CN113717511B

CN113717511B - Mxene-based flame-retardant unsaturated resin material and preparation method thereof

Info

Publication number: CN113717511B
Application number: CN202111133747.0A
Authority: CN
Inventors: 高明; 王寄羽; 孙彩云
Original assignee: North China Institute of Science and Technology
Current assignee: Dragon Totem Technology Hefei Co ltd; Shanghai Yongqing Environmental Protection New Material Co ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2022-11-18
Anticipated expiration: 2041-09-27
Also published as: CN113717511A

Abstract

The invention discloses an MXene-based flame-retardant unsaturated resin material, and belongs to the technical field of flame-retardant materials. The MXene-based flame-retardant unsaturated resin material comprises the following components in parts by weight: 75.2 to 94 parts of unsaturated polyester resin, 0 to 20 parts of ammonium polyphosphate and 0 to 0.4 part of MXene material, wherein the MXene material can be modified by 1-butyl-3-methylimidazole hexafluorophosphate and a silane coupling agent. The MXene-based flame-retardant unsaturated resin material provided by the invention is further subjected to crosslinking and curing reaction with a curing agent and an accelerator to generate an MXene-based flame-retardant unsaturated resin molding material, and the generated MXene-based flame-retardant unsaturated resin molding material has good flame retardant property.

Description

Mxene-based flame-retardant unsaturated resin material and preparation method thereof

Technical Field

The invention belongs to the technical field of flame-retardant materials, and particularly relates to an Mxene-based flame-retardant unsaturated resin material and a preparation method thereof.

Background

The unsaturated polyester resin is formed by condensation polymerization of dihydric alcohol and saturated dibasic acid at high temperature, the main chain of the unsaturated polyester resin contains polymerizable double bonds, and the unsaturated polyester resin is copolymerized with various alkene monomers under the action of an initiator to obtain the thermosetting plastic with a body structure. The unsaturated polyester resin has excellent process properties of high strength, light weight, radiation resistance, earthquake resistance, heat insulation, electric insulation, microwave transmission and the like, and can be molded at normal temperature and normal pressure, so that the unsaturated polyester resin is widely used as coating, putty, adhesive, artificial marble, buttons, corrugated boards, building materials, automobile shells and the like. However, the unsaturated polyester resin is flammable, and places using the material are easy to have fires, so that immeasurable loss is caused to lives and properties, and therefore, the optimization of the flame retardant property of the unsaturated resin material is particularly urgent.

In actual production, the flame retardance of unsaturated polyester resin is improved by adding flame retardants, and most of the added flame retardants are phosphorus, boron, aluminum, nitrogen flame retardants and halogen-containing flame retardants. When the flame retardant containing phosphorus, boron, aluminum and nitrogen is adopted, the flame retardant can play a good flame retardant effect when the dosage of the flame retardant is larger, and the mechanical property of the high polymer is seriously influenced because the dosage of the flame retardant is larger; although the halogen-containing flame retardant is less in dosage and has less influence on the physical and mechanical properties of the high polymer, the halogen-containing flame retardant can generate a large amount of smoke at high temperature, even toxic smoke, and has great limitation on the use of materials for public transportation and buildings. Therefore, the development of the unsaturated polyester resin material with less flame retardant consumption, good flame retardant effect and less smoke generation has great significance.

Disclosure of Invention

In order to solve the problems, the invention aims to provide an unsaturated resin material which has the advantages of less flame retardant consumption, good flame retardant effect and less smoke generation.

In order to achieve the purpose, the invention provides the following technical scheme:

one of the technical schemes of the invention is that the MXene-based flame-retardant unsaturated resin material comprises the following components in parts by weight: 75.2-94 parts of unsaturated polyester resin, 0-20 parts of ammonium polyphosphate and 0-0.4 part of MXene material, wherein the content of ammonium polyphosphate is not 0 and the content of MXene material is not 0.

Further, the coating comprises the following components in parts by weight: 77-78 parts of unsaturated polyester resin, 17 parts of ammonium polyphosphate and 0.4 part of MXene material.

Further, the coating comprises the following components in parts by weight: 5363 portions of unsaturated polyester resin 77.644 portions, 17 portions of ammonium polyphosphate and 0.4 portion of MXene material.

