Titanium dioxide / epoxy resin composite material with fire warning function and preparation method and application thereof

Abstract

The application discloses a titanium dioxide / epoxy resin composite material with a fire early warning function and a preparation method and application thereof, and is composed of core-shell structure titanium dioxide nanoparticles and an epoxy resin; the core-shell structure titanium dioxide nanoparticles take nanometer titanium dioxide as a core and a phosphorus-containing polymer as a shell; the epoxy resin is bisphenol A type epoxy resin E51, the adding amount of the core-shell structure titanium dioxide nanoparticles is 2-15 wt% of the epoxy resin; and the phosphorus-containing polymer is formed by the reaction and polymerization of a first compound and a second compound. The core-shell structure titanium dioxide nanoparticles have the functions of flame retardation, mechanical reinforcement, ultraviolet shielding and fire early warning, can simultaneously endow the epoxy resin with good flame retardation, mechanical reinforcement, ultraviolet shielding and fire early warning performance, and provide a feasible idea for solving the problems of mechanical strength reduction, poor dispersibility, complicated steps and poor fire early warning performance in the preparation process of the multifunctional epoxy resin.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hybrid nanomaterials, and particularly relates to a titanium dioxide / epoxy resin composite material with fire warning function and a preparation method and application thereof. BACKGROUND

[0002] In today's society, fire has caused serious threat to people's life and property safety, and the upgrading of traditional industries and the development of strategic emerging industries have put forward higher demands for fire warning materials with fire retardant function. Among them, adding inorganic nanoparticles with light, heat, magnetic and other functions to the flame-retardant polymer matrix is an important way to endow the flame-retardant polymer matrix with fire warning performance. However, the multi-step addition of additives in the preparation process of the flame-retardant polymer composite material with fire warning performance makes the preparation of the flame-retardant polymer composite material with fire warning performance very cumbersome. At the same time, the poor compatibility between inorganic nanoparticles and the matrix also seriously affects the fire warning performance of the polymer composite material. Therefore, the preparation of the flame-retardant polymer composite material with fire warning performance still has many challenges.

[0003] It is a new research trend in the development of fire warning materials to integrate the organic components with flame retardance and good dispersibility with inorganic nanoparticles with electrical and thermal functions at the microscale to realize single addition to endow the polymer material with fire warning performance. Traditional fire warning materials can usually only provide monitoring and alarm functions after fire occurs. SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provide a titanium dioxide / epoxy resin composite material with fire warning function.

[0005] Another object of the present application is to provide a preparation method of the titanium dioxide / epoxy resin composite material.

[0006] Still another object of the present application is to provide the application of the titanium dioxide / epoxy resin composite material prepared by the preparation method.

[0007] The specific principle of the present application is as follows:

[0008] When the titanium dioxide / epoxy resin composite material is subjected to high temperature or suffers from flame burning, the titanium dioxide in the core-shell structure titanium dioxide nanoparticles can catalyze the hydroxyl groups on the borate ester on the surface to react with the epoxy resin at high temperature, rapidly remove the oxygen-containing groups on the surface of the epoxy resin, and reduce to a polymer with excellent electrical conductivity.

[0009] In addition, when the temperature is high or the material is subjected to burning, the phosphorus-containing polymer in the core-shell structure titanium dioxide nanoparticles decomposes first to produce some phosphorus-containing acid, which promotes the carbonization of the polymer matrix to form a carbon layer, which makes the contact between the reduced polymers more close, further reducing the resistance.

[0010] In addition, the remaining titanium dioxide nanoparticles are also uniformly dispersed in the carbon layer. Since titanium dioxide is a wide-band semiconductor material, its electrical conductivity increases rapidly with temperature. In the presence of boric acid ester, the electrical conductivity of titanium dioxide increases further after losing a small amount of oxygen, thereby reducing the resistance in the circuit.

[0011] The above three mechanisms together cause a sharp rise in current in the circuit, triggering a fire alarm.

