Method for analyzing content of binder in solid austempered aluminum bonded explosive by adopting curing rate

Abstract

The invention provides a method for analyzing the content of a binder in a solid-austempered aluminum bonded explosive by adopting a curing rate. The method comprises the following steps: step 1, determining the curing rate of the binder; and 2, extracting and separating the solid-austempered aluminum bonded explosive sample by using a solvent to obtain a solution and residual solids, and calculating the content of the residual solids by using a weighing method. And 3, digesting the residual solid with strong acid to obtain a liquid containing aluminum ions, and determining the aluminum content with a complexometric titration method to obtain the aluminum powder content in the residual solid. And 4, according to the content of the residual solid obtained in the step 2 and the content of the aluminum powder in the residual solid obtained in the step 3, obtaining the amount of the cured high polymer in the residual solid by adopting a subtraction method. And step 5, calculating the content of the binder in the solid austempered aluminum bonded explosive by combining the curing rate of the binder obtained in the step 1. The invention solves the problems that the binder component in the formula of the solid austempered aluminum explosive is partially chemically changed in the technical process to form a high polymer, and single component separation and quantitative analysis detection are difficult to carry out by adopting a conventional method.

Description

Technical Field

[0001] The present invention belongs to the technical field of physical and chemical detection of propellants and explosives, relates to GAP-based aluminized explosive, and particularly relates to an analysis method for the binder content in GAP-based aluminized explosive by using the curing rate. Background Art

[0002] Polymer bonded explosive (PBX) is a very important insensitive explosive used in the research and development of equipment by various countries at present. Especially in penetration warheads against hard targets, this kind of explosive shows obvious advantages. PBX explosive utilizes the explosive performance of high-energy explosives and the excellent mechanical properties of polymer materials, making the comprehensive indexes of the explosive far superior to those of early cast explosives and wax-insensitive explosives, and is the main research direction of various models at present.

[0003] GAP-based aluminized explosive is a typical thermosetting cast PBX explosive. It is mixed with high-energy explosive HMX, etc. using a low-molecular-weight prepolymer as a binder, poured into the warhead at a certain temperature, and the curing process is adopted. The curing process is to obtain good mechanical properties and form a product with certain mechanical properties. The formula components of GAP-based aluminized explosive are mainly HMX, aluminum powder, binder, etc. The binder is a mixture, including low-molecular-weight prepolymer compounds that polymerize upon heating, and small-molecule compounds that can act as solvents in the binder and play roles such as coating, insensitive, and plasticizing in the explosive process.

[0004] The detection of explosive formula components is an important part of product quality assurance. It is not only an important part of the supervision and standard acceptance of the manufacturing process of explosive products, but also an important guarantee for the storage quality and safety of the charge of related model products. Therefore, the detection of the formula components of GAP-based aluminized explosive is an indispensable important part of the quality detection in the production process and the product quality supervision. Usually, the analysis method of mixed explosive components mainly separates different components by dissolving and extracting them with different solvents, and then quantifies the content of the components according to the change in weight. However, during the production of GAP-based aluminized explosive, the high-molecular-weight prepolymer in the binder component crosslinks to form an elastomer, and due to the large molecular weight of the elastomer, it is insoluble in common solvents. In addition, only part of the binder added in the process of GAP-based aluminized explosive crosslinks. When separating with solvents, it is difficult to completely separate each component independently, so the solvent extraction method cannot be used for component separation. In the manufacturing process of conventional mixed explosives, their components do not undergo chemical changes, while in the curing process of PBX, some of its components undergo chemical changes, forming polymers coating the elemental explosives, which poses a problem for the analysis of the binder component content in the explosive formula.

[0005] There is no relevant literature report on the accurate detection of the binder component content of GAP-based aluminized explosive in the prior art. Summary of the Invention

[0006] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide an analysis method for the binder content in GAP aluminized explosive by using the curing rate, so as to solve the technical problems that the binder in the prior art is difficult to separate and quantitatively analyze and detect.

