WO2021043142A1

WO2021043142A1 - Mesoporous silicon resin flame retardant, preparation method therefor and flame retardant composite material thereof

Info

Publication number: WO2021043142A1
Application number: PCT/CN2020/112885
Authority: WO
Inventors: 戴李宗; 王秀; 杨杰; 陈婷; 彭超华; 洪静; 申应军; 鹿振武; 陈国荣; 曾碧榕; 罗伟昂
Original assignee: 厦门大学; 金旸（厦门）新材料科技有限公司
Priority date: 2019-09-02
Filing date: 2020-09-01
Publication date: 2021-03-11
Also published as: CN110628085A; CN110628085B

Abstract

Disclosed are a mesoporous silicon resin flame retardant, a preparation method therefor and a flame retardant composite material thereof. The flame retardant is prepared by reacting graphene oxide bearing an epoxy group with an amino-modified mesoporous silicon dioxide, and then loading same with zinc hydroxystannate. By utilizing the shielding barrier effect of graphene, the adsorption of a combustible gas by the mesoporous silicon dioxide and the synergistic flame retardation effect of catalytic charring of the zinc hydroxystannate, the smoke suppressant and flame retardant properties of a polymer material can be improved. The preparation method therefor is simple and feasible, and has a broad application prospect in the field of the smoke suppression and flame retardation of polymers.

Description

Mesoporous silicone resin flame retardant, preparation method and flame retardant composite material thereof

Technical field

The invention belongs to the field of polymer flame retardant, and particularly relates to a mesoporous silicone resin flame retardant, a preparation method and a flame retardant composite material.

Background technique

Because polymer materials have good mechanical, physical and chemical properties and corrosion resistance, they are widely used in automobiles, aerospace, electronic components and other fields. However, polymer materials are easy to burn, and toxic and harmful gases will be generated during the combustion process, so there is a huge fire hazard, which greatly limits the practical application of polymer materials, so improving the smoke suppression and flame retardant properties of polymer materials is extremely important. Currently widely used flame retardants include phosphorus flame retardants, nitrogen flame retardants, silicon flame retardants and inorganic flame retardants. Inorganic flame retardants are less harmful, have good smoke suppression effects, and can improve the flame retardant properties of composite materials and the mechanical properties of materials. At present, most flame retardants will produce a large amount of smoke during the combustion process, and the smoke suppression effect is not good. Therefore, the preparation of a new type of flame retardant with smoke suppression function is still the research focus that needs to be explored.

Summary of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art, and provide a mesoporous silicone resin flame retardant, a preparation method and a flame retardant composite material, and solve the above-mentioned problems in the background art.

One of the technical solutions adopted by the present invention to solve its technical problems is to provide a mesoporous silicone resin flame retardant, the structural formula of which is shown in Figure 5, wherein the mesoporous silica includes MCM-41 or SBA-15 .

The second technical solution adopted by the present invention to solve its technical problem is: the preparation method of the above mesoporous silicon flame retardant is provided, and the synthesis route is shown in FIG. 6.

The specific steps include:

(1) Add tetraethyl silicate, template, catalyst, water and ethanol to the reaction vessel, stir at room temperature for 1-12h, then react in a tetrafluoroethylene reactor at 100-120℃ for 18-48h, filter A white precipitate is obtained, dried at 50-100°C and calcined at 550°C for 6h to obtain mesoporous silica (MCM-41 or SBA-15).

In a preferred embodiment of the present invention, the template is one of cetyltrimethylammonium bromide, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer Kind.

In a preferred embodiment of the present invention, the catalyst is one of ammonia water and hydrochloric acid.

In a preferred embodiment of the present invention, the molar ratio of the tetraethyl silicate, template, catalyst, water and ethanol is 1:0.1-0.5:5-15:130-150:0-60.

