Preparation method and application of novel modified amine epoxy curing agent
阅读说明：本技术 一种新型改性胺环氧固化剂的制备方法及应用 (Preparation method and application of novel modified amine epoxy curing agent ) 是由 夏益青 盛玉萍 刘淋泽 王炼 颜帅 石锐 赵星宇 高晨 廖斌 李新跃 于 2021-08-18 设计创作，主要内容包括：本发明涉及固化剂技术领域,具体涉及一种新型改性胺环氧固化剂的制备方法及应用。制备方法包括：以酚源、胺源和醛在溶剂中发生Mannich反应制备得到苯并噁嗪,将苯并噁嗪和多元胺进行开环反应得到所述新型改性胺环氧固化剂。本发明通过苯并噁嗪与多元胺的反应,将酚曼尼希桥结构引入改性胺固化剂中,促进多元胺与环氧树脂的固化反应。通过采用不同种类的苯并噁嗪树脂对多元胺进行改性,调控改性胺固化剂结构中酚曼尼希桥结构的种类和含量,实现固化温度和固化时间的调节,满足环氧树脂不同的工艺条件和性能要求。多元胺中引入苯并噁嗪,能精准调控酚醛胺的比例,进而改善传统曼尼希碱改性胺固化剂高游离甲醛含量等不足,符合绿色环保要求,扩展了涂料、粘接剂、复合材料等方面的应用。(The invention relates to the technical field of curing agents, in particular to a preparation method and application of a novel modified amine epoxy curing agent. The preparation method comprises the following steps: the novel modified amine epoxy curing agent is prepared by performing Mannich reaction on a phenol source, an amine source and aldehyde in a solvent to prepare benzoxazine, and performing ring-opening reaction on the benzoxazine and polyamine. According to the invention, through the reaction of benzoxazine and polyamine, a phenol Mannich bridge structure is introduced into the modified amine curing agent, so that the curing reaction of the polyamine and the epoxy resin is promoted. By adopting different types of benzoxazine resin to modify polyamine, the types and the content of phenol Mannich bridge structures in the modified amine curing agent structure are regulated, the curing temperature and the curing time are regulated, and different process conditions and performance requirements of epoxy resin are met. The benzoxazine is introduced into the polyamine, so that the proportion of the phenolic amine can be accurately regulated, the defects of high free formaldehyde content and the like of the traditional Mannich base modified amine curing agent are overcome, the requirements of environmental protection are met, and the application of the coating, the adhesive, the composite material and the like is expanded.)
1. A novel modified amine epoxy curing agent is characterized in that the structural formula is shown as the formula (1):
wherein R is1The corresponding phenol is selected from one or more of phenol, o-methyl phenol, M-methyl phenol, p-methyl phenol, o-allyl phenol, p-allyl phenol, guaiacol, salicylaldehyde, vanillin, eugenol, naphthol, p-halophenol, p-diphenol, resorcinol, bisphenol S, bisphenol A, bisphenol F, bisphenol E, bisphenol B, bisphenol M and bisphenol Z;
R2the corresponding amine is selected from aniline, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-xylylenediamine, naphthylamine, benzylamine, methylbenzylamine, p-aminobenzylamine, benzidine, 4' -diaminodiphenylmethane, and p-toluidineAnilide, o-methylaniline, m-methylaniline, 4-ethylaniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, 3, 5-dimethylaniline, 4' -diaminodiphenyl ether, furfurylamine, methylamine, ethylamine, propylamine, isopropylamine, butylamine, t-butylamine, cyclohexylamine, 1,3, 5-triaminobenzene, N, N-bis (3-aminopropyl) methylamine, N, N-dimethyl-1, 3-diaminopropane, tetramethylpropylenediamine, dimethyldipropylenetriamine, 4-dimethylaminobutylamine, N-methyl-1, 3-propylenediamine, N, N, N-tetrakis (3-aminopropyl) -1, 4-butylenediamine, tris (3-aminopropyl) amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, One or more of pentaethylenehexamine, polyethylenepolyamine, divinylpropylamine, 1,6 hexanediamine, ethylenediamine, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurities, 4' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4' -diaminodicyclohexylmethane, methylcyclohexanediamine, aminoethylpiperazine, methylcyclopentanediamine, o-diaminomethylcyclopentane, (2, 3-dimethyl) dibutylenetriamine, triaminononane, dicyandiamide, adipic dihydrazide, mixed amine, and hybrid amine;
R3the corresponding polyamine is selected from 1,6 hexanediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, divinylpropylamine, 1,6 hexanediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurities, methylcyclopentanediamine, 4' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4' -diaminodicyclohexylmethane, 4' -bis-sec-butylaminodiphenylmethane, 4' -methylenebis (2, 6-diethylaniline), 4' -methylenebis (6-methyl-2-ethylaniline), methylcyclohexanediamine, m-phenylenediamine, aminoethylpiperazine, m-xylylenediamine, menthanediamine, isophoronediamine, dicyandiamide, adipic acid dihydrazide, hyamine and one or more of heteroamine;
the value range of n is that n is more than or equal to 2.
