Hyperbranched intumescent flame retardant / co-curing agent, preparation method thereof, flame-retardant modified epoxy resin and application thereof

Abstract

The invention relates to a hyperbranched intumescent flame retardant / co-curing agent and a preparation method thereof as well as flame-retardant modified epoxy resin and application thereof, and the hyperbranched intumescent flame retardant / co-curing agent is prepared by taking 3-amino-1, 2-propylene glycol, triethylamine, cyanuric chloride, phosphorus oxychloride and organic polyamine as raw materials through a three-step substitution reaction. On one hand, the flame retardant has various flame-retardant structures such as triazine and phosphate, belongs to a single-molecule intumescent flame retardant, and has an excellent flame-retardant effect due to mutual synergism of different flame-retardant structures; and on the other hand, the flame retardant has a polyamine structure and a hyperbranched structure which can participate in an epoxy curing reaction, the polyamine structure can enable flame retardant molecules to be stably distributed in an epoxy resin material in a covalent bond manner, and the hyperbranched structure can endow the epoxy resin material with good mechanical properties. Limit oxygen index (LOI), vertical combustion UL-94 and mechanical property test results show that the flame retardant shows excellent flame retardance and impact resistance, and the problem that flame retardance and other comprehensive properties of an epoxy resin material are difficult to consider can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardants, and specifically relates to a hyperbranched intumescent flame retardant / co-curing agent and a preparation method thereof, a flame retardant modified epoxy resin and an application thereof. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Epoxy resin (EP) has excellent properties such as low shrinkage and high electrical insulation performance, and has been widely used in adhesives, coatings, construction and other industries. However, like most polymers, a fatal flaw of epoxy resin is its inherent flammability. In the absence of safety, the application of epoxy resin in many fields is limited. Therefore, it is of great significance to improve the flame retardant properties of epoxy resin.

[0004] Intumescent flame retardants (IFRs) are widely used in different materials because of their condensed phase flame retardant activity. This type of flame retardant can generally promote the production of higher carbon residues in the combustion process of the material, and more effectively reduce the emission of heat and toxic gases (CO). Traditional intumescent flame retardants represented by ammonium polyphosphate (APP) and melamine are generally mixed into the matrix by physical means, which can easily lead to the destruction of mechanical properties and the opacity of the appearance of epoxy thermosetting resins. Hyperbranched flame retardants have the advantages of many branching points, rich functional groups, diversified functions and high compatibility with polymer matrices. They can improve the mechanical properties of polymer materials and enhance impact resistance; reactive organophosphorus flame retardants, due to the construction of covalent bonds, not only avoid the degradation of EP mechanical properties, but also can achieve high expansion ratios of EP composites by reducing the softening temperature of EP, thereby enhancing the flame retardant properties of EP composites. However, traditional hyperbranched triazine flame retardants with rich nitrogen sources need to add APP to enhance the flame retardant properties when flame-retardant modified EP. The introduction of multiple flame retardants inevitably causes the degradation of EP mechanical properties. Reactive intumescent flame retardants have low functionality, which affects the cross-linked network structure of epoxy resins and makes it difficult to meet higher toughness requirements. In addition, the synthesis steps are complicated, the product purity requirements are high, and the production cost is high. Hyperbranched flame retardants that are rich in nitrogen and phosphorus elements and polyamine curing units have not yet been seen.

[0005] Therefore, through molecular structure design, multiple epoxy curing unit amine groups, phosphorus elements in the intumescent flame retardant system, and triazine structures are integrated into a single molecule to develop a hyperbranched multifunctional intumescent flame retardant / curing agent. This achieves a balance between flame retardancy and comprehensive performance of EP composite materials and reduces the preparation cost of flame retardants. This is of great significance for the development of high-performance epoxy resin materials and for meeting the use requirements of epoxy resin materials in complex application scenarios. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a hyperbranched intumescent flame retardant / co-curing agent and a preparation method thereof, a flame-retardant modified epoxy resin and its application, so as to solve the problem that the flame retardancy and other comprehensive properties of epoxy resin materials are difficult to take into account. The present invention is based on molecular modular design, and different functional modules such as the amine group of the epoxy curing unit, the phosphorus element in the intumescent flame retardant system, and the triazine structure are assembled through synthetic chemistry to accurately construct a hyperbranched multifunctional intumescent flame retardant / curing agent. The specific molecular construction method is: through the nucleophilic substitution reaction of the highly reactive C-Cl bond in cyanuric chloride and 3-amino-1,2-propylene glycol, the triazine structure is introduced into the flame retardant molecule as the core of the molecular structure, and phosphorus oxychloride is used as a connection point. Through the highly reactive P-Cl bond, the hydroxyl group and the primary amine are sequentially reacted, and the phosphate and secondary amine structures are introduced into the flame retardant molecule. The flame retardant can give the EP composite material excellent flame retardant properties and good mechanical properties.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0008] In a first aspect, the present invention provides a hyperbranched intumescent flame retardant / co-curing agent, the structural formula of which is shown below:

[0009]

[0010] Among them, n, m, and p are integers.

[0011] For example, n, m, and p are integers such as 1, 2, 3, and 4.

[0012] In a second aspect, the present invention provides a method for preparing the hyperbranched intumescent flame retardant / co-curing agent, comprising the following steps:

[0013] 3-amino-1,2-propanediol and triethylamine are added to tetrahydrofuran in proportion, mixed, cyanuric chloride is added thereto at -3 to 3°C, mixed, heated to 65 to 75°C, reacted for 12 to 18 hours, to obtain intermediate product I;

[0014] Add the intermediate product I and triethylamine to the first solvent in proportion, mix well, add phosphorus oxychloride at -3-3°C, raise the temperature to 20-40°C, and react for a set time to obtain the intermediate product II;

[0015] The intermediate product II and triethylamine are added to the second solvent in proportion, mixed, and then an organic polyamine is added thereto at -3 to 3°C, the temperature is raised to 20-40°C, and the reaction is carried out for a set time to obtain a hyperbranched intumescent flame retardant / co-curing agent.

[0016] Triethylamine is used as an acid binding agent to neutralize the hydrogen chloride produced in the reaction system, thereby promoting the reaction.

[0017] Tetrahydrofuran only acts as a solvent in the reaction system, dissolving the reactants and providing an environment for the reactants to interact with each other.

[0018] In some embodiments, 3-amino-1,2-propanediol and triethylamine are added to tetrahydrofuran in proportion, mixed, cyanuric chloride is added thereto at 0° C., mixed, and then heated to 70° C. for reaction for 12-18 hours to obtain intermediate product I;

[0019] Add the intermediate product I and triethylamine to the first solvent in proportion, mix well, add phosphorus oxychloride at 0°C, raise the temperature to 20-40°C, and react for a set time to obtain the intermediate product II;

[0020] The intermediate product II and triethylamine are added to the second solvent in proportion, mixed, and then an organic polyamine is added thereto at 0°C, the temperature is raised to 20-40°C, and the reaction is carried out for a set time to obtain a hyperbranched intumescent flame retardant / co-curing agent.

[0021] The intermediate product I has the following chemical structural formula:

[0022]

[0023] The intermediate product II has the following chemical structural formula:

[0024]

[0025] The preparation reaction process is as follows:

[0026]

[0027] In some embodiments, the molar ratio of 3-amino-1,2-propylene glycol to cyanuric chloride is 3-5:1. For example, the molar ratio may be 3:1; 4:1; or 5:1.

[0028] In some embodiments, the molar ratio of the intermediate product I to phosphorus oxychloride is 1:0.5-2. For example, the molar ratio may be: 1:0.6; 1:0.7; 1:0.9; 1:0.95; 1:1; 1:1.05; 1:1.1; 1:1.15; 1:2.

[0029] In some embodiments, the molar ratio of the intermediate product II to the organic polyamine is 1:1-2, such as 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:1.5, 1:1.55, 1:1.6, 1:1.65, 1:1.7.

[0030] In some embodiments, when preparing intermediate product I, the molar ratio of 3-amino-1,2-propanediol to triethylamine is 1:1-1.1;

[0031] When preparing the intermediate product II, the molar ratio of the intermediate product I to triethylamine is 1:1-1.1;

[0032] When preparing the hyperbranched intumescent flame retardant / co-curing agent, the molar ratio of the intermediate product II to triethylamine is 1:1-1.1.

[0033] In some embodiments, the first solvent is selected from tetrahydrofuran, acetonitrile, dioxane, acetone, dimethylformamide (DMF), or toluene.

[0034] In some embodiments, the second solvent is selected from tetrahydrofuran, acetonitrile, dioxane, dimethylformamide (DMF), acetone, or toluene.