[0012] The technical solution of the present application is as follows:

[0013] A titanium dioxide / epoxy resin composite material with a fire warning function is composed of core-shell structure titanium dioxide nanoparticles with a particle size of 50-200 nm and epoxy resin; the core-shell structure titanium dioxide nanoparticles have titanium dioxide as the core and a phosphorus-containing polymer as the shell;

[0014] The epoxy resin is bisphenol A type epoxy resin E51, and the amount of the core-shell structure titanium dioxide nanoparticles added is 2-15 wt% of the epoxy resin; the phosphorus-containing polymer is obtained by the reaction and polymerization of a first compound and a second compound, wherein:

[0015] The first compound is selected from

[0016]

[0017] The second compound is selected from

[0018] The preparation method of the above-mentioned titanium dioxide / epoxy resin composite material is characterized by comprising the following steps:

[0019] (1) The epoxy resin and the core-shell structure titanium dioxide nanoparticles are stirred and mixed uniformly;

[0020] (2) The curing agent corresponding to the epoxy resin is added to the material obtained in step (1), and the mixture is stirred and mixed uniformly;

[0021] (3) The material obtained in step (2) is cured in a mold, then cooled to room temperature, and demolded to obtain the product;

[0022] The preparation method of the core-shell structure titanium dioxide nanoparticles comprises the following steps:

[0023] A. dispersing the nanometer titanium dioxide, the first compound and the second compound in organic solvents respectively to obtain a titanium dioxide dispersion, a first compound solution and a second compound solution;

[0024] B. adding the first compound solution to the titanium dioxide dispersion and stirring at room temperature for 1-3 hours;

[0025] C. adding the second compound solution to the material obtained in step B and stirring at room temperature for 1-3 hours;

[0026] D. performing solid-liquid separation on the material obtained in step C, and drying the obtained solid to obtain the core-shell structure titanium dioxide nanoparticles;

[0027] The volume ratio of the titanium dioxide dispersion, the first compound solution and the second compound solution is 5-10:5-10:5-10.

[0028] In a preferred embodiment of the present application, the particle size of the nanometer titanium dioxide is 50-200 nm.

[0029] In a preferred embodiment of the present application, the concentration of the titanium dioxide dispersion is 0.5-10 mg / mL.

[0030] In a preferred embodiment of the present application, the concentration of the first compound solution is 1-20 mg / mL.

[0031] In a preferred embodiment of the present application, the concentration of the second compound solution is 1-20 mg / mL.

[0032] In a preferred embodiment of the present application, the organic solvent is ethanol, methanol, dichloromethane, trichloromethane or ethyl acetate.

[0033] In a preferred embodiment of the present application, the particle size of the nanometer titanium dioxide is 50-200 nm, the concentration of the titanium dioxide dispersion is 0.5-10 mg / mL, the concentration of the first compound solution is 1-20 mg / mL, the concentration of the second compound solution is 1-20 mg / mL, and the organic solvent is ethanol, methanol, dichloromethane, trichloromethane or ethyl acetate.

[0034] The application of the titanium dioxide / epoxy resin composite material in preparing a fire warning device.

[0035] A fire warning device comprising the titanium dioxide / epoxy resin composite material and a fire alarm mechanism electrically connected to the titanium dioxide / epoxy resin composite material.

[0036] The present application has the following advantages:

[0037] 1. The preparation method of the present invention is simple to operate, has mild reaction conditions, short cycle, easy post-processing, and is easy to control.

[0038] 2. The core-shell structured titanium dioxide nanoparticles in this invention have a single and stable particle size, regular morphology, and good compatibility with epoxy resin.

[0039] 3. The core-shell structured titanium dioxide nanoparticles in this invention have functions such as flame retardancy, mechanical reinforcement, ultraviolet shielding, and fire warning. They can simultaneously endow epoxy resin with good flame retardancy, mechanical reinforcement, ultraviolet shielding, and fire warning performance, providing a feasible solution to the problems of reduced mechanical strength, poor dispersibility, cumbersome steps, and poor fire warning performance in the preparation of multifunctional epoxy resins.