2. The preparation method of the novel modified amine epoxy hardener as claimed in claim 1, comprising the following steps of subjecting benzoxazine and polyamine to ring-opening reaction to obtain the novel modified amine epoxy hardener, wherein the structural formula of benzoxazine is as shown in formula (2):
3. the method of claim 2, wherein the polyamine is selected from the group consisting of 1, 6-hexanediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, divinylpropylamine, 1, 6-hexanediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurity, methylcyclopentanediamine, 4 '-diaminodicyclohexylmethane, 3' -dimethyl-4, 4 '-diaminodicyclohexylmethane, tetramethylenediamine, 4' -diaminodicyclohexylmethane, and mixtures thereof, 4,4' -bis-sec-butylaminodiphenylmethane, 4' -methylenebis (2, 6-diethylaniline), 4' -methylenebis (6-methyl-2-ethylaniline), methylcyclohexanediamine, m-phenylenediamine, aminoethylpiperazine, m-xylylenediamine, menthanediamine, isophorone diamine, dicyandiamide, adipic acid dihydrazide, hyamine and/or hetero amine.
4. The preparation method of the novel modified amine epoxy curing agent according to claim 2, wherein the molar ratio of the benzoxazine to the polyamine is 1 (1-10); the ring-opening reaction is specifically as follows: reacting for 2-24h at 30-140 ℃ under inert atmosphere.
5. The preparation method of the novel modified amine epoxy curing agent according to claim 2, wherein the benzoxazine is prepared by a Mannich reaction of a phenol source, an amine source and an aldehyde in a solvent.
6. The method for preparing the novel modified amine epoxy hardener as claimed in claim 5, wherein the phenol source is one or more of phenol, o-methylphenol, M-methylphenol, p-methylphenol, o-allylphenol, p-allylphenol, guaiacol, salicylaldehyde, vanillin, eugenol, naphthol, p-halophenol, p-diphenol, resorcinol, bisphenol S, bisphenol A, bisphenol F, bisphenol E, bisphenol B, bisphenol M, bisphenol Z, and the aldehyde is formaldehyde or paraformaldehyde.
7. The method for preparing a novel modified amine epoxy hardener as claimed in claim 5, wherein the amine source is aniline, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-xylylenediamine, naphthylamine, benzylamine, methylbenzylamine, p-aminobenzylamine, benzidine, 4 '-diaminodiphenylmethane, p-methylaniline, o-methylaniline, m-methylaniline, 4-ethylaniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, 3, 5-dimethylaniline, 4' -diaminodiphenyl ether, furfurylamine, methylamine, ethylamine, propylamine, isopropylamine, butylamine, t-butylamine, cyclohexylamine, 1,3, 5-triaminobenzene, N-bis (3-aminopropyl) methylamine, N-dimethyl-1, 3-diaminopropane, tetramethylpropylenediamine, Dimethyldipropylenetriamine, 4-dimethylaminobutylamine, N-methyl-1, 3-propanediamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamines, divinylpropylamine, 1, 6-hexanediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurities, 4 '-diaminodicyclohexylmethane, 3' -dimethyl-4, 4 '-diaminodicyclohexylmethane, methylcyclohexanediamine, aminoethylpiperazine, methylcyclopentamine, o-diamine methylcyclopentane, tetramethylcyclopentane, N, N, N' -tetramethylenetetramine, tetraethylenepentamine, pentamine, pentaethylenehexamine, pentamine, diethylenetriamine, triethylenetetramine, tetramethylethylenediamine, or mixtures thereof, One or more of (2, 3-dimethyl) dibutylenetriamine, triaminononane, dicyandiamide, adipic acid dihydrazide, mixed amine and hybrid amine.
