Nghiên cứu sự phụ thuộc của quá trình phân hủy nhiệt và tốc độ nổ vào thành phần thuốc nổ hỗn hợp trên nền hexogen tt tiếng anh

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF NATIONAL DEFENCE ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY NGUYEN MAU VUONG STUDY THE DEPENDENCE OF THERMAL DECOMPOSITION PROCESS AND VE

MINISTRY OF EDUCATION

AND TRAINING

MINISTRY OF NATIONAL

DEFENCE

ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY

NGUYEN MAU VUONG

STUDY THE DEPENDENCE OF THERMAL DECOMPOSITION PROCESS AND VELOCITY OF DETONATION ON THE COMPOSITION OF EXPLOSIVE MIXTURE BASED ON HEXOGEN

Major: Theoretical and Physical Chemistry

Code: 9 44 01 19

SUMMARY OF DOCTORAL THESIS

Ha Noi - 2020

CôBỘ GIÁO DỤC VÀ ĐÀO

TẠO

BỘ QUỐC PHÒNG

VIỆN KHOA HỌC VÀ CÔNG NGHỆ QUÂN SỰ

The work was completed in :

Academy of Military Science and Technology, Ministry of Defence

Science intructors:

Assoc Prof Dr Ngo Van Giao

Assoc Prof Dr Dang Van Duong

Reviewer 1: Prof Dr Thai Hoang

Vietnam Academmy of Science and Technology

Reviewer 2: Assoc Prof Dr Dam Quang Sang

Military Technical Academy

Reviewer 3: Assoc Prof Dr Ninh Duc Ha

Academy of Military Science and Technology

The thesis is protected at the doctoral thesis evaluation council meeting at:

Military Science and Technology Institute At: ……… , date: … /… /2020

Thesis can be searched at:

- Academy of Military Science and Technology Library

- National Library of Vietnam.

LIST OF SCIENTIFIC WORK PUBLISHED

1 Nguyen Mau Vuong, Ngo Van Giao, Nguyen Ngoc Tu (2014), Thermal decomposition studies on cast mixture of TNT and RDX, Proceedings The

3th Academic Conference on Natural Science for Master and PhD Students from Asean Contries, Publishing House for Science and Technology, p.411-417

2 Nguyen Mau Vuong, Ngo Van Giao, Dang Van Duong (2015), Study the

dependence of velocity of detonation on the composition of mixed explosive

ТГ, Journal of Military Science and Technology Research, Issue numberHH-VL, 10-2015, Academy of Military Science and Technology, p.220-

227

3 Nguyen Mau Vuong, Ngo Van Giao, Dang Van Duong (2015),

Research into thermal decomposition of a mixture of RDX and insensitive,

Proceedings The 4th Academic Conference on Natural Science for Young Scientists, Master and PhD Students from Asean Contries, Publishing

House for Science and Technology, p.216-222

4 Nguyen Mau Vuong, Ngo Van Giao (2016), Study the dependence of velocity of detonation on the composition of mixed explosive A-IX-1,

Journal of Chemistry and Application, number 1(33)/2016, Vietnam Chemical Association, p.42-44

5 Nguyen Mau Vuong, Ngo Van Giao, Dang Van Duong, Research results of dependence of explosive heat on the composition of explosive ТГ, Journal of Chemistry and Application, topical number (02)

/2019, Vietnam Chemical Association, p.4-8

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OPENING

1 The urgency of the thesis

Hexogen or RDX is the common name of cyclonite; 1,3,5-triazocyclohecxan, hay cyclotrimetylen trinitramin, with the formula C3H6O6N6 RDX (symbol is , RDX) is one of the strong classic explosives RDX explosive has a high detonation velocity (8380 m/s at a density of 1.70 g/cm3), a high fertility force measured by the lead bomb method is (450 ÷ 520) ml However, RDX is highly sensitive (70 ÷ 80%), does not tolerate compression and decomposes before melting Therefore, people often use it

1,3,5-trinitro-in comb1,3,5-trinitro-ination with a high-tech explosive (fusible, not decompos1,3,5-trinitro-ing when molten) like TNT to cast into the heart of bombs, mines, bullets, explosive primers or with domestication reduces sensitivity, increases compressive resistance to load into concave bullets, explosive ammunition destroys damage