[0007] In order to solve the above technical problems, the present invention is realized by adopting the following technical solutions:

[0008] An analysis method for the binder content in GAP aluminized explosive by using the curing rate, the method is carried out according to the following steps:

[0009] Step 1, determination of the curing rate of the binder.

[0010] Step 2, extract and separate the GAP aluminized explosive sample with a solvent to obtain a solution and a remaining solid, and calculate the content of the remaining solid by the weighing method.

[0011] Step 3, digest the remaining solid with strong acid to obtain a liquid containing aluminum ions, and determine the aluminum content by complexometric titration to obtain the aluminum powder content in the remaining solid.

[0012] Step 4, according to the content of the remaining solid obtained in Step 2 and the aluminum powder content in the remaining solid obtained in Step 3, use the subtraction method to obtain the amount of the cured polymer in the remaining solid.

[0013] Step 5, calculate the binder content in the GAP aluminized explosive in combination with the curing rate of the binder obtained in Step 1.

[0014] The present invention also has the following technical features:

[0015] The specific process of Step 1 is as follows:

[0016] Step 101, mix the binder and aluminum powder used in the GAP aluminized explosive according to the formulation ratio of the GAP aluminized explosive, and cure according to the same process conditions as those for preparing the GAP aluminized explosive. The sample obtained after curing is called the test sample.

[0017] Step 102, cut the test sample into small pieces, put them into a filter cup, then place the filter cup in an extractor, extract with a solvent, and the remaining solid in the filter cup is weighed after drying, and the content of the remaining solid is calculated.

[0018] Step 103, digest the remaining solid obtained in Step 102 with a mixed acid of nitric acid and perchloric acid, then determine the aluminum content in the remaining solid by complexometric titration, and use the subtraction method to obtain the amount of the cured polymer in the remaining solid.

[0019] Step 104, calculate the curing rate of the binder. The curing rate of the binder is the ratio of the amount of the cured polymer to the amount of the added binder.

[0020] In Step 2, the solvent is one or more combinations of acetone, ethyl acetate, ether, and ethanol.

[0021] In Step 3, the strong acid is one or more combinations of nitric acid and perchloric acid.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] (Ⅰ) The analysis method of the present invention breaks through the basic technical idea of traditional component quantification (i.e., first separating individual components and then quantifying), solves the problem that some of the binder components in the formula of Gualü aluminum explosive have undergone chemical changes during the process and formed polymers, and it is difficult to separate and quantitatively analyze individual components using conventional methods.

[0024] (Ⅱ) The determination of the binder content in the analysis method of the present invention is relatively simple. Because for the same Gualü aluminum explosive, the curing rate of the binder is a constant, so only when initially establishing the method, prepare calibration samples, measure multiple data and take the average value, and then it can be used as a constant in the determination and calculation of the binder content.

[0025] (Ⅲ) The analysis method of the present invention provides a simple and feasible technical idea for the determination of the binder, that is, it can utilize the fact that under certain process conditions, the curing rate of the binder is a definite constant, and partial separation can also obtain the total amount of its formula.

[0026] (Ⅳ) The present invention breaks through the traditional component quantification technical idea of first completely separating components and quantitatively analyzing them one by one, solves the problem that due to some chemical changes of the binder component in the formula of Gualü aluminum explosive during the process, some polymers are formed after curing, and it is difficult to perform complete component separation and quantitative analysis and detection, and provides an analysis method for product quality detection. This method can be applied to the quality detection of mixed explosives in which the binder undergoes a polymerization reaction during the production process.

[0027] The following further elaborates on the specific content of the present invention in conjunction with embodiments. Specific Embodiments

[0028] It should be noted that all raw materials and reagents in the present invention, unless otherwise specified, are all raw materials and reagents known in the prior art and can be obtained from commercial channels. All test methods in the present invention, unless otherwise specified, are conventional methods.

[0029] Through research, the present invention has found that for the same Gu'ao aluminum explosive, under the same process conditions, the curing rate of the same raw material binder is a constant. Based on this discovery, the core of the present invention is to prepare a companion sample according to the process conditions of the explosive formula when initially establishing the method, accurately quantify the curing rate of the binder, and then separate the polymer and aluminum powder as a whole during the detection process, accurately quantify them, and then accurately quantify the aluminum powder therein, so as to accurately obtain the content of the binder.

