Decoloring method of aryloxy polyphosphazene polymer

Abstract

The invention discloses a decolorization method of an aryloxy polyphosphazene polymer, and belongs to the technical field of phosphazene rubber. Comprising the following steps: dissolving about 10% of an aryloxy polyphosphazene polymer in a polar organic solvent, such as tetrahydrofuran, dioxane and N, N-dimethylformamide (DMF), strongly stirring until the aryloxy polyphosphazene polymer is completely dissolved, adding 0.5-1% of acidic activated carbon or activated clay, heating to 60-90 DEG C, continuously stirring for 4-6 hours, and then carrying out reduced pressure suction filtration, so as to obtain an aryloxy polyphosphazene polymer; and pouring the obtained filtrate into 2 times of water under a stirring condition, precipitating to separate out wet glue, and carrying out vacuum drying on the wet glue at 80 DEG C for 3 days to obtain the aryloxy polyphosphazene polymer. The method is simple, effective and high in practicability.

Description

Technical Field

[0001] The invention relates to a decolorization method for aromatic oxide polyphosphazene polymers, and belongs to the technical field of polyphosphazene rubbers. Background Art

[0002] Due to the inorganic structure of its main chain (-P=N-), aromatic oxygen phosphazene polymers are elastomers with excellent properties such as good chemical stability, solvent resistance, oil resistance, low temperature resistance, flame retardancy and good thermal stability. They are widely used in industries such as aerospace, shipbuilding, and functional materials. Their structural formula is shown in the figure below.

[0003]

[0004] During the preparation of aromatic phosphazene polymers, hexachlorocyclotriphosphazene undergoes ring-opening polymerization at high temperatures of 180-250°C to produce dichloropolyphosphazene (R1=R2=Cl), which contains certain coloring impurities. After further substitution reactions, these impurities remain in the polyphosphazene colloid, degrading its quality and seriously affecting the product's application. Therefore, decolorization of polyphosphazene colloids has become a significant public relations challenge.

[0005] The method of washing with ethanol, water, etc. described in the invention patent CN103524745A increases the workload and the amount of waste liquid generated, and still cannot fully achieve the purpose of decolorization. The decolorizing agent selected in the authorized patent CN102515121B is a three-dimensional activated carbon molecular sieve, which is not only expensive, but also added during the ring-opening polymerization reaction. Since small molecules may also be adsorbed and occupy a certain surface of the molecular sieve, there are doubts about whether it can effectively decolorize. The present invention sharply explores decolorizing agents, and obtains acidic decolorizing materials by acidifying activated carbon and activated clay. It has excellent decolorization effect in practice and has great practical value.

[0006] The present invention provides a method for decolorizing an aryloxyphosphazene polymer, which is characterized by comprising the following steps: 1) dissolving 10% of an aryloxypolyphosphazene polymer in a polar organic solvent, such as tetrahydrofuran, dioxane, or N,N-dimethylformamide (DMF), vigorously stirring until completely dissolved, adding 0.5-1% of acidic activated carbon or activated clay, heating the mixture to 60-90°C, continuously stirring for 4-6 hours, and then performing vacuum filtration; pouring the obtained filtrate into twice the amount of water under stirring to precipitate a wet glue; and vacuum drying the wet glue at 80°C for 3 days to obtain the aryloxypolyphosphazene polymer. The method is simple, effective, and highly practical. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for decolorizing aryloxyphosphazene polymers, which can achieve the purpose of decolorizing aryloxyphosphazene polymers, and at the same time significantly improve the product quality (the color becomes lighter, and the product becomes more bright and transparent). Moreover, the method is simple and effective, and is convenient for implementation and popularization.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows: A method for decolorizing aryloxyphosphazene polymers, which is characterized by including the following steps:

