A method for measuring the content of a surface modifier in a coated fine oxidizing agent

Abstract

A kind of measurement method of coating fine oxidant surface modifier content, it is related to solid propellant quality index detection field, including S1: after surface modifier is dissolved, filtration, evaporation, obtain solid insoluble, according to the mass of surface modifier and solid insoluble, obtain the yield of surface modifier;S2: surface modifier, uncoated fine oxidant, water are mixed uniformly, as standard sample turbidity test is carried out, standard sample has multiple, in different standard samples, the content of surface modifier and / or uncoated fine oxidant is different, obtain the turbidity of different standard samples;S3: according to the mass of surface modifier and fine oxidant in standard sample, obtain the theoretical mass content of surface modifier;S4: according to the theoretical mass content of surface modifier, turbidity, the fitting of different standard samples is carried out, obtain the conversion relationship of surface modifier content and turbidity.It can quickly detect the content of surface modifier in fine oxidant.

Description

TECHNICAL FIELD

[0001] The application relates to a turbidity measurement of a coated fine oxidizing agent (hereinafter referred to as fine AP) solution and calculation of turbidity and MM-501 (hereinafter referred to as MM-501) content, the particle size of the coated fine oxidizing agent is less than 20 mu m, and the method is a test calculation method special for the MM-501 component in the fine AP. Belongs to the technical field of solid propellant quality index detection. BACKGROUND

[0002] As a kind of bulk powder material, the oxidizing agent accounts for 70%-75% in the solid propellant, and the fine AP can account for up to 40%, which can directly affect the combustion performance and mechanical properties of the propellant. The fine AP is prone to hygroscopic agglomeration during storage and use, especially in a humid environment, and is more prone to agglomeration under the action of various forces between particles. Therefore, the surface modification technology is an effective means to solve the hygroscopic agglomeration of the powder at present, and the surface modification technology relies on the adsorption, reaction, modification and film coating of the surface active agent, high molecular polymer and the like on the surface of the powder to make the surface have good hydrophobicity, so as to achieve the purpose of preventing hygroscopic agglomeration. The addition of the surface modifier (MM-501) needs accurate technical indexes and mature production process to achieve the purpose of stable product quality. Therefore, it is necessary to test the component content of MM-501 in the fine AP product. The research and development of the test method is one of the important work in the production process of the fine AP.

[0003] However, in the existing related technology, many fine APs do not add surface modifiers, and the fine APs that add surface modifiers are not detected as quality indexes. Therefore, a detection method for the MM-501 content in the fine oxidizing agent is needed. SUMMARY

[0004] The technical problem solved by the application is to overcome the shortcomings of the prior art and provide a method for measuring the MM-501 content in the coated fine oxidizing agent by using the turbidity method, which can quickly and accurately test the turbidity of the fine AP solution by using a turbidimeter and quickly convert the MM-501 component content in the fine AP.

[0005] The technical solution of the application is:

[0006] A method for measuring the content of a surface modifier in a coated fine oxidizing agent, comprising:

[0007] S1: after the surface modifier is dissolved, filtered and evaporated, solid insoluble substances are obtained, and the yield of the surface modifier is obtained according to the mass of the surface modifier and the solid insoluble substances;

[0008] A surface modifier and water are added to the uncoated fine oxidant. After mixing and ensuring the fine oxidant is fully dissolved, the mixture is filtered and dried to obtain a solid insoluble matter. The filtration content of the surface modifier is obtained based on the yield of the solid insoluble matter and the surface modifier, as well as the weight of the uncoated fine oxidant and the surface modifier. The theoretical content of the surface modifier is obtained based on the weight of the uncoated fine oxidant and the surface modifier. The relative deviation between the filtration content and the theoretical content of the surface modifier is ≤2%.

[0009] S2: Mix the surface modifier, uncoated fine oxidant, and water. After the fine oxidant is completely dissolved, use ultrasound to completely disperse the surface modifier. Use this as a standard sample for turbidity testing. There are multiple standard samples. The content of surface modifier and / or uncoated fine oxidant is different in different standard samples, and the turbidity of different standard samples is obtained.

[0010] S3: Based on the mass of surface modifier and fine oxidant in the standard sample, obtain the theoretical mass content of surface modifier;

[0011] S4: Based on the theoretical mass content and turbidity of the surface modifier, different standard samples are fitted to obtain the conversion relationship between the surface modifier content and turbidity.

