after the reaction is finished, pouring the system into distilled water, extracting with ethyl acetate, separating liquid, drying an ethyl acetate layer, distilling under reduced pressure, removing the solvent, washing with water for 3-6 times, and drying in vacuum to obtain a cyano-containing bio-based compound;

(2) dissolving the cyano-containing bio-based compound prepared in the step (1) in a solvent, wherein the concentration of the cyano-containing bio-based compound is maintained between 5% and 30% g/ml, placing the system in an ice-water bath, and dropwise adding trifluoromethanesulfonic acid into the ice-water bath, wherein the molar ratio of the cyano-containing bio-based compound to the system is as follows: 1: 1.5-4 of trifluoromethanesulfonic acid, after the dropwise addition is completed, slowly heating the system to 25-60 ℃, and reacting for 10-48 hours in a nitrogen atmosphere; after the reaction is finished, settling the system in ice water, dropwise adding ammonia water into the ice water to adjust the pH value to be neutral, performing suction filtration, and washing the obtained product for three times to obtain the triazine ring structure containing bio-based triphenol monomer, wherein the structural formula is as follows:

wherein the R groups are as follows:

wherein, is a substituent connected with oxygen, and is a substituent connected with a triazine ring;

(3) adding the triazine ring structure-containing bio-based triphenol monomer prepared in the step (2), a phase transfer catalyst and epoxy chloropropane into a reaction container according to the molar ratio of 1: 0.001-0.5: 10-100, heating to 50-100 ℃, reacting for 2-8 hours in a nitrogen atmosphere, dropwise adding a 25-45 wt% (w/w) sodium hydroxide aqueous solution into the system, wherein the molar ratio of the sodium hydroxide to the triazine ring structure-containing bio-based triphenol monomer is 2-4: 1, and continuously reacting for 1-5 hours in the nitrogen atmosphere at the temperature of 50-100 ℃; after the reaction is finished, carrying out suction filtration, extracting and separating filtrate for 3-6 times by using distilled water, drying an organic layer, then carrying out reduced pressure distillation, removing a solvent, and drying a product in a vacuum oven to obtain the bio-based epoxy resin containing the triazine ring structure, wherein the epoxy value of the bio-based epoxy resin is 0.2-0.56;

(4) and (3) uniformly mixing the triazine ring structure-containing bio-based epoxy resin prepared in the step (3) with a curing agent, pouring the system into a mold after vacuum defoaming, and performing thermosetting molding to obtain a bio-based epoxy resin cured product, namely the triazine ring structure-containing bio-based epoxy resin.

3. The preparation method of the triazine ring structure-containing bio-based epoxy resin as claimed in claim 2, wherein the triazine ring structure-containing bio-based epoxy resin in the step (4) is mixed with a curing agent according to a molar ratio of 1: 0.15-3, the mixture is heated and melted at 150-200 ℃ in a vacuum oven and then uniformly stirred, vacuum defoamed, and after no bubble is generated, the system is poured into a mold, and is subjected to heat preservation at 100-140 ℃ for 1-3 hours, then at 160-180 ℃ for 1-5 hours, then at 190-210 ℃ for 1-5 hours, and finally at 230-250 ℃ for 1-3 hours.

4. The method for preparing the triazine ring structure-containing bio-based epoxy resin according to claim 2 or 3, wherein the aldehyde group-containing bio-based compound in the step (1) is vanillin, o-vanillin, syringaldehyde, salicylaldehyde or hydroxymethylfurfural.

5. The method for preparing a triazine ring structure-containing bio-based epoxy resin according to claim 4, wherein the solvent used in the step (2) is dichloromethane, dichloroethane or chloroform.

6. The method for preparing a triazine ring structure-containing bio-based epoxy resin according to claim 2,3 or 5, wherein the phase transfer catalyst used in the step (3) is benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetrabutylammonium hydrogen sulfate.

7. The method for preparing a triazine ring structure-containing bio-based epoxy resin according to claim 4, wherein the phase transfer catalyst used in the step (3) is benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetrabutylammonium hydrogen sulfate.

