阅读说明：本技术 一种低熔点、易挥发含能材料的动态测压热分析方法 (Dynamic manometric thermal analysis method for low-melting-point and volatile energetic material ) 是由 李志敏 张同来 杨利 黄可奇 王彦娜 夏良洪 张纬经 于 2020-11-30 设计创作，主要内容包括：本发明涉及一种低熔点、易挥发含能材料的动态测压热分析方法,属于含能材料技术领域。为了满足对低熔点、易挥发性含能材料进行热分析的实际需求,本发明所述方法首先对含能材料进行冷冻后再加热,并通过压力传感器和温度传感器得到含能材料分解过程中的实时表观压力和温度值,然后通过TGA法得到材料在不同温度下的蒸气压,将表观压力进行标准化和归一化处理、再减去相应测试温度条件下材料的蒸气压,得到由于分解而导致的压力增加数据,以此数据进行动学和热力处理,得到用于判定该物质热安定性和反应性的基础数据。有效解决了低熔点、易挥发性含能材料分解压力难以测试的问题,实验过程精确、安全、可控、实时在线。(The invention relates to a dynamic pressure measurement thermal analysis method for a low-melting-point and volatile energetic material, belonging to the technical field of energetic materials. In order to meet the actual requirement of thermal analysis on low-melting-point and volatile energetic materials, the method comprises the steps of freezing the energetic materials, then heating the materials, obtaining real-time apparent pressure and temperature values in the decomposition process of the energetic materials through a pressure sensor and a temperature sensor, then obtaining vapor pressure of the materials at different temperatures through a TGA method, standardizing and normalizing the apparent pressure, subtracting the vapor pressure of the materials under the corresponding test temperature condition to obtain pressure increase data caused by decomposition, and performing the action and thermal processing on the data to obtain basic data for judging the thermal stability and reactivity of the materials. The problem that the decomposition pressure of the low-melting-point and volatile energetic material is difficult to test is effectively solved, and the experimental process is accurate, safe, controllable and real-time online.)

1. A dynamic manometric thermal analysis method of low melting point and volatile energetic material is characterized in that: the method comprises the following steps:

(1) the energetic material is put into a closed reaction test tube, a pressure sensor and a temperature sensor are arranged in the reaction test tube, and the energetic material is not contacted with the pressure sensor and the temperature sensor;

(2) placing the reaction test tube in a low-temperature environment for freezing treatment, vacuumizing the reaction test tube after freezing is finished until the pressure is less than 10Pa, and recording the pressure and the temperature in the reaction test tube after the pressure in the reaction test tube is stable;

(3) taking the reaction test tube out of the low-temperature environment, placing the reaction test tube in a heating furnace for heating, heating to the temperature to be analyzed, preserving the heat, and recording the pressure and the temperature in the reaction test tube on line in real time; standardizing and normalizing the pressure to obtain a processed pressure value;

(4) weighing the energetic material, testing by adopting a TGA method to obtain the volatilization amount of the energetic material at different temperatures, and calculating to obtain a corresponding vapor pressure value;

(5) and subtracting the vapor pressure value from the processed pressure value at the same temperature to obtain the data of the pressure increase value caused by the decomposition of the energetic material, wherein the data is used for carrying out thermal analysis on the energetic material.

2. The dynamic manometric thermal analysis method of low melting point, volatile energetic material according to claim 1, characterized in that: the low-melting-point and volatile energetic material is an energetic material which is liquid at room temperature, a sticky energetic material, a solid energetic material with a melting point of less than or equal to 100 ℃ or a sensitive energetic material.

3. The dynamic manometric thermal analysis method of low melting point, volatile energetic material according to claim 1, characterized in that: and (1) carrying out nitrogen replacement on the reaction test tube, and then filling the energetic material.

4. The dynamic manometric thermal analysis method of low melting point, volatile energetic material according to claim 1, characterized in that: and (3) placing the reaction test tube in liquid nitrogen for solidification in the step (2).

5. The dynamic manometric thermal analysis method of low melting point, volatile energetic material according to claim 1, characterized in that: and (4) heating in the step (3) at a heating rate of 1-5 ℃/min.

