Flame-retardant ammonium polyphosphate derivatives, process for their preparation and use

Abstract

The application discloses a flame-retardant ammonium polyphosphate derivative, a preparation method and application thereof. The flame-retardant ammonium polyphosphate derivative has the structure shown in the following formula, wherein n is a positive integer of 15-25. The ammonium polyphosphate derivative is used in lyocell fiber materials and has excellent flame-retardant performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparation of flame retardants. More particularly, it relates to a flame-retardant ammonium polyphosphate derivative, a preparation method and application thereof. BACKGROUND

[0002] The sustainable development of the environment has become a basic principle of every industry, and the production of synthetic fibers and natural fibers in the textile field is severely restricted. Regenerated cellulose fibers are attracting more and more attention due to their advantages of wide raw material sources, low cost and easy degradation. Therefore, the development of renewable fibers is crucial to sustainable development. Lyocell fiber is a solvent-type regenerated cellulose fiber, known as "Tencel". The essence of Lyocell fiber is cellulose, which belongs to renewable resources. The solvent recovery rate in the preparation process of Lyocell fiber is more than 95%, no toxic substances are discharged, and the produced fiber can also be naturally degraded. Therefore, Lyocell fiber is also known as "green fiber". At the same time, Lyocell fiber has good air permeability and luster and is widely used in life. However, its low oxygen index and flammability limit its use, so it is necessary to modify Lyocell fiber to have flame retardant properties.

[0003] Halogen-based flame retardants are highly efficient, but they release toxic gases during combustion, which is harmful to humans and the environment. Therefore, halogen-based flame retardants are gradually prohibited. As a substitute for halogen-based flame retardants, phosphorus-based flame retardants have been widely researched and developed in recent years and are used to prepare flame-retardant fabrics. Phosphorus-based flame retardants produce phosphoric acid and polyphosphoric acid, which can accelerate the formation of carbon layer, and PO radicals in the gas phase can adsorb H and HO radicals, inhibiting the chain reaction of combustion. Blending and finishing are two main methods for flame-retardant treatment of Lyocell fiber. The method of adding flame retardants to Lyocell fiber during the spinning process is relatively simple, but the addition of flame retardants will affect the crystallinity and mechanical properties of the fiber. The finishing method has attracted widespread attention due to its simple operation process and less influence on the inherent properties of Lyocell fiber. The finishing method can be divided into dipping, layer-by-layer self-assembly, sol-gel method, etc. The layer-by-layer self-assembly method realizes the required weight gain of flame retardants through multi-step deposition, thereby obtaining ideal flame retardant properties. However, the preparation process of layer-by-layer self-assembly is complex and time-consuming, which limits its large-scale application. The sol-gel method requires the preparation of a flame retardant gel solution, and the process is relatively complex. SUMMARY

[0004] Based on the above facts, the purpose of the present application is to provide a flame-retardant ammonium polyphosphate derivative, a preparation method and application thereof. The ammonium polyphosphate derivative is used in Lyocell fiber materials and has excellent flame retardant properties.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] A flame-retardant ammonium polyphosphate derivative has the following structure:

[0007]

[0008] Wherein, n is a positive integer of 15-25.

[0009] The ammonium polyphosphate (APP) in the structure of the ammonium polyphosphate derivative provided in the technical solution has been widely used as an efficient and economical phosphorus-based flame retardant. At the same time, tyramine is a bio-based aromatic monoamine, and the amino group in its structure can be used as a gas source, and the benzene ring as a carbon source can enhance its carbonization ability. The combination of APP and tyramine can prepare a bio-based P-N flame retardant, which can exhibit excellent flame retardant performance, thereby retarding the lyocell fiber.

[0010] In another aspect, the present application provides a preparation method of the ammonium polyphosphate derivative as described above, comprising the following steps:

[0011] Under the condition of water as the solvent, the ammonium polyphosphate and tyramine are reacted in a nitrogen atmosphere to obtain the ammonium polyphosphate derivative.

[0012] Further, the preparation process of the ammonium polyphosphate derivative is as follows:

[0013]

[0014] Further, the temperature of the reaction is 60-80℃, and the time is 4-5h.

[0015] Further, the mass ratio of the ammonium polyphosphate and tyramine is 1:0.9-2.