[0030] The analysis method of the present invention separates the sample by solvent extraction. The remaining solid is aluminum powder and the cured polymer. The content of the remaining solid is calculated by the weighing method; the remaining solid is digested with strong acid to convert the aluminum powder into aluminum ions, and then the content of aluminum powder is determined by complexometric titration; the content of the binder is calculated based on the amount of the polymer in the binder in the remaining solid after extraction and the curing coefficient.

[0031] The following gives specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent transformations made on the basis of the technical solutions of the present application fall within the protection scope of the present invention.

[0032] Example 1:

[0033] This example provides an analysis method for the content of the binder in Gu'ao aluminum-bonded explosive by using the curing rate, specifically for the determination of the content of the binder in the Gu'ao aluminum-001 explosive formula. This method is carried out according to the following steps:

[0034] Step 1, determination of the curing rate of the binder:

[0035] Step 101, mix the binder and aluminum powder used in the Gu'ao aluminum-001 bonded explosive according to the formula ratio of the Gu'ao aluminum-001 bonded explosive, and cure them under the same process conditions as those for preparing the Gu'ao aluminum-001 bonded explosive. The sample obtained after curing is called the companion sample.

[0036] In Step 101, the process conditions include temperature and curing time, both of which are known temperature and curing time.

[0037] Step 102, weigh about 1 g of the companion sample on a weighing paper, cut it into small pieces of about 2 mm×2 mm×2 mm with a blade, pour all of them into a No. 3 filter cup that has been weighed to a constant weight, weigh it accurately to 0.0001 g. Add 30 mL of acetone to the bottom flask of the extractor, place the filter cup containing the sample in the extractor, and reflux and extract at 90°C for 4 h. Then place the extracted filter cup and residue in an oven at 100°C±5°C for drying for 1 h, take it out and cool it in a desiccator for 30 min, and weigh it. Calculate the content of the remaining solid, that is, the combined amount of aluminum powder and the cured polymer.

[0038] Step 103: Transfer all the remaining solids obtained in Step 102 into a beaker, add a mixed acid of perchloric acid and concentrated nitric acid with a volume ratio of 1:1, cover it with a watch glass, place it on an enclosed electric furnace for heating, adjust the temperature switch to keep the solution in the beaker slightly boiling until the solution becomes completely clear, cool it to room temperature, and transfer it to a 100 mL volumetric flask and make up the volume with water.

[0039] Use a pipette to measure 20 mL of the above solution into a 250 mL volumetric flask, then use a pipette to add 20 mL of EDTA standard solution, add 2 - 3 drops of xylenol orange indicator, and use ammonia water solution and dilute nitric acid to adjust the pH value to 4 - 6. Place it on an electric furnace and heat it to boiling for 3 - 4 minutes, cool it to room temperature, add 7 mL of 10% hexamethylenetetramine buffer solution, and then titrate with lead nitrate standard solution until the solution turns red, and read the titration volume. Calculate the aluminum powder content in the accompanying sample. Then calculate the content of the cured polymer by the difference method.

[0040] Step 104: Calculate the curing rate of the binder. The curing rate of the binder is the ratio of the amount of the cured polymer to the amount of the added binder.

[0041] Specifically in this embodiment, prepare 5 accompanying samples, measure the content of the cured polymer in each of them respectively, calculate the ratio of the polymer to the binder in the original formula, and take the average of the 5 data as the curing rate. The specific data is shown in Table 1.

[0042] Table 1 Curing Rate of the Binder of Gu'ao Aluminum - 001 Series Explosives

[0043]

[0044] Step 2: Extract and separate the Gu'ao aluminum - bonded explosive sample with a solvent to obtain a solution and remaining solids, and calculate the content of the remaining solids by the weighing method.