Technical Field

The invention relates to a dynamic pressure measurement thermal analysis method for a low-melting-point and volatile energetic material, belonging to the technical field of energetic materials.

Background

At present, with the continuous development of national defense equipment technology, low-melting-point and volatile energetic materials have been widely applied on a large scale, and comprise cloud explosion agents, high-density mixed hydrocarbons and the like. The liquid cloud explosive is flammable and volatile liquid hydrocarbon, can spontaneously combust at normal temperature, even causes fire and explosion, has huge detonation power, and is widely applied to modern weaponry. Therefore, there is a need for thorough research and understanding of the properties of such low melting point, volatile energetic materials to ensure safety in production and use.

The vacuum stability of the energetic material is one of methods for accelerated aging tests of the energetic material, the thermal reaction, thermal decomposition, the process of producing gas products and the gas production rate of the material caused by double factors of heat and low pressure in the processes of high vacuum degree, high-temperature heating and long-time storage are mainly examined, and the obtained test result has important application value for guiding the safe operation and controlling the storage conditions in the processes of production, use, storage and transportation.

In order to study the vacuum stability of energetic materials, the thermal decomposition process of the sample under vacuum and heated conditions was measured by capillary mercury column manometer method in the early days. Because the capillary tube has a cold end, the low-melting-point and volatile samples are quickly volatilized and solidified at the cold end, and cannot participate in the heating process, so that the thermal stability of the full-scale samples to be tested cannot be truly checked.

With the development of measurement technology, the microelectronic sensor technology is rapidly developed, the novel pressure sensor can also adapt to the measurement requirement of micro-pressure change, a pressure compensation type test technology, an external pressure sensor test technology and the like appear, but due to the same problems of cold ends and the fact that a reaction test tube cannot be sealed for a long time under a high-temperature condition, measurement data are inaccurate, and the novel pressure sensor cannot be well applied to the test of the thermal stability of low-melting-point and volatile samples.

Disclosure of Invention

In view of the above, the present invention provides a Dynamic Pressure Thermal Analysis (DPTA) method for a low melting point volatile energetic material.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a dynamic manometric thermal analysis method of a low melting point, volatile energetic material, the method steps comprising:

(1) the method comprises the following steps of (1) filling an accurate amount of the energetic material into a closed reaction test tube, wherein a pressure sensor and a temperature sensor are arranged in the reaction test tube, and the energetic material is not in contact with the pressure sensor and the temperature sensor;

(2) placing the reaction test tube in a low-temperature environment for freezing treatment, vacuumizing the reaction test tube after freezing is finished until the pressure is less than 10Pa, and recording the pressure and the temperature in the reaction test tube after the pressure in the reaction test tube is stable; during freezing treatment, the ambient temperature is lower than the freezing point of the energetic material;

(3) taking the reaction test tube out of the low-temperature environment, placing the reaction test tube in a heating furnace for heating, heating to the temperature to be analyzed, preserving the heat, and recording the pressure and the temperature in the reaction test tube on line in real time; standardizing and normalizing the pressure to obtain a processed pressure value;

(4) weighing a certain amount of the energetic material, testing by adopting a thermogravimetric analysis (TGA) method to obtain the volatilization amount of the energetic material at different temperatures, and calculating to obtain a corresponding vapor pressure value;

(5) and subtracting the vapor pressure value from the processed pressure value at the same temperature to obtain the data of the pressure increase value caused by the decomposition of the energetic material, wherein the data is used for carrying out thermal analysis on the energetic material.

Further, the low-melting-point and volatile energetic material is an energetic material which is liquid at room temperature, a sticky energetic material, a solid energetic material with a melting point of less than or equal to 100 ℃ or a sensitive energetic material.

Further, the energetic material is filled into the reaction test tube after nitrogen gas replacement in the step (1). And converting reactive gases such as water vapor, carbon dioxide and the like in the reaction test tube into nitrogen, vacuumizing to reach a Pa-level pressure, and ensuring that the built-in pressure sensor and the temperature sensor only generate comprehensive pressure when tested in the reaction test tube.

Further, in the step (2), the reaction test tube is placed in liquid nitrogen for solidification.

Further, the heating rate in the step (3) is 1-5 ℃/min.

