Flame-retardant lightweight elastomeric material and method for its production

Abstract

The present application relates to a kind of flame-retardant lightweight elastomer material and its preparation method, belong to polymer material technical field.The component of the elastomer material is: modified flame retardant 3.5-5.2wt%, multi-ene base crosslinking agent 2.5-3.5wt%, accelerator 0.1-0.13wt%, lubricant 1.4-1.8wt% and antioxidant 0.15-0.2wt%, the balance is POE resin;Modified flame retardant is formed by the reaction of o-aminobenzyl alcohol and formaldehyde Hydroxyl-containing triazine compound, that is, intermediate 1, by mercaptoacetic acid and methyl allyl tri-sulfide click addition reaction, form carboxyl-terminated intermediate 2, finally by intermediate 2 and intermediate 1 esterification;Modified flame retardant is designed by molecule, in high temperature ignition process, by molecular level stage type flame retardant, realize high efficient fire suppression and low smoke low loss.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to a flame-retardant lightweight elastomer material and a preparation method thereof. BACKGROUND

[0002] Polyolefin elastomer (POE) is a thermoplastic elastomer realized in-situ polymerization by using metallocene catalysts of ethylene and alpha-olefins, wherein the polyethylene chain crystallization zone plays the role of physical crosslinking point, has typical plastic properties, and after adding a certain amount of alpha-olefins, the crystallization zone of the polyethylene chain is weakened to form an amorphous zone showing rubber elasticity, and has the dual characteristics of plastic and rubber, has the characteristics of good elasticity, impact resistance, corrosion resistance, tensile strength and the like, especially has excellent low-temperature toughness and lightweight characteristics, and is widely used in new energy cable, building sealing and the like. However, the POE material has poor flame retardancy, which seriously limits its application in safety-sensitive scenarios.

[0003] In order to expand the application of POE material in flame-retardant products, the existing technical means mainly introduces a certain amount of flame retardant into the POE material to give it flame-retardant properties, but there are the following technical defects: inorganic flame retardants such as magnesium hydroxide, aluminum hydroxide and ceramic materials generally have a high addition amount, which seriously deteriorates the toughness of the POE matrix, and increases the density of the material, thereby limiting its application in lightweight products; organic flame retardants such as phosphorus-nitrogen flame retardants generate carbonized substances and flame-retardant gases by decomposition to achieve efficient flame retardation, thereby significantly improving the flame retardancy of POE to a certain extent, but the gas source generated by the rapid decomposition of such flame retardants carries phosphorus compounds, forms a large-pore, fluffy carbon layer on the surface of the material, forms a smoke release channel, and results in high smoke density, and the fluffy carbon layer significantly deteriorates the mechanical strength of the material. SUMMARY

[0004] In order to solve the technical problems mentioned in the background, the purpose of the present application is to provide a flame-retardant lightweight elastomer material and a preparation method thereof.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] A flame-retardant lightweight elastomer material, and the specific components are as follows: modified flame retardant 3.5-5.2wt%, polyene crosslinking agent 2.5-3.5wt%, accelerator 0.1-0.13wt%, lubricant 1.4-1.8wt% and antioxidant 0.15-0.2wt%, and the balance is POE resin.

[0007] The modified flame retardant is prepared by the following method:

[0008] Step A1: Dissolve o-aminobenzyl alcohol and acetone under nitrogen protection, control the temperature at 15-30℃ by water bath, add formaldehyde solution and stir for 6-9h, then add sodium bicarbonate solution and continue to react at 45-55℃ for 1.6-2.2h, after the reaction is completed, remove acetone by rotary evaporation, then add deionized water to the substrate and mix, separate the aqueous phase and dry to obtain intermediate 1;

[0009] Further, the amount ratio of o-aminobenzyl alcohol, formaldehyde, sodium bicarbonate and acetone is 0.1 mol: 0.16-0.18 mol: 0.2-0.3 g: 130-170 mL, o-aminobenzyl alcohol and formaldehyde react to form a triazine compound, and the specific reaction route is as follows:

[0010]