[0045] Specifically in this embodiment, weigh about 1 g of the explosive sample on a weighing paper, cut it into small pieces about 2 mm × 2 mm × 2 mm with a blade, pour all of them into a No. 3 filter cup that has been weighed to a constant weight, weigh it accurately to 0.0001 g. Add 30 mL of acetone to the bottom flask of the extractor, place the filter cup containing the sample in the extractor, and reflux and extract at 90 °C for 4 h. Then place the extracted filter cup and the remaining solids in an oven at 100 °C ± 5 °C for drying for 1 h, take it out and cool it in a desiccator for 30 min, and then weigh it.

[0046] In this embodiment, the small molecules in the Gu'ao aluminum - bonded explosive sample dissolve into the solvent to form a solution.

[0047] In this embodiment, the remaining solids in the Gu'ao aluminum - bonded explosive sample are aluminum powder and cured polymer.

[0048] Step 3: Digest the remaining solid with strong acid to obtain a liquid containing aluminum ions, and determine the aluminum content by complexometric titration to obtain the aluminum powder content in the remaining solid.

[0049] In this embodiment, the strong acid can convert the aluminum powder in the remaining solid into aluminum ions.

[0050] Specifically in this embodiment, transfer all the remaining solid in the filter cup in Step 2 to a beaker, add a mixed acid of perchloric acid and concentrated nitric acid with a volume ratio of 1:1, cover with a watch glass, place on a closed electric furnace for heating, adjust the temperature switch to keep the solution in the beaker slightly boiling until the solution is completely clear, cool to room temperature, and transfer to a 100 mL volumetric flask and make up the volume with water.

[0051] Measure 20 mL of the above solution with a pipette and transfer it to a 250 mL volumetric flask. Then, add 20 mL of EDTA standard solution with a pipette, add 2 - 3 drops of xylenol orange indicator, and adjust the pH value to 4 - 6 with ammonia water solution and nitric acid solution. Place on an electric furnace and heat to boiling for 3 - 4 minutes, cool to room temperature, add 7 mL of 10% hexamethylenetetramine buffer solution, and then titrate with lead nitrate standard solution until the solution turns red, and read the titration volume.

[0052] Calculate the aluminum powder content based on the complexometric titration reaction relationship.

[0053] Step 4: According to the content of the remaining solid obtained in Step 2 and the aluminum powder content in the remaining solid obtained in Step 3, calculate the amount of the cured polymer in the remaining solid by the subtraction method.

[0054] Step 5: Calculate the content of the binder in the Gualv aluminized explosive by combining the curing rate of the binder obtained in Step 1.

[0055] Application verification:

[0056] Extract 5 batches of products produced by Gualv aluminized explosive - 001 for testing. The test results of the binder content in the Gualv aluminized explosive - 001 formula are shown in Table 2.

[0057] Table 2 Test results of the binder content in the Gualv aluminized explosive - 001 formula

[0058] Sample Number Binder / % Aluminum Powder / % GuAo Aluminum - 001 - 01 11.17 10.06 GuAo Aluminum - 001 - 02 11.09 10.08 GuAo Aluminum - 001 - 03 11.24 10.10 GuAo Aluminum - 001 - 04 11.30 9.90 GuAo Aluminum - 001 - 05 11.01 10.12

[0059] It can be seen from the above test results that the parallel error of the test results by this method is small, which can fully meet the requirements of the process and analysis error. The analysis method is simple, reliable and practical.

[0060] Example 2:

[0061] This embodiment provides an analysis method for the binder content in Guao aluminum-bonded explosive by using the curing rate, specifically for the determination of the binder content in the Guao aluminum-002 explosive formula. This method is carried out according to the following steps:

[0062] Step 1, determination of the curing rate of the binder:

[0063] Step 101, mix the binder and aluminum powder used in the Guao aluminum-002 bonded explosive according to the formula ratio of the Guao aluminum-002 bonded explosive, and cure under the same process conditions as those for the preparation of the Guao aluminum-002 bonded explosive. The sample obtained after curing is called the test sample.

[0064] In Step 101, the process conditions include temperature and curing time, both of which are known temperature and curing time.