(2) Add mesoporous silica, aminopropyltriethoxysilane, water and ethanol to the reaction vessel, stir at 70-100°C for 18-36h, then add graphene oxide and stir at room temperature for 4-10h, Centrifugal washing with ethanol, vacuum drying at 50-100°C, and thermal reduction at 600°C under nitrogen atmosphere for 3-8h to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

In a preferred embodiment of the present invention, the mass ratio of the mesoporous silica, aminopropyltriethoxysilane, water, ethanol and graphene oxide is 1:0.5～1.5:0.05～0.1:100～ 200: 0.1~1.

(3) Add mesoporous silica grafted reduced graphene oxide, zinc sulfate, sodium stannate and water into the reaction vessel, stir at 50-100℃ for 3-6h, and wash with ethanol by centrifugation, 50-100℃ The mesoporous silicon flame retardant is obtained after vacuum drying.

In a preferred embodiment of the present invention, the mass ratio of the mesoporous silica grafted reduced graphene oxide, zinc sulfate, sodium stannate and water is 1:0.5～1.5:0.5～1.5:80～120 .

The third technical solution adopted by the present invention to solve its technical problem is to provide a flame-retardant composite material, which includes a polymer material, the above-mentioned mesoporous silicon flame retardant and a curing agent, and the mesoporous silicon flame retardant passes through and A corresponding flame-retardant composite material is prepared by blending high-molecular materials, and the mesoporous silicon flame retardant is 0.1-20 wt% of the high-molecular material.

The polymer material is one of E51 bisphenol A epoxy resin (EP), nylon resin (PA) and ABS.

The curing agent is 4,4-diaminodiphenylmethane (DDM), and the mass ratio of the polymer material to the curing agent is 3 to 5:1.

In a preferred embodiment of the present invention, an epoxy resin flame-retardant composite material, the preparation method includes: taking epoxy resin prepolymer, adding the mesoporous silicon flame retardant and solvent at 60-140°C, and stirring To be transparent, evacuate until no bubbles are generated, then add the curing agent, after complete dissolution, cure at 110～130℃ for 3～5h, 130～150℃ for 1～3h, 170～190℃ for 1～3h, The epoxy resin flame-retardant composite material is obtained. The solvent is one of acetone, chloroform and dichloromethane.

In a preferred embodiment of the present invention, a thermoplastic flame-retardant composite material is prepared. The preparation method includes: taking a thermoplastic polymer material and the mesoporous silicon flame-retardant, drying them in a vacuum oven at 60-120°C, and placing them in a certain proportion. Melt blending in a twin screw extruder. The temperature of the three stages of the extruder was set to 210 to 230, 220 to 230, and 220 to 230°C, respectively. After cooling, the blend is cut into pellets, dried in a drying oven, and injection molded into a standard sample by an injection molding machine to obtain the thermoplastic flame-retardant composite material. The thermoplastic polymer material is one of the PA and ABS.

The beneficial effects of the present invention:

(1) The mesoporous silicon flame retardant with smoke suppression function of the present invention contains a mesoporous structure, which can effectively delay the diffusion of combustible gas generated during the combustion of polymer materials, thereby improving the smoke suppression effect of polymer materials. By changing the template and catalyst, two mesoporous silicon flame retardants can be obtained. The mesoporous pore diameters of the two flame retardants are different. Among them, the SBA-15 series flame retardants with larger pore diameters have better smoke suppression performance, which proves The influence of the pore size on the smoke suppression effect of polymer materials;

(2) The thermally reduced graphene in the mesoporous silica flame retardant has a shielding and barrier effect, and has a synergistic flame retardant effect with mesoporous silica in practical applications. The corresponding flame retardant sample has high thermal stability and smoke suppression. The advantages of good effect and good flame retardant performance;

(3) The zinc hydroxystannate supported on the surface of the mesoporous silicon flame retardant has the effect of catalyzing carbon formation, which can catalytically degrade the combustible gas generated during the combustion of polymer materials into carbon, and further improve the smoke suppression and flame retardancy of polymer materials performance.