[0012] The fine oxidizing agent is completely soluble in water.

[0013] The surface modifier content after filtration = mass of solid insoluble matter / [(mass of uncoated fine oxidant + weight of surface modifier) ​​* yield of surface modifier].

[0014] The theoretical content of surface modifier in step S1 = weight of surface modifier / (mass of uncoated fine oxidant + weight of surface modifier).

[0015] In the standard sample, 10-15 ml of water and 0-0.0050 g of surface modifier are added to every 1 g of uncoated fine oxidant.

[0016] In step S1, the yield of the surface modifier = mass of solid insoluble matter / mass of surface modifier.

[0017] In step S3, the theoretical mass content of the surface modifier in the standard sample = the mass of the surface modifier in the standard sample / (mass of the surface modifier + mass of the uncoated fine oxidant).

[0018] The fine oxidant is fine AP, and the surface modifier is MM-501.

[0019] The standard sample is: 20.0000 g of uncoated fine AP, 200 ml of water, (0-0.2100) g of MM-501, to obtain the conversion relationship between the content of the surface modifier and the turbidity: MM-501 content (%) = 0.02491 + 0.007018 x turbidity - 0.000011 x turbidity 2 .

[0020] In summary, the present application at least includes the following beneficial technical effects:

[0021] The turbidity of the fine AP solution is tested by the weight method combined with the turbidity method, which has certain stability, good parallelism, is used for measuring and calculating the content of MM-501 in the fine AP, and is more accurate and fast. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The present application is compared with the results of the pure weight method;

[0023] Figure 2 The fitting curve graph of turbidity and MM-501 content. DETAILED DESCRIPTION

[0024] The present application will be described below in conjunction with specific embodiments, but not limited thereto, and the general technical personnel in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present application, and all equivalent technical solutions also belong to the scope of the present application. The patent protection scope of the present application should be defined by the claims.

[0025] In the embodiments of the present application, the fine oxidant is fine AP, and the surface modifier is MM-501. A method for measuring the content of MM-501 in coated fine oxidant by turbidity method is specifically disclosed, which comprises the following steps:

[0026] S11: After the surface modifier is dissolved, filtered and evaporated, solid insoluble matter is obtained, and the yield of the surface modifier is obtained according to the mass of the surface modifier and the solid insoluble matter.

[0027] Specifically, the yield of the dissolved and filtered MM-501 is obtained by the following steps:

[0028] The loss of the same MM-501 sample during the dissolution and filtration process is tested, and the repeatability test of the yield of the sample after filtration is performed.

[0029] A certain amount (1.0±0.1 g) of prepared MM-501 (M1) is weighed, a certain amount of 300 ml of water is added, and stirring is performed for 5 min.

[0030] The total weight (M2) of the evaporating dish and the water system filter membrane is weighed. The sand core funnel device and the filter membrane are connected and installed.

[0031] The stirred MM-501 suspension was poured into the funnel using a glass rod as a guide, and the circulating pump was turned on to perform the filtration. The beaker was cleaned at least three times and added to the filter, and the filter funnel was cleaned until no particles adhered. After the filtration was completed, the filter membrane and the filtrate were moved together into the evaporating dish, which was placed in the oven and dried at a constant temperature of 70°C for 1 h. After cooling, the total weight of the evaporating dish, filter membrane, and product (M3) was measured. The test results are shown in Table 2.

[0032] According to the weighing results, the yield of MM-501 was calculated, and the calculation formula is shown in (1)

[0033]

[0034] Table 2: MM-501 yield test

[0035]

[0036] According to the MM-501 dissolution and filtration of 5 parallel tests, the average yield of MM-501 was 81.61%.

[0037] S12: Verify that the fine oxidizing agent is completely dissolved in water, and the steps are as follows:

[0038] A repetitive test of the MM-501 content was performed on the same batch of uncoated fine AP sample to determine that there were no insoluble substances in the uncoated fine AP.

[0039] A certain amount (30.0±0.1g) of fine AP (M4) was weighed, a certain amount of 300ml water was added, and stirring was performed for 5min to ensure that the fine AP was fully dissolved.

[0040] The total weight of the evaporating dish and the water-based filter membrane (M5) was measured. The sand core funnel device and the filter membrane were connected and installed.

