阅读说明：本技术 一种无卤阻燃剂及其制备方法 (Halogen-free flame retardant and preparation method thereof ) 是由 罗群 邱永福 程志毓 常学义 范洪波 于 2021-09-22 设计创作，主要内容包括：本发明公开了一种复配型无卤低烟阻燃剂,包括三种阻燃剂组分：第一组分是无规接枝纳米氢氧化铝和二茂铁基的线型聚乙烯亚胺ATH-PEI-Fc,第二组分是聚丙烯胺-二茂铁甲酸离子复合物PAH-Fc,第三组分是三-二茂铁甲酰胺基三聚氰胺ME-3Fc。阻燃剂通过上述三种组分按照一定的配比复配而成,将阻燃剂按照一定的比例加入到热塑性弹性体TPU中,通过挤出成型加工获得TPU-P材料,实验证明,TPU-P材料的无焰烟密度＜250,有焰烟密度＜100,具有良好的消烟效果。(The invention discloses a compound halogen-free low-smoke flame retardant, which comprises three flame retardant components: the first component is linear polyethyleneimine ATH-PEI-Fc of randomly grafted nano aluminum hydroxide and ferrocenyl, the second component is polyacrylamide-ferrocenecarboxylic acid ion complex PAH-Fc, and the third component is tri-ferrocenecarboxamido melamine ME-3 Fc. The flame retardant is compounded by the three components according to a certain proportion, the flame retardant is added into the thermoplastic elastomer TPU according to a certain proportion, and the TPU-P material is obtained by extrusion molding, and experiments prove that the TPU-P material has a flameless smoke density of less than 250 and a flaming smoke density of less than 100 and has a good smoke abatement effect.)

1. A halogen-free flame retardant is characterized in that: the flame retardant comprises a first flame retardant component, namely linear polyethyleneimine ATH-PEI-Fc randomly grafted with nano aluminum hydroxide and ferrocenyl, a second flame retardant component, namely polyacrylamide-ferrocenecarboxylic acid ion complex PAH-Fc, and a third flame retardant component, namely tri-ferrocenecarboxamido melamine ME-3Fc, wherein the chemical structural formulas of the components are as follows:

。

2. a method for preparing the halogen-free flame retardant of claim 1, comprising the steps of:

s1: synthesizing a first flame retardant component ATH-PEI-Fc;

s2: synthesizing a second flame retardant component PAH-Fc;

s3: synthesizing a third flame retardant component ME-3 Fc;

s4: the halogen-free flame retardant is prepared by mixing the components according to a certain proportion and carrying out ball milling and drying.

3. The method of claim 2, wherein the synthesis of ATH-PEI-Fc comprises the following steps:

s11: dissolving ferrocenecarboxylic acid in anhydrous dichloromethane, and adding oxalyl chloride for reaction;

s12: filtering dichloromethane and excessive oxalyl chloride, dissolving in dichloromethane again, adding linear polyethyleneimine for reaction, and performing rotary evaporation to remove the solvent to obtain a PEI-Fc solution;

s13: adding a silane coupling agent KH560 into an acetic acid solution with a pH value ranging from 4 to 5 for reaction for a certain time, and then adding nano-scale aluminum hydroxide ATH for further reaction to prepare an ATH solution;

s14: and adding the PEI-Fc solution into the ATH solution for reaction to prepare the ATH-PEI-Fc.

4. The method according to claim 3, wherein the step S12 is performed by adding linear polyethyleneimine and magnetically stirring under argon atmosphere at room temperature.

5. The method according to claim 3, wherein in step S13, the silane coupling agent KH560 is added and then the reaction is carried out in an oil bath under magnetic stirring at 80 degrees.

6. The method of claim 2, wherein the synthesis of PAH-Fc comprises the steps of:

s21: placing ferrocenecarboxylic acid and sodium hydroxide in a solution containing ethanol and water for reaction for a certain time;

s22: and adding polyacrylamide hydrochloride into the solution for further reaction to prepare the PAH-Fc.