Description of the drawings

Figure 1 TEM spectrum of the mesoporous silica obtained in Example 1, where (A-C) is MCM-41 and (D-F) is SBA-15.

Figure 2 XRD pattern of the mesoporous silicon flame retardant obtained in Example 1.

Fig. 3 is a vertical combustion experiment combustion process diagram of the flame-retardant epoxy resin obtained in Example 1.

Figure 4 The heat release and smoke release curves of the flame-retardant epoxy resin obtained in Example 3, in which (A) the heat release curve of the EP composite material, and (B) the smoke release curve of the EP composite material.

Figure 5 is the structural formula of the mesoporous silicon flame retardant of the present invention.

Figure 6 is the synthetic route of the mesoporous silicon flame retardant of the present invention.

Among them, the glossy spheres in FIGS. 5 and 6 represent silica, and the spheres with particles on the surface are mesoporous silica supported by zinc hydroxystannate.

detailed description

Example 1

1. Preparation of mesoporous silicon flame retardant:

(1) Add 4.7g of tetraethyl silicate, 2.5g of cetyltrimethylammonium bromide, 13.2g of ammonia, 50g of water and 60g of ethanol to the reaction vessel, stir at room temperature for 2h, and then add tetrafluoroethylene Reacted at 105℃ for 24h in the reactor, filtered to obtain white precipitate, dried at 100℃ and calcined at 550℃ for 6h to obtain mesoporous silica MCM-41; add 7.2g tetraethyl silicate and 3g polycyclic ring to the reaction vessel Ethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, 87.5mL 2M hydrochloric acid and 22.5g water, stirred at 40℃ for 20h, and then reacted in a tetrafluoroethylene reactor at 100℃ for 48h, The white precipitate was obtained by filtration, and calcined at 550°C for 6 hours after drying at 100 to obtain mesoporous silica SBA-15.

The pore structure of mesoporous silica MCM-41 and SBA-15 was observed with a transmission electron microscope, and the measured results are shown in Figure 1.

(2) Add 1g of mesoporous silica, 1g of aminopropyltriethoxysilane, 100g of water and 50g of ethanol to the reaction vessel, stir at 75℃ for 24h, then add 0.33g of graphene oxide and stir for 4h at room temperature, It was washed with ethanol by centrifugation, dried under vacuum at 60°C and thermally reduced at 600°C under nitrogen atmosphere for 4h to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

(3) Add 1g of mesoporous silica grafted reduced graphene oxide, 1g zinc sulfate, 1g sodium stannate and 100g water into the reaction vessel, stir at 60℃ for 4h, wash with ethanol by centrifugation, and dry at 60℃ in vacuum Then the mesoporous silicon flame retardant is obtained.

The phase structure of the above mesoporous silicon flame retardant was measured by an X-ray diffractometer, and the measured result is shown in Figure 2.

2. Preparation of flame-retardant epoxy resin:

Weigh 28g of epoxy resin prepolymer, heat it to 80℃, add 1wt%g of mesoporous silicon flame retardant and 30mL of acetone and ultrasonically stir until it is transparent, pump air until no bubbles are generated, and then add 7g of curing agent 4,4-II Amino diphenylmethane (DDM) is completely dissolved, then poured into an aluminum mold, and cured at 120°C for 4 hours, 140°C for 2 hours, and 180°C for 2 hours to obtain flame-retardant epoxy resin.

Take the obtained flame-retardant epoxy resin for a vertical combustion experiment, and the combustion process is shown in Figure 3.

According to GB/T 2406-2009, the oxygen index of epoxy resin is 26.2%.