[0016] Further, the mass ratio of the ammonium polyphosphate and tyramine is 1:(0.9-1.1). When the obtained ammonium polyphosphate derivative is used for flame retardation of lyocell fiber material, it can significantly improve the limiting oxygen index, reduce the vertical burning damage length, reduce the total heat release, and improve the carbon residue rate, etc.

[0017] In another aspect, the present application provides a flame-retardant lyocell fiber material, which is prepared from raw materials comprising lyocell fiber and the ammonium polyphosphate derivative as described above.

[0018] Further, the ammonium polyphosphate derivative is combined on the lyocell fiber by impregnation.

[0019] Further, in the raw materials, the mass ratio of the ammonium polyphosphate derivative to the lyocell fiber is (0.07-0.08):1.

[0020] In another aspect, the present application provides a method for preparing the flame-retardant lyocell fiber material as described above, comprising the following steps:

[0021] At room temperature, the lyocell fiber is soaked in the aqueous solution of the ammonium polyphosphate derivative for 5 min, and then is placed in an oven for drying, so as to obtain the flame-retardant lyocell fiber material.

[0022] Further, the concentration of the aqueous solution of the ammonium polyphosphate derivative is 10-11 wt%.

[0023] Further, the drying condition is 70-75℃ oven drying for 1-1.1 h.

[0024] In another aspect, the present application provides the use of the flame-retardant lyocell fiber material as described above in the preparation of flame-retardant fabric.

[0025] The present application has the following advantages:

[0026] The ammonium polyphosphate derivative provided by the present application is applied in lyocell fiber, which significantly improves the flame-retardant performance of the lyocell fiber, and under a low addition amount, the limiting oxygen index of the lyocell fiber can reach more than 35%, greatly reducing the damage length of the lyocell fiber in the vertical burning test, and also taking into account the flexibility of the lyocell fiber.

[0027] The preparation method of the flame retardant provided by the present application uses water as the solvent, which is green, environmentally friendly, non-polluting, has few synthesis steps, simple operation, and high raw material utilization rate. BRIEF DESCRIPTION OF DRAWINGS

[0028] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0029] Figure 1 The infrared spectrum of the phosphoramide derivative flame retardant is shown.

[0030] Figure 2 The TG graph of the flame-retardant lyocell fiber obtained in Example 1 and Example 2 is shown.

[0031] Figure 3 The vertical burning digital photo of the flame-retardant lyocell fiber obtained in Example 1 and Example 2 is shown. DETAILED DESCRIPTION

[0032] In order to more clearly illustrate the present application, the present application will be further described below with reference to the preferred embodiments and the accompanying drawings. In the drawings, similar components are denoted by the same reference numerals. It should be understood by those skilled in the art that the specific description below is illustrative rather than limiting, and should not limit the protection scope of the present application.

[0033] Example 1

[0034] Preparation of a flame retardant lyocell fiber, comprising the following steps:

[0035] A lyocell fiber with a size of 15cm*6cm, mass of 2.7g; 30cm*8.9cm, mass of 5.0g; 4cm*16cm, mass of 2.1g is added to 100g of water by the method of immersion, soaked in water for 5min, and then dried in an oven at 70℃ for 1h to obtain the lyocell fiber.

[0036] A pure lyocell fiber is obtained. Its limiting oxygen index can reach 18.3% (tested by Netzsch LOI 901 oxygen index analyzer according to GB / T 5454-1997), and the damage length of the lyocell fiber in vertical burning is 30.0cm (tested by CZF-3 type vertical burning instrument according to GB / T 5455-2014), and the round height of its softness performance is 2.0cm (flexibility is measured by flat circle method according to IS 7016 part 11).

[0037] Example 2

[0038] A high-efficiency flame-retardant ammonium polyphosphate derivative, the preparation comprising the following steps:

[0039] Under a nitrogen atmosphere, 10g of ammonium polyphosphate is added to a three-necked flask with water as the solvent, and the temperature is kept at 60℃, and kept at 400rpm for 0.5h, then 10g of tyramine is added to the three-necked flask, and the system temperature is raised to 80℃, and kept at 400rpm for 4h, then the solvent of the mixed solution is removed by rotary evaporation at 80℃, then dried in an oven at 80℃ for 8h, and finally the white solid obtained is the ammonium polyphosphate derivative.