8. The preparation method of the novel modified amine epoxy curing agent according to claim 5, wherein the molar ratio of the phenol source to the amine source to the aldehyde is 1:1: 2.0-2.5; the solvent is one or more of water, toluene, 1, 4-dioxane, cyclohexanone, ethyl acetate, trichloromethane, xylene, butanone, methyl isobutyl ketone, DMF, DMAc and NMP; the mass fraction of the phenol source, the amine source and the aldehyde in the solvent is 20-90%.
9. The method for preparing the novel modified amine epoxy hardener as claimed in claim 5, comprising the steps of: and (3) uniformly mixing the phenol source and the aldehyde in a solvent, adding the amine source in batches, heating to 80-110 ℃, and stirring for reacting for 4-12h to obtain the product benzoxazine.
10. Use of the novel modified amine epoxy hardener of claim 1 in coatings, adhesives and composites requiring cure at moderate and/or room temperatures.
Technical Field
The invention relates to the technical field of curing agents, in particular to a preparation method and application of a novel modified amine epoxy curing agent.
Background
Epoxy resin is a common thermosetting resin, and the molecular structure of the epoxy resin contains one or more active epoxy groups. But the curing agent is added to cure the epoxy resin, the curing shrinkage rate is low, and the cured product has excellent thermal stability, mechanical property, adhesion, dielectric property and processability, so the epoxy resin is widely applied to the fields of coatings, industrial molds, adhesives, aerospace, electronic materials and the like. Among them, there are various kinds of curing agents, including amines, alkalis, acid anhydrides, thiols, and the like. Since the network morphology and the crosslinking density of the epoxy resin are determined by the curing agent, different types of curing agents affect the physical properties of the epoxy resin, the gelation time, and other properties. Therefore, the research and development of diversified curing agents are widely regarded by the academic and business circles at home and abroad.
In recent years, several domestic enterprises and research institutions have successively developed novel phenolic amines. The amine raw material mainly comprises aliphatic amine, alicyclic amine and aromatic amine. The phenolic raw material is also changed from simple monophenol to cardanol, nonylphenol and the like; the aldehyde raw material is changed into paraformaldehyde, salicylaldehyde and the like from a formaldehyde water solution. Due to the change of the raw materials, the phenolic aldehyde amine curing agent has different properties, and the market application of the phenolic aldehyde amine curing agent is expanded. For example: CN107082871B adopts a new raw material containing two amino groups and carboxyl groups, namely lysine, and carboxyl groups are introduced into the molecules of the cardanol aldehyde amine curing agent, so that the cardanol modified amine curing agent has higher activity at low temperature, the curing reaction is promoted, the curing speed can be improved, the cardanol modified amine curing agent can be rapidly cured at low temperature to form a film, and a better technical effect is achieved. CN102952454B provides a modified phenol aldehyde amine epoxy primer composition containing cashew nut shell oil for metal surface corrosion prevention and a preparation method thereof, which can effectively overcome the problems of the traditional marine primer. CN 111936544A solves the problems associated with phenolic amines and phenolic amine containing curing agents by providing a low viscosity curing agent (< 3000cP at 25 ℃) which can be used in neat form or which can be dissolved in a minimum (<20 wt%) of organic solvent or diluent to effect curing of the epoxy resin. Furthermore, the phenolic amine curing agent can provide dry curing of the epoxy coating at ambient temperature (25 ℃) within <8 hours or at 5 ℃ within <16 hours. However, there are still some disadvantages in these phenol-aldehyde amine curing agents, such as: too high content of formaldehyde, poor designability of the molecular structure of the curing agent and the like.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a preparation method and application of a novel modified amine epoxy curing agent. The defects of high free formaldehyde content and the like of the traditional Mannich base modified amine curing agent are overcome, the requirements of environmental protection are met, and the application of the coating, the adhesive, the composite material and the like is expanded.