[0040] 4. The core-shell structured titanium dioxide nanoparticles in this invention can combine the nano-titanium dioxide core with phosphorus-containing polymers at the nanoscale and exert a synergistic effect. This enables fire warning materials with flame-retardant functions to effectively suppress and warn of fires in the early stages, thereby greatly reducing the losses caused by fires. Attached Figure Description

[0041] Figure 1 The infrared spectrum is shown for the core-shell structured titanium dioxide nanoparticles (TiO2@FR) prepared in Example 1 of this invention.

[0042] Figure 2 The image shows the XRD pattern of the core-shell structured titanium dioxide nanoparticles (TiO2@FR) prepared in Example 2 of this invention.

[0043] Figure 3 This is a transmission electron microscope (TEM) image of the core-shell structured titanium dioxide nanoparticles (TiO2@FR) prepared in Example 5 of this invention. Detailed Implementation

[0044] The technical solution of the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings.

[0045] In the following embodiments:

[0046] The structural formula of A is:

[0047] The structural formula of B is:

[0048] The structural formula of C is

[0049] The structural formula of D is:

[0050] The structural formula of E is:

[0051] Example 1

[0052] The preparation of the core-shell structured titanium dioxide nanoparticles of this example is as follows:

[0053] (1) Nanometer titanium dioxide with a particle size of 200 nm was ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titanium dioxide dispersion; A and D were each dissolved in anhydrous ethanol to obtain A and D solutions each with a concentration of 1 mg / mL.

[0054] (2) 10 mL of the 1 mg / mL A solution was added to the material prepared in step (1), and the reaction was stirred at room temperature for 2 h.

[0055] (3) 10 mL of the 1 mg / mL D solution was added to the material prepared in step (2), and the reaction was stirred at room temperature for 2 h.

[0056] (4) The unreacted raw materials were removed by centrifugation, and washed twice with anhydrous ethanol.

[0057] (5) After the reaction was completed, the solid and liquid were separated, and the solid was dried to obtain the core-shell structured titanium dioxide nanoparticles. Figure 1 The FTIR spectrum of the core-shell structured titanium dioxide nanoparticles of this example is shown in Figure 1.

[0058] The preparation of the titanium dioxide / epoxy resin composite material of this example is as follows:

[0059] (1) 100 parts by weight of an epoxy resin and 5 parts by weight of the core-shell structured titanium dioxide nanoparticles prepared in this example were mixed uniformly at 100°C under stirring;

[0060] (2) In the material prepared in step (1), 25 parts by weight of a curing agent (DDM) was added, and the mixture was uniformly stirred at 100°C to obtain a uniform solution;

[0061] (3) The material prepared in step (2) was poured into a specific mold that had been preheated, and cured at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0062] (4) After the curing was completed, the temperature was lowered to room temperature, the mold was removed, and the titanium dioxide / epoxy resin composite material was obtained. The test results are shown in Table 1.

[0063] Example 2

[0064] The preparation of the core-shell structured titanium dioxide nanoparticles of this example is as follows:

[0065] (1) The nano-titania with a particle size of 200 nm was ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titania dispersion solution; B and D were respectively dissolved in anhydrous ethanol to obtain a 1 mg / mL B solution and a 1 mg / mL D solution.

[0066] (2) 10 mL of the 1 mg / mL B solution was added to the material prepared in step (1), and the reaction was stirred at room temperature for 2 h.

[0067] (3) 10 mL of the 1 mg / mL D solution was added to the material prepared in step (2), and the reaction was stirred at room temperature for 2 h.

[0068] (4) The unreacted raw materials were removed by centrifugation, and washed twice with anhydrous ethanol.

[0069] (5) After the reaction was completed, the solid and liquid were separated, and the solid was dried to obtain the core-shell structure titania nanoparticles. Figure 2 The XRD spectrum of the core-shell structure titania nanoparticles of this example is shown in Figure 1.

[0070] The preparation of the titania / epoxy resin composite material of this example is as follows:

[0071] (1) 100 parts by weight of the epoxy resin and 5 parts by weight of the core-shell structure titania nanoparticles prepared in this example were stirred and mixed uniformly at 100°C;

[0072] (2) In the material prepared in step (1), 25 parts by weight of a curing agent (DDM) was added, and the mixture was stirred and mixed uniformly at 100°C to obtain a uniform solution;

[0073] (3) The material prepared in step (2) was poured into a specific mold which had been preheated, and cured at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0074] (4) After the curing was completed, the temperature was lowered to room temperature, and the mold was removed to obtain the titania / epoxy resin composite material. The test results are shown in Table 1.