Advantageous effects

In order to meet the actual requirement of thermal analysis on low-melting-point and volatile energetic materials, the method comprises the steps of firstly condensing the energetic materials, then heating the materials, obtaining real-time apparent pressure and temperature values in the decomposition process of the energetic materials through a pressure sensor and a temperature sensor, then obtaining vapor pressure of the materials at different temperatures through a TGA method, standardizing and normalizing the apparent pressure, subtracting the vapor pressure of the materials under the corresponding test temperature condition to obtain pressure increase data caused by decomposition, and performing the action and thermal processing on the data to obtain basic data for judging the thermal stability and reactivity of the materials. The problem that the decomposition pressure of the low-melting-point and volatile energetic material is difficult to test is effectively solved, and the experimental process is accurate, safe, controllable and real-time online.

Drawings

FIG. 1 is a graph of the thermal decomposition net outgassing pressure for the material described in example 1 of the present invention;

FIG. 2 is a graph of the thermal decomposition net outgassing pressure for the material described in example 2 of the present invention;

Detailed Description

The present invention will be described in further detail with reference to specific examples.

Example 1

(1) Slowly filling nitrogen into the bottom of the reaction test tube, replacing air in the reaction test tube, and keeping the reaction test tube for 5 min; then, 1.0000 +/-0.0010 g of a sample of 2, 4-Dinitroanisole (DNAN) to be tested is loaded into the reaction test tube, and the reaction test tube is tightly sealed by plugging a plug with a temperature sensor and a pressure sensor.

(2) The reaction test tube was inserted into a dewar flask containing liquid nitrogen and condensed, and after 10min the sample was frozen to a hard solid. And connecting the vacuumizing pipeline to the reaction test tube, opening the vacuumizing pump, vacuumizing the reaction test tube to below 10Pa, and waiting for the pressure and temperature values measured in the reaction test tube to be stabilized.

(3) Placing the test tube into a heating furnace, setting the heating rate to be 2 ℃/min, keeping the temperature to be 100 ℃, and keeping the time to be 48 h; recording the pressure and temperature in the reaction test tube in real time on line; standardizing and normalizing the pressure to obtain a processed pressure value P_ap；

(4) In addition, 8mg of DNAN sample is weighed and evenly spread at the bottom of the platinum crucible, the heating rate is set to be 10 ℃/min, and the vapor pressure P at 100 ℃ is measured by a TGA method₀8.26 Pa;

(5) will P_apMinus P₀And obtaining a thermal decomposition net outgassing pressure curve of the DNAN, and using the data to perform thermal stability analysis on the energetic material as shown in FIG. 1.

Example 2

(1) Slowly filling nitrogen into the bottom of the reaction test tube, replacing air in the reaction test tube, and keeping the reaction test tube for 5 min; then, 1.0000 +/-0.0010 g of a 3, 4-dinitrofurazan-based furazan (DNTF) sample to be tested is loaded into a reaction test tube, and the reaction test tube is tightly sealed by a plug with a temperature sensor and a pressure sensor.

(2) The reaction test tube was inserted into a dewar flask containing liquid nitrogen and condensed, and after 10min the sample was frozen to a hard solid. And connecting the vacuumizing pipeline to the reaction test tube, opening the vacuumizing pump, vacuumizing the reaction test tube to below 10Pa, and waiting for the pressure and temperature values measured in the reaction test tube to be stabilized.

(3) Placing the test tube into a heating furnace, and arrangingPlacing the mixture at a constant temperature of 100 ℃ for 48h with a heating rate of 2 ℃/min; recording the pressure and temperature in the reaction test tube in real time on line; standardizing and normalizing the pressure to obtain a processed pressure value P_ap；

(4) Additionally, 8mg of DNTF sample is weighed and evenly spread at the bottom of a platinum crucible, the heating rate is set to 10 ℃/min, and the vapor pressure P at 100 ℃ is measured by a TGA method₀5.55 Pa;

(5) will P_apMinus P₀And obtaining a thermal decomposition net outgassing pressure curve of the DNAN, and using the data to perform thermal stability analysis on the energetic material as shown in FIG. 2.

In summary, the invention includes but is not limited to the above embodiments, and any equivalent replacement or local modification made under the spirit and principle of the invention should be considered as being within the protection scope of the invention.