[0035] In some embodiments, the organic polyamine is any one of pentaethylenehexamine, tetraethylenepentamine, triethylenetetramine, diethylenetriamine, 1,4-diaminobutane, ethylenediamine, 1,6-hexanediamine, 1,7-heptanediamine, etc., or a mixture thereof.

[0036] In a third aspect, the present invention provides a flame retardant modified epoxy resin, which includes an epoxy resin matrix and a flame retardant incorporated therein, wherein the flame retardant is the hyperbranched intumescent flame retardant.

[0037] In some embodiments, the method for preparing the flame retardant modified epoxy resin comprises the following steps:

[0038] Heat the epoxy resin matrix to 100-115°C, then add the flame retardant into the epoxy resin, mix well, and vacuum to remove bubbles to obtain a primary mixture;

[0039] Add the curing agent into the primary mixture, mix well, and obtain the secondary mixture.

[0040] Preferably, the method further includes injecting the flame retardant modified epoxy resin into a mold to prepare a target component.

[0041] More preferably, the method of heating and curing the target component is: firstly heating and curing at 80-100° C. for 1-3 hours, and then curing at 140-150° C. for 4-8 hours.

[0042] In a fourth aspect, the present invention provides applications of the flame retardant modified epoxy resin in the fields of electricity, textiles, construction or transportation.

[0043] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0044] The hyperbranched intumescent flame retardant / co-curing agent provided by the present invention has both a gas-source triazine structure and an acid-source phosphate structure, and is a single-molecule intumescent flame retardant, wherein the triazine structure rich in nitrogen can be decomposed at high temperature to release gases such as nitrogen and ammonia, and the phosphate structure can be decomposed at high temperature to form an acid that is dehydrated to form carbon, thereby promoting the EP composite material to form an intumescent carbon layer with a low thermal conductivity. The design of the single-molecule intumescent flame retardant solves the problems of uneven mixing of multiple components in the intumescent flame retardant system and uncoordinated performance of the flame retardant functions of multiple molecules;

[0045] The hyperbranched intumescent flame retardant / co-curing agent provided by the present invention contains a secondary amine structure and a hyperbranched structure. A multi-stage amine that can participate in the EP curing reaction is introduced into the molecular structure, and the flame retardant can be fixed in the EP structure through a covalent bond, thereby solving the problems of easy precipitation of the additive flame retardant, which leads to attenuation of the flame retardant performance of the coating, and reduced mechanical properties of the EP composite material. In addition, the introduction of the hyperbranched structure gives the flame retardant structure a certain flexibility, thereby enhancing the impact resistance of the EP composite material.

[0046] The flame retardant preparation method provided by the invention has simple synthesis process, easy post-processing such as product purification, product yield of more than 90%, and is easy to control and industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0048] Figure 1 These are the test results of the impact resistance of EP composite materials.

[0049] Figure 2 The tensile strength test results of EP composite materials.

[0050] Figure 3 These are the test results of flexural strength of EP composite materials. DETAILED DESCRIPTION

[0051] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0052] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0053] Example 1

[0054] (1) Preparation of intermediate product I

[0055] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I with a yield of 98%.

[0056] The chemical structure of intermediate product I is as follows:

[0057]

[0058] (2) Preparation of intermediate II

[0059] 34.82g of intermediate product I and 30.36g of triethylamine were added to 500ml of dioxane and stirred evenly. 46g of phosphorus oxychloride was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product II, with a yield of 96%.

[0060] The chemical structure of intermediate II is as follows:

[0061]

[0062] (3) Preparation of product HBIR-0

[0063] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 6.61g of 1,4-diaminobutane was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The product HBIR-0 was obtained after the solvent was removed by rotary evaporation under reduced pressure, with a yield of 90%.

[0064] The chemical structure of HBIR-0 is as follows:

[0065]

[0066] The product HBIR-0 prepared in this example was 1 H NMR (400MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak δ (ppm) corresponds to the following: δ1.49, 2.71, 3.74-3.78, 3.96-4.03, 4.21, 4.24, 4.39, 4.79, 4.80, 5.72, 7.22. This is consistent with the chemical environment of H in the product HBIR-0.

[0067] Example 2

[0068] (1) Preparation of intermediate product I

[0069] 39.54g of 3-amino-1,2-propylene glycol and 54.25g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 18h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I with a yield of 98.5%.

