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

Abstract

The present application relates to a kind of hyperbranched intumescent flame retardant / cosolidifying agent and its preparation method, flame-retardant modified epoxy resin and its application, the hyperbranched intumescent flame retardant / cosolidifying agent with 3-amino-1,2-propanediol, triethylamine, cyanuric chloride, phosphorus oxychloride, organic polyamine as raw material, can be prepared by three-step substitution reaction.One aspect, the flame retardant has multiple flame-retardant structures such as triazine, phosphate ester, belongs to single-molecule intumescent flame retardant, different flame-retardant structures are mutually synergistic, with excellent flame-retardant effect.Another aspect, the flame retardant has polyamine structure and hyperbranched structure that can participate in epoxy curing reaction, and polyamine structure can make flame retardant molecules stably distributed in epoxy resin material by covalent bond, and hyperbranched structure can give epoxy resin material good mechanical properties.Limiting oxygen index (LOI), vertical burning UL-94 and mechanical property test results show that the flame retardant exhibits excellent flame-retardant performance and impact resistance, can solve the problem that the flame-retardant and other comprehensive performance of epoxy resin material are difficult to take into account.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flame retardants, and particularly relates to a hyperbranched intumescent flame retardant / cocuring agent, a preparation method thereof, a flame-retardant modified epoxy resin and application thereof. BACKGROUND

[0002] The statements herein are provided only to complement the background of the present application and are not necessarily indicative of the prior art.

[0003] Epoxy resin (EP) has excellent properties such as low shrinkage and high electrical insulation, and is widely used in adhesives, coatings, construction and other industries. However, like most polymers, one of the fatal defects of epoxy resin is its inherent flammability. Without safety, the application of epoxy resin in many fields is limited. Therefore, it is of great significance to improve the flame retardant performance of epoxy resin.

[0004] Intumescent flame retardant (IFR) is widely used in different materials due to its condensed phase flame retardant activity. This flame retardant can generally promote the production of higher residual carbon content during the combustion process of the material, and more effectively reduce the emission of heat and toxic gas (CO). Traditional intumescent flame retardants represented by ammonium polyphosphate (APP) and melamine are generally mixed into the matrix by physical means, which can easily cause damage to the mechanical properties and opaque appearance of the epoxy thermosetting resin. The flame retardant with hyperbranched structure has the advantages of multiple branching points, rich functional groups, diversified functions and high compatibility with polymer matrix, which can improve the mechanical properties of polymer materials and enhance the impact resistance. The reactive organic phosphorus flame retardant can not only avoid the degradation of the mechanical properties of EP, but also can reduce the softening temperature of EP to achieve high expansion ratio of EP composite, thereby enhancing the flame retardant performance of EP composite. However, the traditional hyperbranched triazine flame retardant with rich nitrogen source needs to add APP to enhance the flame retardant performance when modifying EP, and the introduction of multiple flame retardants inevitably causes the degradation of the mechanical properties of EP. The reactive intumescent flame retardant has small functionality, which affects the crosslinked network structure of epoxy resin, and is difficult to meet the higher toughness requirement. Moreover, the synthesis steps are complex, the product purity is high, and the production cost is high. The hyperbranched flame retardant with rich nitrogen, phosphorus elements and polyamine curing unit has not been seen.

[0005] Therefore, by molecular structure design, the amine group of multiple epoxy curing units, the phosphorus element in the intumescent flame retardant system and the triazine structure are integrated into a single molecule, a hyperbranched multifunctional intumescent flame retardant / curing agent is developed, the flame retardation and comprehensive performance of EP composite are considered, and the preparation cost of the flame retardant is reduced. It is of great significance to develop high-performance epoxy resin materials and meet the use requirements of epoxy resin materials in complex application scenarios. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a hyperbranched intumescent flame retardant / cocuring agent, a preparation method thereof, a flame-retardant modified epoxy resin and an application thereof, so as to solve the problem that the flame retardance and other comprehensive performance of the epoxy resin material are difficult to be balanced. The present application is based on molecular modular design, and different functional modules such as amine groups of an epoxy curing unit, phosphorus elements in an intumescent flame-retardant system and triazine structures are assembled through synthetic chemistry to precisely construct a hyperbranched multifunctional intumescent flame retardant / curing agent. The specific molecular construction method is as follows: through nucleophilic substitution reaction of the high-reactivity C-Cl bond in cyanuric chloride and 3-amino-1,2-propanediol, triazine structures are introduced into the flame retardant molecules as the molecular structure core; through sequential reaction of the high-reactivity P-Cl bond with hydroxyl and primary amine respectively, phosphate and secondary amine structures are introduced into the flame retardant molecules. The flame retardant can endow the EP composite material with excellent flame retardance and good mechanical properties.

[0007] In order to achieve the above-mentioned purpose, the present application is realized through the following technical scheme:

[0008] In the first aspect, the present application provides a hyperbranched intumescent flame retardant / cocuring agent, and the structural formula is as follows:

[0009]

[0010] Wherein, n, m and p are integers.