[0040] A flame-retardant lyocell fiber, the preparation comprising the following steps:

[0041] A lyocell fiber with a size of 30cm*8.9cm, mass of 5.0g is added to a water solution of the flame-retardant ammonium polyphosphate derivative with a total weight of 100g by the method of immersion, soaked in water for 5min, and then dried in an oven at 70℃ for 1h to obtain the lyocell fiber.

[0042] The weight percentage of the polyphosphoric acid ammonium derivative in the aqueous solution of the flame retardant polyphosphoric acid ammonium derivative is 10wt%, and the flame retardant content of the flame-retardant lyocell fiber obtained is 7-8wt%. The limiting oxygen index can reach 35.9% (tested by Netzsch LOI 901 oxygen index analyzer according to GB / T 5454-1997), and the damage length of the lyocell fiber in vertical combustion is 6.3cm (tested by CZF-3 type vertical combustion instrument according to GB / T 5455-2014). The softness performance of the circle height is 2.1cm (flexibility is measured by flat circle method according to IS 7016 part 11).

[0043] Example 3

[0044] A high-efficiency flame-retardant polyphosphoric acid ammonium derivative, the preparation thereof comprising the following steps:

[0045] Under a nitrogen atmosphere, 10g of polyphosphoric acid ammonium is added to a three-necked flask with water as the solvent, and the temperature is kept at 60°C, and kept at a rotation speed of 400rpm for 0.5h, then 20g of tyramine is added to the three-necked flask, and the system temperature is raised to 80°C, and kept at a rotation speed of 400rpm for 4h, then the solvent of the mixed solution is removed by rotary evaporation at 80°C, then dried in an oven at 80°C for 8h, and finally the white solid obtained is the polyphosphoric acid ammonium derivative.

[0046] A flame-retardant lyocell fiber, the preparation thereof comprising the following steps:

[0047] By the method of immersion, a lyocell fiber with a size of 30cm*8.9cm and a mass of 5.0g is added to an aqueous solution of the flame retardant polyphosphoric acid ammonium derivative with a total weight of 100g, soaked in water for 5min, and then dried in a 70°C oven for 1h to obtain the lyocell fiber.

[0048] The weight percentage of the polyphosphoric acid ammonium derivative in the aqueous solution of the flame retardant polyphosphoric acid ammonium derivative is 10wt%, and the flame retardant content of the flame-retardant lyocell fiber obtained is 7-8wt%. The limiting oxygen index can reach 34.8% (tested by Netzsch LOI 901 oxygen index analyzer according to GB / T 5454-1997), and the damage length of the lyocell fiber in vertical combustion is 9.8cm (tested by CZF-3 type vertical combustion instrument according to GB / T 5455-2014). The softness performance of the circle height is 2.2cm (flexibility is measured by flat circle method according to IS 7016 part 11).

[0049] Comparative Example 1

[0050] Example 2 was repeated, except that the ammonium polyphosphate derivative was replaced with ammonium polyphosphate, while all other conditions remained unchanged, to prepare flame-retardant lyocell fibers. Its limiting oxygen index reached only 34.7%, and the damage length of the lyocell fibers in vertical burning was 9.6 cm. Its flexibility roundness was 2.4 cm (flexibility was determined using the flat loop method according to IS 7016 part 11).

[0051] Comparative Example 2

[0052] Example 2 was repeated, except that the tyramine was replaced with o-aminophenol, while the other conditions remained the same, to obtain a flame retardant.

[0053] Following the conditions of Example 2, with all other conditions unchanged, the flame retardant was replaced with that of Comparative Example 2 to prepare flame-retardant lyocell fibers. The limiting oxygen index reached only 33.3%, and the fiber damage length in vertical burning was 10.2 cm. The round height of its flexibility was 2.3 cm (flexibility was determined using the flat loop method according to IS 7016 part 11).

[0054] The infrared spectrum of the phosphoryl ammonium derivative flame retardant obtained in the examples is as follows: Figure 1 As shown, the values ​​were measured using a ThermoNicolet Nexus 670 spectrometer, ranging from 4000 to 500 cm⁻¹. -1 As can be seen from the figure, the synthesis of the phosphoric acid ammonium derivative was successful.

