JP2019089919A - Production system, method and program of crosslinkage model - Google Patents

Abstract

To provide a production system of a crosslinkage model in which production of a short distance intramolecular loop structure is suppressed even without troublesome setting, and binding of particles for exhibiting proper physical quantity is increased.SOLUTION: A system has a reaction treatment execution part 11 for repeatedly executing a reaction treatments binding a polymer particle 2 and a crosslinking agent particle 3 in a prescribed distance each other at prescribed timing with crosslinking probability T1 set to the polymer particle 2, and a binding condition setting part 12 for setting either a binding possible condition and a binding impossible condition used in a next reaction treatment on the crosslinking agent particle 3 already bound to the polymer particle 2. The binding possible condition make binding of the crosslinking agent particle 3 possible, and a prescribed number N1 of the polymer particles 2b with the polymer particles 2a bound to the crosslinking agent particle 3 as a center impossible. The binding impossible condition makes binding of the crosslinking agent particle 3 and the polymer particles 2a bound to the crosslinking agent particle 3 impossible.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a crosslink model generation system, method and program used to calculate viscoelasticity by molecular dynamics calculation.

  For example, it is difficult to observe the cross-linking distribution by experiment for a vulcanized rubber which is vulcanized by adding a crosslinking agent such as sulfur to unvulcanized rubber. It is known that the cross-linking distribution affects the viscoelasticity, and if it is possible to analyze the relationship between the cross-linking distribution of particles and the viscoelasticity by computer simulation using CAE (Computer Aided Engineering), it is preferable to advance research and development. Conceivable.

  As a method of generating a cross-linking model in which a plurality of polymer particles are linked by beads and a crosslinking model in which cross-linking agent particles are linked, all polymer particles are cross-linked to a polymer model in which multiple polymer particles are linked by beads It is known to carry out a crosslinking process (reaction process) by molecular dynamics calculation, which is set to be capable of binding to an agent particle. In the reaction process, polymer particles constituting the polymer model and crosslinker particles within a predetermined distance are bonded with a predetermined probability.

  However, since the crosslinker particles bonded to the polymer particles constituting the polymer model have a high probability of being close to the polymer particles on both sides of the bonded polymer particles, they easily bond to the polymer particles. Then, as shown in FIG. 4C, a short distance intramolecular loop structure in which one crosslinker particle 3 is bonded to two adjacent polymer particles 2 is generated. Since the intramolecular loop structure does not contribute to the expression of physical quantities such as stress in molecular simulation using a crosslinking model of rubber or the like, it is preferable not to be generated in order to suppress the calculation cost.

  As another method of generating a crosslinking model, for example, Non-Patent Document 1 discloses that crosslinkable particles are specified for a polymer model. The setting of the crosslinkable particles is performed by specifying the number of non-crosslinkable particles disposed between the crosslinkable particles. According to this, for example, when the first and 80th crosslinkable particles are designated, the particles in between are set as non-crosslinkable particles. It is disclosed to make the distribution of crosslinks non-uniform by changing the number of non-crosslinkable particles placed between the crosslinkable particles.

  In some cases, the method according to Non-Patent Document 1 can suppress the formation of an intramolecular loop structure. However, in order to react all the crosslinker particles, it is necessary to properly determine the distance between the crosslinkable particles, which is troublesome. If the distance between the crosslinkable particles is large, the number of crosslinkable sites in the polymer model decreases and the crosslinker particles are left. Conversely, if the distance between the crosslinkable particles is reduced, all crosslinker particles can be reacted, but an intramolecular loop structure may be generated. In particular, when the crosslinker particles are relatively large relative to the polymer model, the distance between the crosslinkable particles must be reduced, and it is difficult to avoid the formation of an intramolecular loop structure.

FY 2009-FY 2011 Achievement Report Nanotechnology / Advanced materials practical research and development "R & D of rubber material for ultra-low fuel consumption tire by three-dimensional nano hierarchical structure control", February 2012, new administrative agency new energy · National Institute of Advanced Industrial Science and Technology, pages 8-9

  The present invention has been made in view of such problems, and its object is to suppress the generation of an intramolecular loop structure without making troublesome settings, and to express an appropriate physical quantity. It is an object of the present invention to provide a system, method and program for generating a crosslink model, in which the binding of particles is increased.

  The present invention takes the following measures to achieve the above object.

