A method for constructing a calculation model of the binding energy between components of a high polymer bonded explosive

Abstract

This invention provides a method for constructing a model to calculate the binding energy between components of a polymer-bonded explosive. The method includes the following steps: calculating the total energy of the polymer-bonded explosive, the total energy of the main charge excluding the polymer binder, and the total energy of the polymer binder excluding the main charge. The binding energy between the main charge and the polymer binder is then equal to the total energy of the polymer-bonded explosive. This is followed by subtracting the total energy of the main charge excluding the polymer binder, and then subtracting the total energy of the polymer binder excluding the main charge. Molecular mechanics is used to calculate the total energy of the material. After applying molecular mechanics, 100 frames of material molecular trajectories are taken, and the total energy of each frame's molecular structure conformation is calculated. The average value is then calculated to obtain the binding energy between the main charge and the polymer binder. This invention provides a method for constructing a model to calculate the binding energy between components of a polymer-bonded explosive, which helps improve the design and research level of polymer-bonded explosives.

Description

Technical Field

[0001] This invention belongs to the field of mixed explosives and relates to the charging process of polymer-bonded explosives, specifically to a method for constructing a calculation model of the binding energy between components of polymer-bonded explosives. Background Technology

[0002] In polymer-bonded explosives, the binder is typically an organic polymer. It acts as a binding component in the mixed explosive, primarily serving a binding function, but can also act as a desensitizer, plasticizer, and explosive carrier. The polymer binder binds, coats, and desensitizes highly sensitive explosives. Through appropriate molding and processing methods, utilizing the excellent mechanical properties of polymers, mixed explosives can be manufactured into products with good moldability and excellent physical and mechanical properties. They can also be made into various physical states and specific shapes to meet diverse application requirements. In mixed explosive design, after determining the appropriate polymer binder, it is necessary to determine which binders bond more stably with the main explosive. Currently, there is no fully mature theory in this field. For example, the "similar polarity" principle applies to most substances, but it is only an empirical qualitative principle, lacking quantitative criteria. The principle of similar solubility parameters can be quantitatively calculated, but it is not applicable to strongly polar polymer-solvent systems. Based on the principle that the greater the binding energy between components, the more stable the bonded explosive, a method for constructing a calculation model for the binding energy between components of polymer-bonded explosives is proposed to describe the bonding stability of each component during the loading process.

[0003] Chinese invention patent CN201810909986.2 discloses a method for calculating the interfacial bonding energy of layered metal composite materials. This invention belongs to the field of composite material interfacial bonding performance research, proposing to use the magnitude of the interfacial bonding energy to judge the quality of the interfacial bonding energy of composite materials at the microscopic level. However, this invention can only evaluate layered metal composite materials and cannot be extended to the field of mixed explosives, and it does not take into account the principles of statistical mechanics.

[0004] Therefore, it is necessary to invent a calculation model for the binding energy between components of a polymer-bonded explosive, considering the two components of the bonded explosive, and describing the bonding stability of the two components during the loading process. Summary of the Invention

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for constructing a calculation model for the binding energy between components of a polymer-bonded explosive includes:

[0007] S1: Calculate the molecular weight of the main charge and the degree of polymerization of the binder based on the component mass ratio of the polymer-bonded explosive, the relative molecular mass of the main charge, and the relative molecular mass of the binder.

[0008] S2: Based on the parameters in S1, calculate the total energy E of the polymer-bonded explosive using molecular mechanics methods. all Total energy E of the main charge explo Total energy E of the binder poly The bonding energy E between the main charge and the binder bind E equals the total energy E of the polymer-bonded explosive all Subtract the total energy E of the main charge explo Subtract the total energy E of the adhesive. poly ;

[0009]

[0010] The unit of energy is kJ / mol;

[0011] Take 100 frames of material molecular trajectories, calculate the corresponding total energy of each frame of molecular structure conformation, and then take the average value to obtain the binding energy between the main charge and the polymer binder.

[0012] Optionally, step S2 further includes the following steps:

[0013] Step S21: Calculate the total energy of each material using molecular mechanics methods;

[0014] Total molecular energy E total It can be represented as:

[0015] E total =E c +E b +E t +E v +E h +E e +E d ;

[0016] In the formula: Ec is the bond stretching energy, E b It is the bond angle bending energy, E t It is the dihedral torsional energy, E v It is the van der Waals action energy, E h It is the hydrogen bond interaction energy, E e It is the electrostatic interaction energy, E d It is the dipole interaction energy; each energy term consists of a certain potential energy function form and force field parameters; the energy unit is kJ / mol;

[0017] Step S22: After using molecular mechanics methods, 100 frames of material molecular trajectories are taken. The total energy of each frame's molecular structure conformation is calculated, and then the average value is taken to obtain the binding energy between the main charge and the polymer binder, i.e.:

[0018]

[0019] N is the number of frames.

