CN110790983A - Toughening type high polymer material flame retardant and processing method thereof - Google Patents

Abstract

The invention discloses a toughening type high polymer material flame retardant and a processing method thereof, belonging to the technical field of flame retardants. The product developed by the invention comprises microcrystalline wax, nano monolithic silicate, calcium gluconate modified nano plant fiber and isocyanate. When the product is prepared, the microcrystalline wax is heated and melted, then the nano monolithic silicate and the calcium gluconate modified nano plant fiber are added, and the mixture is stirred and dispersed to obtain a molten dispersion liquid; and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product. After the product obtained by the invention is added into a high polymer material, the material has good compatibility, and the toughening and flame retardant properties can be considered at the same time.

Description

Toughening type high polymer material flame retardant and processing method thereof

Technical Field

The invention relates to the technical field of flame retardants, in particular to a toughening type high polymer material flame retardant and a processing method thereof.

Background

High molecular materials are widely used in various fields of national economy and people's life because of their excellent properties and low price. However, most of high polymer materials are flammable and combustible materials, have high heat release rate and high heat value during combustion, are fast in flame propagation speed, are not easy to extinguish, and generate dense smoke and toxic gas, thereby causing great threat to life safety of people and harm to environment. Therefore, how to improve the flame retardancy of polymer materials has become an urgent problem to be solved in the current fire-fighting work.

The flame retardant is used for improving the flame resistance of the material, namely, the tissue material is ignited and the flame propagation is inhibited. Flame retardants can be classified into additive type and reactive type according to the relationship between the flame retardant and the substrate to be flame-retarded. Flame retardants are often classified into halogen-based, organic phosphorus-based, halogen-phosphorus-based, nitrogen-based, phosphorus-nitrogen-based, aluminum-magnesium-based, inorganic phosphorus-based, boron-based, molybdenum-based, and the like, depending on the kind of flame retardant element. The most industrially used flame retardants at present are halides, phosphates, antimony oxide, aluminum hydroxide and zinc borate.

However, although there are many available flame retardant systems, the amount of the flame retardant must be large with the improvement of the flame retardant performance requirement of the polymer material, and after a large amount of the flame retardant is added, the original advantageous performance of the polymer material must be reduced, especially good toughness, so that the polymer material becomes brittle, and finally the polymer material cannot give consideration to both good flame retardant and flexibility.

Disclosure of Invention

The invention aims to provide a toughening type high polymer material flame retardant and a processing method thereof, which aim to solve the problem that the good toughness and flame retardant property of a high polymer material are difficult to be considered after a flame retardant is added into the high polymer material in the prior art.

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

the toughened high polymer material flame retardant comprises the following raw materials in parts by weight: 4-8 parts of microcrystalline wax, 10-15 parts of nano monolithic silicate, 20-30 parts of calcium gluconate modified nano plant fiber and 0.3-0.8 part of isocyanate.

Further, the silicate is any one of sepiolite or montmorillonite.

Further, interlayer cations of the silicate are substituted with hydrogen ions.

Further, the plant fiber is any one of flax fiber or sisal fiber.

Further, the calcium gluconate is connected with the nano plant fiber through a chemical bond.

Further, the isocyanate is isocyanate with a benzene ring in the molecular structure.

Further, the isocyanate having a benzene ring in the molecular structure is: toluene diisocyanate, and diphenylmethane diisocyanate.

The invention also provides a processing method of the toughening type high polymer material flame retardant, which comprises the following specific processing steps:

(1) preparing raw materials;

(2) heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing to obtain molten dispersion liquid;

(3) and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product.

Further, the specific processing steps include:

(1) preparing raw materials;

(2) preparation of nano monolithic silicate: ultrasonically dispersing silicate in hydrochloric acid, adding an anionic surfactant after hydrothermal reaction, continuously dispersing, drying, and roasting at a low temperature of 160-180 ℃ to obtain nano monolithic silicate;

(3) heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing to obtain molten dispersion liquid;

(4) and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product.