Example 2

1. Preparation of mesoporous silicon flame retardant:

(2) Add 1g of mesoporous silica, 1.5g of aminopropyltriethoxysilane, 100g of water and 50g of ethanol to the reaction vessel, stir at 75℃ for 24h, then add 0.99g of graphene oxide and stir for 4h at room temperature , Washed with ethanol by centrifugation, dried under vacuum at 60°C and thermally reduced at 600°C under nitrogen atmosphere for 4h to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

(3) Add 1g of mesoporous silica grafted reduced graphene oxide, 1.5g zinc sulfate, 1.5g sodium stannate and 100g water into the reaction vessel, stir at 60℃ for 4h, centrifuge and wash with ethanol, 60℃ The mesoporous silicon flame retardant is obtained after vacuum drying.

2. Preparation of flame-retardant epoxy resin:

Weigh 28g of epoxy resin prepolymer, heat it to 80℃, add 3wt% mesoporous silicon flame retardant and 30mL acetone and ultrasonically stir until transparent, pump air until no bubbles are generated, then add 7g curing agent 4,4-diamino Diphenylmethane (DDM) is completely dissolved, then poured into an aluminum mold, and cured at 120°C for 4 hours, 140°C for 2 hours, and 180°C for 2 hours to obtain flame-retardant epoxy resin.

According to GB/T 2406-2009, the oxygen index of epoxy resin is 28.1%.

Example 3

1. Preparation of mesoporous silicon flame retardant:

(2) Add 1g of mesoporous silica, 1g of aminopropyltriethoxysilane, 100g of water and 50g of ethanol to the reaction vessel, stir at 75℃ for 24h, then add 0.55g of graphene oxide and stir for 4h at room temperature, It was washed with ethanol by centrifugation, dried under vacuum at 60°C and thermally reduced at 600°C under nitrogen atmosphere for 4h to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

(3) Add 1g of mesoporous silica grafted reduced graphene oxide, 1.2g zinc sulfate, 1.2g sodium stannate and 100g water into the reaction vessel, stir at 60℃ for 4h, and wash with ethanol by centrifugation, 60℃ The mesoporous silicon flame retardant is obtained after vacuum drying.

2. Preparation of flame-retardant epoxy resin:

Weigh 28g of epoxy resin prepolymer, heat it to 80℃, add 5wt% mesoporous silicon flame retardant and 30mL acetone and ultrasonically stir until it is transparent, pump air until no bubbles are generated, then add 7g curing agent 4,4-diamino Diphenylmethane (DDM) is completely dissolved, then poured into an aluminum mold, and cured at 120°C for 4 hours, 140°C for 2 hours, and 180°C for 2 hours to obtain flame-retardant epoxy resin.

Take the obtained flame-retardant epoxy resin for cone calorimeter test, and the heat release and smoke release curves are shown in Figure 4.

According to GB/T 2406-2009, the oxygen index of epoxy resin is 29.8%.

Example 4

1. Preparation of mesoporous silicon flame retardant:

(2) Add 1g of mesoporous silica, 1g of aminopropyltriethoxysilane, 100g of water and 50g of ethanol to the reaction vessel, stir at 75℃ for 24h, then add 0.66g of graphene oxide and stir for 4h at room temperature, It was washed with ethanol by centrifugation, dried under vacuum at 60°C and thermally reduced at 600°C under nitrogen atmosphere for 4h to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

(3) Add 1g of mesoporous silica grafted reduced graphene oxide, 0.5g zinc sulfate, 0.5g sodium stannate and 100g water into the reaction vessel, stir at 60℃ for 4h, and wash with ethanol by centrifugation, 60℃ The mesoporous silicon flame retardant is obtained after vacuum drying.

2. Preparation of flame-retardant nylon resin:

Weigh 30 g of nylon PA and 0.92 g (3 wt%) of mesoporous silicon flame retardant, dry them in a vacuum oven at 80°C, and place them in a twin-screw extruder for melt blending. The temperature of the 3 stages of the extruder was set to 220, 225, and 230°C, respectively. After cooling, the blend was cut into pellets, dried in a drying oven at 60°C, and injection molded into a standard sample using an injection molding machine to obtain the flame-retardant nylon resin.

According to GB/T 2406-2009, the oxygen index of flame-retardant nylon resin is 25.6%.