[0075] Example 3

[0076] The preparation of the core-shell structure titania nanoparticles of this example is as follows:

[0077] (1) The nano-titania with a particle size of 200 nm was ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titania dispersion solution; C and D were respectively dissolved in anhydrous ethanol to obtain a 1 mg / mL C solution and a 1 mg / mL D solution.

[0078] (2) In the material prepared in step (1), 10 mL of 1 mg / mL solution of C was added, and the reaction was stirred at room temperature for 2 h.

[0079] (3) In the material prepared in step (2), 10 mL of 1 mg / mL solution of D was added, and the reaction was stirred at room temperature for 2 h.

[0080] (4) The unreacted raw materials were removed by centrifugation, and washed twice with anhydrous ethanol.

[0081] (5) After the reaction was completed, the solid and liquid were separated, and the solid part was dried to obtain the core-shell structured titanium dioxide nanoparticles.

[0082] The preparation of the titanium dioxide / epoxy resin composite material of the present embodiment is as follows:

[0083] (1) 100 parts by weight of epoxy resin and 5 parts by weight of the core-shell structured titanium dioxide nanoparticles prepared in the present embodiment were uniformly mixed by stirring at 100°C;

[0084] (2) In the material prepared in step (1), 25 parts by weight of a curing agent (DDM) was added, and the mixture was uniformly stirred at 100°C to obtain a uniform solution;

[0085] (3) The material prepared in step (2) was poured into a specific mold which had been preheated, and cured at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0086] (4) After the curing was completed, the temperature was lowered to room temperature, and the mold was removed to obtain the titanium dioxide / epoxy resin composite material. The test results are shown in Table 1.

[0087] Example 4

[0088] The preparation of the core-shell structured titanium dioxide nanoparticles of the present embodiment is as follows:

[0089] (1) Nanometer titanium dioxide with a particle size of 200 nm was ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titanium dioxide dispersion solution; A and E were dissolved in anhydrous ethanol to obtain A solution and E solution with a concentration of 1 mg / mL.

[0090] (2) In the material prepared in step (1), 10 mL of 1 mg / mL solution of A was added, and the reaction was stirred at room temperature for 2 h.

[0091] (3) In the material prepared in step (2), 10 mL of 1 mg / mL solution of E was added, and the reaction was stirred at room temperature for 2 h.

[0092] (4) The unreacted raw materials were removed by centrifugation, and washed twice with anhydrous ethanol.

[0093] (5) After the reaction is completed, solid-liquid separation is performed, and the solid part is dried to obtain the core-shell structured titanium dioxide nanoparticles.

[0094] The preparation of the titanium dioxide / epoxy resin composite material of the present example is as follows:

[0095] (1) 100 parts by weight of epoxy resin and 5 parts by weight of the core-shell structured titanium dioxide nanoparticles prepared in the present example are uniformly mixed by stirring at 100°C;

[0096] (2) 25 parts by weight of a curing agent (DDM) is added to the material prepared in step (1), and the mixture is uniformly stirred at 100°C to obtain a uniform solution;

[0097] (3) The material prepared in step (2) is poured into a specific mold that has been preheated, and cured at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0098] (4) After the curing is completed, the temperature is lowered to room temperature, and the mold is removed to obtain the titanium dioxide / epoxy resin composite material. The test results are shown in Table 1.

[0099] Example 5

[0100] The preparation of the core-shell structured titanium dioxide nanoparticles of the present example is as follows:

[0101] (1) Nanometer titanium dioxide with a particle size of 150 nm is ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titanium dioxide dispersion solution; A and D are separately dissolved in anhydrous ethanol to obtain A and D solutions with a concentration of 1 mg / mL.

[0102] (2) 10 mL of the 1 mg / mL A solution is added to the material prepared in step (1), and the mixture is stirred at room temperature for 2 h.