Currently, the military has invested in RDX'sproduction on an industrial scale Same with the TNT's production line, this line has been in production for the past time At the same time, the military has been and will continue to invest in production lines and repair of mortar bullets, anti-tank bullets and low-level anti-aircraft missiles However, studies on the process of thermal decomposition, the dependence of detonation velocity

on the mixture components on the RDX platform, although already mentioned but still limited This research determines the ability of the technology to load mixed explosive into the bomb core, researching the effect of ingredients on explosive speed will determine the power of explosives This issue has also been studied but is not have much public documents

Especially in our country, this subject has not been mentioned We received technology transfer, load making under contract, but there is no scientific basis to serve the design and manufacture of new types of ammunition suitable to the level of technology and combat capability for our army Therefore, the PhD student: "Studying the dependence of explosive speed and decomposition process on the composition of explosive mixture based on hexogen" is not only scientifically meaningful but also practical, urgent as a scientific basis for the research, design and manufacture of new types of ammunition suitable to the technological and operational conditions of the army

In calculating the design of bullets and explosive blocks currently, the world has used the copyrighted software ANSYS (Autodyn, LS-Dyna), MSC (Nastran, Dytran) to simulate explosive effects with accuracy , very high reliability From these simulations, people shorten the time and money

to come up with an optimal design for each type of product in accordance with the set goals Each ammunition design (or explosive device) will be optimized with a specific type of explosive

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In the military, with the initial tactical specifications set for the design of ammunition, bombs and mines, especially with the use of concave explosive effect, the parameters put in the software for the most important explosive were density, detonation velocity When changing these important parameters, the results obtained are completely different for

a given design There will be parameters to ensure that the design achieves the optimal effect of the explosion, sometimes it is economically optimal while still ensuring the initial specifications Therefore, it is urgent to set up

a manual of explosive systems (with all important parameters) At the same time, studying the thermal decomposition process will help determine the safe casting temperature range, the half-life of the drug depends on the storage temperature This is also the basis to determine the durability of the product and guide the storage conditions of ammunition storage

2 The objectives of the thesis

Research theoretical and experimental basis on the explosion process of two explosive explosives on the basis of RDX (T, A-IX-1) to build the orientation database for setting up a single explosive component suitable for use in researching and designing shaped bullets, concave bullets, bullets with strong destructive power; determine the safe casting temperature range, predict the life of the product based on the calculation of the half-life of explosives and indicate the importance of temperature factor

to the life of the product in preservation process, fire safety of bullets and explosives

3 The content of the thesis research

- Calculate the dependence of oxygen balance, oxygen coefficient, assumed molecular formula, explosive heat on the composition of combined explosive T, A-IX-1

- Determination of kinematic parameters of the decomposition process when changing explosive components T nổ, A-IX-1 From there, calculate the half-life of explosives, predict product durability

- Determining the experimental equation depending on the explosive speed, explosive heat on explosive components T, A-IX-1

4 Scientific, practical and new contributions of the thesis

- Starting from the actual need to study these two types of explosives in order to build a database for the design of a single component

in accordance with the requirements of the design and manufacture of bullets (especially concave bullet, bullet shaping), bombs and mines

- Based on the method of thermal analysis, determining the safe casting temperature range, predicting the life of the product based on the calculation of the half-life of explosives and showing the importance of the factor temperature to the shelf life of the product during safe storage of fire and explosion

* The layout of the thesis

The thesis includes: Introduction, four chapters, conclusions, list of references

Heading

Describe the urgency of the thesis topic, general overview of the objectives, content, research methods, scientific and practical meanings of the thesis and briefly introduce the layout of the thesis

Chapter I Overview

Analyzing and evaluating the domestic and foreign research situation, related issues and issues to be addressed in the thesis

Chapter II Research methods

Presentation of prototyping methods, calculation methods and measurement methods for explosive explosives

Chapter III Results and Discussion

This chapter focuses on solving the researched content of the thesis

CONTENTS OF THE THESIS CHAPTER I: OVERVIEW

Regarding RDX explosives and RDX-based mixtures, analyzing and evaluating domestic and foreign research situation, related issues and issues to be addressed in the thesis