Example 5

1. Preparation of mesoporous silicon flame retardant:

2. Preparation of flame-retardant nylon resin:

Weigh 28 g of nylon PA and 1.58 g (5 wt%) of mesoporous silicon flame retardant, dry them in a vacuum oven at 80° C., and place them in a twin-screw extruder for melt blending. The temperature of the 3 stages of the extruder was set to 220, 225, and 230°C, respectively. After cooling, the blend was cut into pellets, dried in a drying oven at 60°C, and injection molded into a standard sample using an injection molding machine to obtain the flame-retardant nylon resin.

According to GB/T 2406-2009, the oxygen index of flame-retardant nylon resin is 28.8%.

Example 6

1. Preparation of mesoporous silicon flame retardant:

(2) Add 1g of mesoporous silica, 0.5g of aminopropyltriethoxysilane, 100g of water and 50g of ethanol to the reaction vessel, stir at 75℃ for 24h, then add 0.16g of graphene oxide and stir for 4h at room temperature , Washed with ethanol by centrifugation, dried under vacuum at 60°C and thermally reduced at 600°C under nitrogen atmosphere for 4h to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

2. Preparation of flame-retardant ABS composite materials:

28g of ABS and 0.92g (3wt%) of mesoporous silicon flame retardant were weighed, dried in a vacuum oven at 80°C, and then placed in a twin-screw extruder for melt blending. The temperature of the 3 stages of the extruder was set to 210, 215, and 220°C, respectively. After cooling, the blend was cut into pellets, dried in a drying oven at 60°C, and injection molded into a standard sample using an injection molding machine to obtain the flame-retardant nylon resin.

According to GB/T 2406-2009, the oxygen index of the flame-retardant ABS composite material is 24.3%.

Example 7

1. Preparation of mesoporous silicon flame retardant:

(2) Add 1g of mesoporous silica, 1g of aminopropyltriethoxysilane, 100g of water and 50g of ethanol to the reaction vessel, stir at 75℃ for 24h, then add 0.55g of graphene oxide and stir for 4h at room temperature, Centrifugal washing with ethanol, vacuum drying at 60°C, and thermal reduction at 600°C under nitrogen atmosphere for 4 hours to obtain reduced graphene oxide grafted with mesoporous silica (MCM-41 or SBA-15).

2. Preparation of flame-retardant ABS composite materials:

28g of ABS and 1.58g (5wt%) of mesoporous silicon flame retardant were weighed, dried in a vacuum oven at 80°C, and then placed in a twin-screw extruder for melt blending. The temperature of the 3 stages of the extruder was set to 210, 215, and 220°C, respectively. After cooling, the blend was cut into pellets, dried in a drying oven at 60°C, and injection molded into a standard sample using an injection molding machine to obtain the flame-retardant nylon resin.

According to GB/T 2406-2009, the oxygen index of the flame-retardant ABS composite material is 27.9%.

The above are only preferred embodiments of the present invention, so the scope of implementation of the present invention cannot be limited accordingly. That is to say, equivalent changes and modifications made according to the scope of the patent of the present invention and the contents of the specification should still be covered by the present invention. Within range.

Industrial applicability

The invention discloses a mesoporous silicone resin flame retardant, a preparation method and a flame retardant composite material thereof. The flame retardant reacts through the reaction of graphene oxide with epoxy groups and amino-modified mesoporous silica. It is prepared by loading zinc hydroxystannate. The use of graphene's shielding and barrier, the adsorption of combustible gas by mesoporous silica, and the synergistic flame retardant effect of zinc hydroxystannate catalyzed into carbon can improve the smoke suppression and flame retardancy of polymer materials. The preparation method is simple and feasible, has broad application prospects in the field of polymer smoke suppression and flame retardancy, and has industrial practicability.

