Halogen-free flame-retardant acrylic acid material containing amino acid, and preparation method therefor

Abstract

A halogen-free flame-retardant acrylic acid material containing an amino acid. A preparation method therefor comprises the following steps: (1) emulsification and dispersion: respectively adding deionized water, an emulsifier, an acrylate monomer, an initiator and a flame-retardant monomer into an emulsifying kettle, and stirring the mixture for 30-60 minutes after the addition is finished, to perform emulsification and dispersion, so as to prepare an emulsified liquid; (2) nucleophilic addition reaction: adding the emulsified liquid into a reaction kettle, heating same to 30-60°C, and then adding an amino acid thereto, wherein the temperature of the reaction system is maintained constant during the process until the reaction is finished; (3) curing and degassing the reacted materials, and then filtering same to obtain an acrylate emulsion containing an amino acid; (4) adding a defoaming agent and a thickening agent into the emulsion in step (3), and adjusting the product quality; and (5) filtering and filling the materials to obtain a flame-retardant material.

Description

Amino acid-containing acrylic halogen-free flame retardant material and preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the field of fine chemical technology, and in particular to an amino acid-containing acrylic halogen-free flame retardant material and a preparation method thereof. BACKGROUND

[0002] Halogen-free of flame retardants has become an irresistible historical trend. Although halogen-based flame retardants have the advantage of high cost performance, they produce a large amount of toxic and corrosive gas during combustion, which has caused people's concern about environmental problems. In the existing research, the development of flame retardants is developing towards a more green and environmentally friendly direction, and bio-based flame retardants have gradually become the mainstream research direction. However, how to ensure the flame retardant efficiency and durability of the flame retardant still needs to be faced with challenges. Therefore, bio-based hydrophobic flame retardants with excellent performance are currently in urgent need of functional products in the market.

[0003] Amino acids are a class of common small molecule compounds, and are basic building blocks of biological functional macromolecules. Amino acids are widely available, abundant, and structurally diverse. Amino acids contain amino and carboxyl groups in their structure. Amino groups can be used as reaction sites and can be used to synthesize nitrogen-containing flame retardants, which have strong designability. In traditional technology, glycine and triazine rings are combined to prepare a synergist for intumescent flame retardant systems. Patent CN111440357B discloses a full-bio-based flame retardant, a flame-retardant PLA composite material and a preparation method thereof, which uses biologically derived phytic acid and sulfur-containing amino acid as raw materials to synthesize a full-bio-based flame retardant; patent CN114249768A uses amino acids, aldehyde compounds and phosphorus-containing compounds to prepare amino acid-based phosphorus flame retardants. However, the above-mentioned bio-based flame retardant technology is not perfect, mainly in that the reaction system is relatively complicated and the overall flame retardant effect needs to be further improved.

[0004] Therefore, the main technical problems existing in the existing flame retardant system are:

[0005] (1) Halogen-based flame retardants produce a large amount of toxic and corrosive gas during combustion, which is harmful to the environment and human body.

[0006] (2) The bio-based flame retardant technology is not perfect, and the flame retardant effect needs to be improved. SUMMARY

[0007] The purpose of the present application is to provide an amino acid-containing acrylic halogen-free flame retardant material and a preparation method thereof.

[0008] The purpose of the present application is achieved by the following technical solutions:

[0009] Amino acid-containing acrylic halogen-free flame-retardant material, characterized in that the flame-retardant material is prepared by reacting amino acid and acrylic ester emulsion; and has the following structure represented by the formula:

[0010] R1=CHCONH-R2

[0011] wherein R1 is a unit of the acrylic ester emulsion, and R2 is a unit of the amino acid.

[0012] The amino acid is at least one of glycine, phenylalanine, tyrosine, arginine, aspartic acid, glutamic acid, lysine, threonine, serine and tryptophan.

[0013] The preparation method of the flame-retardant material, characterized in that it comprises the following steps:

[0014] ① Emulsification and dispersion: adding deionized water, emulsifier, acrylic ester monomer, initiator and flame-retardant monomer into an emulsification kettle respectively, and stirring for 30-60 minutes for emulsification and dispersion to prepare an emulsion;

[0015] ② Nucleophilic addition reaction: adding the emulsion into a reaction kettle, and then adding amino acid when the temperature is 30-60℃, and keeping the temperature of the reaction system unchanged until the reaction is completed;

[0016] ③ After the reaction, the material is aged, degassed, filtered and an amino acid-containing acrylic ester emulsion is prepared;

[0017] ④ Adding defoaming agent and thickening agent to the emulsion of ③ to adjust the quality of the product;

[0018] ⑤ Filtering and filling the material to prepare the flame-retardant material.