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

[0012] In the second aspect, the present application provides a preparation method of the hyperbranched intumescent flame retardant / cocuring agent, comprising the following steps:

[0013] 3-amino-1,2-propanediol and triethylamine are added into tetrahydrofuran in proportion, mixed, cyanuric chloride is added thereto at-3 to 3 DEG C, after mixing, the temperature is increased to 65 to 75 DEG C, and reaction is carried out for 12 to 18 hours to obtain an intermediate product I;

[0014] The intermediate product I and triethylamine are added into a first solvent in proportion, mixed, phosphorus oxychloride is added thereto at-3 to 3 DEG C, the temperature is increased to 20 to 40 DEG C, and reaction is carried out for a set time to obtain an intermediate product II;

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

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

[0017] Tetrahydrofuran is only used as a solvent in the reaction system, dissolving each reactant and providing an environment for interaction between each reactant.

[0018] In some embodiments, 3-amino-1,2-propanediol and triethylamine are added into tetrahydrofuran in proportion, mixed, and cyanuric chloride is added into the mixture at 0°C. After mixing, the temperature is raised to 70°C and the reaction is carried out for 12-18 hours to obtain intermediate product I.

[0019] Intermediate product I and triethylamine are added into a first solvent in proportion, mixed, and phosphorus oxychloride is added into the mixture at 0°C. The temperature is raised to 20-40°C and the reaction is carried out for a set time to obtain intermediate product II.

[0020] Intermediate product II and triethylamine are added into a second solvent in proportion, mixed, and organic polyamine is added into the mixture at 0°C. The temperature is raised to 20-40°C and the reaction is carried out for a set time to obtain hyperbranched intumescent flame retardant / cocuring 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-propanediol and cyanuric chloride is 3-5:1. For example, it can be specifically 3:1; 4:1; or 5:1.

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

[0029] In some embodiments, the molar ratio of intermediate product II and organic polyamine is 1:1-2. For example, it can be specifically 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, or 1:1.7.

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

[0031] In the preparation of the intermediate product II, the molar ratio of the intermediate product I and triethylamine is 1:1-1.1;

[0032] In the preparation of the hyperbranched intumescent flame retardant / cocuring agent, the molar ratio of the intermediate product II and 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 application provides a flame-retardant modified epoxy resin, which comprises 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] The epoxy resin matrix is heated to 100-115℃, then the flame retardant is added into the epoxy resin, mixed, vacuumed to remove bubbles, to obtain a primary mixture;

[0039] The curing agent is added into the primary mixture, mixed, to obtain a secondary mixture.

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

[0041] Further preferably, the method for heating and curing the target component is as follows: first heated and cured at 80-100℃ for 1-3h, then heated and cured at 140-150℃ for 4-8h.

[0042] In a fourth aspect, the present application provides the use of the flame-retardant modified epoxy resin in the fields of electric power, textile, construction or transportation.

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

[0044] The hyperbranched intumescent flame retardant / cosolidifying agent provided by the application has both gas source triazine structure and acid source phosphate structure, is a single molecule intumescent flame retardant, the triazine structure rich in nitrogen element can decompose and release nitrogen gas, ammonia gas and the like at high temperature, the phosphate structure decomposes into acid which dehydrates to form carbon layer at high temperature, promoting the EP composite to form intumescent carbon layer with low thermal conductivity, and the design of the single molecule intumescent flame retardant solves the problems of uneven mixing of multi-component intumescent flame retardant system and non-synergistic performance of multi-molecule flame retardant function;

[0045] The hyperbranched intumescent flame retardant / cosolidifying agent provided by the application contains secondary amine structure and hyperbranched structure, the multi-stage amine which can participate in the curing reaction of EP is introduced into the molecular structure, the flame retardant can be fixed in the EP structure through covalent bond, solving the problems of coating flame retardant performance attenuation and EP composite mechanical property reduction caused by easy precipitation of the additive type flame retardant; in addition, the introduction of the hyperbranched structure endows the flame retardant structure with certain flexibility, and enhances the impact resistance of the EP composite.

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

[0047] The drawings accompanying the specification of the application serve to provide further understanding of the application, the illustrative embodiments of the application and the description thereof serve to explain the application, and do not constitute improper limitation on the application.

[0048] Figure 1 EP composite impact resistance test results.

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

[0050] Figure 3 EP composite bending strength test results. DETAILED DESCRIPTION

[0051] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise specified, all technical and scientific terms used in the application have the same meaning as generally understood by those skilled in the art to which the application belongs.

[0052] The application will be further described below in conjunction with the drawings and examples, but it should not be understood as limiting the scope of protection of the application.