7. The method of claim 2, wherein the synthesis of ME-3Fc comprises the steps of:

s31: dissolving ferrocenecarboxylic acid in anhydrous dichloromethane, and adding 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride and 1-hydroxybenzotriazole for reaction for a certain time;

s32: and adding melamine and triethylamine into the solution of the last time for further reaction to prepare the ME-3 Fc.

8. The method according to any one of claims 2 to 7, wherein the ATH-PEI-Fc, PAH-Fc, ME-3Fc are mixed in a ratio of 8:1:1, 7:2:1, 7:1:2, 6:2:2, 5:3:2, or 5:2: 3.

9. A preparation method of a halogen-free low-smoke TPU material comprises the following steps:

a) adding the flame retardant of claim 1 into a thermoplastic polyurethane elastomer (TPU) according to a certain proportion, mixing and drying;

b) and extruding and molding to obtain the halogen-free low-smoke TPU material.

10. The method of claim 9, wherein: an antioxidant and/or a heat stabilizer is also added in the step a).

Technical Field

The invention relates to the technical field of flame retardants, in particular to a halogen-free flame retardant and a preparation method thereof.

Background

The polymer material is widely applied to daily life of people, and most of the polymer materials have oxygen indexes lower than 20 and belong to inflammable substances. The heat, toxic gas and smoke released by the burning of the high molecular material can cause damage to human beings. The flame retardant greatly improves the flame retardant property of the flammable high polymer material. In recent years, halogen-containing flame retardants occupy most of the flame retardant markets, such as decabromodiphenyl oxide, tetrabromobisphenol A, chlorinated paraffin and the like. The use of halogen-containing flame retardants, while reducing the probability of combustion, still release significant amounts of smoke, toxic and corrosive hydrogen halide gases.

With the improvement of flame retardant requirements and the enhancement of environmental awareness, the development of non-halogenated, low-smoke, low-toxicity and efficient flame retardants becomes a technical problem to be solved urgently.

Disclosure of Invention

The invention provides a halogen-free flame retardant and a preparation method thereof, aiming at reducing smoke and toxic hydrogen halide gas released in the combustion process of a flame retardant-containing high polymer material.

In a first aspect, the invention provides a halogen-free flame retardant, which comprises linear polyethyleneimine ATH-PEI-Fc randomly grafted with nano aluminum hydroxide and ferrocenyl, a polyacrylamide-ferrocenecarboxylic acid ion complex PAH-Fc, and tri-ferrocenecarboxamido melamine ME-3Fc, and the chemical structural formula is as follows:

。

on the other hand, the invention also provides a preparation method of the halogen-free flame retardant, which comprises the following steps:

s1: synthesizing a first flame retardant component ATH-PEI-Fc;

s2: synthesizing a second flame retardant component PAH-Fc;

s3: synthesizing a third flame retardant component ME-3 Fc;

s4: the halogen-free flame retardant is prepared by mixing the components according to a certain proportion and carrying out ball milling and drying.

Further, the synthesis of ATH-PEI-Fc comprises the following steps:

s11: dissolving ferrocenecarboxylic acid in anhydrous dichloromethane, and adding oxalyl chloride for reaction;

s12: filtering dichloromethane and excessive oxalyl chloride, dissolving in dichloromethane again, adding linear polyethyleneimine for reaction, and performing rotary evaporation to remove the solvent to obtain a PEI-Fc solution;

s13: adding a silane coupling agent KH560 into an acetic acid solution with a pH value ranging from 4 to 5 for reaction for a certain time, and then adding nano-scale aluminum hydroxide ATH for further reaction to prepare an ATH solution;

s14: and adding the PEI-Fc solution into the ATH solution for reaction to prepare the ATH-PEI-Fc.

Further, the synthesis of PAH-Fc comprises the following steps:

s21: placing ferrocenecarboxylic acid and sodium hydroxide in a solution containing ethanol and water for reaction for a certain time;

s22: and adding polyacrylamide hydrochloride into the solution for further reaction to prepare the PAH-Fc.

Further, the synthesis of ME-3Fc comprises the following steps:

s31: dissolving ferrocenecarboxylic acid in anhydrous dichloromethane, and adding 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride and 1-hydroxybenzotriazole for reaction for a certain time;

s32: and adding melamine and triethylamine into the solution of the last time for further reaction to prepare the ME-3 Fc.