[0019] The molar ratio of the amino acid to the acrylic ester emulsion is 1:0.8-1:8.

[0020] The acrylic ester emulsion is prepared from the following raw materials by weight: acrylic ester monomer 50-60 parts, emulsifier 5-8 parts, initiator 0.5-1.0 parts, flame-retardant monomer 2-10 parts and deionized water 30-40 parts.

[0021] The thickening agent is 1-3 parts.

[0022] The defoaming agent is 0.5-1 part.

[0023] In the raw materials for preparing the acrylic ester emulsion, the acrylic ester monomer is a mixture of acrylic acid, ethyl acrylate, butyl acrylate and methyl methacrylate; preferably, the mass ratio of acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate and vinyl acetate is 2:1:1:1.

[0024] The flame retardant monomer is at least one of ammonium polyphosphate, phosphate ester, tricresyl phosphate, melamine, urea.

[0025] The emulsifier is at least one of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate;

[0026] Preferably, the initiator is at least one of sodium persulfate, potassium sulfate or ammonium persulfate;

[0027] Preferably, the thickening agent is a polyacrylate alkaline thickening agent;

[0028] Preferably, the defoaming agent is a mineral oil defoaming agent or a silicone defoaming agent.

[0029] In the polymerization reaction process of the preparation of the acrylic emulsion, the temperature of the reaction system is controlled at 40-50 DEG C.

[0030] In the step 4, when the defoaming agent and the thickening agent are added into the reaction solution, a bactericide can also be added.

[0031] The amino acid-containing acrylic halogen-free flame-retardant material has good mechanical properties, excellent flame-retardant function and durability, and has a good application prospect in cotton fabric and other materials.

[0032] The amino acid-containing acrylic halogen-free flame-retardant material has the following mechanism:

[0033] 1. The acrylate emulsion is combined with the flame retardant monomer, thereby imparting certain flame retardancy to the emulsion.

[0034] 2. The carboxyl group in the amino acid can undergo dehydration reaction with the carbon source during heating to promote the generation of more carbon. Through the nucleophilic addition reaction of the acrylate emulsion and the amino acid, the structure plays a role in adjusting the ratio and interaction between the acid source, the carbon source and the gas source in the flame-retardant system.

[0035] At the same time, the acrylate monomer is a mixture of acrylic acid, ethyl acrylate, butyl acrylate and methyl methacrylate, which can improve the bonding properties of the polymer and the adhesion of the coating, provide a basis for the later crosslinking and curing of the emulsion, and is conducive to the transfer of monomers from droplets to micelles in the reaction process, thereby improving the reaction rate; the emulsifier can reduce the interfacial tension between the oil phase and the water phase and obtain a stable emulsion system through its emulsification effect. Therefore, the amino acid-containing acrylic halogen-free flame-retardant material prepared by the present application has good mechanical properties, excellent flame-retardant function and durability. DETAILED DESCRIPTION

[0036] The specific embodiments of the present application are described in detail below, but the scope of protection of the present application is not limited by the specific embodiments. It should be noted that the experimental methods used in the following examples are conventional methods unless otherwise specified; the materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0037] Unless otherwise specified, the specific conditions in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are conventional products that can be obtained by commercial purchase. In order to make the purpose, technical scheme and advantages of the examples of the present application clearer, the technical scheme in the examples of the present application will be described clearly and completely below. Preparation Example 1

[0038] Take the following mass fraction components of raw materials: acrylate monomer 50 parts, emulsifier (sodium dodecyl benzene sulfonate) 5 parts, initiator (sodium sulfate) 0.5 parts, deionized water 40 parts, flame retardant monomer (ammonium polyphosphate) 2 parts, wherein the acrylate monomer is acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate, in a mass ratio of 2:1:1:1. The preparation method is as follows:

[0039] Add the above mass fraction of deionized water, emulsifier, acrylate monomer, flame retardant monomer into the emulsification kettle respectively, after the feeding is completed, emulsify and disperse for 30 minutes, and prepare the emulsion. Preparation Example 2