8. The method for preparing a triazine ring structure-containing bio-based epoxy resin according to claim 2,3, 5 or 7, wherein the curing agent in the step (4) is one or a mixture of two or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, ethylenediamine, isophoronediamine, N-aminoethylpiperazine, bis (4-aminocyclohexyl) methane, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, pyromellitic anhydride, phenylketotetracarboxylic dianhydride, ethylene glycol bistrimellitic anhydride, methylcyclohexyltetracarboxylic dianhydride, trimellitic anhydride.

9. The method for preparing a triazine ring structure-containing bio-based epoxy resin according to claim 4, wherein the curing agent in the step (4) is one or a mixture of two or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, ethylenediamine, isophoronediamine, N-aminoethylpiperazine, bis (4-aminocyclohexyl) methane, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, pyromellitic anhydride, phenylketotetracarboxylic dianhydride, ethylene glycol bistrimellitic anhydride, methylcyclohexyltetracarboxylic dianhydride, and trimellitic anhydride.

10. The method for preparing a triazine ring structure-containing bio-based epoxy resin according to claim 5, wherein the curing agent in the step (4) is one or a mixture of two or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, ethylenediamine, isophoronediamine, N-aminoethylpiperazine, bis (4-aminocyclohexyl) methane, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, m-phenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, pyromellitic anhydride, phenylketotetracarboxylic dianhydride, ethylene glycol bistrimellitic anhydride, methylcyclohexyltetracarboxylic dianhydride, and trimellitic anhydride.

Technical Field

The invention belongs to the technical field of bio-based high polymer materials, and particularly relates to a triazine ring structure-containing bio-based epoxy resin and a preparation method thereof.

Background

Epoxy resin is a thermosetting resin which is most widely applied, and has the advantages of good adhesion, mechanical property, electrical insulation, chemical corrosion resistance, good processability, low curing shrinkage and the like, so that the epoxy resin has wide application in various fields such as coatings, adhesives, electronic packaging, composite materials and the like.

However, the epoxy resins currently available are mostly prepared from petroleum-based raw materials, and the bisphenol a type epoxy resin, which is prepared from bisphenol a and epichlorohydrin, accounts for 85% or more of the total epoxy resin production. While epichlorohydrin has been obtained by conversion of glycerol, a bio-based feedstock, bisphenol a is currently only produced from petroleum-based feedstocks. At present, petroleum resources are greatly consumed and are increasingly exhausted, so that the petroleum price is increased dramatically, and meanwhile, a series of severe environmental problems are brought, and great pressure is brought to the development of epoxy resin taking the petroleum resources as main raw materials. In addition, bisphenol a is an endocrine disrupter, poses a great threat to human health and the environment, and has been banned by most countries for materials that come into direct contact with food and human bodies. This also greatly limits the further applications and developments of epoxy resins.

Renewable biomass resources are developed and utilized to prepare a novel bio-based monomer capable of replacing the traditional petroleum-based monomer bisphenol A, and the problems can be effectively solved by further preparing the corresponding bio-based epoxy resin. At present, domestic and foreign research on the aspect has made great progress. For example, Cardanol, Chrysanthos, M, Galy J.preparation and precursors of the Chem, Nie X.Synthesis and Application of the polysaccharide carbohydrate Reactive derivative for Epoxy Resin [ J ]. ACS Sustainable Chemistry & Engineering,2015,3, 1164. 1171. isosorbide, Ma, S, Liu X.Synthesis and precursors of the bio-based epoxide polyol derivative for Polymer [ J ]. 2011,52, 3611. isosorbide, starch, S, Liu X.Synthesis and precursors of the bio-based epoxide polyol derivative for polyurethane Resin [ J ]. 10, 9, J.S. synthesis and precursors of the bio-based epoxide Resin for polyurethane Resin [ J ]. 12, 9, 62, 9, 7, 9, 5. A. B. synthesis and Application of the polysaccharide carbohydrate Reactive Resin, 2. A. synthesis and Application of the aforementioned compounds for formaldehyde, 2. A. supplement, D. A. 2015,5,15930-15939, the bio-based compounds such as furandicarboxylic acid and the like directly react with epichlorohydrin to prepare the bio-based epoxy resin. However, the overall performance of these bio-based epoxy resins is generally lower than bisphenol a type epoxy resins. There have also been some studies on the preparation of bio-based monomers in combination with terephthaloyl chloride in Wan, J, Gan B.A novel bio-based Epoxy Resin with High mechanical stability and reactivity [ J ]. Journal of materials Chemistry A,2015,3, 21907. terephthalic acid chloride, Wan, J, ZoJ. ultrastibia biocompatible Epoxy Resin with High Tg and Low permeability from food Synthesis Properties [ J ]. ACS stable Chemistry & Engineering,2016,4, 2869. melamine 2880. melamine chloride, S, M. variable-modified High viscosity Resin, polystyrene Resin with High reactivity [ J ]. 12. Epoxy Resin, polystyrene. Although the comprehensive performance of the bio-based epoxy resin is greatly improved, the bio-based content of the system is reduced due to the introduction of part of petroleum-based compounds. Therefore, the current research on the bio-based epoxy resin cannot meet the development target of high bio-based content and high performance of the bio-based epoxy resin in scientific research and practical application.