That is, the generation system of the crosslinking model of the present invention is
A system having a plurality of polymer models in which a plurality of polymer particles are linked in a linear or branched manner, and a plurality of crosslinker particles, and generating a crosslink model in which the polymer model and the crosslinker particles are combined,
A molecular dynamics calculation is performed based on analysis conditions set in advance, and a reaction process is performed in which polymer particles and crosslinker particles within a predetermined distance from each other at a predetermined timing are bonded to the polymer particles with the crosslinking probability set. Reaction processing execution units that are repeatedly executed;
And a bonding condition setting unit that sets any of bondable conditions and non-bondable conditions to the conditions used in the next reaction process for the crosslinker particles already bonded to the polymer particles,
The bondable conditions are conditions that make it possible to bond the crosslinker particles and make it impossible to bond a predetermined number of polymer particles centered on the polymer particles bonded to the crosslinker particles,
The non-bonding conditions are conditions that make the cross-linking particles and the polymer particles bound to the cross-linking particles non-bonding.

In this way, by setting the bondable condition and the bondable condition, it is possible to prevent the crosslinker particle already bonded to the polymer particle from bonding to the nearby polymer particle, and to suppress the occurrence of the intramolecular loop structure.
By setting possible binding conditions, the crosslinker particles already bonded can be bonded to another polymer particle, and the reaction process can be continued so that one crosslinker particle is bonded to a plurality of polymer particles. .
By setting the non-bonding condition, other crosslinker particles can be bonded to the polymer particle in a position close to the polymer particle to which the crosslinker particles are bonded, and a site where the crosslinker particles can be bonded can sufficiently be secured in the polymer model. Thus, it is possible to increase the binding of particles to express an appropriate physical quantity.
Therefore, it is possible to suppress the formation of an intramolecular loop structure without any troublesome setting, and to increase the binding of particles for expressing an appropriate physical quantity.

FIG. 1 is a block diagram illustrating a system for generating a crosslinking model of the present invention. Explanatory drawing regarding the bondable conditions and non-bondable conditions set with respect to the polymer particle which comprises a polymer model, and a crosslinking agent particle. The flowchart which shows the model production | generation process routine performed with the production | generation system of this invention. (A) The figure which shows the bonding conditions of the polymer particle of the comparative example 1. FIG. (B) A diagram showing the bonding conditions of the polymer particles of Comparative Example 2. (C) A diagram showing a short distance intramolecular loop structure. FIG. 5 shows stress-elongation ratio curves from a crosslink model obtained by the system and method of the present invention and a crosslink model according to the prior art.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[Generation system of bridge model]
The system of the present embodiment is a system (apparatus) that generates a crosslink model for molecular dynamics calculation, which is used to calculate the viscoelasticity by molecular dynamics calculation. The crosslinking model includes, for example, a rubber obtained by crosslinking a crosslinking agent such as sulfur with a polymer. The crosslinking agent is expressed as crosslinking agent particles, and the polymer is expressed as a polymer model in which a plurality of polymer models are linked in a linear or branched manner.

  As shown in FIG. 1, the system 1 includes an initial setting unit 10, a reaction process execution unit 11, and a combination condition setting unit 12. Each of these units 10 to 12 has software and hardware cooperatively because the CPU executes a model generation processing routine shown in FIG. 3 stored in advance in an information processing apparatus such as a personal computer provided with a CPU, a memory, various interfaces and the like. It is realized by working.

  The initial setting unit 10 shown in FIG. 1 receives an operation from the user via a known operation unit such as a keyboard or a mouse, sets information on the polymer model, sets the crosslinking agent such as sulfur, and molecules required for crosslinking. The setting of various analysis conditions used for dynamics calculation is executed, and these are stored in the memory.

The initial setting unit 10 shown in FIG. 1 is cross-linked in FIG. 2 (b) with respect to each of the polymer particles 2 (indicated by circles in the figure) constituting the linear polymer model shown in FIG. 2 (a). A predetermined first crosslinking probability T1 representing the probability of crosslinking with the agent particle 3 (indicated by a filled circle in the drawing) is set.
In addition, in this embodiment, although the linear model in which several particle | grains were connected in series is mentioned as an example, it is not limited to this. For example, it may be a branched model having a branch.

  The reaction process execution part 11 shown in FIG. 1 performs molecular dynamics calculation based on analysis conditions set in advance, and executes the reaction process at a predetermined timing. As an example of the predetermined timing, there is a time when a predetermined time on analysis has elapsed. The reaction process repeatedly executes a reaction process in which the polymer particles 2 and the crosslinker particles 3 which are within a predetermined distance from each other at a predetermined timing are bonded to the polymer particles 2 with the crosslinking probability (first crosslinking probability T1). .