[0020] Optionally, step S22 further includes:

[0021] In molecular dynamics studies under a given force field, the coordinates r and potential energy E are first obtained from the empirical potential energy function through energy minimization. r The negative value of the first derivative with respect to the coordinates is the force F, with units of N, i.e.:

[0022]

[0023] Then, applying Newton's second law, we obtain the acceleration, which is:

[0024]

[0025] Once we know r, F, and E at a certain time t r We can then determine the force at another moment t+Δt, obtain the new velocity from the new force, derive the new position from the new force and velocity, and finally use molecular mechanics methods to calculate the corresponding total energy for each frame of molecular structure conformation.

[0026] Compared with the prior art, the present invention has the following technical effects:

[0027] (I) The construction method involved in this invention takes into account the wave effect of molecular dynamics and can more accurately predict the binding energy between the main charge and the polymer binder by using the principles of statistical mechanics.

[0028] (II) The construction method involved in this invention starts from the molecular structure of polymer-bonded explosives and constructs a calculation model to describe the binding energy between components in polymer-bonded explosives, thereby reducing the dependence on experimental techniques.

[0029] (III) The construction method involved in this invention helps to improve the design and research level of polymer-bonded explosives. Detailed Implementation

[0030] The present invention will be described in detail below with reference to specific embodiments.

[0031] In this invention, the energy unit is kJ / mol, the force unit is N Newton, and the material refers to the different components in the explosive, with different components made of different materials.

[0032] The method for constructing a computational model for the bonding between polymer-bonded explosive components of the present invention includes the following steps:

[0033] S1: Calculate the molecular weight of the main charge and the degree of polymerization of the binder based on the component mass ratio of the polymer-bonded explosive, the relative molecular mass of the main charge, and the relative molecular mass of the binder.

[0034] S2: Calculate the total energy E of the polymer-bonded explosive based on the parameters in S1. all Total energy E of the main charge explo Total energy E of the binder poly The bonding energy E between the main charge and the binder bind E equals the total energy E of the polymer-bonded explosive all Subtract the total energy E of the main charge explo Subtract the total energy E of the adhesive. poly ;

[0035] E bind =E all -E explo -E Poly (1.1);

[0036] Furthermore, step S2 also includes the following steps:

[0037] Step S21: When calculating the total energy of the material, molecular mechanics is used. Based on classical Newtonian mechanics, molecular mechanics can quickly calculate the conformation, energy, and various properties of molecules. It views a molecule as a collection of atoms held together by elastic forces, where each chemical bond has a standard bond length and bond angle. To adjust its geometry, a molecule must bring its bond lengths and bond angles close to their standard values ​​while minimizing non-bonded interactions. Therefore, the structure of each real molecule is a compromise of mutually constraining forces. Total molecular energy E total It can be represented as:

[0038] E total =E c +E b +E t +E v +E h +E e +E d (1.2);

[0039] In the formula E c Ec is the bond stretch energy, E is the bond stretch energy, E b It is the bond angle bending energy, E t It is the dihedral torsional energy, E v It is the van der Waals action energy, E h It is the hydrogen bond interaction energy, E e It is the electrostatic interaction energy, E dIt is the dipole interaction energy. Each energy term consists of a certain potential energy function and force field parameters. Conventionally, these parameters and functions are collectively referred to as the force field.

[0040] Step S22: After using molecular mechanics methods, 100 frames of material molecular trajectories are taken. The total energy of each frame's molecular structure conformation is calculated, and then the average value is taken to obtain the binding energy between the main charge and the polymer binder, i.e.:

[0041]

[0042] Furthermore, step S22 also includes the following:

[0043] Molecular dynamics is an effective method in molecular mechanics for dynamically studying the structure and properties of materials under specific force fields by utilizing parameters such as force, velocity, and position. Molecular dynamics neglects the quantum effects of nuclear motion, and at every moment, electrons are in the ground state of their corresponding atomic structures. In molecular dynamics studies under a given force field, the coordinates r and potential energy E are first obtained from the empirical potential energy function through energy minimization. r The negative value of the first derivative with respect to the coordinates is the force F, that is:

[0044]

[0045] Then, applying Newton's second law, we obtain the acceleration, which is:

[0046]

[0047] Once we know r, F, and E at a certain time t r We can then determine the force at another moment t+Δt, obtain the new velocity from the new force, derive the new position from the new force and velocity, and finally use molecular mechanics methods to calculate the corresponding total energy for each frame of molecular structure conformation.