Further, the specific processing steps include:

(1) preparing raw materials;

(2) preparation of nano monolithic silicate: ultrasonically dispersing silicate in hydrochloric acid, adding an anionic surfactant after hydrothermal reaction, continuously dispersing, drying, and roasting at a low temperature of 160-180 ℃ to obtain nano monolithic silicate;

(3) preparing calcium gluconate modified nano plant fiber: adding the nano plant fiber into a sodium periodate solution, heating, stirring, reacting, filtering, washing and drying to obtain pretreated nano plant fiber, heating, ball-milling and carrying out solid phase reaction on the nano plant fiber and calcium gluconate, and discharging to obtain calcium gluconate modified nano plant fiber;

(4) heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing to obtain molten dispersion liquid;

(5) and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product.

Has the advantages that:

according to the technical scheme, the microcrystalline wax and the nano monolithic silicate are introduced, when the product is used as a flame retardant to be added into a high polymer material, the microcrystalline wax can be used as a plasticizer in the processing process of the high polymer material, meanwhile, the microcrystalline wax can be heated and melted, and the melted microcrystalline wax can carry the nano monolithic silicate to diffuse towards the surface layer of the high polymer material, so that a monolithic silicate structure is formed on the surface layer of the high polymer material; in addition, according to the technical scheme, the calcium gluconate modified nano plant fiber is introduced, firstly, the calcium gluconate can form a shielding layer on the surface of the plant fiber, and in the combustion process, more energy needs to be consumed to destroy the structure, so that the cracking mode of the nano plant fiber is changed, the cracking temperature is increased, calcium carbonate can be generated after calcium ions are heated, calcium carbonate can be decomposed to generate calcium oxide and carbon dioxide along with further increase of the temperature, the carbon dioxide can play a role in diluting oxygen and combustible gas in air, the calcium oxide can form a heat-insulating and oxygen-insulating barrier together with the surface of a residual calcium carbonate product, and the reaction is an endothermic reaction and can effectively reduce the ambient temperature around the product; in addition, the calcium gluconate and the nano plant fiber are connected through chemical bonds, more heat is consumed for pyrolysis, the thermal stability and the carbon residue rate of the nano plant fiber are improved, calcium ions can catalyze the dehydration reaction of an active center of a system, so that the initial degradation temperature of the nano plant fiber is reduced, the nano plant fiber is cracked at a lower temperature, the combustible gas generated by cracking directly overflows due to the fact that the combustible gas cannot reach an ignition point, and the heat fed back to the fiber by combustion is reduced, further prevention of the continuous cracking of the residual fiber is facilitated, the reaction of the nano plant fiber and the calcium gluconate on the surface layer to generate coke at the lower temperature is dominant, the generated coke can cover the surface of the fiber with calcium oxide, calcium carbonate and the like, and the entering of flame retardant oxygen and the diffusion of heat can play a good flame retardant barrier role; in addition, the silicate with a single-layer structure and the fibrous nano plant fibers are combined with each other, one is dispersed in the polymer matrix, and the other is dispersed on the surface layer, so that good internal and external toughening effects are achieved.

According to the technical scheme, cations among layers in the framework of the monolithic layer silicate are replaced by hydrogen ions, so that the Si-O framework among the layers is converted into Si-OH, active silicon hydroxyl groups can be subjected to dehydration condensation when a fire is heated, the monolithic layer layered silicates which are independent from each other are connected by silicon-oxygen bonds to form a compact whole, moisture generated by dehydration plays good roles of diluting and cooling, the compact whole strengthens the heat insulation effect of a heat insulation layer, and the flame retardant property of the product is further improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Preparation of nano monolithic silicate: the method comprises the following steps of mixing a layered silicate and 5-10% of hydrochloric acid in a mass ratio of 1: 10-1: 20, mixing, performing ultrasonic dispersion at an ultrasonic frequency of 45-80 kHz, performing hydrothermal reaction for 3-5 h at a temperature of 160-180 ℃ and a pressure of 2.0-6.0 MPa, adding sodium dodecyl benzene sulfonate, performing ultrasonic dispersion for 10-20 min, drying, roasting at a low temperature of 160-180 ℃ for 1-2 h, and discharging to obtain nano monolithic silicate;