[0041] The stirred solution was poured into the funnel using a glass rod as a guide, and the circulating pump was turned on to perform the filtration. The beaker was cleaned at least three times and added to the filter, and the filter funnel was cleaned until no particles adhered. After the filtration was completed, the filter membrane and the filtrate were moved together into the evaporating dish, which was placed in the oven and dried at a constant temperature of 70°C for 1 h. After cooling, the total weight of the evaporating dish, filter membrane, and product (M6) was measured. The test results are shown in Table 3.

[0042] Table 3: Uncoated fine AP content

[0043]

[0044] From the data in Table 3, it can be seen that, excluding the loss during the experiment and the weighing error, the test result of the insoluble impurity content of the uncoated fine AP is 0.

[0045] S13: The surface modifier and water are added to the uncoated fine oxidizing agent, mixed and the fine oxidizing agent is fully dissolved, then filtered and dried to obtain solid insoluble matter; the filtered content of the surface modifier is obtained according to the yield of the solid insoluble matter, the surface modifier, the weight of the uncoated fine oxidizing agent and the surface modifier, the theoretical content of the surface modifier is obtained according to the weight of the uncoated fine oxidizing agent and the surface modifier, and the filtered content of the surface modifier is basically equal to the theoretical content of the surface modifier.

[0046] Specifically, the uncoated AP is added with a certain amount of MM-501, and the theoretical and actual amounts are verified as follows:

[0047] A certain amount of 300 ml of water is added to the uncoated fine AP (30.0±0.1 g), and stirred for 5 min to ensure that the fine AP is fully dissolved.

[0048] The total weight (M5) of the evaporating dish and the water filter membrane is weighed. The sand core funnel device and the filter membrane are connected and installed.

[0049] The stirred suspension is poured into the funnel with a glass rod as a flow guide, and the circulating pump is started to filter. The beaker is washed at least three times and added to the funnel for filtration, and the filter funnel is washed until no particles adhere. After filtering is completed, the filter membrane and the filtrate are moved into the evaporating dish together, and placed in an oven at a constant temperature of 70°C for 1 h. After cooling, the total weight (M6) of the evaporating dish, the filter membrane and the product is weighed. The test results are shown in Table 4.

[0050] According to the weighing results, the content of MM-501 in the filtered fine AP is calculated, and the calculation formula is shown in (2)

[0051]

[0052] Wherein M4 is the sum of the mass of MM-501 and AP.

[0053] Table 4: Yield of uncoated fine AP directly added with MM-501

[0054]

[0055] S2: The surface modifier, uncoated fine oxidizing agent and water are mixed, the fine oxidizing agent is dissolved, and the surface modifier is completely dispersed by ultrasonic, which is used as a standard sample for turbidity test. There are multiple standard samples, and the contents of the surface modifier and / or uncoated fine oxidizing agent in different standard samples are different, and the turbidity of different standard samples is obtained.

[0056] S3: The theoretical mass content of the surface modifier is obtained according to the mass of the surface modifier and the fine oxidizing agent in the standard sample.

[0057] S4: According to the theoretical mass content of the surface modifier and the turbidity, different standard samples are fitted to obtain the conversion relationship between the surface modifier content and the turbidity.

[0058] The specific steps of steps S2-S4 are as follows:

[0059] Pure MM-501 is used as a standard sample for the preparation of a standard solution. A certain amount of ground MM-501 is weighed, 20.000 g of uncoated fine AP is added, 200 ml of water is added, and after the fine AP is completely dissolved, the MM-501 is completely dispersed by ultrasonic, and the turbidity is tested as a standard sample. The test results are shown in Table 5.

[0060] Table 5: Test results of standard samples

[0061]

[0062]

[0063] According to the test results above, the data is subjected to quadratic curve fitting, and the fitting results are shown in Figure 2 .

[0064] According to the fitting curve, the conversion relationship between the MM-501 content and the turbidity is obtained:

[0065] MM-501 content (%) = 0.02491 + 0.007018 x turbidity - 0.000011 x turbidity 2

[0066] Turbidity test parallelism verification:

[0067] From the collected fine AP samples with different MM-501 contents, samples with different MM-501 contents are selected for turbidity parallel test, and the test results are shown in Table 6. From the data analysis, the turbidity test of the same sample solution has certain error, but the parallelism can meet the test requirements.