[0048] In molecular dynamics simulations, a force field generally comprises three parts: atom type, potential function, and force field parameters. Different force fields typically have different functional forms or force field parameters. The potential function in the force field represents the interactions between atoms or molecules. From the initial pair potential, it has evolved to the current many-body potential, which considers not only the interactions between atoms but also the influence of atomic positions on the electron cloud. Currently, the most commonly used many-body force field is the COMPASS force field, whose functional form is as follows:

[0049]

[0050] The above functions mainly include covalent and non-covalent bond terms. The first 11 terms characterize internal coordinates such as bond length, bond angle, torsion angle, and dihedral angle, while the 12th and 13th terms represent Coulomb interaction and electrostatic interaction terms between atoms.

[0051] The binding energy calculation model between polymer-bonded explosive components disclosed in this invention can calculate the binding energy between other mixed explosive components, reflecting the general law of the binding energy of mixed explosives.

[0052] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All different force fields made based on the technical solutions of this application fall within the protection scope of the present invention.

[0053] Example 1:

[0054] Following the above technical solution, this embodiment uses a method for constructing a model to calculate the binding energy between polymer-bonded explosive components to model and calculate the binding energy of polymer-bonded explosive (CL-20 / PEG).

[0055] The polymer-bonded explosive (CL-20 / PEG), by mass fraction, has the following composition: hexanitrohexaazaisowrutzane (CL-20): polyvinyl alcohol (PEG) = 93.5: 6.5. CL-20 has a relative molecular weight of 31536, and PEG has a degree of polymerization of 50 and a relative molecular weight of 2252.

[0056] Using the COMPASS force field, the total energy of each component is shown in the table below:

[0057]

[0058]

[0059]

[0060]

[0061] Using the binding energy calculation model proposed in this invention, the average binding energy between CL-20 and PEG in polymer-bonded explosives (CL-20 / PEG) is -425.76 kcal / mol.

[0062] The above description is merely a preferred embodiment of this invention and is not intended to limit the scope of protection of this invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention are included within the scope of protection of this invention.

Claims

1. A method for constructing a calculation model for the binding energy between components of a polymer-bonded explosive, characterized in that, include: S1: Calculate the molecular weight of the main charge and the degree of polymerization of the binder based on the component mass ratio of the polymer-bonded explosive, the relative molecular mass of the main charge, and the relative molecular mass of the binder. S2: Based on the parameters in S1, calculate the total energy of the polymer-bonded explosive using molecular mechanics methods. E all Total energy of the main charge E explo Total energy of the adhesive E poly The bonding energy between the main charge and the binder E bind Equal to the total energy of polymer-bonded explosives E all Subtract the total energy of the main charge E explo Subtract the total energy of the adhesive. E poly ; ； The unit of energy is kJ / mol; Take 100 frames of material molecular trajectories, calculate the corresponding binding energy of each frame of molecular structure conformation, and then take the average value to obtain the binding energy between the main charge and the polymer binder.

2. The method for constructing a calculation model for the binding energy between components of a polymer-bonded explosive according to claim 1, characterized in that, Step S2 further includes the following steps: Step S21: Calculate the total energy of each material using molecular mechanics methods; Total molecular energy E all Represented as: ； In the formula: Ec It is the bond stretching energy. E b It is the bending energy of the bond angle. E t It is the dihedral torsional energy. E v It is the van der Waals action energy. E h It is the hydrogen bond interaction energy. E e It is electrostatic energy. E d It is the dipole interaction energy; each energy term consists of a certain potential energy function form and force field parameters; the energy unit is kJ / mol; Step S22: After using molecular mechanics methods, 100 frames of material molecular trajectories are taken. The binding energy of each frame's molecular structure conformation is calculated, and then the average value is taken to obtain the binding energy between the main charge and the polymer binder, i.e.: ； N is the number of frames.

3. The method for constructing a calculation model for the binding energy between components of a polymer-bonded explosive according to claim 2, characterized in that, Step S22 further includes: In molecular dynamics studies under a given force field, the coordinates are first obtained from the empirical potential energy function through energy minimization. r Potential energy E r The negative value of the first derivative with respect to the coordinates is the force F, with units of N, i.e.: ； Then, applying Newton's second law, we obtain the acceleration, which is: ； Once a certain moment is known t of r , F and E r Then we can know another moment. t+Δt The force is used to determine the new velocity, and the new position is obtained from the new force and velocity. Then, using molecular mechanics methods, the total energy of each frame of molecular structure conformation is calculated.

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