  As shown in FIG. 2 (c), the bonding condition setting unit 12 shown in FIG. 1 is capable of bonding to the crosslinker particles 3 already bonded to the polymer particles 2 under the conditions used in the next reaction process. And set one of the unjoinable conditions. FIG. 2 (c) shows the unbondable particles without hatching, without filling the unbondable particles. In the present embodiment, one of the combining condition and the non-binding condition is set at random, but it is not limited to this. For example, it may be based on a predetermined rule such as allocation in order.

  As shown in FIG. 2 (c), the condition capable of being combined enables the crosslinker particles 3 to be combined, and a predetermined number N1 (four in the figure) centering on the polymer particles 2a combined with the crosslinker particles 3 The conditions under which the polymer particles 2b of (1) can not be bonded. The other polymer particles 2c can be bonded. In the present embodiment, the predetermined number N1 is set to four, but can be changed as appropriate.

  The non-bonding conditions are conditions under which the crosslinker particles 3 and the polymer particles 2a bonded to the crosslinker particles 3 can not be bonded. The other polymer particles 2b, 2c are attachable.

  The bonding condition setting unit 12 shown in FIG. 1 sets bonding conditions for all the crosslinker particles 3 already bonded to the polymer particles 2. Thereafter, the reaction process execution unit 11 performs molecular dynamics calculation, and executes the next reaction process at a predetermined timing. The setting of the bonding conditions by the bonding condition setting unit 12 and the bonding conditions until all the crosslinker particles 3 are bonded to a predetermined number (two in the present embodiment) of polymer particles 2 per one crosslinker particle 3 The execution of the reaction process by the reaction process execution unit 11 used is repeated.

[Method of generating a crosslinking model]
A method of generating a crosslinking model using the above system 1 will be described with reference to FIG.

  First, in step ST1, the initial setting unit 10 shown in FIG. 1 is based on the set data, as shown in FIG. 2 (a), for all the polymer particles 2 constituting the polymer model, the crosslinker particles A predetermined first crosslinking probability T1 indicating the probability of crosslinking with 3 is set.

  In the next step ST2, the reaction processing execution unit 11 shown in FIG. 1 performs molecular dynamics calculation based on analysis conditions set in advance, and polymer particles 2 and crosslinker particles within a predetermined distance from each other at predetermined timing. A reaction process is carried out in which 3 and 3 are bonded to the polymer particle 2 with the crosslinking probability (first crosslinking probability T1).

Specifically, in the present embodiment, LAMMPS (Large-scale Atomic / Molecularly Massively Parallel Simulator) is used for calculation of molecular dynamics. In LAMMPS, setting and reaction processing of the first crosslinking probability T1 are performed by executing the following command.
fix BOND all bond / create 1000 2 3 1.1 prob 0.8 123 iparam 3 4 jparam 2 4
Here, an identifier is assigned to each particle. The identifier “2” means polymer particles 2 and the identifier “3” means crosslinker particles 3. In this command, when a predetermined time (1000 steps) has elapsed in analysis, a predetermined distance is set to 1.1 for the bond between the polymer particle 2 having the identifier “2” and the crosslinker particle 3 having the identifier “3”, The first crosslinking probability T1 is 0.8. The next 3 in iparam represents the maximum number of bonded polymer particles, and 4 represents the identifier after reaction. That is, when the number of bonds is 3, the polymer particle 2 having the identifier "2" changes to the identifier "4" and is excluded from the target of the crosslinking reaction. Also, 2 next to jparam represents the maximum number of cross-linked goods particles, and 4 represents the identifier after reaction. The crosslinked particles 3 having the identifier “3” change to the identifier “4” when the number of bonds is 2, and are excluded from the target of the crosslinking reaction.

  In the next step ST3, the bonding condition setting unit 12 shown in FIG. 1 is capable of bonding and not being bondable to the conditions used in the next reaction process with respect to the crosslinker particles 3 already bonded to the polymer particles 2. Set one of the In this embodiment, they are set randomly. The setting of the bonding conditions performed in step ST3 is repeatedly performed (ST4: NO) until the setting is performed for all the crosslinker particles 3 already bonded to the polymer particles 2 (ST4: YES).

  In the next step ST5, it is determined whether a predetermined termination condition is satisfied, and when it is determined that the predetermined termination condition is not satisfied (ST5: NO), the process proceeds to step ST2, and the reaction process execution unit 11 Molecular dynamics calculation and reaction processing are performed according to the conditions (ST2). If it is determined that the predetermined termination condition is satisfied (ST5: YES), the model generation processing is terminated because the crosslinking model is generated. The predetermined termination conditions in the present embodiment are set such that all the crosslinker particles 3 are bonded to a predetermined number (two) of polymer particles 2 per one crosslinker particle 3, but can be set as appropriate. It is.