One of the technical schemes of the invention is a novel modified amine epoxy curing agent, the structural formula is shown as the formula (1):
wherein R is1The corresponding phenol is selected from phenol, o-methylphenol, m-methylphenol, p-methylphenol, o-allylphenol, p-allylphenolOne or more of phenylphenol, guaiacol, salicylaldehyde, vanillin, eugenol, naphthol, p-halophenol, p-diphenol, resorcinol, bisphenol S, bisphenol A, bisphenol F, bisphenol E, bisphenol B, bisphenol M, bisphenol Z;
R2the corresponding amine is selected from aniline, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-xylylenediamine, naphthylamine, benzylamine, methylbenzylamine, p-aminobenzylamine, benzidine, 4 '-diaminodiphenylmethane, p-methylaniline, o-methylaniline, m-methylaniline, 4-ethylaniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, 3, 5-dimethylaniline, 4' -diaminodiphenyl ether, furfurylamine, methylamine, ethylamine, propylamine, isopropylamine, butylamine, tert-butylamine, cyclohexylamine, 1,3, 5-triaminobenzene, N-bis (3-aminopropyl) methylamine, N-dimethyl-1, 3-diaminopropane, tetramethylpropylenediamine, dimethyldipropylenetriamine, 4-dimethylaminobutylamine, N-methyl-1, 3-propanediamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamine, divinylpropylamine, 1, 6-hexanediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurity, 4' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4' -diaminodicyclohexylmethane, methylcyclohexanediamine, aminoethylpiperazine, methylcyclopentamine, o-diaminomethylcyclopentane, (2, 3-dimethyl) dibutylenetriamine, triaminononane, tetramethylenediamine, triaminononane, triaminetriamine, and mixtures thereof, One or more of dicyandiamide, adipic acid dihydrazide, mixed amine and hybrid amine;
R3the corresponding polyamine is selected from 1,6 hexanediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, divinylpropylamine, 1,6 hexanediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurities, methylcyclopentanediamine, 4' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4' -diaminodicyclohexylmethane, 4' -bis-sec-butylaminodiphenylmethane, 4' -methylenebis (2, 6-diethyl esterPhenylamine), 4' -methylenebis (6-methyl-2-ethylaniline), methylcyclohexanediamine, m-phenylenediamine, aminoethylpiperazine, m-xylylenediamine, menthanediamine, isophorone diamine, dicyandiamide, adipic acid dihydrazide, hyamine and one or more of hetero amines;
the value range of n is that n is more than or equal to 2.
According to the second technical scheme, the preparation method of the novel modified amine epoxy curing agent comprises the following steps of carrying out ring-opening reaction on benzoxazine and polyamine to obtain the novel modified amine epoxy curing agent, wherein the structural formula of the benzoxazine is shown as a formula (2):
the specific reaction route is as follows:
further, the polyamine is selected from the group consisting of 1,6 hexamethylenediamine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, divinylpropylamine, 1,6 hexamethylenediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurities, methylcyclopentanediamine, 4' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4' -diaminodicyclohexylmethane, 4' -bis-sec-butylaminodiphenylmethane, 4' -methylenebis (2, 6-diethylaniline), 4' -methylenebis (6-methyl-2-ethylaniline), one or more of methylcyclohexanediamine, m-phenylenediamine, aminoethylpiperazine, m-xylylenediamine, menthanediamine, isophoronediamine, dicyandiamide, adipic acid dihydrazide, hyamine and hetero-amine.
Further, the mixing molar ratio of the benzoxazine to the polyamine is 1 (1-10); the ring-opening reaction is specifically as follows: reacting for 2-24h at 30-140 ℃ under inert atmosphere.
Further, the benzoxazine is prepared by a Mannich reaction of a phenol source, an amine source and aldehyde in a solvent. The specific reaction route is as follows:
further, the phenol source is one or more of phenol, o-methyl phenol, M-methyl phenol, p-methyl phenol, o-allyl phenol, p-allyl phenol, guaiacol, salicylaldehyde, vanillin, eugenol, naphthol, p-halophenol, p-diphenol, resorcinol, bisphenol S, bisphenol a, bisphenol F, bisphenol E, bisphenol B, bisphenol M, bisphenol Z, and the aldehyde is formaldehyde or paraformaldehyde.