[0103] (3) 10 mL of the 1 mg / mL D solution is added to the material prepared in step (2), and the mixture is stirred at room temperature for 2 h.

[0104] (4) The unreacted raw materials are removed by centrifugation, and the material is washed twice with anhydrous ethanol.

[0105] (5) After the reaction is completed, solid-liquid separation is performed, and the solid part is dried to obtain the core-shell structured titanium dioxide nanoparticles as shown in Figure 3 .

[0106] The preparation of the titanium dioxide / epoxy resin composite material of the present example is as follows:

[0107] (1) 100 parts by weight of epoxy resin and 10 parts by weight of the core-shell structured titanium dioxide nanoparticles prepared in this example were mixed uniformly under stirring at 100°C;

[0108] (2) 25 parts by weight of a curing agent (DDM) was added to the material prepared in step (1), and the mixture was mixed uniformly under mechanical stirring at 100°C until a uniform solution was obtained;

[0109] (3) The material prepared in step (2) was poured into a specific mold which had been preheated, and cured at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0110] (4) After curing was completed, the temperature was lowered to room temperature, the mold was removed, and a titanium dioxide / epoxy resin composite material was obtained. The test results are shown in Table 1.

[0111] Example 6

[0112] The preparation of the core-shell structured titanium dioxide nanoparticles of this example was as follows:

[0113] (1) Nanometer titanium dioxide with a particle size of 150 nm was ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titanium dioxide dispersion; A and D were separately dissolved in anhydrous ethanol to obtain A solution and D solution, both with a concentration of 1 mg / mL.

[0114] (2) 10 mL of 1 mg / mL A solution was added to the material prepared in step (1), and the reaction was stirred at room temperature for 2 h.

[0115] (3) 10 mL of 1 mg / mL D solution was added to the material prepared in step (2), and the reaction was stirred at room temperature for 2 h.

[0116] (4) The unreacted raw materials were removed by centrifugation, and washed twice with anhydrous ethanol.

[0117] (5) After the reaction was completed, the solid and liquid were separated, and the solid part was dried to obtain the core-shell structured titanium dioxide nanoparticles.

[0118] The preparation of the titanium dioxide / epoxy resin composite material of this example was as follows:

[0119] (1) 100 parts by weight of epoxy resin and 15 parts by weight of the core-shell structured titanium dioxide nanoparticles prepared in this example were mixed uniformly under stirring at 100°C;

[0120] (2) 25 parts by weight of a curing agent (DDM) was added to the material prepared in step (1), and the mixture was mixed uniformly under mechanical stirring at 100°C until a uniform solution was obtained;

[0121] (3) Pour the material prepared in step (2) into a specific mold which has been preheated, and cure at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0122] (4) After the completion of curing, cool to room temperature, demold, and obtain the titanium dioxide / epoxy resin composite material. The test results are shown in Table 1.

[0123] Example 7

[0124] The preparation of the core-shell structure titanium dioxide nanoparticles of the present example is as follows:

[0125] (1) Ultrasonically disperse 200 nm-sized nanometer titanium dioxide in 10 mL of anhydrous ethanol to obtain a 1 mg / mL titanium dioxide dispersion; dissolve A and D in anhydrous ethanol to obtain A solution and D solution, both having a concentration of 10 mg / mL.

[0126] (2) Add 5 mL of 10 mg / mL A solution to the material prepared in step (1), and stir at room temperature for 2 h.

[0127] (3) Add 5 mL of 10 mg / mL D solution to the material prepared in step (2), and stir at room temperature for 2 h.

[0128] (4) Centrifuge to remove unreacted raw materials, and wash twice with anhydrous ethanol.

[0129] (5) After the completion of the reaction, separate the solid and liquid, and dry the solid part to obtain the core-shell structure titanium dioxide nanoparticles.

[0130] The preparation of the titanium dioxide / epoxy resin composite material of the present example is as follows:

[0131] (1) Stir and mix 100 parts by weight of epoxy resin and 5 parts by weight of the core-shell structure titanium dioxide nanoparticles prepared in the present example at 100°C until uniform;

[0132] (2) Add 25 parts by weight of a curing agent (DDM) to the material prepared in step (1), and stir and mix mechanically at 100°C until a uniform solution is obtained;

[0133] (3) Pour the material prepared in step (2) into a specific mold which has been preheated, and cure at 120°C for 4 h, at 140°C for 2 h, and at 180°C for 2 h.