[0070] (2) Preparation of intermediate II

[0071] 34.82g of intermediate product I and 30.36g of triethylamine were added to 500ml of dioxane and stirred evenly. 46g of phosphorus oxychloride was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product II, with a yield of 96%.

[0072] (3) Preparation of product HBIR-0

[0073] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 6.61g of 1,4-diaminobutane was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The product HBIR-0 was obtained after the solvent was removed by rotary evaporation under reduced pressure, with a yield of 91%.

[0074] Example 3

[0075] (1) Preparation of intermediate product I

[0076] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I with a yield of 98%.

[0077] (2) Preparation of intermediate II

[0078] 34.82g of intermediate product I and 33.40g of triethylamine were added to 500ml of dioxane and stirred evenly. 46g of phosphorus oxychloride was slowly added dropwise in an ice-water bath, and stirring was continued for 18h after returning to room temperature. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product II, with a yield of 96%.

[0079] (3) Preparation of product HBIR-0

[0080] Add 11.76g of intermediate II and 15.18g of triethylamine to 300ml of dioxane and stir evenly. Slowly add 6.61g of 1,4-diaminobutane in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter, wash with water, and dry. After removing the solvent by rotary evaporation under reduced pressure, the product HBIR-0 can be obtained with a yield of 95%.

[0081] Example 4

[0082] (1) Preparation of intermediate product I

[0083] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I with a yield of 98%.

[0084] (2) Preparation of intermediate II

[0085] 34.82g of intermediate product I and 30.36g of triethylamine were added to 500ml of dioxane and stirred evenly. 46g of phosphorus oxychloride was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product II, with a yield of 96%.

[0086] (3) Preparation of product HBIR-0

[0087] 11.76g of intermediate II and 16.70g of triethylamine were added to 300ml of dioxane and stirred evenly. 6.61g of 1,4-diaminobutane was slowly added dropwise in an ice-water bath, and the mixture was stirred for 18h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The product HBIR-0 was obtained after the solvent was removed by rotary evaporation under reduced pressure, with a yield of 91%.

[0088] Example 5

[0089] (1) Preparation of intermediate product I

[0090] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0091] (2) Preparation of intermediate II

[0092] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0093] (3) Preparation of product HBIR-1

[0094] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 7.74g of diethylenetriamine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-1, with a yield of 92%.

[0095] The chemical structure of HBIR-1 is as follows:

[0096]

[0097] The product HBIR-1 prepared in this example was 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak δ (ppm) corresponds to the following: δ2.62, 2.74, 3.05, 3.74-3.78, 3.96-4.03, 4.21, 4.39, 4.40, 4.50, 4.79, 5.72, 7.22, which is consistent with the chemical environment of H in the product HBIR-1.

[0098] Example 6

[0099] (1) Preparation of intermediate product I

[0100] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0101] (2) Preparation of intermediate II

[0102] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0103] (3) Preparation of product HBIR-1

[0104] 11.76g of intermediate II and 16.70g of triethylamine were added to 300ml of dioxane and stirred evenly. 7.74g of diethylenetriamine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 18h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-1, with a yield of 93%.

[0105] Example 7

[0106] (1) Preparation of intermediate product I

[0107] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0108] (2) Preparation of intermediate II

[0109] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0110] (3) Preparation of product HBIR-1

[0111] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 6.97g of diethylenetriamine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-1, with a yield of 92%.

[0112] Example 8

[0113] (1) Preparation of intermediate product I

[0114] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0115] (2) Preparation of intermediate II

[0116] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0117] (3) Preparation of product HBIR-1

[0118] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 8.51g of diethylenetriamine was slowly added dropwise in an ice-water bath, and stirring was continued for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-1, with a yield of 91%.

[0119] Example 9

[0120] (1) Preparation of intermediate product I

[0121] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0122] (2) Preparation of intermediate II

[0123] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0124] (3) Preparation of product HBIR-2

[0125] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 10.97g of triethylenetetramine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-2, with a yield of 95%.

[0126] The chemical structure of HBIR-2 is as follows:

[0127]

[0128] The product HBIR-2 prepared in this example was 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak δ (ppm) corresponds to the following: δ2.62, 2.65, 2.74, 3.74-3.78, 3.96-4.03, 4.21, 4.24, 4.39, 4.40, 4.50, 4.79, 5.72, 7.22, which is consistent with the chemical environment of H in the product HBIR-2.