Furthermore, the MXene material is transition metal carbide (nitride), which is a graphene-like material containing transition metal and has a molecular formula of Ti ₃ C ₂ X _n (X＝OH；n＝1，2，3)。

Further, the preparation method of the etching solution comprises the following steps: dissolving 0.5-2 g LiF in 20-50mL 5-10M HCl solution, and mixing to obtain etching solution; the Ti ₃ A1C ₂ The solid-liquid ratio of the etching solution to the etching solution is 0.5-2g, 20-50 mL, and the reaction temperature is 35-55 ℃.

Further, the MXene material is subjected to modification treatment, and the modification method comprises the following steps: dispersing MXene materials into absolute ethyl alcohol, then adding 1-butyl-3-methylimidazole hexafluorophosphate and water, then dripping a silane coupling agent into the mixture, reacting, filtering, washing, drying and grinding the mixture to obtain the modified MXene materials.

Further, the solid-to-liquid ratio of the MXene material to the anhydrous ethanol is 1g.

The second technical scheme of the invention is that the MXene-based flame-retardant unsaturated resin molding material is prepared by reacting the MXene-based flame-retardant unsaturated resin material with a curing agent and an accelerator.

Further, the mass ratio of the MXene-based flame-retardant unsaturated resin material to the curing agent to the accelerator is 94.

Compared with the prior art, the invention has the following beneficial effects:

(1) The MXene-based flame-retardant unsaturated resin material with good flame-retardant performance is prepared by mixing the efficient wood flame retardant ammonium polyphosphate and the MXene material with the unsaturated polyester resin, the efficient wood flame retardant ammonium polyphosphate and a small amount of MXene material added into the MXene-based flame-retardant unsaturated resin material can promote a series of reactions such as material decomposition, dehydration and the like during combustion, and a continuous and compact carbon layer without holes is formed on the surface of the unsaturated resin material, so that oxygen and heat exchange can be effectively blocked, and further, the internal matrix is prevented from being continuously combusted. The ammonium polyphosphate can solidify the carbon layer, the MXene material can improve the toughness and the continuity of the carbon layer on the surface of the material, and the total heat release amount, the mass change rate, the heat release rate and the CO of the unsaturated polyester resin are effectively reduced by matching the MXene material and the unsaturated polyester resin ₂ The release amount and the fire hazard, and the flame retardant property of the unsaturated polyester resin material is improved.

(2) The transition metal carbon (nitride) (MXene) prepared by the invention is a novel two-dimensional nano material, has a structure of a transition metal-containing graphene-like material, theoretically has a barrier effect and a catalytic effect, and has a good flame retardant effect on a polymer. Meanwhile, compared with other two-dimensional nano materials, the Mxene also has the advantages of large specific surface area, mild preparation conditions, easily controlled surface and the like. However, the catalytic effect of titanium in transition metal carbon (nitride) (MXene) is weak, the flame retardant requirement is difficult to achieve when the transition metal carbon (nitride) (MXene) is used alone, and the transition metal carbon (nitride) (MXene) is used as a nano material, has clustering effect among particles and is difficult to uniformly disperse, is used for solving the problem that functional modified substances which are easy to agglomerate and poor in dispersity in the application are only limited to surfactants or cation exchange resins, and has obvious organic molecule compatibilization unicity and combustible group introduction limitation. In view of the above, the MXene is functionally regulated and controlled by adopting the strong catalytic char-forming group, the dispersibility and the flame retardance of the MXene are improved by increasing the three-dimensional protection effect and the catalytic effect of the MXene, the flame retardance and the smoke suppression performance of the MXene material are improved, the MXene material treated by the modification method can be better and more uniformly dispersed into an MXene-based flame-retardant unsaturated resin material system, and the MXene-based flame-retardant unsaturated resin material prepared by the modification method has better flame retardance.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a thermogravimetric plot of UPR0, UPR1, UPR2, UPR3 samples;

FIG. 2 is a graph of heat release rate for UPR0, UPR1, UPR2, UPR3 samples;

FIG. 3 is a graph of smoke release rate for UPR0, UPR1, UPR2, UPR3 samples;

FIG. 4 is a photograph of carbon residue from UPR0, UPR1, UPR2, UPR3 samples subjected to cone calorimeter measurements, wherein (a) and (b) are UPR0, (c) and (d) are UPR1, (e) and (f) are UPR2, and (g) and (h) are UPR3.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. It is intended that the specification and examples be considered as exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