Further, the amine source is aniline, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-xylylenediamine, naphthylamine, benzylamine, methylbenzylamine, p-aminobenzylamine, benzidine, 4 '-diaminodiphenylmethane, p-methylaniline, o-methylaniline, m-methylaniline, 4-ethylaniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, 3, 5-dimethylaniline, 4' -diaminodiphenyl ether, furfurylamine, methylamine, ethylamine, propylamine, isopropylamine, butylamine, t-butylamine, cyclohexylamine, 1,3, 5-triaminobenzene, N-bis (3-aminopropyl) methylamine, N-dimethyl-1, 3-diaminopropane, tetramethylpropylenediamine, dimethyldipropylenetriamine, 4-dimethylaminobutylamine, N-methyl-1, 3-propanediamine, N, N-tetrakis (3-aminopropyl) -1, 4-butanediamine, tris (3-aminopropyl) amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, polyethylenepolyamine, divinylpropylamine, 1, 6-hexanediamine, ethylenediamine, N, N-bis (2-aminoethyl) -1, 2-ethylenediamine, N-methyl-2, 2-diaminodiethylamine, trientine impurity, 4' -diaminodicyclohexylmethane, 3 ' -dimethyl-4, 4' -diaminodicyclohexylmethane, methylcyclohexanediamine, aminoethylpiperazine, methylcyclopentamine, o-diaminomethylcyclopentane, (2, 3-dimethyl) dibutylenetriamine, triaminononane, tetramethylenediamine, triaminononane, triaminetriamine, and mixtures thereof, One or more of dicyandiamide, adipic acid dihydrazide, mixed amine and hybrid amine.
Further, the molar ratio of the phenol source to the amine source to the aldehyde is 1:1: 2.0-2.5; the solvent is one or more of water, toluene, 1, 4-dioxane, cyclohexanone, ethyl acetate, trichloromethane, xylene, butanone, methyl isobutyl ketone, DMF, DMAc and NMP; the mass fraction of the phenol source, the amine source and the aldehyde in the solvent is 20-90%.
Further, the method specifically comprises the following steps: and (3) uniformly mixing the phenol source and the aldehyde in a solvent, adding the amine source in batches, heating to 80-110 ℃, and stirring for reacting for 4-12h to obtain the product benzoxazine.
The third technical scheme of the invention is the application of the novel modified amine epoxy curing agent in coating, adhesive and composite materials with medium-temperature and/or room-temperature curing requirements.
Further, the medium temperature range is 80-110 ℃, and the room temperature range is 20-40 ℃.
Compared with the prior art, the invention has the beneficial effects that:
according to the invention, through the reaction of benzoxazine and polyamine, a phenol Mannich bridge structure is introduced into the modified amine curing agent, so that the curing reaction of the polyamine and the epoxy resin is promoted. The adjustment of the curing temperature and the curing time is realized by regulating the type and the content of the phenol Mannich bridge structure in the structure of the modified amine curing agent, and different process conditions and performance requirements of the epoxy resin are met. The benzoxazine is introduced into the polyamine, so that the proportion of the phenolic amine can be accurately regulated, the defects of high free formaldehyde content and the like of the traditional Mannich base modified amine curing agent are overcome, the requirements of environmental protection are met, and the application of the coating, the adhesive, the composite material and the like is expanded.
The invention adopts a two-step method, wherein phenol, amine and aldehyde are firstly adopted to synthesize benzoxazine through Mannich reaction, and then the benzoxazine is adopted to modify different polyamines, so as to finally form a novel modified amine curing agent. Due to the flexible molecular structure design of the benzoxazine and the diversity of the polyamine, a modified amine curing agent system suitable for different use requirements can be designed by selecting the type of the benzoxazine and the polyamine and regulating and controlling the proportion of the benzoxazine and the polyamine, a convenient and effective amine curing agent modification method is provided, and the type of the modified amine curing agent is greatly enriched.
The curing agent of the invention introduces a Mannich bridge structure into the molecular structure of the curing agent due to the access of benzoxazine, thereby promoting the reaction between an epoxy group and an amino group. In addition, the use of excessive formaldehyde can be eliminated through a two-step synthesis process, so that the formaldehyde content in the modified amine curing agent is effectively controlled, the construction conditions are improved, and the effect of environmental protection is achieved.
Drawings
FIG. 1 is an infrared spectrum of a benzoxazine prepared in example 1;
FIG. 2 is an infrared spectrum of the novel modified amine curative-I prepared in example 2;
FIG. 3 is an infrared spectrum of the novel modified amine curative-II prepared in example 3;
FIG. 4 is an infrared spectrum of the novel modified amine curative-III prepared in example 4.
Detailed Description
Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.
It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.
As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.