[0053] Example 1

[0054] (1) Preparation of intermediate product I

[0055] Put 39.54g 3-amino-1,2-propanediol, 43.92g triethylamine into 500ml tetrahydrofuran, stir uniformly under ice water bath condition, put 26.68g cyanuric chloride into the reaction system, restore room temperature to react for 2h, then heat to 70°C to continue to react for 12h. Filter to remove by-product triethylamine hydrochloride after the reaction is finished, remove the solvent by rotary evaporation under reduced pressure after the filtrate is treated, and the intermediate product I is obtained with a yield of 98%.

[0056] The chemical structural formula of the intermediate product I is as follows:

[0057]

[0058] (2) Preparation of the intermediate product II

[0059] Put 34.82g intermediate product I and 30.36g triethylamine into 500ml dioxane, stir uniformly, slowly drop 46g phosphorus oxychloride under ice water bath condition, continue to stir for 24h after the room temperature is restored. Filter to remove by-product triethylamine hydrochloride after the reaction is finished, remove the solvent by rotary evaporation under reduced pressure after the filtrate is treated, and the intermediate product II is obtained with a yield of 96%.

[0060] The chemical structural formula of the intermediate product II is as follows:

[0061]

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

[0063] Put 11.76g intermediate product II and 15.18g triethylamine into 300ml dioxane, stir uniformly, slowly drop 6.61g 1,4-diaminobutane under ice water bath condition, continue to stir for 24h after the room temperature is restored. Filter, wash with water, dry, remove the solvent by rotary evaporation under reduced pressure after the reaction is finished, and the product HBIR-0 is obtained with a yield of 90%.

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

[0065]

[0066] The product HBIR-0 prepared in this example is subjected to 1 H NMR (400MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak value δ (ppm) corresponds as follows: δ 1.49, 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] Add 39.54 g of 3-amino-1,2-propanediol and 54.25 g of triethylamine into 500 ml of tetrahydrofuran, stir uniformly under ice water bath condition, add 26.68 g of cyanuric chloride into the reaction system, restore room temperature and react for 2 h, then raise the temperature to 70°C and continue to react for 18 h. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration, remove the solvent from the filtrate by rotary evaporation under reduced pressure, and the intermediate product I is obtained with a yield of 98.5%.

[0070] (2) Preparation of intermediate product II

[0071] Stir 34.82 g of intermediate product I and 30.36 g of triethylamine in 500 ml of dioxane, slowly add 46 g of phosphorus oxychloride dropwise under ice water bath condition, continue to stir for 24 h after the temperature is restored to room temperature. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration, remove the solvent from the filtrate by rotary evaporation under reduced pressure, and the intermediate product II is obtained with a yield of 96%.

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

[0073] Stir 11.76 g of intermediate product II and 15.18 g of triethylamine in 300 ml of dioxane, slowly add 6.61 g of 1,4-diaminobutane dropwise under ice water bath condition, continue to stir for 24 h after the temperature is restored to room temperature. After the reaction is completed, filter, wash with water, dry, and remove the solvent from the filtrate by rotary evaporation under reduced pressure, and the product HBIR-0 is obtained with a yield of 91%.

[0074] Example 3

[0075] (1) Preparation of intermediate product I

[0076] Add 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine into 500 ml of tetrahydrofuran, stir uniformly under ice water bath condition, add 26.68 g of cyanuric chloride into the reaction system, restore room temperature and react for 2 h, then raise the temperature to 70°C and continue to react for 12 h. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration, remove the solvent from the filtrate by rotary evaporation under reduced pressure, and the intermediate product I is obtained with a yield of 98%.

[0077] (2) Preparation of intermediate product II

[0078] Stir 34.82 g of intermediate product I and 33.40 g of triethylamine in 500 ml of dioxane, slowly add 46 g of phosphorus oxychloride dropwise under ice water bath condition, continue to stir for 18 h after the temperature is restored to room temperature. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration, remove the solvent from the filtrate by rotary evaporation under reduced pressure, and the intermediate product II is obtained with a yield of 96%.

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

[0080] Add 11.76 g of intermediate product II and 15.18 g of triethylamine into 300 ml of dioxane, stir uniformly, slowly drop 6.61 g of 1,4-diaminobutane under ice water bath condition, continue stirring for 24 h after recovering room temperature. After the reaction is completed, filter, wash with water, dry, and remove the solvent by rotary evaporation under reduced pressure to obtain product HBIR-0 with a yield of 95%.

[0081] Example 4

[0082] (1) Preparation of intermediate product I

[0083] Add 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine into 500 ml of tetrahydrofuran, stir uniformly under ice water bath condition, add 26.68 g of cyanuric chloride into the reaction system, recover room temperature to react for 2 h, and then heat to 70°C to continue to react for 12 h. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration, remove the solvent by rotary evaporation under reduced pressure to obtain intermediate product I with a yield of 98%.

[0084] (2) Preparation of intermediate product II

[0085] Add 34.82 g of intermediate product I and 30.36 g of triethylamine into 500 ml of dioxane, stir uniformly, slowly drop 46 g of phosphorus oxychloride under ice water bath condition, continue stirring for 24 h after recovering room temperature. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration, remove the solvent by rotary evaporation under reduced pressure to obtain intermediate product II with a yield of 96%.