[0011] Step A2: Pre-mix benzoin dimethyl ether and tetrahydrofuran, then add methyl allyl trisulfide and mercaptoacetic acid mixture, apply 35-50 mW / cm 2 UVA ultraviolet light for 1.5-2.2h, after the reaction is completed, remove tetrahydrofuran by rotary evaporation to obtain intermediate 2;

[0012] Further, the amount ratio of methyl allyl trisulfide, mercaptoacetic acid, benzoin dimethyl ether and tetrahydrofuran is 0.1 mol: 0.1 mol: 25-35 mg: 80-100 mL, methyl allyl trisulfide and mercaptoacetic acid react to form a carboxyl-terminated modification, and the specific reaction route is as follows:

[0013]

[0014] Step A3: Mix intermediate 1, intermediate 2, p-toluenesulfonic acid and anhydrous toluene, protect with dry nitrogen, heat to 90-100℃ and stir for 4-5h, then add dicyclohexyl carbodiimide and continue to heat to 110℃ for 1-1.2h, after the reaction is completed, remove toluene by rotary evaporation, wash the substrate with ethanol solution and dry to obtain a modified flame retardant;

[0015] Further, the amount ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid, dicyclohexyl carbodiimide and anhydrous toluene is 0.1 mol: 0.3 mol: 3.5-4.5 g: 1.8-2.3 g: 350-420 mL, intermediate 1 and intermediate 2 esterify, and the specific reaction route is as follows:

[0016]

[0017] Preferably, the polyene-based crosslinking agent is triallyl isocyanurate, which has good reactivity and can crosslink with the modified flame retardant and POE thermal degradation products at high temperatures in a fire to form a dense carbonized layer, thereby improving the flame retardant effect.

[0018] Preferably, the promoter is triphenylphosphine, which has high-temperature catalysis and promotes the decomposition and recrosslinking of the polysulfide in the modified flame retardant molecule.

[0019] Preferably, the lubricant is ethylene bis-stearamide, which has stable lubrication in the POE system and is beneficial to the molding of the elastic material.

[0020] A preparation method of a flame-retardant lightweight elastic material, specifically: uniformly mixing raw materials, melt mixing and extruding by a double-screw extruder, and then pelletizing to obtain the flame-retardant lightweight elastic material.

[0021] The beneficial effects of the present application are:

[0022] The present application introduces a modified flame retardant into a POE matrix to improve the flame retardance of the matrix while maintaining the stability of the matrix under ignition conditions; the modified flame retardant is prepared by reacting o-aminobenzyl alcohol and formaldehyde to form a triazine compound containing a hydroxyl group, i.e., intermediate 1, by click addition reaction of mercaptoacetic acid and methyl allyl trisulfide to form intermediate 2 with a carboxyl group at the end, and by esterification of intermediate 2 and intermediate 1; in the fire ignition process, molecular-level stage flame retardation is achieved to achieve efficient fire suppression and low smoke and low loss, specifically:

[0023] In the first stage, the polysulfide branched chain decomposes to generate sulfur radicals under high temperature, which accurately capture the pyrolysis olefin chain of POE to form a dense crosslinked network in the near layer of the modified flame retardant molecule; in the second stage, the triazine structure in the middle of the modified flame retardant molecule decomposes to release fire-retardant gas, which is sealed by the outer layer of high crosslinked network and is not easy to be released, forming a honeycomb-like microcavity inside the matrix to block the heat conduction path and reduce the internal temperature rise rate; in the third stage, under the condition of continuous ignition and temperature rise, the high crosslinked layer containing benzene ring carbonizes to form a stable carbon layer to inhibit the deepening of combustion, and the dense carbon layer delays the escape rate of the fire-retardant gas to maintain the sustained concentration of the gas at the combustion front, avoiding the loosening and cracking of the carbon layer caused by the concentrated release of the gas in the traditional intumescent system, and maintaining the mechanical property stability of the material under fire. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0025] Embodiment 1: preparation of a flame-retardant lightweight elastic material, the specific implementation process is as follows:

[0026] (1) Synthesis of modified flame retardant

[0027] Step A1: Take o-aminobenzyl alcohol and acetone under nitrogen protection, control the temperature of water bath at 15℃, add formaldehyde solution and stir for 9h, then add sodium bicarbonate solution and continue to react at 45℃ for 2.2h, wherein the amount ratio of o-aminobenzyl alcohol, formaldehyde, sodium bicarbonate and acetone is 0.1mol:0.16mol:0.2g:130mL, the formaldehyde solution is an industrial raw material with a mass fraction of 44%, and the sodium bicarbonate solution is a saturated aqueous solution at room temperature. After the reaction is completed, remove the acetone by rotary evaporation, then add deionized water to the substrate and mix, separate the aqueous phase and dry to obtain intermediate 1.

[0028] Step A2: Take benzoin dimethyl ether and tetrahydrofuran, then add methyl allyl trithioether and mercaptoacetic acid, and apply 35mW / cm 2 irradiate and stir for 2.2h, wherein the amount ratio of methyl allyl trithioether, mercaptoacetic acid, benzoin dimethyl ether and tetrahydrofuran is 0.1mol:0.1mol:25mg:80mL. After the reaction is completed, remove the tetrahydrofuran by rotary evaporation to obtain intermediate 2.

[0029] Step A3: Take intermediate 1, intermediate 2, p-toluenesulfonic acid and anhydrous toluene, and mix them, then protect them by introducing dry nitrogen, heat to 90℃ and stir for 5h, then add dicyclohexyl carbodiimide and continue to heat to 110℃ for 1.2h, wherein the amount ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid, dicyclohexyl carbodiimide and anhydrous toluene is 0.1mol:0.3mol:3.5g:1.8g:350mL. After the reaction is completed, remove the toluene by rotary evaporation, clean and dry the substrate with ethanol solution to obtain the modified flame retardant.

[0030] (2) Preparation of elastomer material

[0031] Take the components according to weight percentage: modified flame retardant 3.5wt%, made by the present embodiment; polyene crosslinking agent 2.5wt%, select industrial-grade triallyl isocyanurate raw material; accelerator 0.1wt%, select industrial-grade triphenylphosphine raw material; lubricant 1.8wt%, select industrial-grade ethylene bis-stearamide raw material; antioxidant 0.15wt%, select antioxidant 1076 and antioxidant 168 for composite use according to weight ratio 2:1; and the rest is POE resin, select POE resin raw material type 6502.

[0032] Put each component raw material into a high-speed mixer and mix at 1200rpm for 5min, then put the mixed material into a twin-screw extruder, control the barrel temperature to be set as: zone 1 150℃, zone 2 160℃, zone 3 170℃, zone 4 180℃, zone 5 180℃, zone 6 175℃, melt and mix the mixed material, extrude and pelletize to obtain the flame-retardant lightweight elastomer material.

[0033] Example 2, preparation of flame-retardant lightweight elastomer material, the specific implementation process as follows:

[0034] (1) Synthesis of modified flame retardant

[0035] Step A1: take o-aminobenzyl alcohol and acetone under nitrogen protection, water bath control temperature is 30℃, add formaldehyde solution stirring reaction 6h, then add sodium bicarbonate solution and heating to 55℃ continue to react 1.6h, wherein, o-aminobenzyl alcohol, formaldehyde, sodium bicarbonate and acetone dosage ratio is 0.1mol:0.18mol:0.3g:170mL, formaldehyde solution is mass fraction of 44% of industrial raw materials, sodium bicarbonate solution is saturated aqueous solution at room temperature, reaction end spin evaporation remove acetone, then add deionized water to the substrate and mix, separate the water phase and dry, get intermediate 1.

[0036] Step A2: take benzoin dimethyl ether and tetrahydrofuran pre-mixed, then add methyl allyl sulfide and mercaptoacetic acid mixture, using UVA ultraviolet radiation 50mW / cm 2 Irradiation stirring reaction 1.5h, wherein, methyl allyl sulfide, mercaptoacetic acid, benzoin dimethyl ether and tetrahydrofuran dosage ratio is 0.1mol:0.1mol:35mg:100mL, reaction end spin evaporation remove tetrahydrofuran, get intermediate 2.