Example 1
18.82g (0.2mol) of phenol, 13.2g (0.44mol) of paraformaldehyde and 200mL of toluene are sequentially added into a three-neck flask provided with a mechanical stirrer, a condenser and a thermometer, and the three-neck flask is placed in an oil bath to slowly raise the temperature to 55 ℃; and then adding 20.44g (0.2mol) of N, N-dimethyl-1, 3-diaminopropane into three batches at intervals of 15min, wherein the mass fraction of solute in the system is 30%, slowly heating to 85 ℃ after the N, N-dimethyl-1, 3-diaminopropane is completely added, stirring for reacting for 4h, washing and drying after the reaction is finished to obtain a light yellow product, namely the benzoxazine P-dampa, the structure of which is shown in the formula (3), and the yield is 92.7%.
The prepared benzoxazine was subjected to infrared spectroscopic analysis, and the results are shown in fig. 1. As can be seen from the figure, 921cm-1Is a characteristic absorption peak of the oxazine ring of 1034cm-1And stretching vibration peak of C-O-C, 1137cm-1The peak of C-N-C stretching vibration is shown. Therefore, the structure of the synthesized benzoxazine P-dampa is correct.
Example 2
4.42g (0.02mol) of benzoxazine P-dampa prepared in example 1 and 2.33g (0.02mol) of hexamethylenediamine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the mixture is placed in an oil bath to slowly raise the temperature to 90 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 5 hours to react to obtain a curing agent-I (I), wherein the structure of the curing agent is shown as the formula (4), and the yield is 95.6%.
The infrared spectroscopic analysis of the prepared curing agent-I was carried out, and the results are shown in FIG. 2. As can be seen from the figure, 921cm-1The characteristic peak of oxazine ring disappears, 3313cm-1The absorption peak at-OH is generated, 1137cm-1Has a C-N-C vibration peak at 1381cm-1Is in the position of-CH3The peak of vibration of (1). This indicates that the synthesized compound has a correct structure.
Example 3
4.42g (0.02mol) of benzoxazine P-dampa prepared in example 1 and 2.92g (0.02mol) of triethylene tetramine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the mixture is placed in an oil bath to be slowly heated to 100 ℃ under the conditions of no solvent and nitrogen protection, and stirred for reaction for 4 hours to obtain curing agent-II (II), wherein the structure of the curing agent-II is shown as a formula (5), and the yield of the curing agent-II is 98.1%.
The infrared spectroscopic analysis of the obtained curing agent-II was carried out, and the results are shown in FIG. 3. As can be seen from the figure, 921cm-1The characteristic peak of the oxazine ring disappears, 3282cm-1The absorption peak of-OH is generated, 1117cm-1Has a C-N-C vibration peak at 1380cm-1Is in the position of-CH3The peak of vibration of (1). This indicates that the synthesized compound has a correct structure.
Example 4
4.42g (0.02mol) of benzoxazine P-dampa prepared in example 1 and 3.79g (0.02mol) of tetraethylenepentamine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the three-necked flask is placed in an oil bath to slowly raise the temperature to 80 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 6 hours to obtain curing agent-III (III), the structure of which is shown in formula (6), and the yield of which is 90.9%.
The infrared spectroscopic analysis of the obtained curing agent-III was carried out, and the results are shown in FIG. 4. As can be seen from the figure, 921cm-1The characteristic peak of the oxazine ring disappears, 3283cm-1The absorption peak of-OH is generated and is 1118cm-1Has a C-N-C vibration peak at 1380cm-1Is in the position of-CH3The peak of vibration of (1). This indicates that the synthesized compound has a correct structure.
The curing agents prepared in examples 2,3 and 4 were mixed with epoxy E-44, and the gelation time thereof was measured, and the results are shown in Table 1. As can be seen from the table, the three curing agents have short gelation time after being mixed with the epoxy resin, so that the curing agents can realize medium-temperature curing of the epoxy resin. Curing agent-I has a relatively long gelation time, i.e., it has a long processing window prior to curing.
TABLE 1
Example 5
18.82g (0.2mol) of phenol, 13.2g (0.44mol) of paraformaldehyde and 250mL of toluene are sequentially added into a three-neck flask provided with a mechanical stirrer, a condenser and a thermometer, and the three-neck flask is placed in an oil bath to slowly raise the temperature to 50 ℃; and then adding 39.65g (0.2mol) of 4, 4-diaminodiphenylmethane at intervals of 15min in three batches, wherein the mass fraction of the solute in the system is 32.7%, slowly heating to 80 ℃ after the 4, 4-diaminodiphenylmethane is completely added, stirring for reaction for 5h, washing and drying after the reaction is finished to obtain a light yellow product, namely the benzoxazine P-ddm, the structure of which is shown in the formula (7), and the yield of which is 95.3%.