  In order to confirm the effectiveness of the above system and method, a crosslink model described below was generated, and molecular dynamics calculations were performed using the crosslink model to obtain a stress-extension ratio curve. In all of the following, the polymer lengths are equal.

Comparative Example 1
All 1,600 crosslinker particles 3 were bonded to a 100 polymer model in which 100 polymer particles 2 are connected.
As shown in FIG. 4A, the crosslinking probability was set to the same probability so that all the polymer particles react with the crosslinking agent particle 3 with the same probability, and a crosslinking model was generated.

Comparative example 2
As shown in FIG. 4 (b), based on the description of Non-Patent Document 1, a polymer particle which can be cross-linked by skipping one end of a molecular chain in a polymer model is set, and other particles can not be crosslinked. Set to generate a crosslinking model. The hatched polymer particles 2 are not bondable, and the unshaded polymer particles 2 are bondable.

Example 1
A cross-linking model was generated using the apparatus and method described in the present invention.

FIG. 5 shows stress-extension ratio curves for Comparative Examples 1 and 2 and Example 1, respectively. According to FIG. 5, it can be seen that in Example 1, stress is appropriately developed from the time when the elongation ratio is low compared to Comparative Examples 1 and 2. This is considered to be because the crosslinker particle 3 creates a structure that contributes to the development of stress, since the generation of the intramolecular loop structure is avoided.
Therefore, it is possible to suppress the generation of the intramolecular loop structure without causing troublesome setting, and to express an appropriate physical quantity.

As described above, the generation system of the crosslinking model of the present embodiment is
In a system having a plurality of polymer models in which a plurality of polymer particles 2 are linked in a linear or branched manner, and a plurality of crosslinker particles 3, and generating a crosslink model in which the polymer model and the crosslinker particles 3 are combined. There,
Molecular dynamics calculation is performed based on analysis conditions set in advance, and polymer particles 2 and crosslinker particles 3 within a predetermined distance from each other at predetermined timing are bonded to polymer particles 2 with a crosslinking probability T1 set. A reaction processing execution unit 11 that repeatedly executes the reaction processing;
And a bonding condition setting unit 12 for setting any one of bonding possible conditions and bonding impossible conditions to the conditions used in the next reaction process for the crosslinker particles 3 already bonded to the polymer particles 2;
The bondable conditions are conditions under which the crosslinker particles 3 can be bonded and the polymer particles 2b of a predetermined number N1 centering on the polymer particles 2a bonded to the crosslinker particles 3 can not be bonded,
The non-bonding conditions are conditions under which the crosslinker particles 3 and the polymer particles 2a bonded to the crosslinker particles 3 can not be bonded.

The method of generating the crosslinking model of the present embodiment is
In a system having a plurality of polymer models in which a plurality of polymer particles 2 are linked in a linear or branched manner, and a plurality of crosslinker particles 3, and generating a crosslink model in which the polymer model and the crosslinker particles 3 are combined. There,
Molecular dynamics calculation is performed based on analysis conditions set in advance, and polymer particles 2 and crosslinker particles 3 within a predetermined distance from each other at predetermined timing are bonded to polymer particles 2 with a crosslinking probability T1 set. Step ST2 of repeatedly executing the reaction process;
And, for the crosslinker particles 3 already bonded to the polymer particles 2, a step ST3 of setting any of bondable conditions and non-bondable conditions to the conditions used in the next reaction process,
The bondable conditions are conditions under which the crosslinker particles 3 can be bonded and the polymer particles 2b of a predetermined number N1 centering on the polymer particles 2a bonded to the crosslinker particles 3 can not be bonded,
The non-bonding conditions are conditions under which the crosslinker particles 3 and the polymer particles 2a bonded to the crosslinker particles 3 can not be bonded.

Thus, by setting the bondable condition and the bondable condition, it is possible to prevent the crosslinker particle 3 already bonded to the polymer particle 2 from bonding to the nearby polymer particle 2 and suppress the generation of the intramolecular loop structure. it can.
By setting the conditions that allow bonding, the crosslinker particles 3 that have already been bonded can be bonded to the other polymer particles 2, and the reaction process is continued such that one crosslinker particle 3 is bonded to a plurality of polymer particles 2. can do.
By setting the non-bonding condition, another crosslinker particle 3 can be bonded to the polymer particle in a position close to the polymer particle 2a to which the crosslinker particle 3 is bonded, and a location where the crosslinker particle 3 can be bonded in the polymer model It is possible to secure sufficient and increase the binding of particles to express an appropriate physical quantity.
Therefore, it is possible to suppress the formation of an intramolecular loop structure without any troublesome setting, and to increase the binding of particles for expressing an appropriate physical quantity.