[0065] Step 102, weigh about 1 g of the test sample on a weighing paper, cut it into small pieces of about 2 mm×2 mm×2 mm with a blade, and pour all of them into a No. 3 filter cup that has been weighed to a constant weight. Weigh it accurately to 0.0001 g. Add 30 mL of acetone and ethyl acetate to the bottom flask of the extractor, place the filter cup containing the sample in the extractor, and reflux and extract at 90 °C for 4 h. Then place the extracted filter cup and the remaining solid in an oven at 100 °C±5 °C for drying for 1 h, take it out and cool it in a desiccator for 30 min, and weigh it. Calculate the total amount of aluminum powder and the cured polymer.

[0066] Step 103, transfer all the remaining solid obtained in Step 102 to a beaker, use a mixed acid of perchloric acid and concentrated nitric acid with a volume ratio of 1:1, cover it with a watch glass, place it on a closed electric furnace for heating, adjust the temperature switch to keep the solution in the beaker slightly boiling until the solution is completely clear, cool it to room temperature, and transfer it to a 100 mL volumetric flask and make up the volume with water.

[0067] Use a pipette to measure 20 mL of the above solution into a 250 mL volumetric flask, then use a pipette to transfer 20 mL of the EDTA standard solution, add 2 - 3 drops of xylenol orange indicator, and use ammonia water solution and dilute nitric acid to adjust the pH value to 4 - 6. Place it on an electric furnace and heat it to boiling for 3 min - 4 min, cool it to room temperature, add 10 mL of 10% hexamethylenetetramine buffer solution, and then titrate with the lead nitrate standard solution until the solution turns red, and read the titration volume. Calculate the aluminum powder content in the test sample. Then use the subtraction method to calculate the content of the cured polymer.

[0068] Step 104, calculate the curing rate of the binder. The curing rate of the binder is the ratio of the amount of the cured polymer to the amount of the added binder.

[0069] Prepare 5 test samples, measure the content of the cured polymer in each of them respectively, calculate the ratio of the polymer to the binder in the original formula, and take the average of the 5 data as the curing rate. The specific data are shown in Table 3.

[0070] Table 3 Curing rate of the binder of Gu'ao aluminum - 002 series explosives

[0071]

[0072] In the second step, extract and separate the Gu'ao aluminum - bonded explosive sample with a solvent to obtain a solution and the remaining solid, and calculate the content of the remaining solid by the weighing method.

[0073] Specifically in this embodiment, weigh about 1 g of the explosive sample on a weighing paper, cut it into small pieces of about 2 mm×2 mm×2 mm with a blade, pour all of them into a No. 3 filter cup that has been weighed to a constant weight, weigh it accurately to 0.0001 g. Add a mixture of 30 mL of acetone and ethyl acetate to the bottom flask of the extractor, place the filter cup containing the sample in the extractor, and reflux and extract at 90 °C for 4 h. Then place the extracted filter cup and the remaining solid in an oven at 100 °C±5 °C for drying for 1 h, take it out and cool it in a desiccator for 30 min, and then weigh it.

[0074] In this embodiment, the small molecules in the Gu'ao aluminum - bonded explosive sample dissolve into the solvent to form a solution.

[0075] In this embodiment, the remaining solid in the Gu'ao aluminum - bonded explosive sample is aluminum powder and cured polymer.

[0076] In the third step, digest the remaining solid with strong acid to obtain a liquid containing aluminum ions, and determine the aluminum content by complexometric titration to obtain the aluminum powder content in the remaining solid.

[0077] In this embodiment, the strong acid can convert the aluminum powder in the remaining solid into aluminum ions.

[0078] Specifically in this embodiment, transfer all the remaining solid in the filter cup in the second step to a beaker, add a mixed acid of perchloric acid and concentrated nitric acid with a volume ratio of 1:1, cover it with a watch glass, place it on a closed - type electric furnace for heating, adjust the temperature switch to keep the solution in the beaker slightly boiling until the solution becomes completely clear, cool it to room temperature, and transfer it to a 100 mL volumetric flask and make up the volume with water.