[0134] (4) After the completion of curing, cool to room temperature, demold, and obtain the titanium dioxide / epoxy resin composite material. The test results are shown in Table 1.

[0135] Example 8

[0136] The preparation of the core-shell structured titanium dioxide nanoparticles in this embodiment is as follows:

[0137] (1) Nano-sized titanium dioxide with a particle size of 150 nm was ultrasonically dispersed in 10 mL of anhydrous ethanol to obtain a titanium dioxide dispersion with a concentration of 1 mg / mL; A and D were dissolved in anhydrous ethanol to obtain solutions A and D with a concentration of 20 mg / mL, respectively.

[0138] (2) Add 5 mL of 20 mg / mL solution A to the material obtained in step (1) and stir at room temperature for 2 h.

[0139] (3) Add 5 mL of 20 mg / mL D solution to the material obtained in step (2) and stir at room temperature for 2 h.

[0140] (4) Centrifuge to remove unreacted raw materials and wash twice with anhydrous ethanol.

[0141] (5) After the reaction is completed, the solid and liquid are separated, and the solid part is dried to obtain the core-shell structured titanium dioxide nanoparticles.

[0142] The preparation of the titanium dioxide / epoxy resin composite material in this embodiment is as follows:

[0143] (1) 100 parts by weight of epoxy resin and 15 parts by weight of core-shell structured titanium dioxide nanoparticles prepared in this embodiment were stirred and mixed evenly at 100°C.

[0144] (2) Add 25 parts by weight of curing agent (DDM) to the material obtained in step (1) and mix it evenly by mechanical stirring at 100°C until a homogeneous solution is obtained;

[0145] (3) Pour the material obtained in step (2) into a preheated mold and cure at 120°C for 4 hours, 140°C for 2 hours, and 180°C for 2 hours.

[0146] (4) After curing, the temperature was lowered to room temperature and the material was demolded to obtain the titanium dioxide / epoxy resin composite material. The test results are shown in Table 1.

[0147] Comparative Example 1

[0148] 100 parts by weight of epoxy resin and 25 parts by weight of DDM were mechanically mixed at 100°C until homogeneous. The resulting material was poured into a preheated mold and cured at 160°C for 2 hours. After curing, the mixture was slowly cooled to room temperature and demolded to obtain the reference epoxy resin. The test results are shown in Table 1.

[0149] The above nano-titanium dioxide particles make the titanium dioxide / epoxy resin composite quickly lose oxygen-containing groups at high temperature or when subjected to flame burning, thus reducing its resistance. The titanium dioxide / epoxy resin composite with fire warning function is used as a fire-retardant coating and connected to a connecting circuit. When the fire-retardant coating burns, the decrease of the resistance of the mixed titanium dioxide / epoxy resin composite therein causes a sharp rise of the current in the connecting circuit, thus triggering the fire alarm mechanism (the fire alarm mechanism, the titanium dioxide / epoxy resin composite prepared in the above examples in the fire-retardant coating and the connecting circuit together constitute a fire warning device). Based on the above principle, the fire warning time of Examples 1-8 and Comparative Example 1 is measured, and the test results are shown in Table 1.

[0150] Table 1 Fire-retardant, mechanical reinforcing, ultraviolet shielding and fire warning properties of the epoxy resin compositions prepared in the above examples and comparative example

[0151]

[0152]

[0153] The above description is only the preferred embodiments of the present application, and thus cannot limit the scope of the present application. Any equivalent changes and modifications made according to the scope of the present patent and the content of the specification should still fall within the scope of the present application.