Claims

A mesoporous silicone resin flame retardant, characterized in that the structural formula is as follows:

Among them, ZHS is zinc hydroxystannate, and MCM-41 and SBA-15 are mesoporous silica.
A method for preparing mesoporous silicone resin flame retardant, which is characterized in that: amino-modified mesoporous silica is prepared by using tetraethyl silicate, template, catalyst, water and ethanol, and then mixed with epoxy resin The graphene oxide reacts with the group to obtain the reduced graphene oxide grafted with mesoporous silica, which is then loaded with zinc hydroxystannate to prepare the mesoporous silicon flame retardant; wherein the template is cetyltrimethyl One of ammonium bromide, polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, and the catalyst is one of ammonia water and hydrochloric acid.
The method for preparing a mesoporous silicone resin flame retardant according to claim 1, characterized in that it comprises the following steps:

(1) Mix tetraethyl silicate, template, catalyst, water and ethanol, stir at room temperature for 1-12h, then react at 100-120℃ for 18-48h, filter to obtain white precipitate, and dry at 50-100℃ Then calcined at 550°C for 6 hours to obtain mesoporous silica, the mesoporous silica including MCM-41 or SBA-15;

(2) Mix the mesoporous silica prepared in step (1) with aminopropyltriethoxysilane, water and ethanol, stir at 70～100℃ for 18～36h, then add graphene oxide and stir at room temperature 4 ～10h, centrifugal washing with ethanol, vacuum drying at 50-100℃, and thermal reduction at 600℃ under nitrogen atmosphere for 3～8h to obtain mesoporous silica grafted reduced graphene oxide;

(3) Mix the mesoporous silica grafted reduced graphene oxide, zinc sulfate, sodium stannate and water prepared in step (2), stir at 50-100°C for 3-6h, and wash with ethanol by centrifugation. The mesoporous silicon flame retardant is obtained after vacuum drying at ~100°C.
The method for preparing a mesoporous silicone resin flame retardant according to claim 3, wherein the molar ratio of tetraethyl silicate, template, catalyst, water and ethanol in said step (1) is 1 ：0.1～0.5:5～15:130～150:0～60.
The method for preparing a mesoporous silicone resin flame retardant according to claim 3, characterized in that: in the step (2), mesoporous silica, aminopropyltriethoxysilane, water, ethanol and oxidation The mass ratio of graphene is 1:0.5-1.5:0.05-0.1:100-200:0.1-1.
The method for preparing a mesoporous silicone resin flame retardant according to claim 3, characterized in that: in the step (3), mesoporous silica grafted reduced graphene oxide, zinc sulfate, sodium stannate and The mass ratio of water is 1:0.5～1.5:0.5～1.5:80～120.
A flame-retardant composite material, characterized in that it comprises a mesoporous silicone resin flame retardant according to claim 1, and further comprises a polymer material and a curing agent, and the mesoporous silicon flame retardant is a polymer material的0.1-20wt%.
The flame-retardant composite material according to claim 7, wherein the polymer material is one of E51 bisphenol A epoxy resin, nylon resin or ABS; the curing agent is 4,4 -Diaminodiphenylmethane; the mass ratio of the polymer material to the curing agent is 3 to 5:1.
A flame-retardant composite material according to claim 7, wherein the epoxy resin prepolymer is taken, and the mesoporous silicon flame retardant and solvent are added at 60-140°C, stirred until transparent, and evacuated until No air bubbles are generated, then add the curing agent, after completely dissolving, cure at 110～130℃ for 3～5h, 130～150℃ for 1～3h, 170～190℃ for 1～3h to obtain epoxy resin flame retardant Composite materials.
A flame-retardant composite material according to claim 7, characterized in that: nylon resin or ABS, and mesoporous silicon flame retardant are dried in a vacuum oven at 60-120°C, and placed in a twin-screw extruder Melt blending, the three-stage temperature of the extruder is respectively set at 210-230°C, 220-230°C, and 220-230°C; the blend is cooled and pelletized, dried, and injected to obtain the thermoplastic flame-retardant composite material.