[0079] Use a pipette to measure 20 mL of the above - mentioned solution into a 250 mL volumetric flask, then use a pipette to add 20 mL of the EDTA standard solution, add 2 - 3 drops of xylenol orange indicator, adjust the solution with ammonia water and nitric acid solution to adjust the pH value to 4 - 6. Place it on an electric furnace and heat it to boiling for 3 min - 4 min, cool it to room temperature, add 7 mL of 10% hexamethylenetetramine buffer solution, and then titrate it with a lead nitrate standard solution until the solution turns red, and read the titration volume.

[0080] Calculate the aluminum powder content according to the complexometric titration reaction relationship formula.

[0081] Step 4: According to the content of the remaining solid obtained in Step 2 and the aluminum powder content in the remaining solid obtained in Step 3, calculate the amount of the cured polymer in the remaining solid by the subtraction method.

[0082] Step 5: Calculate the content of the binder in the Gualv aluminum-bonded explosive by combining the curing rate of the binder obtained in Step 1.

[0083] Application verification:

[0084] Extract 5 batches of products produced by Gualv aluminum-002 explosive for testing. The test results of the binder content in the formula of Jua aluminum-4 explosive are shown in Table 4.

[0085] Table 4 Test results of the binder content in the formula of Gualv aluminum-002 explosive

[0086] Sample Number Binder / % Aluminum Powder / % GuAo Aluminum - 002 - 01 9.24 25.06 GuAo Aluminum - 002 - 02 8.85 24.60 GuAo Aluminum - 002 - 03 8.74 24.58 GuAo Aluminum - 002 - 04 9.35 24.95 GuAo Aluminum - 002 - 05 9.34 24.60

[0087] It can be seen from the above test results that the parallel error of the test results by this method is small, and it can fully meet the requirements of the process and analysis error.

Claims

1. An analytical method for the binder content in Gu'ao aluminized explosive using the curing rate, characterized in that, The method is carried out according to the following steps: Step 1, determination of the curing rate of the binder; Step 2, extracting and separating the Gu'ao aluminum-bonded explosive sample with a solvent to obtain a solution and the remaining solid, and calculating the content of the remaining solid by the weighing method; Step 3, digesting the remaining solid with strong acid to obtain a liquid containing aluminum ions, and determining the aluminum content by complexometric titration to obtain the aluminum powder content in the remaining solid; Step 4, according to the content of the remaining solid obtained in Step 2 and the aluminum powder content in the remaining solid obtained in Step 3, using the subtraction method to obtain the amount of the cured polymer in the remaining solid; Step 5, calculating the content of the binder in the Gu'ao aluminum-bonded explosive in combination with the curing rate of the binder obtained in Step 1.

2. The analysis method of the binder content in the Gu'ao aluminum-bonded explosive as described in claim 1, characterized in that, The specific process of Step 1 is as follows: Step 101, mixing the binder and aluminum powder used in the Gu'ao aluminum-bonded explosive according to the formulation ratio of the Gu'ao aluminum-bonded explosive, and curing under the same process conditions as those for the preparation of the Gu'ao aluminum-bonded explosive. The sample obtained after curing is called the test sample; Step 102, cutting the test sample into small pieces, loading them into a filter cup, then placing the filter cup in an extractor and extracting with a solvent. The remaining solid is left in the filter cup. After drying the remaining solid, weighing it and calculating the content of the remaining solid; Step 103, digesting the remaining solid obtained in Step 102 with a mixed acid of nitric acid and perchloric acid, then determining the aluminum content in the remaining solid by complexometric titration, and using the subtraction method to obtain the amount of the cured polymer in the remaining solid; Step 104, calculating the curing rate of the binder. The curing rate of the binder is the ratio of the amount of the cured polymer to the amount of the added binder.

3. The method for analyzing the binder content in the Gu'ao aluminum-bonded explosive according to claim 1 by using the curing rate is characterized in that, In Step 2, the solvent is one or a combination of more than one of acetone, ethyl acetate, ether, and ethanol.

4. The analysis method for the binder content in the Gu'ao aluminized explosive as described in claim 1, characterized in that, In Step 3, the strong acid is one or a combination of more than one of nitric acid and perchloric acid.

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