[0055] The TG diagrams of the flame-retardant lyocell fibers obtained in Examples 1 and 2 are shown below. Figure 2 As shown in the figure, the experimental method was to raise the temperature from 30°C to 800°C at a rate of 10°C / min under a nitrogen atmosphere. From the figure, we can see that the addition of ammonium polyphosphate derivative flame retardant increases the residual carbon rate of flame-retardant Lyocell fiber.

[0056] Digital photographs of the vertical combustion of flame-retardant lyocell fibers obtained in Examples 1 and 2 are shown below. Figure 3 As shown in the digital photograph, we can see that the damaged length of Lyocell fibers is significantly reduced after adding ammonium polyphosphate derivative flame retardants.

[0057] The properties of the materials obtained from the above embodiments and comparative examples are shown in Table 1 below.

[0058] Table 1

[0059] Examples / Comparative Examples LOI (%) Vertical burn damage length (cm) Total heat released (MJ / m 2 )]]> Residual carbon rate (%) Softness (cm) Example 1 18.3 30.0 6.3 12.1 2.0 Example 2 35.9 6.3 2.7 35.6 2.1 Example 3 34.8 9.8 2.9 34.6 2.2 Comparative Example 1 34.7 9.6 3.1 34.7 2.4 Comparative Example 2 33.3 10.2 3.0 34.5 2.3

[0060] Conclusion: From the performance comparison in Table 1, it can be seen that the flame retardant properties of Example 2 and Comparative Example 1 and Comparative Example 2 are improved, indicating that the P, N system flame retardant has a positive effect on lyocell fiber. However, the damage length of lyocell fiber in the vertical combustion of Comparative Example 1 and Comparative Example 2 is much higher than that of Example 2, which may be caused by the poor carbonization between the flame retardant used in Comparative Example 1 and Comparative Example 2 and the raw material. Compared with Comparative Example 1 and Comparative Example 2, Example 2 has better flame retardant and softness effect, which is because the selected flame retardant raw material has better compatibility with the matrix, and the dispersion of the synthesized ammonium polyphosphate derivative on the lyocell fiber is better, so the flame retardant and softness effect is better. The above results show that the lyocell fiber prepared by using the raw material and the ratio of the raw material provided in the embodiments of the present application has excellent flame retardant properties.

[0061] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. A flame-retardant lyocell fibre material, characterized in that, The flame-retardant lyocell fiber material is prepared from raw materials comprising lyocell fiber and flame-retardant ammonium polyphosphate derivative; the ammonium polyphosphate derivative has the structure shown in the following formula: ； wherein n is a positive integer of 15-25.

2. The flame retardant lyocell fibre material according to claim 1, characterized in that, The preparation method of the ammonium polyphosphate derivative comprises the following steps: reacting ammonium polyphosphate and tyramine under the condition of water as solvent and in nitrogen atmosphere to obtain the ammonium polyphosphate derivative.

3. The flame retardant lyocell fibre material according to claim 2, characterized in that The reaction temperature is 60-80℃ and the reaction time is 4-5h.

4. The flame retardant lyocell fibre material according to claim 2, characterized in that, The mass ratio of ammonium polyphosphate to tyramine is 1:(0.9-1.1).

5. The flame retardant lyocell fiber material according to claim 1, characterized in that, The ammonium polyphosphate derivative is combined on the lyocell fiber by impregnation.

6. The flame retardant lyocell fiber material according to claim 1, characterized in that, In the raw materials, the mass ratio of ammonium polyphosphate derivative to lyocell fiber is (0.07-0.08):

1.

7. A process for the production of flame retardant lyocell fibre material according to any one of claims 1 to 6, characterised in that, comprising the following steps: lyocell fiber is soaked in the aqueous solution of ammonium polyphosphate derivative for 5min at room temperature, and then is placed in an oven for drying to obtain the flame-retardant lyocell fiber material.

8. The preparation method according to claim 7, characterized in that, The concentration of the aqueous solution of ammonium polyphosphate derivative is 10-11wt%; The drying condition is 70-75℃ oven drying for 1-1.1h.

9. Use of the flame-retardant lyocell fiber material according to any one of claims 1-6 in the preparation of flame-retardant fabric.

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