[0040] Take the following mass fraction components of raw materials: acrylate monomer 60 parts, emulsifier (sodium dodecyl sulfate) 8 parts, initiator (potassium sulfate) 1 part, deionized water 35 parts, flame retardant monomer (tricresyl phosphate) 10 parts, wherein the acrylate monomer is acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate, in a mass ratio of 2:1:1:1. The preparation method is as follows:

[0041] Add the above mass fraction of deionized water, emulsifier, acrylate monomer, flame retardant monomer into the emulsification kettle respectively, after the feeding is completed, emulsify and disperse for 60 minutes, and prepare the emulsion. Preparation Example 3

[0042] Take the following mass fraction components of raw materials: acrylate monomer 55 parts, emulsifier (sodium dodecyl sulfate) 6 parts, initiator (ammonium persulfate) 0.8 parts, deionized water 30 parts, flame retardant monomer (melamine) 6 parts, wherein the acrylate monomer is acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate, in a mass ratio of 2:1:1:1. The preparation method is as follows:

[0043] The emulsifying kettle was added with the above-mentioned mass fraction of deionized water, emulsifier, acrylate monomer and flame-retardant monomer respectively, and after the feeding was completed, emulsification and dispersion were carried out for 50 minutes to prepare an emulsion.

[0044] In the above preparation example

[0045] The emulsion can also be prepared by replacing the flame-retardant monomer with phosphate, urea or a mixture thereof. Example 1

[0046] The following mass fraction of components were taken: 55 parts of the acrylate emulsion obtained in Preparation Example 2, 110 parts of amino acid, 1 part of thickening agent (polyacrylate alkaline thickening agent) and 0.5 part of defoaming agent (mineral oil defoaming agent).

[0047] The preparation method of the amino acid-containing acrylate halogen-free flame-retardant material is as follows:

[0048] ① Emulsification and dispersion: the emulsifying kettle was added with deionized water, emulsifier, acrylate monomer, initiator and flame-retardant monomer respectively, and after the feeding was completed, emulsification and dispersion were carried out for 30-60 minutes to prepare an emulsion;

[0049] ② Nucleophilic addition reaction: the emulsion was added to the reaction kettle, the temperature was raised to 30°C, and then phenylalanine was added, and the temperature of the reaction system was kept constant during the process until the reaction was completed;

[0050] ③ After the reaction, the material was aged, degassed, filtered and an amino acid-containing acrylate emulsion was prepared;

[0051] ④ The emulsion of ③ was added with defoaming agent and thickening agent, and the product quality was adjusted;

[0052] ⑤ The material was filtered and filled to prepare a flame-retardant material.

[0053] Note: after the reaction of the second step, infrared detection showed that there was an infrared absorption peak corresponding to amide group (-CONH-) at 3100 cm -1 . Examples 2-5

[0054] The following mass fraction of components were taken:

[0055] Table 1: Raw material component ratio of amino acid-containing acrylate halogen-free flame-retardant material in Examples 2-5

[0056]

[0057] The flame-retardant material containing acrylate emulsion was prepared by using the preparation method in Example 1. Comparative Example 1

[0058] The flame-retardant material was prepared by the method of Example 1 of reference patent document CN114249768A. The amount of amino acid used was the same as in Example 1. Comparative Example 2

[0059] The emulsion in Preparation Example 1 of the present application was matured and degassed, filtered, and then a defoaming agent and a thickening agent were added to prepare the flame-retardant material. Test Example 1

[0060] The flame-retardant materials prepared in Examples 1-5 and Comparative Examples 1-2 were compared in terms of afterflame time and limiting oxygen index as follows.

[0061] The products prepared in Examples 1-5 and Comparative Examples 1-2 were used as soaking solutions for cotton fabric. The cotton fabric was soaked in the above-mentioned solution at 70°C for 1 h, and the mass ratio of the cotton fabric to the volume of the flame-retardant material (emulsion) was 1:20. After soaking, the cotton fabric was passed through a mangle to maintain a liquid retention rate of 100%, and then the cotton fabric was passed through a continuous stenter dryer at 190°C for 5 min. Finally, the flame-retardant material (emulsion) adhering to the surface of the cotton fabric was washed clean, and then the cotton fabric was dried in an oven at 60°C. The above-mentioned procedure was repeated once, and the limiting oxygen index of the cotton fabric was determined (ASTM D2863-2000), the vertical burning test was performed (ASTM D6413-99), and the flame-retardant washability test was performed (AATCC 61-2006). The test results are shown in Table 2.