Example 6
Sequentially adding 21.63g (0.2mol) of p-methylphenol, 13.2g (0.44mol) of paraformaldehyde and 200mL of xylene into a three-necked bottle provided with a mechanical stirrer, a condenser and a thermometer, and slowly heating to 52 ℃ in an oil bath; and then adding 39.65g (0.2mol) of 4, 4-diaminodiphenylmethane at intervals of 15min in three batches, wherein the mass fraction of the solute in the system is 42.5%, slowly heating to 120 ℃ after the 4, 4-diaminodiphenylmethane is completely added, stirring for reaction for 3h, and washing and drying after the reaction is finished to obtain a light yellow product, namely benzoxazine PC-ddm, the structure of which is shown in a formula (8), and the yield of which is 90.3%.
Example 7
Adding 32.84g (0.2mol) of eugenol, 13.2g (0.44mol) of paraformaldehyde and 200mL of 1, 4-dioxane in sequence into a three-neck flask provided with a mechanical stirrer, a condenser and a thermometer, and slowly heating to 55 ℃ in an oil bath; and then adding 39.65g (0.2mol) of 4, 4-diaminodiphenylmethane at intervals of 15min in three batches, wherein the mass fraction of the solute in the system is 42.8%, slowly heating to 90 ℃ after the 4,4' -diaminodiphenylmethane is completely added, stirring for reacting for 6h, and washing and drying after the reaction is finished to obtain a light yellow product, namely benzoxazine EUG-ddm, the structure of which is shown in a formula (9), and the yield of which is 87.5%.
Example 8
Sequentially adding 32.84g (0.2mol) of eugenol, 13.2g (0.44mol) of paraformaldehyde and 200mL of 1, 4-dioxane into a three-neck flask provided with a mechanical stirrer, a condenser and a thermometer, and slowly heating to 50-55 ℃ in an oil bath; and then adding 20.44g (0.2mol) of N, N-dimethyl-1, 3-diaminopropane at intervals of 15min in three batches, wherein the mass fraction of the solute in the system is 30 percent, the mass fraction of the solute in the system is 33.2 percent, after 4,4' -diaminodiphenylmethane is completely added, slowly heating to 85-90 ℃, stirring for reaction for 5 hours, washing and drying after the reaction is finished, and obtaining a light yellow product, namely the benzoxazine EUG-dampa, the structure of which is shown in the formula (10), and the yield of which is 84.5 percent.
Example 9
The benzoxazine P-ddm 8.69g (0.02mol) prepared in example 5 and the hexamethylenediamine 2.33g (0.02mol) are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the three-necked flask is placed in an oil bath to slowly raise the temperature to 80 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 5 hours to react to obtain the novel modified amine curing agent, wherein the structure of the novel modified amine curing agent is shown as a formula (11), and the yield of the novel modified amine curing agent is 94.2%.
Example 10
The benzoxazine PC-ddm 9.25g (0.02mol) and tetraethylenepentamine 3.79g (0.02mol) prepared in example 6 are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the three-necked flask is placed in an oil bath to slowly raise the temperature to 90 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 5 hours to react to obtain the novel modified amine curing agent, wherein the structure of the novel modified amine curing agent is shown as a formula (12), and the yield is 91.3%.
Example 11
11.50g (0.02mol) of benzoxazine EUG-ddm prepared in example 7 and 3.79g (0.02mol) of tetraethylenepentamine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the three-necked flask is placed in an oil bath to slowly raise the temperature to 80 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 5 hours to react to obtain the novel modified amine curing agent, wherein the structure of the curing agent is shown as a formula (13), and the yield is 96.7%.
Example 12
5.81g (0.02mol) of benzoxazine EUG-dampa prepared in example 8 and 3.79g (0.02mol) of tetraethylenepentamine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the three-necked flask is placed in an oil bath to slowly raise the temperature to 60 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 6 hours to obtain a novel modified amine curing agent, wherein the structure of the curing agent is shown as a formula (14), and the yield is 89.8%.