Example 1

1、MXene(Ti ₃ C ₂ X _n ) Preparation of the Material

1g LiF was dissolved in 30mL 6M HCl solution to prepare an etching solution, which was then magnetically treated at 45 deg.CUnder stirring with force 1g of Ti ₃ A1C ₂ Slowly adding the mixture into the etching solution to react for 7 hours. After the reaction is finished, washing and centrifugal separation are carried out by deionized water, and the washing is repeated for a plurality of times until the pH value is obtained>6 dark green supernatant. And then, carrying out ice-bath ultrasonic treatment on the obtained precipitate in absolute ethyl alcohol for 1h, carrying out centrifugal separation, adding 40mL of deionized water into the precipitate, carrying out ultrasonic treatment for 20min, centrifuging, and carrying out freeze drying on the supernatant for 24 h to obtain the MXene material.

2. MXene-based flame-retardant unsaturated resin material and preparation of MXene-based flame-retardant unsaturated resin molding material

(1) Selection of the amount of ammonium polyphosphate (APP)

Setting the total mass of MXene-based flame-retardant unsaturated resin materials as 94 parts, setting the content of MXene materials as 0 part, weighing the raw materials according to the APP content of 0 part, 8 parts, 10 parts, 13 parts, 15 parts, 17 parts, 19 parts and 20 parts, and the balance Unsaturated Polyester Resin (UPR), adding MXene into the unsaturated polyester resin, uniformly mixing by ultrasonic for 0.5h, adding APP with the particle size of 200 meshes, stirring for 10min to prepare 8 different MXene-based flame-retardant unsaturated resin materials, and then adding a curing agent and an accelerator into each prepared MXene-based flame-retardant unsaturated resin material (in terms of mass ratio, MXene-based flame-retardant unsaturated resin material: curing agent: accelerator =94, namely (UPR + APP 3: curing agent: accelerator = 94): the method comprises the steps of firstly preserving heat at 60 ℃ for 4 hours, then preserving heat at 80 ℃ for 8 hours to obtain 8 groups of MXene-based flame-retardant unsaturated resin molding material sample strips, measuring oxygen indexes of the obtained groups of MXene-based flame-retardant unsaturated resin molding material sample strips by using an oxygen index determinator, strictly performing the measurement according to the standard of GB-T2406-1993 under the condition of adjustable oxygen and nitrogen mixed gas, and judging the flame retardant effect of the MXene-based flame-retardant unsaturated resin molding material according to the measured oxygen indexes. The composition of each group of MXene-based flame-retardant unsaturated resin material and the oxygen index of MXene-based flame-retardant unsaturated resin molding material sample strips (the total mass of the molding material sample strips is 100 g) obtained by crosslinking and curing are shown in Table 1.

TABLE 1

As can be seen from Table 1, the MXene-based flame-retardant unsaturated resin molding material obtained when the APP amount is 17 parts is good in flame-retardant effect, the promotion of further increasing the amount of the APP on the basis of 17 parts is very limited, in order to ensure the effective utilization of raw materials while promoting the flame-retardant property of the material, unnecessary resource waste is not caused, the amount of the APP is fixed to 17 parts, and the amount of the MXene material is further selected on the basis.

(2) Selection of MXene material dosage

The preparation method comprises the following steps of setting the total mass of MXene-based flame-retardant unsaturated resin materials as 94 parts, setting the content of APP as 17 parts, weighing the raw materials according to the MXene material content as 0.5 part, 1 part, 1.5 parts and 2 parts, and the balance of UPR, adding MXene into unsaturated polyester resin, uniformly mixing by ultrasonic for 0.5h, adding APP with the granularity of 200 meshes, stirring for 10min to prepare 4 different groups of MXene-based flame-retardant unsaturated resin materials, and adding a curing agent and an accelerator into each group of MXene-based flame-retardant unsaturated resin materials (UPR: accelerator =94:3, namely (UPR + APP + MXene material): accelerator = 94): the temperature is kept at 60 ℃ for 4h and then at 80 ℃ for 8h to obtain 4 groups of MXene-based flame-retardant unsaturated resin molding material sample strips, the oxygen index of each group of MXene-based flame-retardant unsaturated resin molding material sample strips is measured, and the component composition of each group of MXene-based flame-retardant unsaturated resin material and the oxygen index of the MXene-based flame-retardant unsaturated resin molding material sample strips (the total mass of the molding material sample strips is 100 g) obtained by crosslinking and curing are shown in Table 2.