So far, no document or patent reports that the epoxy resin containing the triazine ring structure full-bio-based carbon source is prepared from bio-based monomers through corresponding structure transformation. The introduction of the triazine ring structure can effectively improve the heat resistance, the mechanical property and the flame retardant property of the epoxy resin. The epoxy resin containing the triazine ring structure prepared from the bio-based raw materials can effectively solve the problem that the epoxy resin excessively depends on petroleum-based raw materials, meets the requirements of sustainable development and energy conservation, and is favorable for promoting the further development of the bio-based epoxy resin.

Disclosure of Invention

The invention aims to provide a triazine ring structure-containing bio-based epoxy resin and a preparation method thereof. The bio-based epoxy resin provided by the invention is obtained by converting bio-based raw materials, and accords with the concept of environmental protection and sustainability. Compared with the traditional bisphenol A type and tetraglycidyl amine type epoxy resin, the thermal stability, the mechanical property and the flame retardant property are obviously improved. The preparation method provided by the invention is simple, easy to implement and suitable for large-scale industrial production.

The technical scheme of the invention is as follows:

a triazine ring structure-containing bio-based epoxy resin has the following structure:

wherein the R groups are as follows:

wherein, is a substituent connected with oxygen, and is a substituent connected with triazine ring.

A preparation method of bio-based epoxy resin containing triazine ring structure comprises the following steps:

(1) dissolving anhydrous ferric trichloride into anhydrous DMF, and adding an aldehyde group-containing bio-based compound and hydroxylamine hydrochloride into a reaction system, wherein the anhydrous DMF is prepared according to the weight ratio of 1g of anhydrous ferric trichloride: 5-80 ml of anhydrous DMF is added according to the molar ratio, and the reaction raw materials are anhydrous ferric trichloride according to the molar ratio: aldehyde group-containing bio-based compounds: adding hydroxylamine hydrochloride in a ratio of 1: 1-4: 2-6; then heating the system to 120-160 ℃, and reacting for 3-10 hours; after the reaction is finished, pouring the system into distilled water, extracting with ethyl acetate, separating liquid, drying an ethyl acetate layer, distilling under reduced pressure, removing the solvent, washing with water for 3-6 times, and drying in vacuum to obtain a cyano-containing bio-based compound;

(2) dissolving the cyano-containing bio-based compound prepared in the step (1) in a solvent, wherein the concentration of the cyano-containing bio-based compound is maintained between 5% and 30% g/ml, placing the system in an ice-water bath, and dropwise adding trifluoromethanesulfonic acid into the ice-water bath, wherein the molar ratio of the cyano-containing bio-based compound to the system is as follows: 1: 1.5-4 of trifluoromethanesulfonic acid, after the dropwise addition is completed, slowly heating the system to 25-60 ℃, and reacting for 10-48 hours in a nitrogen atmosphere; after the reaction is finished, settling the system in ice water, dropwise adding ammonia water into the ice water to adjust the pH value to be neutral, performing suction filtration, and washing the obtained product for three times to obtain the triazine ring structure containing bio-based triphenol monomer, wherein the structural formula is as follows:

wherein the R groups are as follows:

wherein, is a substituent connected with oxygen, and is a substituent connected with a triazine ring;