CHAPTER II: SUBJECTS AND METHODS OF THE STUDY

2.2.1 Method of calculating oxygen balance and oxygen coefficient

2.2.2 Method of measurement and calculation of explosive heat

2.2.3 Methods and equipment for determining the explosion rate

2.2.4 Thermal analysis method

2.2.5 Conformity assessment method and thermal endurance by DSC 2.2.6 Method of calculating kinematic parameters

2.2.7 Scanning electron microscope SEM

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g2.2.8 Measurement of particle size distribution by laser scattering

2.2.9 Method of manufacturing research samples

2.2.10 Methods for determining the composition of explosive products.2.2.11 Methods of processing empirical data

CHAPTER III RESULTS AND DISCUSSION

3.1 Oxygen balance and oxygen factor and composition of explosive products

3.1.1 Calculation of factors and components of explosive products

3.1.1.2 Explosive system A-IX-1

Table 3.3 Oxygen balance and oxygen factor of dynamite A-IX-13

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gTable 3.4 Oxygen balance and oxygen factor of explosive A-IX-11

of explosive A-IX-13 can be approximated as follows:

A-IX-1 (6.5): C4.05H8.12O6.04N6.00= 0.08CO2 + 3.32H2O + 2.56CO + 0.74H2 + 1.41C +3.00N2 A-IX-1 (6.0): C3.96H7.94O6.04N6.00 = 0.14CO2 + 3.26H2O + 2.50CO + 0.71H2 + 1.33C +3.00N2 A-IX-1 (5.5): C3.88H7.77O6.04N6.00 = 0.19CO2 + 3.21H2O + 2.44CO + 0.68H2 + 1.25C +3.00N2 A-IX-1 (5.0): C3.80H7.60O6.03N6.00 = 0.25CO2 + 3.15H2O + 2.38CO + 0.65H2 + 1.17C +3.00N2

Based on the above results and applying the Avakian method to calculate the composition of explosive products, the decomposition reaction

of explosive A-IX-11 (5.0) can be approximated as follows:

A-IX-1 (6.5): C4.10H8.25O6.00N6.00 = 0.03CO2 + 3.35H2O + 2.60CO + 0.77H2 + 1.47C +3.00N2 A-IX-1 (6.0): C4.01H8.06O6.00N6.00 = 0.08CO2 + 3.30H2O + 2.54CO + 0.74H2 + 1.39C +3.00N2 A-IX-1 (5.5): C3.83H7.70O6.00N6.00 = 0.14CO2 + 3.24H2O + 2.47CO + 0.70H2 + 1.30C +3.00N2 A-IX-1 (5.0): C3.83H7.70O6.00N6.00 = 0.20CO2 + 3.18H2O + 2.41CO + 0.67H2 + 1.22C +3.00N2

3.1.2 Experimental qualitative composition of explosive products

The quantitative analysis is extremely complex and not enough equipment to implement so the subject has used the existing equipment to determine the calculation of the explosive product components of the combination explosive representative ТГ-50, A-IX-13 and A-IX-11 with CTH content of 5.5%

Use NARL8514 Lightweight gas analyzer MODEL 4016, showing the results of explosive gas products on the gas chromatography clearly show the pic of CO2, CO, N2 O2 gas is made weak in explosive products of drugs A-IX-1, not existing in explosive products of explosives ТГ-50

The result is also consistent with the calculation of the oxygen balance and the oxygen coefficient of the explosives The more explosives there are negative (or A less positive) than the amount of oxygen in the explosive product The presence of oxygen in the composition of an explosion caused by itself in a bomb when a vacuum can not fully complete the atmosphere (oxygen-ready) reaches 0.03-0.04 bar, so the remaining stain for the A-IX-1 explosive product is reasonable For explosives ТГ-50 due to the more negative coefficient (-47.82%) It is recommended that the

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goxygen itself involved in the reaction of the produced (C, CO) products is stronger and almost no stain is detected

Using an infrared absorption measurement device Jasco 4600, the resulting absorption spectrometer of the liquid product is similared to the infrared absorption spectrum of the sample ionized distilled water samples

As such, it is obvious that the condensation fluid on the main is H2O Use ofscanning electron micrograph JSM-6510 LV-X-ray dispersing probes for the composition of solid products of explosive A-IX-

13, A-IX-11, ТГ-50, theresults obtained from solid products show the apparent presence of carbon Besides, there are also elements: Cu, Zn, W,