TABLE 2

As can be seen from Table 2, the flame retardant effect of UPR can be improved by using MXene materials and APP in a matching manner to a certain extent, but with the further increase of the concentration ratio of the MXene materials, the limiting oxygen index of the system is reduced, which shows that the flame retardant effect of the MXene-based flame-retardant unsaturated resin molding material cannot be enhanced by adding excessive MXene materials, but the process of promoting the material to dehydrate and form carbon by using the APP flame retardant is interfered, the excessive MXene materials can cause the formed carbon layer to have no continuity and integrity, and further the flame retardant property of the MXene-based flame-retardant unsaturated resin molding material is reduced, so that the flame retardant effect is better when the content of the MXene materials is 0.5 part.

In order to obtain more excellent flame-retardant effect and to find whether comparable or even more excellent flame-retardant effect can still be obtained under the condition of reducing the dosage of the MXene material, tests of 0.1 part, 0.2 part, 0.3 part and 0.4 part of the dosage of the MXene material are respectively carried out, and the component compositions of various groups of MXene-based flame-retardant unsaturated resin materials and the oxygen indexes of MXene-based flame-retardant unsaturated resin molding material splines obtained by crosslinking and curing are shown in Table 3.

TABLE 3

As can be seen from Table 3, the flame retardant effect of the MXene-based flame retardant unsaturated resin molding material obtained when the amount of APP was 17 parts and the amount of MXene material was 0.4 part was the best.

Example 2

1、MXene(Ti ₃ C ₂ X _n ) Modification of (2)

(1) Weighing 0.2g of MXene material prepared in the embodiment 1, dispersing the MXene material into 50mL of absolute ethyl alcohol, and sealing and ultrasonically dispersing for 30min by using a preservative film to obtain uniform dispersion liquid of the MXene material;

(2) Adding 1mL of 1-butyl-3-methylimidazole hexafluorophosphate (IL) and 20mL of deionized water, then carrying out magnetic stirring, adding 0.1mL (2 drops) of silane coupling agent KH550 (3-aminopropyltriethylsilane) in the stirring process, and carrying out stirring reaction for 1 hour;

(3) And (4) carrying out suction filtration, washing for 3 times by using absolute ethyl alcohol, drying, and grinding to obtain the modified MXene material.

The preparation method comprises the following steps of setting the total mass of MXene-based flame-retardant unsaturated resin materials as 94 parts, setting the content of APP as 17 parts, setting the content of modified MXene materials as 0.4 part, weighing the raw materials in parts by mass, adding MXene into unsaturated polyester resin, uniformly mixing by ultrasonic for 0.5h, adding APP with the granularity of 200 meshes, stirring for 10min, mixing to prepare an MXene-based flame-retardant unsaturated resin material, and adding a curing agent and an accelerator (in mass ratio, MXene-based flame-retardant unsaturated resin material: accelerator =94: the MXene-based flame-retardant unsaturated resin molding material sample strips are obtained by firstly preserving heat at 60 ℃ for 4h and then preserving heat at 80 ℃ for 8h, the oxygen index of the MXene-based flame-retardant unsaturated resin molding material sample strips is measured, and the component composition of the MXene-based flame-retardant unsaturated resin material and the oxygen index of the MXene-based flame-retardant unsaturated resin molding material sample strips (the total mass of the molding material sample strips is 100 g) obtained by crosslinking and curing are shown in Table 4.

TABLE 4

Comparing the oxygen index data in table 4 with the oxygen index data of 0.4 part of unmodified MXene material in the MXene-based flame-retardant unsaturated resin material in table 3, it can be found that the MXene-based flame-retardant unsaturated resin molding material obtained by using the modified MXene material has better flame retardant property, namely the flame retardant effect on UPR is better when the modified MXene material and APP are used in a matching manner.