  In the present embodiment, setting of bonding conditions and execution of the reaction process using the bonding conditions are repeated until all the crosslinker particles 3 are bonded to the predetermined number of polymer particles 2 per one crosslinker particle 3.

  In this way, it is possible to obtain a crosslinking model in which all the crosslinker particles 3 are bonded to the polymer model.

  In the present embodiment, the combining condition setting unit 12 randomly sets the combining possible condition and the combining impossible condition.

  In this way, the reaction of the crosslinking agent particles 3 can be facilitated.

  The computer program according to the present embodiment is a program that causes a computer to execute the steps constituting the above method. By executing this program, it is also possible to obtain the effects of the above method. In other words, it can be said that the above method is used.

  As mentioned above, although embodiment of this invention was described based on drawing, it should be thought that a specific structure is not limited to these embodiment. The scope of the present invention is indicated not only by the description of the embodiments described above but also by the claims, and further includes all modifications within the meaning and scope equivalent to the claims.

  For example, the order of execution of each process such as operations, procedures, steps, and steps in the apparatuses, systems, programs, and methods shown in the claims, the specification, and the drawings is the output order of the previous process. It can be realized in any order as long as it is not used in processing. Even if the flow in the claims, the description and the drawings is described using “first”, “next” and the like for convenience, it does not mean that execution in this order is essential. .

  For example, although each unit 10 to 12 shown in FIG. 1 is realized by executing a predetermined program by the CPU of the computer, each unit may be configured by a dedicated memory or a dedicated circuit.

  In the system of the present embodiment, the units 10 to 12 are mounted on one computer, but the units 10 to 12 may be distributed and mounted on a plurality of computers.

  It is possible to adopt the structure adopted in each of the above-described embodiments in any other embodiment. The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

2 ... polymer particle 3 ... crosslinker particle 11 ... reaction processing execution unit 12 ... bonding condition setting unit

Claims (7)

A system having a plurality of polymer models in which a plurality of polymer particles are linked in a linear or branched manner, and a plurality of crosslinker particles, and generating a crosslink model in which the polymer model and the crosslinker particles are combined,
A molecular dynamics calculation is performed based on analysis conditions set in advance, and a reaction process is performed in which polymer particles and crosslinker particles within a predetermined distance from each other at a predetermined timing are bonded to the polymer particles with the crosslinking probability set. Reaction processing execution units that are repeatedly executed;
And a bonding condition setting unit that sets any of bondable conditions and non-bondable conditions to the conditions used in the next reaction process for the crosslinker particles already bonded to the polymer particles,
The bondable conditions are conditions that make it possible to bond the crosslinker particles and make it impossible to bond a predetermined number of polymer particles centered on the polymer particles bonded to the crosslinker particles,
The system for generating a crosslinking model, wherein the non-bonding conditions are conditions under which the crosslinker particles and the polymer particles bonded to the crosslinker particles can not be bonded.   The system according to claim 1, wherein the setting of the binding conditions and the execution of the reaction process using the binding conditions are repeated until all the crosslinker particles bind to a predetermined number of polymer particles per crosslinker particle.   The system according to claim 1, wherein the coupling condition setting unit randomly sets the coupling possible condition and the coupling impossible condition. A computer generates a cross-linking model in which a plurality of polymer models includes a plurality of polymer models in which a plurality of polymer particles are linked in a linear or branched form and a plurality of crosslinker particles, and the polymer model and the crosslinker particles are combined There,
A molecular dynamics calculation is performed based on analysis conditions set in advance, and a reaction process is performed in which polymer particles and crosslinker particles within a predetermined distance from each other at a predetermined timing are bonded to the polymer particles with the crosslinking probability set. Repeatedly executing steps,
Setting any one of bondable conditions and non-bondable conditions to the conditions used in the next reaction process for the crosslinker particles already bonded to the polymer particles,
The bondable conditions are conditions that make it possible to bond the crosslinker particles and make it impossible to bond a predetermined number of polymer particles centered on the polymer particles bonded to the crosslinker particles,
The method for generating a crosslinking model, wherein the non-bonding condition is a condition that makes the cross-linking agent particle and the polymer particle bonded to the cross-linking agent particle non-bonding.   5. The method according to claim 4, wherein the setting of the bonding conditions and the execution of the reaction process using the bonding conditions are repeated until all the crosslinker particles are bonded to a predetermined number of polymer particles per one crosslinker particle.   The method according to claim 4 or 5, wherein one of the combining condition and the non-binding condition is set at random.   A program that causes a computer to execute the method according to any one of claims 4 to 6.

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