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

[0087] Add 11.76 g of intermediate product II and 16.70 g of triethylamine into 300 ml of dioxane, stir uniformly, slowly drop 6.61 g of 1,4-diaminobutane under ice water bath condition, continue stirring for 18 h after recovering room temperature. After the reaction is completed, filter, wash with water, dry, and remove the solvent by rotary evaporation under reduced pressure to obtain product HBIR-0 with a yield of 91%.

[0088] Example 5

[0089] (1) Preparation of intermediate product I

[0090] To 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine in 500 ml of tetrahydrofuran, 26.68 g of cyanuric chloride was added under stirring in an ice water bath. The reaction was continued at room temperature for 2 h and then at 70°C for 12 h. The reaction was terminated by removing triethylamine hydrochloride by filtration. The filtrate was concentrated by rotary evaporation to give intermediate I.

[0091] (2) Preparation of intermediate II

[0092] To 34.82 g of intermediate I and 30.36 g of triethylamine in 500 ml of dioxane, 46 g of phosphorus oxychloride was added dropwise under stirring in an ice water bath. The reaction was continued at room temperature for 24 h. The reaction was terminated by removing triethylamine hydrochloride by filtration. The filtrate was concentrated by rotary evaporation to give intermediate II.

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

[0094] To 11.76 g of intermediate II and 15.18 g of triethylamine in 300 ml of dioxane, 7.74 g of diethylenetriamine was added dropwise under stirring in an ice water bath. The reaction was continued at room temperature for 24 h. The reaction was terminated by filtration, washing with water and drying. The product HBIR-1 was obtained by rotary evaporation to remove the solvent. The yield was 92%.

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

[0096]

[0097] The product HBIR-1 prepared in this example was subjected to 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak δ (ppm) corresponds to the following: δ 2.62, 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 I

[0100] To 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine in 500 ml of tetrahydrofuran, 26.68 g of cyanuric chloride was added under stirring in an ice water bath. After the reaction was carried out at room temperature for 2 h, it was continued at 70 °C for 12 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to remove the solvent, and the intermediate product I was obtained.

[0101] (2) Preparation of the intermediate product II

[0102] To 34.82 g of the intermediate product I and 30.36 g of triethylamine in 500 ml of dioxane, 46 g of phosphorus oxychloride was added dropwise under stirring in an ice water bath. After the reaction was carried out at room temperature for 24 h, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to remove the solvent, and the intermediate product II was obtained.

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

[0104] To 11.76 g of the intermediate product II and 16.70 g of triethylamine in 300 ml of dioxane, 7.74 g of diethylenetriamine was added dropwise under stirring in an ice water bath. After the reaction was carried out at room temperature for 18 h, the product HBIR-1 was obtained by filtration, water washing, drying and removal of the solvent by rotary evaporation, with a yield of 93%.

[0105] Example 7

[0106] (1) Preparation of the intermediate product I

[0107] To 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine in 500 ml of tetrahydrofuran, 26.68 g of cyanuric chloride was added under stirring in an ice water bath. After the reaction was carried out at room temperature for 2 h, it was continued at 70 °C for 12 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to remove the solvent, and the intermediate product I was obtained.

[0108] (2) Preparation of the intermediate product II

[0109] To 34.82 g of the intermediate product I and 30.36 g of triethylamine in 500 ml of dioxane, 46 g of phosphorus oxychloride was added dropwise under stirring in an ice water bath. After the reaction was carried out at room temperature for 24 h, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to remove the solvent, and the intermediate product II was obtained.

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

[0111] To 300 ml of dioxane, 11.76 g of intermediate II and 15.18 g of triethylamine were added and stirred uniformly, 6.97 g of diethylenetriamine was slowly added dropwise under ice water bath condition, and after the temperature was returned to room temperature, the stirring was continued for 24 h. After the reaction was completed, the product HBIR-1 was obtained by filtering, washing with water, drying, and removing the solvent by rotary evaporation under reduced pressure, with a yield of 92%.

[0112] Example 8

[0113] (1) Preparation of intermediate I

[0114] To 500 ml of tetrahydrofuran, 39.54 g of 3-amino-l,2-propanediol and 43.92 g of triethylamine were added and stirred uniformly, and 26.68 g of cyanuric chloride was added to the reaction system, and after the temperature was returned to room temperature, the reaction was continued for 2 h, and then the temperature was increased to 70°C and the reaction was continued for 12 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtering, and the intermediate I was obtained by removing the solvent by rotary evaporation under reduced pressure.

[0115] (2) Preparation of intermediate II

[0116] To 500 ml of dioxane, 34.82 g of intermediate I and 30.36 g of triethylamine were added and stirred uniformly, and 46 g of phosphorus oxychloride was slowly added dropwise under ice water bath condition, and after the temperature was returned to room temperature, the stirring was continued for 24 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtering, and the intermediate II was obtained by removing the solvent by rotary evaporation under reduced pressure.