Effect verification

Preparing MXene-based flame-retardant unsaturated resin material according to the APP content of 0 part and the MXene material content of 0 part, adding a curing agent and an accelerator in proportion to form MXene-based flame-retardant unsaturated resin molding material sample strips serving as blank reference groups, wherein the sample strips are numbered as UPR0; preparing an MXene-based flame-retardant unsaturated resin material according to the APP content of 17 parts and the MXene material content of 0 part, adding a curing agent and an accelerator in proportion, and forming an MXene-based flame-retardant unsaturated resin forming material sample strip as an experimental group 1, wherein the sample strip is numbered UPR1; preparing an MXene-based flame-retardant unsaturated resin material according to the APP content of 17 parts and the MXene material content of 0.4 part, adding a curing agent and an accelerator in proportion, and forming an MXene-based flame-retardant unsaturated resin forming material sample strip serving as an experimental group 2 and numbered as UPR2; preparing MXene-based flame-retardant unsaturated resin material according to the APP content of 17 parts and the modified MXene material content of 0.4 part, adding a curing agent and an accelerant in proportion, and forming into MXene-based flame-retardant unsaturated resin forming material sample strips serving as an experimental group 3, wherein the sample strips are numbered as UPR3. The composition of each group of MXene-based flame-retardant unsaturated resin material and the oxygen index of MXene-based flame-retardant unsaturated resin molding material specimens (the total mass of the molding material specimens is 100 g) obtained by crosslinking and curing are shown in Table 5.

TABLE 5

The sample labels UPR0, UPR1, UPR2 and UPR3 in Table 5 respectively represent pure unsaturated polyester resin UPR, APP/UPR/MXene and APP/UPR/modified MXene, and as can be seen from Table 5, the oxygen index of pure UPR0 is only 20.9, and the pure UPR belongs to a flammable material and does not have flame retardant property, because a carbon layer generated after combustion is loose, oxygen can continuously enter the material and further can be continuously combusted; the oxygen index of the UPR1 sample material added with 17 parts of APP is increased to 25.9, but the material still belongs to a combustible material, and the material has certain flame retardance at the moment, because the APP can promote the material to generate a carbon layer, but the carbon layer is also cracked when the temperature is too high, and the material is further combusted; the oxygen index of the UPR2 sample material added with 17 parts of APP and 0.4 part of MXene material is improved to 28.0, and the UPR2 sample material belongs to a flame-retardant material and has good flame retardant property; the oxygen index of the UPR3 sample material added with 17 parts of APP and 0.4 part of modified MXene material reaches 29.0, the material belongs to a flame retardant material, the flame retardant property is more outstanding, because the MXene material and the modified MXene material are added, a carbon layer is more compact, the oxygen is isolated from entering, the flame retardant purpose is achieved, particularly, the modified MXene material can be more uniformly dispersed, the effect is more obvious, the APP and the MXene material can have a better synergistic flame retardant effect after being compounded, the flame retardant property of MXUPR can be effectively improved, and the MXene-based flame retardant unsaturated resin material prepared by mixing the APP, the MXene material has good flame retardant property.

1. Horizontal vertical Combustion analysis

And (3) performing horizontal and vertical combustion analysis on the control group samples and the experimental group samples, and executing the test method according to the GB 2408-80 standard to obtain the flame retardant standard grade of each group of samples, wherein the flame retardant standard grade is shown in Table 6.

TABLE 6

As can be seen from Table 6, the combustion rating of UPR0 is V ₂ The UPR1 grade after 17 APP additions was raised to V ₁ The grade of the sample material is improved to V after the MXene material is added ₀ And the result is consistent with the oxygen index result, so that the compounding of APP and MXene materials can be obtained, the flame retardant property of UPR can be improved, and the MXene-based flame-retardant unsaturated resin material prepared by mixing UPR, APP and MXene materials has good flame retardant property.

2. Thermogravimetric analysis

The thermogravimetric analysis is carried out on the samples of the control group and the experimental group, the thermogravimetric curves are shown in figure 1, as can be seen from figure 1, the thermogravimetric curves of the four samples before 100 ℃ are very straight and almost have no weight loss, the thermogravimetric curves of the four samples between 100 ℃ and 300 ℃ are smoothly reduced, the pure UPR is reduced fastest and is decomposed at about 300 ℃, the decomposition temperatures of the UPR1, UPR2 and UPR3 samples are about 350 ℃, the thermogravimetric curves of the UPR1, UPR2 and UPR3 within the range of 350-400 ℃ are at the right of UPR0, and the final weight loss UPR0 is more than UPR1 and more than UPR2 and more than UPR3, which shows that the thermal stability of the material added with APP and MXene is improved, the APP can form a carbon layer so as to protect the matrix structure, the internal continuous combustion is delayed and prevented, the flame retardant effect is achieved, and the flame retardant effect of the APP and the modified MXene material is the best.