[0037] Step A3: take intermediate 1, intermediate 2, p-toluenesulfonic acid and anhydrous toluene mixture, dry nitrogen protection, heating to 100℃ stirring reaction 4h, then add dicyclohexyl carbodiimide continue heating to 110℃ reaction 1h, wherein, intermediate 1, intermediate 2, p-toluenesulfonic acid, dicyclohexyl carbodiimide and anhydrous toluene dosage ratio is 0.1mol:0.3mol:4.5g:2.3g:420mL, reaction end spin evaporation remove toluene, substrate with ethanol solution cleaning, drying, get modified flame retardant.

[0038] (2) Preparation of elastomer material

[0039] According to the weight percentage, take the components: modified flame retardant 5.2wt%, made by the example; polyene crosslinking agent 3.5wt%, select the industrial grade triallyl isocyanurate raw material; accelerator 0.13wt%, select the industrial grade triphenyl phosphine raw material; lubricant 1.4wt%, select the industrial agent ethylene bis stearyl amide raw material; antioxidant 0.2wt%, select the antioxidant 1076 and antioxidant 168 according to the weight ratio of 2:1 composite use; the rest is POE resin, select the 6502 type POE resin raw material.

[0040] The raw materials of each component were added into a high-speed mixer and mixed at 1200 rpm for 5 min, and then the mixture was added into a twin-screw extruder, and the barrel temperature was set as follows: 150 ℃ for zone 1, 160 ℃ for zone 2, 170 ℃ for zone 3, 180 ℃ for zone 4, 185 ℃ for zone 5, and 180 ℃ for zone 6. The mixture was melt-mixed, extruded and pelletized to obtain the flame-retardant lightweight elastomer material.

[0041] Example 3, preparation of a flame-retardant lightweight elastomer material, the specific implementation process is as follows:

[0042] (1) Synthesis of modified flame retardant

[0043] Step A1: Dissolve o-aminobenzyl alcohol and acetone in a nitrogen atmosphere, control the temperature of the water bath at 20 ℃, add formaldehyde solution and stir for 8 h, then add sodium bicarbonate solution and heat to 50 ℃ for 2 h, wherein the amount ratio of o-aminobenzyl alcohol, formaldehyde, sodium bicarbonate and acetone is 0.1 mol:0.17 mol:0.25 g:160 mL, the formaldehyde solution is an industrial raw material with a mass fraction of 44%, and the sodium bicarbonate solution is a saturated aqueous solution at room temperature. After the reaction is completed, remove the acetone by rotary evaporation, then add deionized water to the substrate and mix, separate the aqueous phase and dry to obtain intermediate 1.

[0044] Step A2: Mix benzoin dimethyl ether and tetrahydrofuran, then add methyl allyl trisulfide and mercaptoacetic acid, and apply UVA ultraviolet light at 45 mW / cm 2 Irradiate and stir for 1.7 h, wherein the amount ratio of methyl allyl trisulfide, mercaptoacetic acid, benzoin dimethyl ether and tetrahydrofuran is 0.1 mol:0.1 mol:30 mg:90 mL. After the reaction is completed, remove the tetrahydrofuran by rotary evaporation to obtain intermediate 2.

[0045] Step A3: Mix intermediate 1, intermediate 2, p-toluenesulfonic acid and anhydrous toluene, and protect with dry nitrogen, heat to 90 ℃ and stir for 4.5 h, then add dicyclohexyl carbodiimide and heat to 110 ℃ for 1.2 h, wherein the amount ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid, dicyclohexyl carbodiimide and anhydrous toluene is 0.1 mol:0.3 mol:4 g:2 g:380 mL. After the reaction is completed, remove the toluene by rotary evaporation, wash the substrate with ethanol solution and dry to obtain the modified flame retardant.