[0009] In a polar organic solvent, such as tetrahydrofuran, dioxane, N,N-dimethylformamide (DMF), dissolve 10% of the aryloxyphosphazene polymer, stir strongly until completely dissolved, add 0.5-1% of acidic activated carbon or acidic activated clay, heat to 60-90 °C, continue to stir for 4-6 hours, cool the treatment liquid to room temperature, then carry out vacuum filtration, pour the obtained filtrate into 2 volumes of water under stirring conditions for precipitation to obtain wet glue, and dry the wet glue in vacuum at 80 °C for 3 days to obtain the aryloxyphosphazene polymer. This method is simple and effective, and has strong practicability. Description of the Drawings

[0010] Table 1. Results of Examples 1-8

[0011] Figure 1 . For the comparison diagram of the aryloxyphosphazene polymer raw material and after decolorization

[0012] Figure 2 . For the light transmittance comparison diagram of the aryloxyphosphazene polymer raw material and after decolorization Detailed Embodiments

[0013] In order to better understand the present invention, the present invention will be further described below in conjunction with embodiments. The content of the present invention covers but is not limited to the following embodiments.

[0014] Preparation of acidic activated carbon and activated clay: Weigh 50 g of activated carbon and dissolve it in 200 mL of water to form a slurry, add inorganic acid (hydrochloric acid, sulfuric acid or phosphoric acid) until the pH value is less than 2, continue to stir for 2-5 hours, then filter, wash twice with water, and finally dry in an oven at 110 °C for 8 hours to obtain acidic activated carbon.

[0015] The preparation method of acidic activated clay is the same as above.

[0016] Example 1

[0017] In a 200 mL three-necked flask equipped with a cooling and stirring device, add 100 mL of tetrahydrofuran, add 10 g of aryloxyphosphazene polymer, stir vigorously until completely dissolved, add 0.05 g of acidic activated clay, heat under reflux, continue stirring for 4 - 6 hours, cool to room temperature, then carry out vacuum filtration under reduced pressure. The obtained filtrate is poured into 2 times the amount of water under stirring conditions to precipitate wet glue. The wet glue is dried in vacuo at 80 °C for 3 days to obtain aryloxyphosphazene polymer, and weigh it.

[0018] Example 2

[0019] In a 200 mL three-necked flask equipped with a cooling and stirring device, add 100 mL of dioxane, add 10 g of aryloxyphosphazene polymer, stir vigorously until completely dissolved, add 0.05 g of acidic activated clay, heat at 80 °C, continue stirring for 4 - 6 hours, cool to room temperature, then carry out vacuum filtration under reduced pressure. The obtained filtrate is poured into 2 times the amount of water under stirring conditions to precipitate wet glue. The wet glue is dried in vacuo at 80 °C for 3 days to obtain aryloxyphosphazene polymer, and weigh it.

[0020] Example 3

[0021] In a 200 mL three-necked flask equipped with a stirring device, add 100 mL of N,N-dimethylformamide (DMF), add 10 g of aryloxyphosphazene polymer, stir vigorously until completely dissolved, add 0.05 g of acidic activated clay, heat at 80 °C, continue stirring for 4 - 6 hours, cool to room temperature, then carry out vacuum filtration under reduced pressure. The obtained filtrate is poured into 2 times the amount of water under stirring conditions to precipitate wet glue. The wet glue is dried in vacuo at 80 °C for 3 days to obtain aryloxyphosphazene polymer, and weigh it.

[0022] Example 4

[0023] Adopt the same method as in Example 1, and change the acidic activated clay to acidic activated carbon.

[0024] Example 5

[0025] Adopt the same method as in Example 2, and change the acidic activated clay to acidic activated carbon.

[0026] Example 6

[0027] Adopt the same method as in Example 3, and change the acidic activated clay to acidic activated carbon.

[0028] Example 7

[0029] Adopt the same method as in Example 1, and the addition amount of acidic activated clay is 0.1 g.

[0030] Example 8

[0031] Using the same method as in Example 2, the added amount of acid-activated bleaching earth was 0.1 g.