3. Analysis of carbon residue

The carbon residue rate is the mass percentage of the original mass after the material is burned under certain temperature and external conditions. And weighing the weight of each group of sample strips before thermogravimetric analysis and the weight of the sample strips after thermogravimetric analysis for a certain time at a certain temperature, and calculating the carbon residue rate of each group. The carbon residue rates of pure UPR, APP/UPR/MXene and APP/UPR/modified MXene are calculated to be 7.78%, 16.68%, 23.82% and 27.56% under the condition of 700 ℃, and the calculated carbon residue rates show that the carbon residue rates of UPR1, UPR2 and UPR3 group sample materials are greatly improved relative to the pure UPR, which also shows that the APP, MXene materials and modified MXene materials have obvious effect on flame-retardant modification of the materials from the aspect of the action mechanism of carbon-forming flame-retardant. Under the same condition, the carbon residue rate of the UPR3 material is better than that of UPR1 and UPR2 materials, which shows that the charring effect of APP/UPR/modified MXene is strongest after the materials are ignited, and the MXene material is endowed with stronger catalytic charring capability by the modifying group, so that the transfer and diffusion of oxygen and heat are effectively blocked, the internal base material is protected from being damaged, the flame retardant property is good, and the MXene-based flame retardant unsaturated resin material prepared by mixing the UPR, the APP and the MXene materials has the best flame retardant property.

4. Cone calorimetry analysis

Taking the samples of the control group and the experimental group according to ISO5660, wherein the heat radiation amount is 50kW/m ² The test was carried out under the experimental conditions of (1).

(1) Rate of heat release

Heat Release Rate (HRR) is a measureOne of the very important parameters of fire spread and fire development provides us with a measure of the size of the fire, called fire intensity. The larger the HRR, the more energy is transferred to the surface of the material per unit time, the higher the thermal degradation rate of the material and the more volatile combustibles are generated, and thus the propagation of the flame is accelerated. Thus the greater the HRR, the greater the risk of the material in a fire. The HRR curves of the UPR0, UPR1, UPR2 and UPR3 sample materials are shown in FIG. 2. From FIG. 2, it can be seen that the PHRR value of the pure UPR reaches 650kW/m ² Above, after 17 parts of APP are added, the PHRR value of the UPR1 spline is reduced to 500kW/m ² . 0.4 part of MXene material and APP are compounded, and the PHRR value of the UPR2 of the MXene-based flame-retardant unsaturated resin molding material prepared by mixing the MXene material and the APP with UPR is not greatly changed, but is reduced by 23 percent compared with pure UPR. 0.4 part of modified MXene material and APP are compounded, and the PHRR value of the UPR3 of the MXene-based flame-retardant unsaturated resin molding material prepared by the compounding and UPR is greatly changed from 500kW/m of pure UPR ² Reduced to 350kW/m ² And the reduction is 30 percent. Meanwhile, the HRR curve of pure UPR is greatly different from the HRR curve shape of APP/UPR/modified MXene. The HRR curve of pure UPR has only one peak value of heat release rate, while APP/UPR/modified MXene has two peaks, and the first peak of the APP/UPR/modified MXene system appears probably due to the heat release peak of combustion of flammable gas generated by the decomposition of UPR under heating. The phosphorus source flame retardant is heated to decompose, and promotes the high molecular material to be quickly decomposed through a series of reactions, and the high molecular material is dehydrated and carbonized on the surface of the material to form a continuous, compact and cavity-free carbon layer. This charcoal layer can completely cut off oxygen and heat exchange and then reach the purpose that prevents the further burning of material, and then slows down thermal degradation speed, and the volume of the flammable gas that generates reduces, so the heat that the burning produced also reduces, and HRR reduces to peak valley has appeared on the curve. The second peak of APP/UPR/modified MXene appears because of the further oxidation of the formed carbon layer, and although the heat release rate at the valley of the peak is the lowest, the THR still continues to increase, and when a certain temperature is reached, the carbon layer is further oxidized and burnt to generate a new carbon layer with the inner part of the matrix, thereby causing the second peak to appear. Pure UPR is easily generated by decomposition during combustionThe combustion gas, however without the formation of a tight char layer, does not protect the polymer internal matrix, so the material matrix degrades very quickly, the rate of flammable gas generation is very high, the heat released by combustion is also very large, the flame does not extinguish until the UPR can no longer provide the fuel needed for combustion, and therefore exists as a single peak on the HRR curve. For APP/UPR/modified MXene materials, the HRR curve has a similar trend to that of unsaturated resins, but the maximum heat release rate is the smallest, which shows that MXene and APP can promote the formation of a high-quality carbon layer which can effectively prevent the heat exchange between the inner matrix and the outside and effectively isolate oxygen so as to achieve the flame retardant effect. The HRR curve also shows that the TTI (ignition time) of APP/UPR/modified MXene is longest, which indicates that the material is the most difficult to ignite and has the best flame retardance.