O, Cl, Si, Pb, K These elements are present as a result of decomposition of compounds that are in the fire medicine and explosive medicine in the copper differential The substances are: Si, KClO4, W, Pb (N3)2, Zn The casing is made from copper (Cu)

The results are clearly visible to the existence of C, CO, CO2, N2, H2O in explosive decomposition products of all three types of explosives

In addition, there are O2 in explosive products A-IX-1 Currently, there is

no sufficiently sensitive measuring head to determine the presence of H2 in explosive products

3.2 Study the compatibility of the system

RDX has the original distribution as shown in Figure 3.14, surface image as Figure 3.15 Photos of explosive surface TГ after mixing are shown in Figures 3.16 and 3.17

Pic 3.14 Particle size

distribution of RDX

Pic 3.15 SEM image of grain surface of RDX

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Pic 3.16 SEM image of the outer

surface TГ after casting

Pic 3.17 SEM image of inner surface TГ after casting

SEM images show the adhesion, encapsulation of RDX explosive particles by molten TNT TNT here is also similar to the domesticated substance, which binds explosive particles that are not subject to RDX compression

Parameter measurement results are shown in Table 3.12

Table 3.12 Explosive parameters of explosives according to DSC curve

No Compound name Tonset, oC Tp, oC ∆Tp, o

C Conclude

2 TГ-60/40 229.7773 241.8040 -1.2695 Compatible The ∆Tp result shows that TNT is compatible with RDX Thus, the use of these two explosives to create a new explosive mixture is perfectly suitable

3.2.2 Explosive system A-IX-1

Images of A-IX-1 explosive surface after mixing are shown in

3.21

Pic 3.8 SEM image of A-IX-1 explosive surface

SEM images show the adhesion, encapsulation of RDX explosive particles by a mixture of domesticated substances Thus, mechanically, the mixture of domestication is suitable for wrapping RDX explosive particles,

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gwhich makes the surface has a sensitive and favorable layer for bonding process by compression method We obtain the physical parameters according to Table 3.13

Table 3.13 Decomposition parameters of types A-IX-1

No Compound name Tonset Tp, oC ∆Tp, o

3.3 Isothermal decomposition process of explosive

Similarly, the results of the temperature of decomposition start of the mixture also changes in a small range, from (215,3 ÷ 219,2) oC when the heating rate of 5 °C/minute, only lower than the captured temperature The decomposition head of RDX (220.6 oC) is about 5.3 oC Thus, it can be seen that these explosive mixtures are absolutely durable when using water

or steam to melt the mixture at a temperature of (100 ÷ 150) oC serving casting into bombs and bullets

From the two comments above, it is shown that the combination of these two explosives together to create a new explosive mixture in the study area still fully retains the casting technology of TNT and ensures fire safety with temperature Casting when using water (or steam) as TNT melting solvent

At the same time, also from the results of decomposition durability

of ТГ mixture in the range (215,3 ÷ 219,2) o

C when heating speed 5 o

C/min, showing a special attention in the pouring technology: Do not use a direct source of heat above 200 °C to melt the ТГ mixture because of the very high risk of fire and explosion, causing unsafe loading of bombs and ammunition (even when war occurs) Ideally, to ensure safety, only use a source of heat not exceeding 150 oC

Based on the results of measurement and graph of Kissinger's equation, the value of the activation energy E, the pre-exponential factor Z

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gand the reaction rate kT at temperature (T) are determined as shown in table 3.18

Table 3.18 Kinematic parameters and reaction rate constants of ТГ mixtures

Bảng 3.19 The decomposition reaction rate of ТГ mixtures

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gFrom the results of the calculation of the decomposition rate constant, found that at the same temperature, the rate constant decreases with increasing TNT content in the mixture This is due to the offset effect, between the activation energy E falling and the pre-factor (frequency) Z decreasing [4], [5] According to the Arrhenius equation, kT is inversely proportional to E and proportional to Z It can be seen that Z decreases when the concentration of TNT increases due to the thickening of the RDX particles due to TNT, making the opportunity for contact between RDX particles plummeted This effect is greater than the activation energy reduction effect E when the TNT content increases Therefore, in general, the reaction rate kT decreases with increasing TNT content

From this constant, we can calculate the half-life at different temperatures as shown in Table 3.20 On this basis, we can see that the durability of the product depends largely on the storage temperature

Table 3.20 The half-life of ТГ mixture