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

[0118] To 300 ml of dioxane, 11.76 g of intermediate II and 15.18 g of triethylamine were added and stirred uniformly, 6.97 g of diethylenetriamine was slowly added dropwise under ice water bath condition, and after the temperature was returned to room temperature, the stirring was continued for 24 h. After the reaction was completed, the product HBIR-1 was obtained by filtering, washing with water, drying, and removing the solvent by rotary evaporation under reduced pressure, with a yield of 92%.

[0119] Example 9

[0120] (1) Preparation of intermediate I

[0121] To 500 ml of tetrahydrofuran, 39.54 g of 3-amino-l,2-propanediol and 43.92 g of triethylamine were added and stirred uniformly, and 26.68 g of cyanuric chloride was added to the reaction system, and after the temperature was returned to room temperature, the reaction was continued for 2 h, and then the temperature was increased to 70°C and the reaction was continued for 12 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtering, and the intermediate I was obtained by removing the solvent by rotary evaporation under reduced pressure.

[0122] (2) Preparation of intermediate II

[0123] To 34.82 g of intermediate I and 30.36 g of triethylamine in 500 ml of dioxane, 46 g of phosphorus oxychloride was added dropwise under ice water bath condition. After the reaction was continued for 24 h at room temperature, the reaction mixture was filtered to remove the by-product triethylamine hydrochloride. The filtrate was evaporated under reduced pressure to give intermediate II.

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

[0125] To 11.76 g of intermediate II and 15.18 g of triethylamine in 300 ml of dioxane, 10.97 g of triethylenetetramine was added dropwise under ice water bath condition. After the reaction was continued for 24 h at room temperature, the reaction mixture was filtered, washed with water and dried. The filtrate was evaporated under reduced pressure to give product HBIR-2 in 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 subjected to 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak value δ (ppm) corresponds to the following: δ 2.62, 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 product HBIR-2.

[0129] Example 10

[0130] (1) Preparation of intermediate I

[0131] To 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine in 500 ml of tetrahydrofuran, 26.68 g of cyanuric chloride was added under ice water bath condition. After the reaction was continued for 2 h at room temperature and then for 12 h at 70 °C, the reaction mixture was filtered to remove the by-product triethylamine hydrochloride. The filtrate was evaporated under reduced pressure to give intermediate I.

[0132] (2) Preparation of intermediate II

[0133] To 34.82 g of intermediate I and 30.36 g of triethylamine in 500 ml of dioxane, 46 g of phosphorus oxychloride was added dropwise under ice water bath condition. After the reaction was continued for 24 h at room temperature, the reaction mixture was filtered to remove the by-product triethylamine hydrochloride. The filtrate was evaporated under reduced pressure to give intermediate II.

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

[0135] Add 11.76 g of intermediate product II and 15.18 g of triethylamine into 300 ml of dioxane, stir uniformly, slowly drop 9.87 g of triethylene tetramine under ice water bath condition, continue stirring for 24 h after recovering room temperature. After the reaction is finished, filter, wash with water, dry, and remove the solvent by rotary evaporation under reduced pressure to obtain product HBIR-2 with a yield of 91%.

[0136] Example 11

[0137] (1) Preparation of intermediate product I

[0138] Add 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine into 500 ml of tetrahydrofuran, stir uniformly under ice water bath condition, add 26.68 g of cyanuric chloride into the reaction system, recover room temperature to react for 2 h, and then heat to 70°C to continue to react for 12 h. After the reaction is finished, remove the by-product triethylamine hydrochloride by filtration, and remove the solvent by rotary evaporation under reduced pressure to obtain intermediate product I.

[0139] (2) Preparation of intermediate product II

[0140] Add 34.82 g of intermediate product I and 30.36 g of triethylamine into 500 ml of dioxane, stir uniformly, slowly drop 46 g of phosphorus oxychloride under ice water bath condition, continue stirring for 24 h after recovering room temperature. After the reaction is finished, remove the by-product triethylamine hydrochloride by filtration, and remove the solvent by rotary evaporation under reduced pressure to obtain intermediate product II.

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

[0142] Add 11.76 g of intermediate product II and 15.18 g of triethylamine into 300 ml of dioxane, stir uniformly, slowly drop 12.07 g of triethylene tetramine under ice water bath condition, continue stirring for 24 h after recovering room temperature. After the reaction is finished, filter, wash with water, dry, and remove the solvent by rotary evaporation under reduced pressure to obtain product HBIR-2 with a yield of 93%.

[0143] Example 12

[0144] (1) Preparation of intermediate product I

[0145] To 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine in 500 ml of tetrahydrofuran, 26.68 g of cyanuric chloride was added under stirring in an ice water bath. The reaction was continued at room temperature for 2 h and then at 70 °C for 12 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to give the intermediate product I.

