A class of flame retardant containing melamine structure, preparation method and application thereof

Abstract

The invention relates to a kind of flame retardant containing melamine structure, its preparation method and its application. The chemical structural formula is: wherein, the substituent R 1 ,R 2 and R 3 It is hydrogen, tert-butyl, n-butyl, cyclohexylalkyl or any one of chlorine, bromine, methyl, methoxy, nitro, amino, hydroxyl-substituted aryl or heteroaryl. The synthesis method is to use carboxylic acid compounds, melamine, aldehyde compounds and isonitrile compounds under the synergistic catalysis of MCM-41 supported copper complex, MIL-101 and p-toluenesulfonic acid in methanol and isopropyl at 50°C. Ugi reaction occurs in a mixed solvent of alcohol, and the product is filtered, extracted and column chromatographed to obtain a melamine-containing flame retardant. This invention describes a new preparation method with simple reaction, few by-products and good selectivity for selectively synthesizing melamine flame retardants. The flame retardant of the present invention has good thermal stability, high flame retardancy, and purity of 97.2%. The raw materials used are easily available, the technology is advanced, and it is easy to be industrialized.

Description

technical field

[0001] The invention relates to a class of flame retardant containing melamine structure, a preparation method and application research thereof. Background technique

[0002] When traditional halogen-containing flame retardant materials are burned, secondary hazards such as smoke, toxic or corrosive gases are emitted, which pose a serious threat to personal safety. Therefore, it is particularly important to find new halogen-free flame retardants. Melamine-based flame retardants have the characteristics of halogen-free and low toxicity; high decomposition temperature, suitable for processing; small impact on mechanical properties; The great development value has caused people to study extensively. In the United Kingdom, Europe and North America, melamine derivatives are used to improve the flame retardancy of polyurethane foam, and have been extended to other types of polymers, such as hard polyurethane foam and thermoplastics. Recently, the application test...

Examples

specific Embodiment approach

[0032] The present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited to the scope expressed in the examples.

[0033] Instruments and reagents:

[0034] The melting point was measured with an X4 melting point apparatus (produced by Beijing Third Optical Instrument Factory), and the thermometer was not calibrated; 1 H NMR and 13 C NMR is measured with Varian Mercury 400 type 400MHz nuclear magnetic resonance instrument or Varian Mercury 600 type 600MHz nuclear magnetic resonance instrument, deuterated chloroform (CDCl 3 ) or deuterated dimethyl sulfoxide (DMSO-d 6 ) as the solvent and TMS as the internal standard; MS was determined using a FinniganTrace mass spectrometer; elemental analysis was determined using a Vario EL III elemental analyzer; the reagents used were domestic (or imported) chemically pure or analytically pure. Solvents methanol and isopropanol were dried.

Embodiment 1

[0036] A method for preparing N-(tert-butyl)-2-(N-(4,6-diamino-1,3,5-triazin-2-yl)formamido)acetamide flame retardant, comprising the following experimental steps:

[0037] Under nitrogen protection, compound melamine 1 (0.378g, 3mmol, 3.0eqv.), formic acid 2a (0.046g, 1.0mmol, 1.0eqv.), formaldehyde 3a (0.030g, 1.0mmol, 1.0eqv.) were added to the reactor successively. ), tert-butylisonitrile 4a (0.091g, 1.1mmol, 1.1eqv.), MeOH:i-PrOH=2:1 (10ml), heated to 50°C and stirred for 30 minutes to dissolve it. After dissolving, add the copper complex (0.025g) supported by the catalyst MCM-41, MIL-101 (0.025g) and p-toluenesulfonic acid (0.017g) and continue to stir while the temperature drops to 40°C. After continuing the reaction for 24h, TLC After the detection reaction was completed, the solvents methanol and ethanol were removed under reduced pressure, and the residue was filtered, extracted and column chromatographed to obtain the target flame retardant Ia with a yield of 57.01%...