[0129] Example 10

[0130] (1) Preparation of intermediate product I

[0131] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0132] (2) Preparation of intermediate II

[0133] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0134] (3) Preparation of product HBIR-2

[0135] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 9.87g of triethylenetetramine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-2, with a yield of 91%.

[0136] Embodiment 11

[0137] (1) Preparation of intermediate product I

[0138] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0139] (2) Preparation of intermediate II

[0140] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0141] (3) Preparation of product HBIR-2

[0142] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 12.07g of triethylenetetramine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-2, with a yield of 93%.

[0143] Example 12

[0144] (1) Preparation of intermediate product I

[0145] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0146] (2) Preparation of intermediate II

[0147] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0148] (3) Preparation of product HBIR-3

[0149] Add 11.76g of intermediate II and 15.18g of triethylamine to 300ml of dioxane and stir evenly. Slowly add 14.20g of tetraethylenepentamine in an ice-water bath and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter, wash with water, and dry. After removing the solvent by rotary evaporation under reduced pressure, the product HBIR-3 can be obtained with a yield of 90%. The chemical structure of HBIR-3 is as follows:

[0150]

[0151] The product HBIR-3 prepared in this example was 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak δ (ppm) corresponds to the following: δ2.62, 2.65, 2.74, 3.29, 3.74-3.78, 3.96-4.03, 4.21, 4.24, 4.39, 4.40, 4.50, 4.79, 5.72, 7.22, which is consistent with the chemical environment of H in the product HBIR-3.

[0152] Embodiment 13

[0153] (1) Preparation of intermediate product I

[0154] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0155] (2) Preparation of intermediate II

[0156] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0157] (3) Preparation of product HBIR-3

[0158] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 12.78g of tetraethylenepentamine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-3, with a yield of 92%.

[0159] Embodiment 14

[0160] (1) Preparation of intermediate product I

[0161] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0162] (2) Preparation of intermediate II

[0163] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0164] (3) Preparation of product HBIR-3

[0165] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 15.62g of tetraethylenepentamine was slowly added dropwise in an ice-water bath, and the mixture was stirred for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-3, with a yield of 91%.

[0166] Embodiment 15

[0167] (1) Preparation of intermediate product I

[0168] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0169] (2) Preparation of intermediate II

[0170] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0171] (3) Preparation of product HBIR-4

[0172] Add 11.76g of intermediate II and 15.18g of triethylamine to 300ml of dioxane and stir evenly. Slowly add 17.43g of pentaethylenehexamine in an ice-water bath and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter, wash with water, and dry. After removing the solvent by rotary evaporation under reduced pressure, the product HBIR-4 can be obtained with a yield of 90%. The chemical structure of HBIR-4 is as follows:

[0173]

[0174] The product HBIR-4 prepared in this example was 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak δ (ppm) corresponds to the following: 2.62, 2.65, 2.74, 3.29, 3.74-3.78, 3.96-4.03, 4.21, 4.24, 4.39, 4.40, 4.50, 4.79, 5.72, 7.22, which is consistent with the chemical environment of H in the product HBIR-4.

[0175] Example 16

[0176] (1) Preparation of intermediate product I

[0177] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0178] (2) Preparation of intermediate II

[0179] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0180] (3) Preparation of product HBIR-4

[0181] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 15.69g of pentaethylenehexamine was slowly added dropwise in an ice-water bath, and stirring was continued for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-4, with a yield of 94%.

[0182] Embodiment 17

[0183] (1) Preparation of intermediate product I

[0184] 39.54g of 3-amino-1,2-propylene glycol and 43.92g of triethylamine were added to 500ml of tetrahydrofuran and stirred evenly in an ice-water bath. 26.68g of cyanuric chloride was added to the reaction system, and the reaction was restored to room temperature for 2h, and then the temperature was raised to 70°C and the reaction was continued for 12h. After the reaction was completed, the by-product triethylamine hydrochloride was filtered out, and the filtrate was subjected to rotary evaporation to remove the solvent under reduced pressure to obtain intermediate product I.

[0185] (2) Preparation of intermediate II

[0186] Add 34.82g of intermediate product I and 30.36g of triethylamine to 500ml of dioxane and stir evenly. Slowly add 46g of phosphorus oxychloride in an ice-water bath, and continue stirring for 24h after returning to room temperature. After the reaction is completed, filter out the by-product triethylamine hydrochloride, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain intermediate product II.