[0146] (2) Preparation of the intermediate product II

[0147] To 34.82 g of the intermediate product I and 30.36 g of triethylamine in 500 ml of dioxane, 46 g of phosphorus oxychloride was added dropwise under stirring in an ice water bath. The reaction was continued at room temperature for 24 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to give the intermediate product II.

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

[0149] To 11.76 g of the intermediate product II and 15.18 g of triethylamine in 300 ml of dioxane, 14.20 g of tetraethylenepentamine was added dropwise under stirring in an ice water bath. The reaction was continued at room temperature for 24 h. After the reaction was completed, the product HBIR-3 was obtained by filtration, water washing and drying. The yield was 90%. The chemical structural formula of HBIR-3 is as follows:

[0150]

[0151] The product HBIR-3 prepared in this example was subjected to 1 H NMR (400 MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak value δ (ppm) corresponds to the following: δ 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-3.

[0152] Example 13

[0153] (1) Preparation of the intermediate product I

[0154] To 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine in 500 ml of tetrahydrofuran, 26.68 g of cyanuric chloride was added under stirring in an ice water bath. The reaction was continued at room temperature for 2 h and then at 70 °C for 12 h. After the reaction was completed, the by-product triethylamine hydrochloride was removed by filtration. The filtrate was concentrated by rotary evaporation to give the intermediate product I.

[0155] (2) Preparation of intermediate product II

[0156] Add 34.82 g of intermediate product I and 30.36 g of triethylamine into 500 ml of dioxane, and stir until uniform. Slowly add 46 g of phosphorus oxychloride dropwise under ice water bath conditions. Continue stirring for 24 h after the temperature is returned to room temperature. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration. The filtrate is subjected to rotary evaporation under reduced pressure to remove the solvent, and intermediate product II is obtained.

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

[0158] Add 11.76 g of intermediate product II and 15.18 g of triethylamine into 300 ml of dioxane, and stir until uniform. Slowly add 12.78 g of tetraethylenepentamine dropwise under ice water bath conditions. Continue stirring for 24 h after the temperature is returned to room temperature. After the reaction is completed, filter, wash with water, and dry. The product HBIR-3 is obtained after the solvent is removed by rotary evaporation under reduced pressure, with a yield of 92%.

[0159] Example 14

[0160] (1) Preparation of intermediate product I

[0161] Add 39.54 g of 3-amino-1,2-propanediol and 43.92 g of triethylamine into 500 ml of tetrahydrofuran, and stir until uniform under ice water bath conditions. Add 26.68 g of cyanuric chloride to the reaction system, and then return the temperature to room temperature and react for 2 h. Continue the reaction at 70°C for 12 h. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration. The filtrate is subjected to rotary evaporation under reduced pressure to remove the solvent, and intermediate product I is obtained.

[0162] (2) Preparation of intermediate product II

[0163] Add 34.82 g of intermediate product I and 30.36 g of triethylamine into 500 ml of dioxane, and stir until uniform. Slowly add 46 g of phosphorus oxychloride dropwise under ice water bath conditions. Continue stirring for 24 h after the temperature is returned to room temperature. After the reaction is completed, remove the by-product triethylamine hydrochloride by filtration. The filtrate is subjected to rotary evaporation under reduced pressure to remove the solvent, and intermediate product II is obtained.

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

[0165] Add 11.76 g of intermediate product II and 15.18 g of triethylamine into 300 ml of dioxane, and stir until uniform. Slowly add 15.62 g of tetraethylenepentamine dropwise under ice water bath conditions. Continue stirring for 24 h after the temperature is returned to room temperature. After the reaction is completed, filter, wash with water, and dry. The product HBIR-3 is obtained after the solvent is removed by rotary evaporation under reduced pressure, with a yield of 91%.

[0166] Example 15

[0167] (1) Preparation of intermediate product I

[0168] Put 39.54g 3-amino-1,2-propanediol and 43.92g triethylamine into 500ml tetrahydrofuran, stir uniformly under ice water bath condition, put 26.68g cyanuric chloride into the reaction system, restore room temperature and react for 2h, then heat to 70°C and continue to react for 12h. Filter out by-product triethylamine hydrochloride after the reaction is completed, remove the solvent by rotary evaporation under reduced pressure, and intermediate product I can be obtained.

[0169] (2) Preparation of intermediate product II

[0170] Put 34.82g intermediate product I and 30.36g triethylamine into 500ml dioxane, stir uniformly, slowly drop 46g phosphorus oxychloride under ice water bath condition, continue to stir for 24h after restoring room temperature. Filter out by-product triethylamine hydrochloride after the reaction is completed, remove the solvent by rotary evaporation under reduced pressure, and intermediate product II can be obtained.