[0068] Table 6: Test results of sample parallelism

[0069]

[0070] Comparison of the method of the present application with the pure weight method:

[0071] Weigh (30±0.1) g of fine AP, pour into a beaker, add 300 ml of distilled water, stir to dissolve and heat to room temperature. During stirring, take a sample and add it to the turbidimeter sample bottle, eliminate air bubbles, wipe the outer surface of the sample bottle, and then test the turbidity. Record the turbidity results. According to the formula (conversion relationship between MM-501 content and turbidity), the content of MM-501 in fine AP is converted.

[0072] The sample for measuring turbidity is weighed, filtered, dried and weighed together with all samples in a beaker, and the content of insoluble substances in fine AP is calculated.

[0073] The content of MM-501 is calculated for two measurement results respectively, and comparison is made, and the results of two methods can be consistent. Figure 1 .

[0074] Table 1: Comparison results of turbidimetry and gravimetry

[0075]

[0076]

[0077] The turbidity of the fine AP solution is tested by using a turbidimeter, and the test has certain stability, and the parallelism is good, the turbidimetry is used for measuring and calculating the content of MM-501 in fine AP, and the turbidimetry is accurate and fast.

[0078] Although the present application is disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application, therefore, the protection scope of the present application should be defined by the scope of the claims of the present application.

Claims

1. A method for measuring the content of a surface modifier in a coated fine oxidizing agent, characterized by: Comprising S1: after dissolving, filtering and evaporating the surface modifier, solid insoluble substances are obtained, and the yield of the surface modifier is obtained according to the mass of the surface modifier and the solid insoluble substances; multiple parallel tests are performed, and the average yield is the final yield; After adding the surface modifier and water to the uncoated fine oxidizing agent, mixing and fully dissolving the fine oxidizing agent, filtering and drying to obtain solid insoluble substances; the filtered content of the surface modifier is obtained according to the mass of the solid insoluble substances, the yield of the surface modifier, and the weight of the uncoated fine oxidizing agent and the surface modifier, the theoretical content of the surface modifier is obtained according to the weight of the uncoated fine oxidizing agent and the surface modifier, and the relative deviation of the filtered content of the surface modifier and the theoretical content of the surface modifier is ≤2%; S2: mix the surface modifier, uncoated fine oxidizing agent and water, and after the fine oxidizing agent is completely dissolved, ultrasonic is used to completely disperse the surface modifier, which is used as a standard sample for turbidity testing; there are multiple standard samples, and the contents of the surface modifier and / or uncoated fine oxidizing agent in different standard samples are different, and the turbidity of different standard samples is obtained; S3: the theoretical mass content of the surface modifier is obtained according to the mass of the surface modifier and the fine oxidizing agent in the standard sample; S4: the conversion relationship between the content of the surface modifier and the turbidity is obtained by fitting different standard samples according to the theoretical mass content of the surface modifier and the turbidity.

2. The method for measuring the content of the surface modifier in the coated fine oxidizing agent according to claim 1, characterized by: The fine oxidizing agent is completely dissolved in water.

3. The method of claim 1, wherein the method is characterized by: The filtered content of the surface modifier = the mass of the solid insoluble substances / [(the mass of the uncoated fine oxidizing agent + the weight of the surface modifier) * the yield of the surface modifier].

4. The method of claim 1, wherein the method is characterized by: The theoretical content of the surface modifier in step S1 = the weight of the surface modifier / (the mass of the uncoated fine oxidizing agent + the weight of the surface modifier).

5. The method of claim 1, wherein the method is characterized by: In the standard sample, 10-15 ml of water and 0-0.0050 g of the surface modifier are added to 1 g of uncoated fine oxidizing agent.

6. The method of claim 1, wherein the method is characterized by: In step S1, the yield of the surface modifier = the mass of the solid insoluble substances / the mass of the surface modifier.

7. The method of claim 1, wherein the method is characterized by: In step S3, the theoretical mass content of the surface modifier in the standard sample = the mass of the surface modifier in the standard sample / (the mass of the surface modifier + the mass of the uncoated fine oxidizing agent).

8. The method of claim 1, wherein the method is characterized by: The fine oxidizing agent is fine AP, and the surface modifier is MM-501.

9. The method of claim 8, wherein the method is characterized by: The standard sample is: 20.0000 g of uncoated fine AP, 200 ml of water, (0-0.2100) g of MM-501, to obtain the conversion relationship between the content of the surface modifier and the turbidity: MM-501 content (%) = 0.02491 + 0.007018 x turbidity - 0.000011 x .

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