Example 13
5.81g (0.02mol) of benzoxazine EUG-dampa prepared in example 8 and 2.92g (0.02mol) of triethylene tetramine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the mixture is placed in an oil bath to be slowly heated to 60 ℃ under the conditions of no solvent and nitrogen protection, and stirred for reaction for 6 hours to obtain a novel modified amine curing agent, wherein the structure of the novel modified amine curing agent is shown as a formula (15), and the yield is 98.5%.
Example 14
5.81g (0.02mol) of benzoxazine EUG-dampa prepared in example 8 and 2.33g (0.02mol) of hexamethylenediamine are sequentially added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer, and the mixture is placed in an oil bath to slowly raise the temperature to 90 ℃ under the conditions of no solvent and nitrogen protection, and stirred for 5 hours to react to obtain the novel modified amine curing agent, wherein the structure of the novel modified amine curing agent is shown as a formula (16), and the yield is 96.1%.
Example 15
9.41g (0.1mol) of phenol, 22.83g (0.1mol) of bisphenol A, 19.8g (0.66mol) of paraformaldehyde and 300mL of toluene are sequentially added into a three-necked flask provided with a mechanical stirrer, a condenser and a thermometer, 29.14g (0.3mol) of furfurylamine is added, the temperature is raised to 90 ℃, stirring reaction is carried out for 5 hours, and washing and drying are carried out after the reaction is finished to obtain yellow liquid, namely benzoxazine P-BA-fa, wherein the yield is 89.2%.
Example 16
28.23g (0.3mol) of phenol, 19.8g (0.66mol) of paraformaldehyde and 300mL of toluene are sequentially added into a three-necked bottle provided with a mechanical stirrer, a condenser and a thermometer, 19.83g (0.1mol) of 4,4' -diaminodiphenylmethane and 9.31g (0.1mol) of aniline are added, the temperature is raised to 90 ℃, the stirring reaction is carried out for 5 hours, and after the reaction is finished, washing and drying are carried out to obtain light yellow liquid, namely benzoxazine P-a-ddm, wherein the yield is 86.7%.
Example 17
Benzoxazine (0.02mol) P-BA-fa prepared in example 15 and hexamethylene diamine (0.02mol) are added into a three-neck flask provided with a magnetic stirring device, a condenser and a thermometer in sequence, and the mixture is placed into an oil bath under the conditions of no solvent and nitrogen protection, the temperature is slowly raised to 60 ℃, and the mixture is stirred and reacted for 4 hours to obtain a novel modified amine curing agent, wherein the yield is 89.3%.
Example 18
The benzoxazine (0.02mol) P-a-ddm prepared in example 16 and (0.02mol) hexamethylenediamine are added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer in sequence, and the mixture is placed in an oil bath under the conditions of no solvent and nitrogen protection, the temperature is slowly raised to 70 ℃, and the mixture is stirred and reacted for 4 hours to obtain the novel modified amine curing agent, wherein the yield is 85.1%.
Example 19
The benzoxazine (0.02mol) P-dampa, (0.01mol) hexanediamine and (0.01mol) triethylene tetramine prepared in the example 1 are added into a three-necked flask provided with a magnetic stirring device, a condenser and a thermometer in sequence, and the mixture is placed in an oil bath to be slowly heated to 80 ℃ under the conditions of no solvent and nitrogen protection, and stirred for reaction for 3.5 hours to obtain the novel modified amine curing agent with the yield of 87.7 percent.
Example 20
Benzoxazine (0.02mol) P-BA-fa, (0.01mol) tetraethylenepentamine and (0.01mol) triethylene tetramine prepared in example 15 are sequentially added into a three-neck flask provided with a magnetic stirring device, a condenser and a thermometer, and the three-neck flask is placed in an oil bath to slowly raise the temperature to 75 ℃ under the conditions of no solvent and nitrogen protection, and stirred for reaction for 3 hours to obtain the novel modified amine curing agent with the yield of 83.9 percent.
Further verification is carried out on the products of examples 9-14 and 17-20, and the result shows that the gelation time of the obtained novel modified amine curing agent is within the range of 10-30s at the temperature of 110 ℃; the gelation time is in the range of 20-40s at 100 deg.C; the gelation time is 40-60s at 90 deg.C; the gelation time is in the range of 60-80s at 80 deg.C.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included therein.