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

[0172] Put 11.76g intermediate product II and 15.18g triethylamine into 300ml dioxane, stir uniformly, slowly drop 17.43g pentaethylenehexamine under ice water bath condition, continue to stir for 24h after restoring room temperature. Filter, wash with water, dry, remove the solvent by rotary evaporation under reduced pressure, and product HBIR-4 can be obtained, with a yield of 90%. The chemical structural formula of HBIR-4 is as follows:

[0173]

[0174] Put product HBIR-4 prepared in this example into 1 H NMR (400MHz, DMSO-d6) nuclear magnetic spectrum analysis. The peak value 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 product HBIR-4.

[0175] Example 16

[0176] (1) Preparation of intermediate product I

[0177] To 39.54g 3-amino-1,2-propanediol, 43.92g triethylamine in 500ml tetrahydrofuran, stir well under ice water bath, add 26.68g cyanuric chloride to the reaction system, then restore room temperature and react for 2h, then heat to 70°C and continue to react for 12h. After the reaction, remove the by-product triethylamine hydrochloride by filtration, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain the intermediate product I.

[0178] (2) Preparation of intermediate product II

[0179] To 34.82g intermediate product I and 30.36g triethylamine in 500ml dioxane, stir well, slowly add 46g phosphorus oxychloride dropwise under ice water bath, continue to stir for 24h after restoring room temperature. After the reaction, remove the by-product triethylamine hydrochloride by filtration, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain the intermediate product II.

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

[0181] To 11.76g intermediate product II and 15.18g triethylamine in 300ml dioxane, stir well, slowly add 15.69g pentaethylenehexamine dropwise under ice water bath, continue to stir for 24h after restoring room temperature. After the reaction, filter, wash with water, dry, and remove the solvent by rotary evaporation under reduced pressure to obtain the product HBIR-4, with a yield of 94%.

[0182] Example 17

[0183] (1) Preparation of intermediate product I

[0184] To 39.54g 3-amino-1,2-propanediol, 43.92g triethylamine in 500ml tetrahydrofuran, stir well under ice water bath, add 26.68g cyanuric chloride to the reaction system, then restore room temperature and react for 2h, then heat to 70°C and continue to react for 12h. After the reaction, remove the by-product triethylamine hydrochloride by filtration, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain the intermediate product I.

[0185] (2) Preparation of intermediate product II

[0186] To 34.82g intermediate product I and 30.36g triethylamine in 500ml dioxane, stir well, slowly add 46g phosphorus oxychloride dropwise under ice water bath, continue to stir for 24h after restoring room temperature. After the reaction, remove the by-product triethylamine hydrochloride by filtration, and remove the solvent from the filtrate by rotary evaporation under reduced pressure to obtain the intermediate product II.

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

[0188] The intermediate product II 11.76 g and triethylamine 15.18 g were added into 300 ml dioxane and stirred to homogeneity. Then, pentaethylenehexamine 19.17 g was added dropwise slowly under ice-water bath. After the reaction mixture was stirred for 24 h at room temperature, the product HBIR-4 was obtained by filtration, water washing and drying. The yield was 92%.

[0189] Example 18

[0190] 1) The epoxy resin 75 g, the DDM curing agent 19 g and the HBIR-1 flame retardant 5.0 g were weighed;

[0191] 2) The flame retardant was added into the epoxy resin at 110 °C, stirred to homogeneity and vacuumed to remove the bubbles to obtain a primary mixture;

[0192] 3) The curing agent was added into the primary mixture at 110 °C, stirred rapidly to dissolve the curing agent into a homogeneous system to obtain a secondary mixture;

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

[0194] Example 19

[0195] The difference between the application example and Example 18 was that the HBIR-2 flame retardant 5.0 g was added in the application example, and the other conditions were the same as those in Example 18, which were not repeated here.

[0196] Example 20

[0197] The difference between the application example and Example 18 was that the HBIR-3 flame retardant 5.0 g was added in the application example, and the other conditions were the same as those in Example 18, which were not repeated here.

[0198] Example 21

[0199] The difference between the application example and Example 18 was that the HBIR-4 flame retardant 5.0 g was added in the application example, and the other conditions were the same as those in Example 18, which were not repeated here.

[0200] Comparative Example 1

[0201] 1) The epoxy resin 75 g and the DDM curing agent 19 g were weighed;

[0202] 2) The curing agent was added into the primary mixture at 110 °C, stirred rapidly to dissolve the curing agent into a homogeneous system to obtain a mixture;

[0203] 3) Inject the mixture into the mold, place it in the oven, first control the heating temperature to 80℃ and cure for 2 hours, then control the heating temperature to 150℃ and cure for 6 hours. After curing, let it cool naturally to room temperature to obtain flame-retardant modified epoxy resin.

[0204] Comparative Example 2

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

[0206] Performance testing:

[0207] The epoxy resins modified with flame retardants obtained in Examples 18-21 and Comparative Examples 1-2 were subjected to LOI (Lack of Opposition Intake) and UL-94 vertical burning tests. The results are shown in Table 1. The LOI test was conducted according to ASTM D2863-19 standard, with sample dimensions of 130 × 6.5 × 3 mm. 2 The UL-94 vertical burning test was conducted according to GB / T2408-2008 standard, with sample dimensions of 130×13×3mm. 2 .