preparing calcium gluconate modified nano plant fiber: mixing nano plant fibers and sodium periodate with the mass fraction of 3-10% in a mass ratio of 1: 10-1: 15, heating and stirring for reaction for 45-80 min at the temperature of 75-85 ℃ and the stirring speed of 300-500 r/min, filtering, collecting a filter cake, washing the filter cake for 3-5 times by using deionized water, drying the washed filter cake to obtain pretreated nano plant fibers, pouring the pretreated nano plant fibers and calcium gluconate into a ball milling tank, ball milling and mixing for 4-6 h at the temperature of 95-100 ℃, and discharging to obtain calcium gluconate modified nano plant fibers;

sequentially taking 4-8 parts of microcrystalline wax, 10-15 parts of nano monolithic silicate, 20-30 parts of calcium gluconate modified nano plant fiber and 0.3-0.8 part of isocyanate according to parts by weight;

heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing for 10-30 min at the rotating speed of 600-800 r/min to obtain a molten dispersion liquid;

and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, keeping the temperature, stirring and dispersing for 10-15 min, stopping keeping the temperature, and cooling to room temperature to obtain the product.

Example 1

Preparation of nano monolithic silicate: mixing sepiolite and 5% hydrochloric acid according to a mass ratio of 1: 10, mixing, performing ultrasonic dispersion at an ultrasonic frequency of 45kHz, performing hydrothermal reaction for 3 hours at a temperature of 160 ℃ and a pressure of 2.0MPa, adding sodium dodecyl benzene sulfonate, performing ultrasonic dispersion for 10 minutes, drying, performing low-temperature roasting for 1 hour at a temperature of 160 ℃, and discharging to obtain the nano monolithic silicate;

preparing calcium gluconate modified nano plant fiber: mixing nano flax fibers and sodium periodate with the mass fraction of 3% according to the mass ratio of 1: 10, mixing, heating and stirring for reaction for 45min at the temperature of 75 ℃ and the stirring speed of 300r/min, filtering, collecting a filter cake, washing the filter cake for 3 times by using deionized water, drying the washed filter cake to obtain pretreated nano plant fiber, pouring the pretreated nano plant fiber and calcium gluconate into a ball milling tank, ball milling and mixing for 4h at the temperature of 95 ℃, and discharging to obtain calcium gluconate modified nano plant fiber;

sequentially taking 4 parts of microcrystalline wax, 10 parts of nano monolithic silicate, 20 parts of calcium gluconate modified nano plant fiber and 0.3 part of toluene diisocyanate according to parts by weight;

heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing at the rotation speed of 600r/min for 10min to obtain molten dispersion liquid;

and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding toluene diisocyanate, keeping the temperature, stirring and dispersing for 10min, stopping keeping the temperature, and cooling to room temperature to obtain the product.

Example 2

Preparation of nano monolithic silicate: mixing sepiolite and 8% hydrochloric acid according to a mass ratio of 1: 15, mixing, performing ultrasonic dispersion at an ultrasonic frequency of 50kHz, performing hydrothermal reaction for 4 hours at a temperature of 170 ℃ and a pressure of 5.0MPa, adding sodium dodecyl benzene sulfonate, performing ultrasonic dispersion for 15 minutes, drying, performing low-temperature roasting at a temperature of 170 ℃ for 1.5 hours, and discharging to obtain the nano monolithic silicate;