[0187] (3) Preparation of product HBIR-4

[0188] 11.76g of intermediate II and 15.18g of triethylamine were added to 300ml of dioxane and stirred evenly. 19.17g of pentaethylenehexamine was slowly added dropwise in an ice-water bath, and stirring was continued for 24h after returning to room temperature. After the reaction was completed, the mixture was filtered, washed with water, and dried. The solvent was removed by rotary evaporation under reduced pressure to obtain the product HBIR-4, with a yield of 92%.

[0189] Embodiment 18

[0190] 1) Weigh 75g of epoxy resin, 19g of diaminodiphenylmethane (DDM) curing agent and 5.0g of HBIR-1 flame retardant;

[0191] 2) adding the flame retardant to the epoxy resin at 110°C, stirring evenly, and vacuuming to remove bubbles to obtain a primary mixture;

[0192] 3) Add the curing agent to the primary mixture at 110°C, and stir rapidly to fully dissolve the curing agent into a uniform system to obtain a secondary mixture;

[0193] 4) The secondary mixture is injected into a mold, placed in an oven, and the heating temperature is first controlled to be 80° C. for curing for 2 hours, and then the heating temperature is controlled to be 150° C. for curing for 6 hours. After the curing is completed, it is naturally cooled to room temperature to obtain a flame-retardant modified epoxy resin.

[0194] Embodiment 19

[0195] The only difference from Example 18 is that 5.0 g of HBIR-2 flame retardant is added in this application example, and the rest is the same as Application Example 18, which will not be repeated here.

[0196] Embodiment 20

[0197] The only difference from Example 18 is that 5.0 g of HBIR-3 flame retardant is added in this application example, and the rest is the same as Application Example 18, which will not be repeated here.

[0198] Embodiment 21

[0199] The only difference from Example 18 is that 5.0 g of HBIR-4 flame retardant is added in this application example, and the rest is the same as Application Example 18, which will not be repeated here.

[0200] Comparative Example 1

[0201] 1) Weigh 75g of epoxy resin and 19g of DDM curing agent;

[0202] 2) Add the curing agent to the primary mixture at 110°C, and stir rapidly to fully dissolve the curing agent into a uniform system to obtain a mixture;

[0203] 3) The mixture is injected into a mold, placed in an oven, and the heating temperature is first controlled to be 80° C. for curing for 2 hours, and then the heating temperature is controlled to be 150° C. for curing for 6 hours. After the curing is completed, the mixture is naturally cooled to room temperature to obtain a flame-retardant modified epoxy resin.

[0204] Comparative Example 2

[0205] The only difference from Example 18 is that 5.0 g of HBIR-0 flame retardant is added in this application example, and the rest is the same as that of Application Example 1, which will not be repeated here.

[0206] Performance Test:

[0207] The flame retardant modified epoxy resins obtained in Examples 18-21 and Comparative Examples 1-2 were subjected to LOI test and UL-94 vertical burning test, and the results are shown in Table 1. The LOI test was conducted in accordance with ASTM D2863-19 standard, and the sample size was 130×6.5×3 mm 2 UL-94 vertical burning test is in accordance with GBT2408-2008 standard, the sample size is 130×13×3mm 2 .

[0208] The results show that the EP composites modified by the hyperbranched intumescent flame retardant can achieve LOI greater than 38%, all passed the UL-94V0 rating, and the flame retardant with the curing unit amine group has no significant difference in flame retardancy compared with the non-reactive curing agent. This shows that the triazine structure and phosphorus element in the hyperbranched intumescent flame retardant play a decisive role in the flame retardancy. The triazine structure releases inert gas at high temperature, and the polyphosphoric acid generated by the decomposition of phosphorus catalyzes the polymer matrix into carbon, forming an intumescent carbon layer that prevents heat and material exchange, and achieves excellent flame retardancy.

[0209] Table 1 Flame retardant performance test results

[0210]

[0211]

[0212] Mechanical properties of the flame retardant modified epoxy resins obtained in Examples 18-21 and Comparative Examples 1-2 were tested. The test results are as follows: Figure 1 , Figure 2 and Figure 3 shown.