[0046] (2) Preparation of elastomer material

[0047] The components are taken by weight percentage: modified flame retardant 4.8wt%, self-made in this embodiment; polyene crosslinking agent 3.1wt%, selected from an industrial-grade triallyl isocyanurate raw material; accelerator 0.12wt%, selected from an industrial-grade triphenylphosphine raw material; lubricant 1.7wt%, selected from an industrial-grade ethylene bis-stearamide raw material; antioxidant 0.18wt%, selected from a composite use of antioxidant 1076 and antioxidant 168 in a weight ratio of 2:1; and the balance is POE resin, selected from a 6502 type POE resin raw material.

[0048] The raw materials of the components are added to a high-speed mixer for mixing at 1200rpm for 5min, the mixture is added to a twin-screw extruder, the barrel temperature is controlled to be set as: zone 1 150℃, zone 2 160℃, zone 3 170℃, zone 4 180℃, zone 5 180℃, and zone 6 175℃, the mixture is melt-mixed, extruded and pelletized to obtain the flame-retardant lightweight elastomer material.

[0049] Example 4, preparation of flame-retardant lightweight elastomer material, the specific implementation process is as follows:

[0050] (1) Synthesis of modified flame retardant

[0051] Step A1: Take o-aminobenzyl alcohol and acetone to be miscible under nitrogen protection, control the temperature of water bath to be 25℃, add formaldehyde solution to stir for 7.5h, then add sodium bicarbonate solution and heat to 50℃ to continue to react for 1.8h, wherein the amount ratio of o-aminobenzyl alcohol, formaldehyde, sodium bicarbonate and acetone is 0.1mol:0.18mol:0.3g:150mL, the formaldehyde solution is an industrial raw material with a mass fraction of 44%, the sodium bicarbonate solution is a saturated aqueous solution at room temperature, after the reaction, remove acetone by rotary evaporation, then add deionized water to the substrate to wash, separate the water phase and dry to obtain intermediate 1.

[0052] Step A2: Take benzoin dimethyl ether and tetrahydrofuran to be premixed, then add methyl allyl trisulfide and mercaptoacetic acid to mix, apply 40mW / cm 2 irradiation to stir for 1.8h, wherein the amount ratio of methyl allyl trisulfide, mercaptoacetic acid, benzoin dimethyl ether and tetrahydrofuran is 0.1mol:0.1mol:30mg:90mL, after the reaction, remove tetrahydrofuran by rotary evaporation to obtain intermediate 2.

[0053] Step A3: Intermediate 1, Intermediate 2, p-toluenesulfonic acid and anhydrous toluene were mixed, and dry nitrogen was introduced for protection. The temperature was raised to 100°C and stirred for 4.5h, then dicyclohexyl carbodiimide was added and the temperature was raised to 110°C and reacted for 1h. The amount ratio of Intermediate 1, Intermediate 2, p-toluenesulfonic acid, dicyclohexyl carbodiimide and anhydrous toluene was 0.1mol:0.3mol:4.2g:1.8g:400mL. After the reaction was completed, toluene was removed by rotary evaporation, and the substrate was washed with ethanol solution and dried to obtain a modified flame retardant.

[0054] (2) Preparation of elastomer material

[0055] The components were taken according to the weight percentage: modified flame retardant 4.5wt%, self-made by the present embodiment; polyene-based crosslinking agent 2.7wt%, industrial-grade triallyl isocyanurate raw material was selected; accelerator 0.11wt%, industrial-grade triphenylphosphine raw material was selected; lubricant 1.45wt%, industrial-grade ethylene bis-stearamide raw material was selected; antioxidant 0.16wt%, antioxidant 1076 and antioxidant 168 were used in a weight ratio of 2:1; the rest was POE resin, and 6502 type POE resin raw material was selected.

[0056] The raw materials of each component were added to the high-speed mixer and mixed at 1200rpm for 5min. The mixture was added to the twin-screw extruder, and the barrel temperature was set to: Zone 1 150°C, Zone 2 160°C, Zone 3 170°C, Zone 4 185°C, Zone 5 180°C, Zone 6 180°C. The mixture was melted, mixed, extruded and granulated to obtain a flame-retardant lightweight elastomer material.