preparing calcium gluconate modified nano plant fiber: mixing nano sisal fiber and sodium periodate with the mass fraction of 5% according to the mass ratio of 1: 12, mixing, heating and stirring for reaction for 60min at the temperature of 80 ℃ and the stirring speed of 400r/min, filtering, collecting a filter cake, washing the filter cake for 4 times by using deionized water, drying the washed filter cake to obtain pretreated nano plant fiber, pouring the pretreated nano plant fiber and calcium gluconate into a ball milling tank, ball milling and mixing for 5h at the temperature of 98 ℃, and discharging to obtain calcium gluconate modified nano plant fiber;

according to the weight parts, sequentially taking 5 parts of microcrystalline wax, 12 parts of nano monolithic silicate, 25 parts of calcium gluconate modified nano plant fiber and 0.5 part of diphenylmethane diisocyanate;

heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing at the rotation speed of 700r/min for 20min to obtain molten dispersion liquid;

and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding diphenylmethane diisocyanate, keeping the temperature, stirring and dispersing for 12min, stopping keeping the temperature, and cooling to room temperature to obtain the product.

Example 3

Preparation of nano monolithic silicate: montmorillonite and 10% hydrochloric acid in a mass ratio of 1: 20, mixing, performing ultrasonic dispersion at an ultrasonic frequency of 80kHz, performing hydrothermal reaction for 5 hours at a temperature of 180 ℃ and a pressure of 6.0MPa, adding sodium dodecyl benzene sulfonate, performing ultrasonic dispersion for 20 minutes, drying, performing low-temperature roasting at a temperature of 180 ℃ for 2 hours, and discharging to obtain the nano monolithic silicate;

preparing calcium gluconate modified nano plant fiber: nano sisal fibers and sodium periodate with the mass fraction of 10% are mixed according to the mass ratio of 1: 15, mixing, heating and stirring for reaction for 80min at the temperature of 85 ℃ and the stirring speed of 500r/min, filtering, collecting a filter cake, washing the filter cake for 5 times by using deionized water, drying the washed filter cake to obtain pretreated nano plant fiber, pouring the pretreated nano plant fiber and calcium gluconate into a ball milling tank, ball milling and mixing for 6h at the temperature of 100 ℃, and discharging to obtain the calcium gluconate modified nano plant fiber;

according to the weight parts, sequentially taking 8 parts of microcrystalline wax, 15 parts of nano monolithic silicate, 30 parts of calcium gluconate modified nano plant fiber and 0.8 part of toluene diisocyanate;

heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing at the rotation speed of 800r/min for 30min to obtain molten dispersion liquid;

and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding toluene diisocyanate, keeping the temperature, stirring and dispersing for 15min, stopping keeping the temperature, and cooling to room temperature to obtain the product.

Comparative example 1

This comparative example differs from example 1 in that: when the nano monolithic layer silicate is prepared, hydrochloric acid is not added, and other conditions are kept unchanged.

Comparative example 2

This comparative example differs from example 1 in that: the nano monolithic layer silicate is not added into the product, and the rest conditions are kept unchanged.

Comparative example 3

This comparative example differs from example 1 in that: the nanometer flax fiber is directly used without modification treatment of calcium gluconate, and the rest conditions are kept unchanged.

Comparative example 4

This comparative example differs from example 1 in that: no microcrystalline wax was added and the remaining conditions were kept constant.

The products obtained in examples 1 to 3 and comparative examples 1 to 4 were subjected to performance tests, and the specific test methods and test results were as follows:

adding the product into high-density polyethylene according to the addition of 50%, and preparing a test sample product by melt blending;

flame retardant property: detecting the oxygen index of the test piece according to GB/T10707;

flexibility: testing the elongation at break of the test piece according to GB/T2490-2000;

the specific test results are shown in table 1:

table 1: product performance detecting meter

	Oxygen index/%	Elongation at break/%
			Example 1	38.8	336.5
Example 2	39.6	345.2
			Example 3	40.1	352.1
Comparative example 1	30.1	330.2
			Comparative example 2	22.3	250.6
Comparative example 3	23.5	280.3
			Comparative example 4	36.4	300.8