Further, the mixing ratio of ATH-PEI-Fc, PAH-Fc and ME-3Fc is 8:1:1, 7:2:1, 7:1:2, 6:2:2, 5:3:2 or 5:2: 3.

In addition, the invention also provides a preparation method of the halogen-free low-smoke TPU material, which comprises the following steps:

a) adding the flame retardant into a thermoplastic polyurethane elastomer TPU according to a certain proportion, mixing and drying;

b) and extruding and molding to obtain the halogen-free low-smoke TPU material.

The invention provides a halogen-free flame retardant and a preparation method thereof, which is characterized in that the halogen-free flame retardant is added into thermoplastic elastomer TPU according to a certain proportion, and the TPU-P material is obtained through extrusion molding, wherein the density of flameless smoke of the TPU-P material is less than 250, the density of flaming smoke is less than 100, and the TPU-P material has a good smoke abatement effect.

Drawings

FIG. 1 is a flow chart of a method for preparing a flame retardant in one embodiment of the present invention;

FIG. 2 is a schematic synthesis scheme of a first component ATH-PEI-Fc of a flame retardant in one embodiment of the present invention;

FIG. 3 is a synthesis scheme of a second component PAH-Fc of a flame retardant in one embodiment of the present invention;

FIG. 4 is a synthesis scheme of a third component ME-3Fc of a flame retardant in one embodiment of the present invention;

FIG. 5 is an infrared spectrum of a flame retardant and components in an embodiment of the invention;

FIG. 6 is a thermogravimetric plot of the flame retardant and its components in one embodiment of the present invention;

FIG. 7 is a graph of flameless combustion specific optical density of a TPU-P material in accordance with an embodiment of the present invention;

FIG. 8 is a graph of flame ratio optical density of a TPU-P material in accordance with an embodiment of the present invention.

Detailed Description

The invention provides a halogen-free flame retardant and a preparation method thereof, and the invention is further explained in detail below in order to make the purpose, technical scheme and effect of the invention clearer and more clear. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a halogen-free flame retardant, which comprises linear polyethyleneimine ATH-PEI-Fc randomly grafted with nano aluminum hydroxide and ferrocenyl, a polyacrylamide-ferrocenecarboxylic acid ion compound PAH-Fc and tri-ferrocenecarboxamido melamine ME-3Fc, and the chemical structural formula is as follows:

。

on the other hand, the invention also provides a preparation method of the halogen-free flame retardant, which comprises the following steps:

a) synthesizing a first flame retardant component ATH-PEI-Fc;

b) synthesizing a second flame retardant component PAH-Fc;

c) synthesizing a third flame retardant component ME-3 Fc;

d) the halogen-free flame retardant is prepared by mixing the components according to a certain proportion and carrying out ball milling and drying.

The skilled person will appreciate that the above steps a), b), c) are not sequential and that the order of synthesis of the individual flame retardant components can be adjusted as desired.

Referring to the synthetic route of ATH-PEI-Fc shown in FIG. 2, the synthesis of ATH-PEI-Fc comprises the following steps:

s11: dissolving ferrocenecarboxylic acid in anhydrous dichloromethane, and adding oxalyl chloride for reaction;

s12: filtering dichloromethane and excessive oxalyl chloride, dissolving in dichloromethane again, adding linear polyethyleneimine for reaction, and performing rotary evaporation to remove the solvent to obtain a PEI-Fc solution;

s13: adding a silane coupling agent KH560 into an acetic acid solution with a pH value ranging from 4 to 5 for reaction for a certain time, and then adding nano-scale aluminum hydroxide ATH for further reaction to prepare an ATH solution;

s14: and adding the PEI-Fc solution into the ATH solution for reaction to prepare the ATH-PEI-Fc.

Illustratively, the first flame retardant component, ATH-PEI-Fc, can be prepared by the following examples.