[0213] In order to evaluate the effect of HBIR on the mechanical properties of EP composites, the toughness of EP-HBIR was first studied by impact test. Figure 1 As shown in the figure, the impact strength of EP / HBIR increases from 10 kJ m -2The results showed that the EP / HBIR-0, EP / HBIR-1, EP / HBIR-2, EP / HBIR-3 and EP / HBIR-4 increased sharply to 14, 25, 27, 28 and 31 kJ m -2 . In particular, the impact strength of EP / HBIR-4 is 3 times that of pure EP and 2.2 times that of EP / HBIR-0, and the tensile strength and flexural strength also have similar trends. The results show that compared with EP, the EP composites modified by hyperbranched intumescent flame retardants have achieved enhanced mechanical properties, and the flame retardants with curing unit amine groups have significantly enhanced mechanical properties compared with non-reactive curing agents.

[0214] In summary, hyperbranched intumescent flame retardants have significant flame retardant enhancement effects, among which the hyperbranched structure can enhance the mechanical properties of EP composites, and the reactive flame retardants may further enhance the mechanical properties of the polymer matrix by improving the EP curing cross-linking network.

[0215] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hyperbranched intumescent flame retardant / co-curing agent, characterized in that: Its structural formula is as follows: Among them, n, m, and p are integers.

2. The method for preparing the hyperbranched intumescent flame retardant / co-curing agent according to claim 1, characterized in that: The steps include: 3-amino-1,2-propanediol and triethylamine are added to tetrahydrofuran in proportion, mixed, cyanuric chloride is added thereto at -3 to 3°C, mixed, heated to 65 to 75°C, reacted for 12 to 18 hours, to obtain intermediate product I; Add the intermediate product I and triethylamine to the first solvent in proportion, mix well, add phosphorus oxychloride at -3-3°C, raise the temperature to 20-40°C, and react for a set time to obtain the intermediate product II; The intermediate product II and triethylamine are added to the second solvent in proportion, mixed, and then an organic polyamine is added thereto at -3 to 3°C, the temperature is raised to 20-40°C, and the reaction is carried out for a set time to obtain a hyperbranched intumescent flame retardant / co-curing agent.

3. The method for preparing a hyperbranched intumescent flame retardant / co-curing agent according to claim 2, characterized in that: The molar ratio of 3-amino-1,2-propylene glycol to cyanuric chloride is 3-5:

1.

4. The method for preparing a hyperbranched intumescent flame retardant / co-curing agent according to claim 2, characterized in that: The molar ratio of intermediate product I to phosphorus oxychloride is 1:0.5-2; Preferably, the molar ratio of the intermediate product II to the organic polyamine is 1:1-2.

5. The method for preparing a hyperbranched intumescent flame retardant / co-curing agent according to claim 2, characterized in that: When preparing intermediate product I, the molar ratio of 3-amino-1,2-propanediol to triethylamine is 1:1-1.1; When preparing the intermediate product II, the molar ratio of the intermediate product I to triethylamine is 1:1-1.1; When preparing the hyperbranched intumescent flame retardant / co-curing agent, the molar ratio of the intermediate product II to triethylamine is 1:1-1.

1.

6. The method for preparing a hyperbranched intumescent flame retardant / co-curing agent according to claim 2, characterized in that: The organic polyamine is any one of pentaethylenehexamine, tetraethylenepentamine, triethylenetetramine, diethylenetriamine, 1,4-diaminobutane, ethylenediamine, 1,6-hexanediamine, 1,7-heptanediamine, or a mixture thereof.

7. A flame retardant modified epoxy resin, characterized in that: The invention comprises an epoxy resin matrix and a flame retardant mixed therein, wherein the flame retardant is the hyperbranched intumescent flame retardant as claimed in claim 1.

8. The method for preparing the flame retardant modified epoxy resin according to claim 7, characterized in that: The steps include: Heat the epoxy resin matrix to 100-115°C, then add the flame retardant into the epoxy resin, mix well, and vacuum to remove bubbles to obtain a primary mixture; Add the curing agent into the primary mixture, mix well, and obtain the secondary mixture.

9. The method for preparing the flame retardant modified epoxy resin according to claim 8, characterized in that: The process also includes injecting the flame retardant modified epoxy resin into a mold to prepare a target component; The method of heating and curing the target component is: first heating and curing at 80-100° C. for 1-3 hours, and then curing at 140-150° C. for 4-8 hours.

10. Use of the flame retardant modified epoxy resin according to claim 7 in the fields of electricity, textiles, construction and transportation.

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