As can be seen from the detection results in Table 1, in comparative example 1, since hydrochloric acid is not added during the preparation of the nano monolithic silicate, the flame retardant effect between monolithic layers is difficult to be enhanced due to dehydration condensation of silicon hydroxyl groups after the product is heated during actual use, so that the flame retardant property is reduced, but the impact on the toughness of the product is relatively small; in the comparative example 2, as the nano monolithic silicate is not added into the product, the flame retardant effect and the toughening effect are both obviously reduced; in the comparative example 3, the nano flax fibers are directly used without being modified by calcium gluconate, so that the flame retardant property is obviously reduced, but the toughness is not obviously reduced; in contrast, comparative example 4, in which microcrystalline wax was added, the flame retardant and toughening effects were reduced, but the effects were not so great.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference thereto is therefore intended to be embraced therein.

Claims (10)

1. The toughening type high polymer material flame retardant is characterized by comprising the following raw materials in parts by weight: 4-8 parts of microcrystalline wax, 10-15 parts of nano monolithic silicate, 20-30 parts of calcium gluconate modified nano plant fiber and 0.3-0.8 part of isocyanate.

2. The flame retardant of a toughened polymer material according to claim 1, wherein the silicate is any one of sepiolite or montmorillonite.

3. The flame retardant of claim 2, wherein the interlayer cations of the silicate are replaced by hydrogen ions.

4. The flame retardant of the toughened polymer material according to claim 1, wherein the plant fiber is any one of flax fiber or sisal fiber.

5. The toughening-type polymer material flame retardant of claim 4, wherein the calcium gluconate is chemically bonded to the nano-plant fiber.

6. The flame retardant of claim 1, wherein the isocyanate is an isocyanate having a benzene ring in the molecular structure.

7. The toughening-type polymer material flame retardant of claim 6, wherein the isocyanate having a benzene ring in the molecular structure is: toluene diisocyanate, and diphenylmethane diisocyanate.

8. A processing method of a toughening type high polymer material flame retardant is characterized by comprising the following specific processing steps:

(1) preparing raw materials;

(2) heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing to obtain molten dispersion liquid;

(3) and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product.

9. The processing method of the toughened polymer material flame retardant according to claim 8, wherein the specific processing steps comprise:

(1) preparing raw materials;

(2) preparation of nano monolithic silicate: ultrasonically dispersing silicate in hydrochloric acid, adding an anionic surfactant after hydrothermal reaction, continuously dispersing, drying, and roasting at a low temperature of 160-180 ℃ to obtain nano monolithic silicate;

(3) heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing to obtain molten dispersion liquid;

(4) and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product.

10. The processing method of the toughened polymer material flame retardant according to claim 9, wherein the specific processing steps comprise:

(1) preparing raw materials;

(2) preparation of nano monolithic silicate: ultrasonically dispersing silicate in hydrochloric acid, adding an anionic surfactant after hydrothermal reaction, continuously dispersing, drying, and roasting at a low temperature of 160-180 ℃ to obtain nano monolithic silicate;

(3) preparing calcium gluconate modified nano plant fiber: adding the nano plant fiber into a sodium periodate solution, heating, stirring, reacting, filtering, washing and drying to obtain pretreated nano plant fiber, heating, ball-milling and carrying out solid phase reaction on the nano plant fiber and calcium gluconate, and discharging to obtain calcium gluconate modified nano plant fiber;

(4) heating and mixing materials: heating and melting microcrystalline wax, adding nano monolithic silicate and calcium gluconate modified nano plant fiber, and stirring and dispersing to obtain molten dispersion liquid;

(5) and (3) cooling: and cooling the molten dispersion liquid, stopping cooling when the microcrystalline wax begins to solidify, adding isocyanate, stirring and dispersing, and cooling to room temperature to obtain the product.