Weighing 1.22 g of dry ferrocenecarboxylic acid (5.3 mmol) and 50 ml of anhydrous dichloromethane, adding the dry ferrocenecarboxylic acid and the dry dichloromethane into a dry three-neck flask, stirring the mixture for half an hour at room temperature under the protection of argon to dissolve the ferrocenecarboxylic acid, quickly adding 2 ml of oxalyl chloride (about 23.6 mmol), reacting the mixture at room temperature for 3 hours, and heating and refluxing the mixture for 1 hour; the dichloromethane and the excessive oxalyl chloride are pumped out by a diaphragm pump, 50 ml of dichloromethane is added for dissolution, then the solution is added into a reaction bottle containing 1.82 g of linear Polyethyleneimine (PEI) and 50 ml of dichloromethane, the reaction is carried out for 12 hours at room temperature under the magnetic stirring of argon protection, the solvent is removed by rotary evaporation to obtain a compound PEI-Fc, 100 ml of ethanol and 20 ml of deionized water are added, and the solution is ultrasonically dispersed to obtain a PEI-Fc solution for later use.

Adding 100 ml of deionized water into a 500 ml flask, adjusting the pH value to 4-5 by using acetic acid, adding 1.25 g of silane coupling agent KH560 (Dow Corning Z-6040) and reacting for 40 minutes at room temperature; 12.5 g of nano-scale aluminum hydroxide ATH is added, oil bath is carried out for 5 hours at 80 ℃ under magnetic stirring, the PEI-Fc solution prepared above is added, and the reaction is continued for 5 hours at 80 ℃. And stopping the reaction, performing suction filtration by using a 0.22-micron microporous filter membrane, washing twice by using water and washing twice by using ethanol, and performing vacuum drying at 60 ℃ for 12 hours to obtain 11.2 g of a first component ATH-PEI-Fc of the flame retardant.

Referring to the synthetic route for PAH-Fc shown in fig. 3, the synthesis of PAH-Fc comprises the following steps:

s21: placing ferrocenecarboxylic acid and sodium hydroxide in a solution containing ethanol and water for reaction for a certain time;

s22: and adding polyacrylamide hydrochloride into the solution for further reaction to prepare the PAH-Fc.

Illustratively, the second flame retardant component PAH-Fc can be prepared by the following examples.

In a 250 ml single-neck flask, 0.5 g ferrocenecarboxylic acid (FcCOOH, 2.17 mmol) and 30 ml absolute ethyl alcohol are added, 87 mg sodium hydroxide and 10 ml deionized water are added, and heating reflux is carried out at 80 ℃ for half an hour; then 203 mg of stirring polyallylamine hydrochloride (PAH, 2.17 mmol) and 20 ml of deionized water are added, the heating reflux is continued for 2 hours, the reaction is stopped, the ethanol is removed by rotation, the filtration and the water washing are carried out for three times, and the 60-degree vacuum drying is carried out for 12 hours, thus obtaining 292.6 mg of tan solid PAH-Fc.

Referring to the synthetic route for ME-3Fc shown in FIG. 4, the synthesis of ME-3Fc comprises the following steps:

s31: dissolving ferrocenecarboxylic acid in anhydrous dichloromethane, and adding 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride and 1-hydroxybenzotriazole for reaction for a certain time;

s32: and adding melamine and triethylamine into the solution of the last time for further reaction to prepare the ME-3 Fc.

Illustratively, the third flame retardant component ME-3Fc can be prepared by the following examples.

Under argon atmosphere, 1.38 g of ferrocenecarboxylic acid (6.0 mmol) and 100 ml of anhydrous dichloromethane are added into a 250 ml dry three-neck flask, an ice-water bath is cooled to about 5 ℃, 1.15 g of 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDCl, 6.0 mmol) and 1-hydroxybenzotriazole (HOBt, 7.2 mmol) are added, and the reaction is carried out for 1 hour at 5 ℃; 252 mg of melamine (2.0 mmol), 1.21 g of triethylamine (12.0 mmol) and 30 ml of dichloromethane were added, and the reaction was continued at 5 ℃ for 3 hours and at room temperature for 24 hours. The reaction was stopped, washed once with aqueous sodium bicarbonate, twice with pure water, dried over anhydrous magnesium sulfate, filtered, the solvent was removed by rotary column chromatography using dichloromethane as eluent to give 0.878 mg of ME-3Fc as an orange-red solid.