[0057] In the comparative example, the modified flame retardant was replaced with 3wt% melamine cyanurate and 1.5wt% flame retardant FR-235, and the rest of the implementation process was the same as that of Example 4.

[0058] Samples were taken from the elastomer material prepared as above, and were hot-pressed into a 3.2mm thick sheet at 165°C and 10MPa. The flame retardant grade was tested according to the UL94 standard. The limiting oxygen index was tested according to ASTM D2863-23. The smoke density was tested according to ASTM E662-2017 standard. The sample was continuously reciprocated with a 2cm / s moving speed for 300s using an alcohol lamp as the ignition source. The ablated layer thickness was measured using a three-coordinate detector. The change rate of tensile strength before and after ignition treatment was tested according to ASTM D412-16. The specific test data is shown in Table 1:

[0059]

[0060] It can be seen from the test data in Table 1 that the samples made of the above elastomers all have good flame retardance, meeting the flame retardance requirements of general products. In the elastomers of the examples, the smoke density during the ignition process is extremely low, the carbon layer after the ignition treatment is thin, the surface quality is better, and the mechanical strength after the ignition decreases lower, which is beneficial to maintaining the stability of the material.

[0061] In the description of the specification, the description referring to the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0062] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A flame-retardant lightweight elastomer material, characterized in that, The specific components are: 3.5-5.2 wt% modified flame retardant, 2.5-3.5 wt% polyene crosslinking agent, 0.1-0.13 wt% accelerator, 1.4-1.8 wt% lubricant, and 0.15-0.2 wt% antioxidant, with the balance being POE resin; The modified flame retardant is prepared by the following method: Step A1: Mix o-aminobenzyl alcohol and acetone under nitrogen protection. The ratio of o-aminobenzyl alcohol, formaldehyde, sodium bicarbonate, and acetone is 0.1 mol: 0.16-0.18 mol: 0.2-0.3 g: 130-170 mL. Control the water bath temperature at 15-30℃, add formaldehyde solution and stir for 6-9 h. Then add sodium bicarbonate solution and raise the temperature to 45-55℃ to continue the reaction for 1.6-2.2 h to prepare intermediate 1. Intermediate 1 is a triazine compound formed by the reaction of o-aminobenzyl alcohol and formaldehyde. Step A2: Premix benzoin dimethyl ether and tetrahydrofuran, then add methyl allyl trisulfide and mercaptoacetic acid and mix. The ratio of methyl allyl trisulfide, mercaptoacetic acid, benzoin dimethyl ether, and tetrahydrofuran is 0.1 mol: 0.1 mol: 25-35 mg: 80-100 mL. Apply UVA ultraviolet light at 35-50 mW / cm². 2 Irradiation and stirring reaction for 1.5-2.2 h to prepare intermediate 2, wherein intermediate 2 is modified by reacting methyl allyl trisulfide and mercaptoacetic acid to form a terminal carboxyl group; Step A3: Mix intermediate 1, intermediate 2, p-toluenesulfonic acid and anhydrous toluene. The ratio of intermediate 1, intermediate 2, p-toluenesulfonic acid, dicyclohexylcarbodiimide and anhydrous toluene is 0.1mol:0.3mol:3.5-4.5g:1.8-2.3g:350-420mL. Purge with dry nitrogen for protection, heat to 90-100℃ and stir for 4-5 hours. Then add dicyclohexylcarbodiimide and continue heating to 110℃ for 1-1.2 hours to prepare the modified flame retardant.

2. The flame-retardant lightweight elastomer material according to claim 1, characterized in that, The polyene crosslinking agent is triallyl isocyanurate.

3. The flame-retardant lightweight elastomer material according to claim 1, characterized in that, The accelerator is triphenylphosphine.

4. The flame-retardant lightweight elastomer material according to claim 1, characterized in that, The lubricant is ethylene bis-stearamide.

5. A method for preparing a flame-retardant lightweight elastomer material according to any one of claims 1-4, characterized in that, Specifically, the raw materials are mixed evenly, melt-blended and extruded using a twin-screw extruder to obtain a flame-retardant lightweight elastomer material.

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