Embodiment 2

[0045] A method for preparing octyl 2-(2-(N-(4,6-diamino-1,3,5-triazin-2-yl)formamido)acetamido)acetate flame retardant, comprising the following experimental steps:

[0046]Under the protection of nitrogen, compound melamine 1 (0.378g, 3mmol, 3.0eqv.), formic acid 2a (0.046g, 1.0mmol, 1.0eqv.), formaldehyde 3a (0.030g, 1.0mmol, 1.0eqv.) were added to the reactor successively. ), n-octyl acetate isonitrile 4b (0.22 g, 1.1 mmol, 1.1 eqv.), MeOH:i-PrOH=2:1 (10 ml), heated to 50°C and stirred for 30 minutes to dissolve it. After dissolving, add the copper complex (0.025g) supported by the catalyst MCM-41, MIL-101 (0.025g) and p-toluenesulfonic acid (0.017g) and continue stirring while the temperature drops to 40°C. After continuing the reaction for 24h, TLC After the detection reaction was completed, the solvents methanol and ethanol were removed under reduced pressure, and the residue was filtered, extracted and column chromatographed to obtain the target flame retardant Ia with...

technical field

[0001] The invention relates to a class of flame retardant containing melamine structure, a preparation method and application research thereof. Background technique

[0002] When traditional halogen-containing flame retardant materials are burned, secondary hazards such as smoke, toxic or corrosive gases are emitted, which pose a serious threat to personal safety. Therefore, it is particularly important to find new halogen-free flame retardants. Melamine-based flame retardants have the characteristics of halogen-free and low toxicity; high decomposition temperature, suitable for processing; small impact on mechanical properties; The great development value has caused people to study extensively. In the United Kingdom, Europe and North America, melamine derivatives are used to improve the flame retardancy of polyurethane foam, and have been extended to other types of polymers, such as hard polyurethane foam and thermoplastics. Recently, the application test...

Examples

specific Embodiment approach

[0032] The present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited to the scope expressed in the examples.

[0033] Instruments and reagents:

[0034] The melting point was measured with an X4 melting point apparatus (produced by Beijing Third Optical Instrument Factory), and the thermometer was not calibrated; 1 H NMR and 13 C NMR is measured with Varian Mercury 400 type 400MHz nuclear magnetic resonance instrument or Varian Mercury 600 type 600MHz nuclear magnetic resonance instrument, deuterated chloroform (CDCl 3 ) or deuterated dimethyl sulfoxide (DMSO-d 6 ) as the solvent and TMS as the internal standard; MS was determined using a FinniganTrace mass spectrometer; elemental analysis was determined using a Vario EL III elemental analyzer; the reagents used were domestic (or imported) chemically pure or analytically pure. Solvents methanol and isopropanol were dried.

Embodiment 1

[0036] A method for preparing N-(tert-butyl)-2-(N-(4,6-diamino-1,3,5-triazin-2-yl)formamido)acetamide flame retardant, comprising the following experimental steps:

[0037] Under nitrogen protection, compound melamine 1 (0.378g, 3mmol, 3.0eqv.), formic acid 2a (0.046g, 1.0mmol, 1.0eqv.), formaldehyde 3a (0.030g, 1.0mmol, 1.0eqv.) were added to the reactor successively. ), tert-butylisonitrile 4a (0.091g, 1.1mmol, 1.1eqv.), MeOH:i-PrOH=2:1 (10ml), heated to 50°C and stirred for 30 minutes to dissolve it. After dissolving, add the copper complex (0.025g) supported by the catalyst MCM-41, MIL-101 (0.025g) and p-toluenesulfonic acid (0.017g) and continue to stir while the temperature drops to 40°C. After continuing the reaction for 24h, TLC After the detection reaction was completed, the solvents methanol and ethanol were removed under reduced pressure, and the residue was filtered, extracted and column chromatographed to obtain the target flame retardant Ia with a yield of 57.01%...

Embodiment 2

[0045] A method for preparing octyl 2-(2-(N-(4,6-diamino-1,3,5-triazin-2-yl)formamido)acetamido)acetate flame retardant, comprising the following experimental steps:

[0046]Under the protection of nitrogen, compound melamine 1 (0.378g, 3mmol, 3.0eqv.), formic acid 2a (0.046g, 1.0mmol, 1.0eqv.), formaldehyde 3a (0.030g, 1.0mmol, 1.0eqv.) were added to the reactor successively. ), n-octyl acetate isonitrile 4b (0.22 g, 1.1 mmol, 1.1 eqv.), MeOH:i-PrOH=2:1 (10 ml), heated to 50°C and stirred for 30 minutes to dissolve it. After dissolving, add the copper complex (0.025g) supported by the catalyst MCM-41, MIL-101 (0.025g) and p-toluenesulfonic acid (0.017g) and continue stirring while the temperature drops to 40°C. After continuing the reaction for 24h, TLC After the detection reaction was completed, the solvents methanol and ethanol were removed under reduced pressure, and the residue was filtered, extracted and column chromatographed to obtain the target flame retardant Ia with...

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