Mixing the flame retardant components at room temperature according to a certain proportion, preferably, the mixing proportion of ATH-PEI-Fc, PAH-Fc and ME-3Fc is 8:1:1, 7:2:1, 7:1:2, 6:2:2, 5:3:2 or 5:2:3, ball-milling by using a nano ball mill, and drying to obtain the halogen-free low-smoke flame retardant. In one embodiment, the mixing ratio of ATH-PEI-Fc, PAH-Fc and ME-3Fc is 8:1:1, and the halogen-free low-smoke flame retardant P is prepared after ball milling and drying.

In addition, the invention also provides a preparation method of the halogen-free low-smoke TPU material, which comprises the following steps:

a) adding the flame retardant into the thermoplastic polyurethane elastomer TPU according to the proportion (such as 10%, 20%, 30%, 40% and the like), mixing and drying;

b) and (3) carrying out extrusion molding at the temperature of 150-230 ℃ by using a double-screw extruder to prepare the halogen-free low-smoke TPU material.

Illustratively, 10% of flame retardant is added into thermoplastic polyurethane elastomer TPU, then other auxiliary agents such as antioxidant, heat stabilizer and the like are added, and after mixing and drying, extrusion molding is carried out by a double-screw extruder at the temperature of 150 ℃ and 230 ℃ to prepare the halogen-free low-smoke TPU material, which is called TPU-P for short.

FIG. 5 is an infrared spectrum of the halogen-free low-smoke flame retardant P and the components. As can be seen from the figure, the infrared spectrum of the flame retardant A component (ATH-PEI-Fc) is 3447cm^-1A strong absorption peak of hydroxyl appears at 2940 cm^-1There is an asymmetric stretching vibration peak of methylene at 1628 cm^-1There are infrared absorption peaks at 1463 and 1018 cm for amine groups^-1The existence of an infrared absorption peak of ferrocenyl indicates that the ATH-PEI-Fc is successfully synthesized. For component B (PAH-Fc), at 1640 cm^-1The deformation vibration peak of H3N + -appears at 1680 cm^-1The presence of a stretching vibration absorption peak of the carbonyl group of the carboxylate radical indicates that PAH-Fc is successfully synthesized. For component C (ME-3Fc), at 1775 cm^-1There are strong absorption peaks of carbonyl groups at 1448 and 1001 cm^-1The infrared absorption peak of ferrocenyl, namely ME-3Fc, was also successfully synthesized. The infrared absorption peaks of the components A, B and C can be seen from the infrared spectrum of the flame retardant P.

In order to further investigate the thermal stability of the flame retardant P and its individual components. Thermogravimetric analysis was performed on the sample, and the thermogravimetric curve is shown in FIG. 6. It can be seen that the flame retardant P and its A, B and C components all have good thermal stability below 200 ℃. The components B and C have obvious weightlessness at 220 ℃, and the component A begins to have weightlessness at 270 ℃. After compounding, the flame retardant P begins to have obvious weight loss at 260 ℃. The flame retardant P is used as a polymer material auxiliary agent, and shows good thermal stability under the thermoforming processing condition of conventional polymer materials.

FIGS. 7 and 8 are the flameless combustion specific optical density curves and the flamed combustion specific optical density profiles, respectively, for TPU-P. As can be seen from the figure, after the halogen-free low-smoke flame retardant P is added, the density of the flameless smoke of the TPU-P material is less than 250, the density of the flaming smoke is less than 100, and the TPU-P material has good smoke abatement effect.

In conclusion, the invention provides a compound type halogen-free low-smoke flame retardant, which comprises three flame retardant components: the first component is linear polyethyleneimine ATH-PEI-Fc of randomly grafted nano aluminum hydroxide and ferrocenyl, the second component is polyacrylamide-ferrocenecarboxylic acid ion complex PAH-Fc, and the third component is tri-ferrocenecarboxamido melamine ME-3 Fc. The flame retardant is prepared by compounding the three components according to a certain proportion. The flame retardant P is added into the thermoplastic elastomer TPU according to a certain proportion, and the TPU-P material is obtained through extrusion molding processing, and experiments prove that the TPU-P material has a flameless smoke density of less than 250 and a flamed smoke density of less than 100, and has a good smoke abatement effect.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.