[0062] Table 2 Test results of afterflame time and limiting oxygen index of the flame-retardant materials prepared in Examples 1-5 and Comparative Examples 1-2

[0063]

[0064] From the above data analysis, it can be seen that the products prepared in the examples have excellent flame retardancy and durability. The examples all have a high oxygen index, and the limiting oxygen index can reach 44.2% at most. Even after 50 washes, the limiting oxygen index can still be maintained at 34.3% at most, reaching the flame-retardant standard for cotton fabric. Compared with Comparative Examples 1 and 2, the products have better synergistic flame-retardant effect.

[0065] The above examples have described the technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modification, supplement, and equivalent replacement within the principle range of the present application should be included in the protection scope of the present application.

Claims

1. An amino acid-containing acrylic halogen-free flame retardant material, characterized by, The flame-retardant material is prepared by reacting raw materials of amino acid and acrylate emulsion; has a structure represented by the following formula: R1=CHCONH-R2 wherein R1 is a unit of acrylate emulsion, and R2 is a unit of amino acid.

2. The flame retardant material of claim 1, wherein, The amino acid is at least one of glycine, phenylalanine, tyrosine, arginine, aspartic acid, glutamic acid, lysine, threonine, serine, and tryptophan.

3. The method for preparing flame-retardant materials according to any one of claims 1-2, characterized in that, The method comprises the following steps: ① Emulsification and dispersion: deionized water, emulsifier, acrylate monomer, initiator, and flame-retardant monomer are added into an emulsification kettle respectively, and then stirred for 30-60 minutes for emulsification and dispersion to prepare an emulsion; ② Nucleophilic addition reaction: the emulsion is added into a reaction kettle, and the temperature is raised to 30-60℃, and then the amino acid is added, and the temperature of the reaction system is kept unchanged until the reaction is completed; ③ After the reaction, the material is aged and degassed, filtered, and then an acrylate emulsion containing amino acid is prepared; ④ The emulsion of ③ is added with defoaming agent and thickening agent, and the product quality is adjusted; ⑤ The material is filtered and filled to prepare the flame-retardant material.

4. The flame retardant material according to any one of claims 1 to 3, characterized in that, The acrylate emulsion is prepared from the following raw materials by weight: acrylate monomer 50-60 parts, emulsifier 5-8 parts, initiator 0.5-1.0 parts, flame-retardant monomer 2-10 parts, deionized water 30-40 parts; the thickening agent 1-3 parts; and the defoaming agent 0.5-1 part.

5. The flame retardant material according to any one of claims 1 to 4, characterized in that, The mass ratio of the amino acid to the acrylate emulsion is 1:0.5-1:

10.

6. The flame retardant material according to any one of claims 3-5, characterized in that, In the raw materials for preparing the acrylate emulsion, the acrylate monomer is a mixture of acrylic acid, ethyl acrylate, butyl acrylate, and methyl methacrylate; preferably, the mass ratio of acrylic acid, butyl acrylate, ethyl acrylate, methyl methacrylate, and vinyl acetate is 2:1:1:

1.

7. The flame retardant material according to any one of claims 3-6, characterized in that, The flame-retardant monomer is at least one of ammonium polyphosphate, phosphate ester, cresyl phosphate, melamine, and urea. Preferably, the emulsifier is at least one of sodium dodecyl sulfate and sodium dodecyl benzene sulfonate. Preferably, the initiator is at least one of sodium persulfate, potassium sulfate, and ammonium persulfate. Preferably, the thickening agent is a polyacrylate alkaline thickening agent. Preferably, the defoaming agent is a mineral oil defoaming agent or a silicone defoaming agent.

8. The method for preparing the flame-retardant material according to claim 3, characterized in that, During the polymerization reaction process of the acrylate emulsion, the temperature of the reaction system is controlled at 40-50℃.

9. The method of producing a flame-retardant material according to any one of claims 3 to 6, characterized in that, In step ④, the bactericide can also be added when the defoaming agent and the thickening agent are added into the reaction liquid; preferably, the bactericide is potassium sorbate or sodium benzoate.

10. Application of the amino acid-containing acrylate halogen-free flame-retardant material of claim 1 or 3 in cotton fabric material.

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