(2) Smoke release rate analysis

The smoke release rate curves of UPR0, UPR1, UPR2 and UPR3 sample materials are shown in figure 3, and as can be seen from figure 3, the peak value of the smoke release rate of UPR1 only added with APP is increased compared with that of pure UPR, the peak value of the smoke release rate of UPR2 after MXene is further added on the basis of the added APP is reduced, smoke release is inhibited due to the barrier effect of MXene serving as a nano sheet, UPR3 added with APP and modified MXene is the lowest smoke release rate, and after the modified MXene is added, the dispersibility is improved, the barrier effect is increased, and the obvious smoke suppression effect is displayed.

5. Direct observation of carbon residue

Photographs of carbon residues of pure UPR, APP/UPR/MXene, APP/UPR/modified MXene sample materials after cone calorimeter testing are shown in FIG. 4, where (a) and (b) are UPR0, (c) and (d) are UPR1, (e) and (f) are UPR2, and (g) and (h) are UPR3. (a) (c), (e), (g) are top views from which very sufficient combustion of UPR0 (a) is directly observed to leave only finely divided flocculent material; UPR1 (c) had a lumpy carbon layer formed, but the carbon layer had ruptured; UPR2 (e) has a larger char layer but is still fractured; whereas UPR3 (g) has a relatively complete and compact carbon layer formation; (b) And (d), (f) and (h) are side views, and the side views show that the carbon layers of UPR1 (d) and UPR2 (f) are completely cracked, and UPR3 (h) is complete, which indicates that the flame retardant properties of UPR1 and UPR2 are not as good as that of UPR3, and further indicates that the flame retardant properties of UPR and APP can be improved by using the modified MXene and APP in combination, and the MXene-based flame retardant unsaturated resin material prepared by mixing UPR, APP and MXene materials has the best flame retardant properties.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included therein.

Claims

1. An MXene-based flame-retardant unsaturated resin material is characterized by comprising the following components in parts by mass: 77-78 parts of unsaturated polyester resin, 17 parts of ammonium polyphosphate and 0.4 part of MXene material;

the MXene material is subjected to modification treatment, and the modification method comprises the following steps: dispersing MXene materials into absolute ethyl alcohol, then adding 1-butyl-3-methylimidazole hexafluorophosphate and water, then dripping a silane coupling agent into the mixture, reacting, filtering, washing, drying and grinding the mixture to obtain the modified MXene materials.

2. The MXene-based flame retardant unsaturated resin material of claim 1, wherein the MXene material is Ti ₃ C ₂ X _n Wherein X = OH, n =1,2 or 3.

3. The MXene-based flame retardant unsaturated resin material of claim 2, wherein the Ti is Ti ₃ C ₂ X _n The preparation method comprises the following steps: mixing Ti ₃ A1C ₂ Adding the mixture into etching liquid for reaction, centrifuging, washing, adding the washed precipitate into absolute ethyl alcohol for ultrasonic treatment for 0.5-1 h, centrifuging, adding deionized water for ultrasonic treatment for 10-30 min, centrifuging, taking supernatant, and freeze-drying to obtain Ti ₃ C ₂ X _n 。

4. The MXene-based flame retardant unsaturated resin material according to claim 3, characterized in thatThe preparation method of the etching liquid comprises the following steps: dissolving 0.5-2 g LiF in 20-50mL 5-10M HCl solution, and mixing to obtain etching solution; the Ti ₃ A1C ₂ The solid-liquid ratio of the etching solution to the etching solution is 0.5-2g, 20-50 mL, and the reaction temperature is 35-55 ℃.

5. The MXene-based flame retardant unsaturated resin material according to claim 1, wherein the solid-to-liquid ratio of MXene material to anhydrous ethanol is 1g.

6. An MXene-based flame-retardant unsaturated resin molding material characterized by being obtained by reacting the MXene-based flame-retardant unsaturated resin material according to any one of claims 1 to 5 with a curing agent and an accelerator.

7. The MXene-based flame-retardant unsaturated resin molding material according to claim 6, wherein the MXene-based flame-retardant unsaturated resin material, the curing agent, and the accelerator are in a mass ratio of 94.