[0032] Comparative Example 1

[0033] In a 200 mL three-necked flask equipped with a cooling and stirring device, 100 mL of dioxane was added, 10 g of aryloxyphosphazene polymer was added, and the mixture was vigorously stirred until completely dissolved. 0.1 g of commercially available activated bleaching earth was added, the heating temperature was 80 °C, and stirring was continued for 4 - 6 hours. Then, the temperature was lowered to room temperature, and then vacuum filtration was carried out under reduced pressure. The obtained filtrate was poured into 2 times the amount of water under stirring conditions to precipitate wet glue. The wet glue was dried in vacuo at 80 °C for 3 days to obtain an aryloxyphosphazene polymer, and it was weighed.

[0034] Comparative Example 2

[0035] Using the same method as in Comparative Example 1, the commercially available activated bleaching earth was changed to commercially available activated carbon.

[0036] From the results table 1 of the examples, the comparison between the aryloxyphosphazene polymer raw material and after decolorization Figure 1 and the comparison of the light transmittance (under the same conditions) between the aryloxyphosphazene polymer raw material and after decolorization Figure 2 It can be seen that the present invention has an obvious decolorization effect on the aryloxyphosphazene polymer. Especially when the decolorizing agent is 1% of the raw material amount, the product presents a yellow and transparent colloid, indicating an obvious effect. Compared with the commercially available decolorizing agents, although they have a certain decolorization effect, the decolorization effect and transparency are poor and cannot meet the product requirements. Therefore, the present invention has good practical effects and application prospects.

[0037] Note: The light transmittance test was carried out by opening a round hole on a box with light, covering it with a release paper, placing the sample on the small hole, and taking a photo with a mobile phone at a distance of 200 mm above to obtain a light transmittance picture.

[0038] Table 1. Results table of the examples

[0039] Example Solvent Additive Product weight (g) Color 1 Tetrahydrofuran Acidic activated clay 9.85 Yellow 2 Dioxane Acidic activated clay 9.83 Dark yellow 3 DMF Acidic activated clay 9.82 Dark yellow 4 Tetrahydrofuran Acidic activated carbon 9.86 Yellow 5 Dioxane Acidic activated carbon 9.85 Dark yellow 6 DMF Acidic activated carbon 9,83 Yellow 7 Tetrahydrofuran Acidic activated clay 9.84 Yellow 8 Dioxane Acidic activated clay 9.82 Yellow Comparative Example 1 Dioxane Commercially available activated clay 9.82 Yellowish red Comparative Example 1 Dioxane Commercially available activated carbon 9.81 Yellowish red 。

Claims

1. A method for decolorizing an aryloxy polyphosphazene polymer, characterized in that, It includes the following steps: Dissolve the aryloxyphosphazene polymer in a polar organic solvent, and stir strongly until it is completely dissolved to obtain an organic solution of the aryloxyphosphazene polymer. Then add acidic activated carbon or activated clay, heat to 60-90 °C, continue stirring for 4-6 hours, then cool to room temperature, carry out vacuum filtration, and pour the obtained filtrate into water with a volume 2 times that of the filtrate under stirring conditions for precipitation to obtain wet glue, and the obtained wet glue is dried in vacuo at 80 °C.

2. The decolorization method of an aryloxy polyphosphazene polymer according to claim 1, characterized in that, The polar organic solvent is selected from one or more of tetrahydrofuran, dioxane, and N,N-dimethylformamide (DMF).

3. A method for decolorizing an aryloxyphosphazene polymer according to claim 1, characterized in that, For every 10 g of the aryloxyphosphazene polymer, 100 mL of the polar organic solvent is used.

4. A method for decolorizing an aryloxyphosphazene polymer according to claim 1, characterized in that, The mass of the acidic activated carbon or activated clay is 0.5-1% of the mass of the aryloxyphosphazene polymer.

5. The preparation of the acidic activated carbon or activated clay according to claim 1 is carried out by using an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid to adjust the pH value to less than 2, and then obtaining it through filtration and drying.

6. The decolorization method of an aryloxy polyphosphazene polymer according to claim 1, characterized in that, Dry in vacuo for 3 days to obtain the aryloxyphosphazene polymer.

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