[0208] The results showed that all EP composites modified with hyperbranched intumescent flame retardants achieved an LOI greater than 38% and passed the UL-94V0 rating. Furthermore, the flame retardant performance of the flame retardant with curing unit amine groups showed no significant difference compared to the non-reactive curing agent. This indicates that the triazine structure and phosphorus element play a decisive role in the flame retardant performance of the hyperbranched intumescent flame retardant. The triazine structure releases inert gases at high temperatures, which, combined with the polyphosphoric acid generated from the decomposition of phosphorus, catalyzes the char formation of the polymer matrix, forming an expanded char layer that prevents heat and mass exchange, thus achieving excellent flame retardant performance.

[0209] Table 1 Flame retardant performance test results

[0210]

[0211]

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

[0213] To evaluate the effect of HBIR on the mechanical properties of EP composites, the toughness of EP-HBIR was first studied using impact tests. Figure 1 As shown, the impact strength of EP / HBIR is 10 kJ / m², which is higher than that of pure EP. -2EP / HBIR-0, EP / HBIR-1, EP / HBIR-2, EP / HBIR-3 and EP / HBIR-4 are 14, 25, 27, 28 and 31 kJ m -2 Particularly, the impact strength of EP / HBIR-4 is 3 times of pure EP, and 2.2 times of EP / HBIR-0, and the tensile strength and flexural strength also have similar trends. The results show that compared with EP, the EP composite modified by hyperbranched intumescent flame retardant realizes the enhancement of mechanical properties, and the flame retardant with amine group curing unit has more significant enhancement of mechanical properties than the non-reactive curing agent.

[0214] In summary, the hyperbranched intumescent flame retardant has significant flame-retardant and reinforcing effect, wherein the hyperbranched structure can enhance the mechanical properties of the EP composite, and the reactive flame retardant can further enhance the mechanical properties of the polymer matrix by improving the EP curing crosslinking network.

[0215] The preferred embodiments of the present application have been described above with the aid of drawings, but the present application is not limited to the above examples, and various modifications and changes can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hyperbranched intumescent flame retardant characterized by: The structural formula is shown as follows: ， Wherein, n, m, p are integers.

2. The process for the preparation of hyperbranched intumescent flame retardant according to claim 1, characterized by the fact that: The method comprises the following steps: 3-amino-1, 2-propanediol and triethylamine are added into tetrahydrofuran in proportion, mixed, and cyanuric chloride is added at-3~3℃, mixed, then warmed to 65~75℃ for 12-18h to obtain intermediate product I; Intermediate product I and triethylamine are added into a first solvent in proportion, mixed, then phosphorus oxychloride is added at-3~3℃, warmed to 20-40℃, and reacted for a set time to obtain intermediate product II; Intermediate product II and triethylamine are added into a second solvent in proportion, mixed, then organic polyamine is added at-3~3℃, warmed to 20-40℃, and reacted for a set time to obtain the hyperbranched intumescent flame retardant.

3. The method for preparing the hyperbranched intumescent flame retardant according to claim 2, characterized in that: The molar ratio of 3-amino-1, 2-propanediol and cyanuric chloride is 3-5:

1.

4. The method for preparing the hyperbranched intumescent flame retardant according to claim 2, characterized in that: In the preparation of intermediate product I, the molar ratio of 3-amino-1, 2-propanediol and triethylamine is 1:1-1.1; In the preparation of intermediate product II, the molar ratio of intermediate product I and triethylamine is 1:1-1.1; In the preparation of the hyperbranched intumescent flame retardant, the molar ratio of intermediate product II and triethylamine is 1:1-1.

1.

5. The method for preparing the hyperbranched intumescent flame retardant according to claim 2, characterized in that: The organic polyamine is any one or mixture of five ethylene hexamine, tetraethylene pentamine, triethylene tetramine, diethylene triamine, and ethylene diamine.

6. A process for the preparation of a flame-retardant modified epoxy resin, characterized in that: The method comprises the following steps: The epoxy resin matrix is heated to 100-115℃, then the flame retardant is added into the epoxy resin, mixed, and vacuumized to remove bubbles to obtain a primary mixture; the flame retardant is the hyperbranched intumescent flame retardant of claim 1; The curing agent is added into the primary mixture, mixed to obtain a secondary mixture.

7. The method of preparing a flame-retardant modified epoxy resin according to claim 6, characterized in that: The process further comprises injecting the flame-retardant modified epoxy resin into a mold to prepare a target component; The method for heating and curing the target component is: first heated and cured at 80-100℃ for 1-3h, then heated and cured at 140-150℃ for 4-8h.

8. The application of the flame-retardant modified epoxy resin prepared by the preparation method of claim 6 or 7 in the fields of electric power, textile, building, and transportation.

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