Claims

1. A titanium dioxide / epoxy resin composite material having a fire warning function, characterized by: The titanium dioxide / epoxy resin composite is composed of core-shell structure titanium dioxide nanoparticles with a particle size of 50-200 nm and an epoxy resin; the core-shell structure titanium dioxide nanoparticles have nano-titanium dioxide as a core and a phosphorus-containing polymer as a shell; The epoxy resin is bisphenol A type epoxy resin E51, and the addition amount of the core-shell structure titanium dioxide nanoparticles is 2-15 wt% of the epoxy resin; the phosphorus-containing polymer is obtained by reaction polymerization of a first compound and a second compound, wherein: The first compound is selected from , and ; The second compound is selected from and ; When the titanium dioxide / epoxy resin composite is subjected to high temperature or suffers from flame burning, the titanium dioxide in the core-shell structure titanium dioxide nanoparticles can catalyze the hydroxyl groups on the borate ester on the surface to react with the epoxy resin at high temperature, rapidly remove the oxygen-containing groups on the surface of the epoxy resin, and reduce to a polymer with excellent electrical conductivity; at the same time, the phosphorus-containing polymer in the core-shell structure nano-titanium dioxide particles decomposes first to generate phosphorus-containing acid, promotes the carbonization of the polymer matrix to form a carbon layer, makes the reduced polymers contact more closely, and further reduces the resistance; and the remaining nano-titanium dioxide is also uniformly dispersed in the carbon layer, and since nano-titanium dioxide is a wide-band semiconductor material, its electrical conductivity rapidly increases with the increase of temperature, and under the synergistic effect of high temperature and borate ester, the electrical conductivity of titanium dioxide further increases after losing a small amount of oxygen, thereby reducing the resistance in the circuit; the above three mechanisms jointly cause the sharp rise of current in the circuit, thereby triggering the fire alarm.

2. The method of producing the titanium dioxide / epoxy resin composite material according to claim 1, characterized by: The method comprises the following steps: (1) uniformly stirring and mixing the epoxy resin and the core-shell structure titanium dioxide nanoparticles; (2) uniformly stirring and mixing the epoxy resin corresponding curing agent in the material obtained in step (1); (3) curing the material obtained in step (2) in a mold, then cooling to room temperature, demolding, and obtaining the titanium dioxide / epoxy resin composite; The preparation method of the core-shell structure titanium dioxide nanoparticles comprises the following steps: A. uniformly dispersing the nano-titanium dioxide, the first compound and the second compound in an organic solvent respectively to obtain a titanium dioxide dispersion, a first compound solution and a second compound solution; B. adding the first compound solution to the titanium dioxide dispersion, and stirring and reacting at room temperature for 1-3 h; C. adding the second compound solution to the material obtained in step B, and stirring and reacting at room temperature for 1-3 h; D. performing solid-liquid separation on the material obtained in step C, and drying the obtained solid to obtain the core-shell structure titanium dioxide nanoparticles; The volume ratio of the titanium dioxide dispersion, the first compound solution and the second compound solution is 5-10: 5-10: 5-10.

3. The production method according to claim 2, characterized by: The particle size of the nano-titanium dioxide is 50-200 nm.

4. The production method according to claim 2, characterized by: The concentration of the titanium dioxide dispersion is 0.5-10 mg / mL.

5. The production method according to claim 2, wherein: The concentration of the first compound solution is 1-20 mg / mL.

6. The production method according to claim 2, wherein: The concentration of the second compound solution is 1-20 mg / mL.

7. The production method according to claim 2, wherein: The organic solvent is ethanol, methanol, dichloromethane, trichloromethane or ethyl acetate.

8. The production method according to claim 2, characterized by: The nano-titanium dioxide has a particle size of 50-200 nm, the titanium dioxide dispersion liquid has a concentration of 0.5-10 mg / mL, the first compound solution has a concentration of 1-20 mg / mL, the second compound solution has a concentration of 1-20 mg / mL, and the organic solvent is ethanol, methanol, dichloromethane, trichloromethane or ethyl acetate.

9. Use of the titanium dioxide / epoxy resin composite material of claim 1 in the preparation of a fire warning device.

10. A fire warning device, characterized by: The fire warning device comprises the titanium dioxide / epoxy resin composite material of claim 1 and a fire warning mechanism electrically connected to the titanium dioxide / epoxy resin composite material.

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