(3) adding the triazine ring structure-containing bio-based triphenol monomer prepared in the step (2), a phase transfer catalyst and epoxy chloropropane into a reaction container according to the molar ratio of 1: 0.001-0.5: 10-100, heating to 50-100 ℃, reacting for 2-8 hours in a nitrogen atmosphere, dropwise adding a 25-45 wt% (w/w) sodium hydroxide aqueous solution into the system, wherein the molar ratio of the sodium hydroxide to the triazine ring structure-containing bio-based triphenol monomer is 2-4: 1, and continuously reacting for 1-5 hours in the nitrogen atmosphere at the temperature of 50-100 ℃; after the reaction is finished, carrying out suction filtration, extracting and separating filtrate for 3-6 times by using distilled water, drying an organic layer, then carrying out reduced pressure distillation, removing a solvent, and drying a product in a vacuum oven to obtain the bio-based epoxy resin containing the triazine ring structure, wherein the epoxy value of the bio-based epoxy resin is 0.2-0.56;

(4) and (3) uniformly mixing the triazine ring structure-containing bio-based epoxy resin prepared in the step (3) with a curing agent, pouring the system into a mold after vacuum defoaming, and performing thermosetting molding to obtain a bio-based epoxy resin cured product, namely the triazine ring structure-containing bio-based epoxy resin.

The aldehyde group-containing bio-based compound in the step (1) is vanillin, o-vanillin, syringaldehyde, salicylaldehyde or hydroxymethylfurfural.

The solvent used in step (2) is dichloromethane, dichloroethane or chloroform.

The phase transfer catalyst used in the step (3) is benzyltriethylammonium chloride, benzyltrimethylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, dodecyltrimethylammonium chloride or tetrabutylammonium hydrogen sulfate.

The curing agent in the step (4) comprises polyamine and acid anhydride, and is one or a mixture of more than two of diethylenetriamine, triethylene tetramine, tetraethylene pentamine, diethylaminopropylamine, ethylenediamine, isophorone diamine, N-aminoethyl piperazine, bis (4-aminocyclohexyl) methane, m-xylylenediamine, diaminodiphenyl methane, diaminodiphenyl sulfone, m-phenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, dodecenyl succinic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, ethylene glycol bistrimellitic anhydride, methylcyclohexenyl tetracarboxylic dianhydride and trimellitic anhydride.

Mixing the triazine ring structure-containing bio-based epoxy resin and a curing agent in a molar ratio of 1: 0.15-3, heating and melting at 150-200 ℃ in a vacuum oven, uniformly stirring, defoaming in vacuum, pouring the system into a mold after no bubbles exist, preserving heat at 100-140 ℃ for 1-3 hours, preserving heat at 160-180 ℃ for 1-5 hours, preserving heat at 190-210 ℃ for 1-5 hours, and preserving heat at 230-250 ℃ for 1-3 hours.

The invention has the beneficial effects that:

(1) the invention provides a method for preparing a compound containing a triazine ring structure from bio-based raw materials, develops a preparation method of a full-rigid bio-based compound containing aromatic heterocycles, and has important significance for constructing a high-performance bio-based high polymer material.

(2) The thermosetting epoxy resin product obtained after final curing of the triazine ring structure-containing bio-based epoxy resin provided by the invention has excellent heat resistance, mechanical properties and flame retardance. Compared with the traditional petroleum-based bisphenol A type and tetraglycidyl amine type epoxy resin, the comprehensive performance is obviously improved. Can be used as high-performance epoxy resin to be applied to the high and new technical fields of aerospace and the like.

(3) The preparation method is simple and efficient, convenient to operate, good in controllability, capable of producing by utilizing the existing chemical equipment, high in yield and purity and suitable for large-scale industrial production.

(4) The triazine ring structure-containing bio-based epoxy resin provided by the invention is completely obtained by converting aldehyde group-containing bio-based monomers and is an epoxy resin of a full bio-based carbon source. The problem that the petroleum-based epoxy resin excessively depends on petrochemical resources at present can be solved, and the development targets of saving the petrochemical resources, being green, environment-friendly and sustainable are met. And has great promotion effect on the development of the bio-based material.

Detailed Description

The following further describes a specific embodiment of the present invention with reference to the drawings and technical solutions.