High impact polystyrene test method, electronic equipment and program product

Abstract

The invention discloses a high impact polystyrene test method, electronic equipment and a program product, and relates to the technical field of high impact polystyrene, the method comprises the following steps: building a fully branched polybutadiene model by using butadiene as a monomer; initiating styrene monomer polymerization by taking the first active site in the polybutadiene model as a seed to obtain a cross-linked phase molecular chain of polybutadiene and polystyrene; mixing the cross-linked phase molecular chain with a plurality of pure polystyrene molecular chains to construct a high-impact polystyrene chemical model; a molecular chain space structure of the high-impact polystyrene chemical model is optimized based on a molecular dynamics simulation principle, and a high-impact polystyrene material model meeting preset physical characteristics of the high-impact polystyrene material is obtained; and simulating a mechanical property change rule of the high impact polystyrene material model in a preset extreme test environment to obtain a test result. By adopting the method, the problem that the test result is inaccurate due to the fact that the test environment is easily limited in an extreme test environment can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high impact polystyrene, in particular to a high impact polystyrene testing method, an electronic device and a program product. BACKGROUND

[0002] High impact polystyrene (HIPS) is a composite material modified by introducing polybutadiene (PB) elastomer phase into a polystyrene (PS) matrix. The core toughening mechanism is derived from the island-in-sea structure of the polystyrene continuous phase wrapping the polybutadiene dispersed phase. HIPS has rigidity, processing fluidity and impact resistance, and becomes a core material for refrigerator liners and other home appliance components.

[0003] The performance of HIPS is closely related to its microstructure. Different grades of products exhibit different mechanical properties due to differences in the branching degree of polybutadiene, PB-PS crosslinking mode, molecular weight distribution and aggregate structure. As a refrigerator liner material, it needs to withstand extreme working conditions. For example, it needs to withstand high temperatures of 160-200℃ during processing, and during use, it faces -30~-40℃ conventional low temperature and -80℃ ultra-low temperature environment of deep-freeze refrigerator. Therefore, low-temperature crack resistance and high-temperature stability are key performance indicators.

[0004] In current HIPS performance testing, the mechanical properties under extreme conditions are generally characterized by outsourcing testing mode. Since the conditions of -80℃ deep-freeze and 200℃ high temperature have strict requirements on equipment, it is difficult for enterprises to cover with their own equipment, resulting in high testing cost, and the accuracy of the results depends on the technical level of the third-party operators, and the consistency of the data is difficult to guarantee. In addition, physical testing cannot achieve precise control of extreme test environment, therefore, the accuracy of the test results is limited due to the restriction of test environment conditions. SUMMARY

[0005] The present application provides a high impact polystyrene testing method, an electronic device and a program product, which can solve the problem of insufficient performance testing means of HIPS under extreme test environment, and the problem of inaccurate test results caused by the restriction of test environment conditions.

[0006] In a first aspect, a high impact polystyrene testing method is provided, the method comprising:

[0007] A fully branched polybutadiene model is constructed with butadiene as a monomer; the polybutadiene model is composed of a complete branch structure formed by a main chain and multiple levels of side chains extending from the main chain;

[0008] The first active site in the polybutadiene model is used as a seed to initiate polymerization of styrene monomers, to obtain a cross-linked phase molecular chain of polybutadiene and polystyrene; the double bond site in the first active site in the polybutadiene model is used to initiate polymerization of styrene monomers to grow a polystyrene chain;

[0009] The cross-linked phase molecular chain is mixed with a plurality of pure polystyrene molecular chains to construct a high-impact polystyrene chemical model;

[0010] Based on the principle of molecular dynamics simulation, the molecular chain space structure of the high-impact polystyrene chemical model is optimized to obtain a high-impact polystyrene material model that meets the preset physical characteristics of the high-impact polystyrene material.

[0011] The mechanical property change rule of the high-impact polystyrene material model in the preset extreme test environment is simulated to obtain a test result.

[0012] In the above technical solution, by constructing a fully branched polybutadiene model with a main chain and multiple side chains, and using the double bond site in the polybutadiene model to initiate polymerization of styrene monomers to grow a polystyrene chain, PB-PS cross-linked phase molecular chains (i.e. cross-linked phase molecular chains of polybutadiene and polystyrene) are generated by polymerization of styrene, and the cross-linked phase molecular chains are mixed with a plurality of pure polystyrene (PS) molecular chains to construct a chemical model that conforms to the real HIPS, which can truly reproduce the cross-linking process of PB-PS, ensure that the molecular structure of the finally generated high-impact polystyrene chemical model is consistent with the molecular structure of the actual HIPS, and avoid performance simulation distortion caused by model simplification. Then, based on molecular dynamics simulation, the molecular chain space structure of the HIPS chemical model is optimized, which can effectively correct the non-real defect molecular chain space structure of the HIPS chemical model, such as molecular chain overlap and spatial conflict, so that the molecular chain arrangement is more consistent with the complex phase structure of the real HIPS, and the HIPS chemical model meets the preset physical characteristics of the HIPS material through optimization, providing a basis for subsequent mechanical property simulation under extreme conditions, solving the problem that the HIPS material model is disconnected from the real material characteristics in traditional simulation. Finally, based on the principle of molecular dynamics, the mechanical property change rule under the preset extreme test environment is simulated to obtain a test result, which can eliminate the need for outsourcing testing and eliminate the adjustment restrictions of the extreme test environment, not only reducing the testing cost, but also avoiding the deviation caused by environmental interference in traditional testing, and improving the accuracy of the test result.

[0013] In a second aspect, the embodiments of the present application provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the method of the first aspect described above.

[0014] In a third aspect, an embodiment of the present application provides a computer readable storage medium, which stores a computer program. The computer program is executed by a processor to implement the method in the first aspect.

[0015] In a fourth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device is caused to execute the method in the first aspect.

[0016] It can be understood that the beneficial effects of the second aspect to the fourth aspect can be referred to the related description in the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a flowchart of a high impact polystyrene testing method provided by an embodiment of the present application;

[0018] Figure 2 is a HIPS density simulation curve diagram in a high impact polystyrene testing method provided by an embodiment of the present application;

[0019] Figure 3 is a HIPS mean square displacement simulation curve diagram in a high impact polystyrene testing method provided by an embodiment of the present application;

[0020] Figure 4 is a schematic diagram of an implementation manner of constructing a polybutadiene model in a high impact polystyrene testing method provided by an embodiment of the present application;

[0021] Figure 5 is a schematic diagram of an implementation manner of constructing a high impact polystyrene material model in a high impact polystyrene testing method provided by an embodiment of the present application;

[0022] Figure 6 is a schematic diagram of an implementation manner of generating a test result in a high impact polystyrene testing method provided by an embodiment of the present application;

[0023] Figure 7 is a HIPS stress-strain curve diagram in a high impact polystyrene testing method provided by an embodiment of the present application;

[0024] Figure 8 is a HIPS density simulation curve diagram in a high impact polystyrene testing method provided by another embodiment of the present application;

[0025] Figure 9 is a HIPS mean square displacement simulation curve diagram in a high impact polystyrene testing method provided by another embodiment of the present application;

[0026] Figure 10A HIPS stress-strain curve in a high impact polystyrene test method provided by another embodiment of the application;

[0027] Figure 11 A structural schematic diagram of an electronic device provided by an embodiment of the application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the application will be described below with reference to the drawings in the embodiments of the application. In the description of the embodiments of the application, unless otherwise specified, " / " represents the meaning of or, for example, A / B can represent A or B; in this document, "and / or" merely describes an association relationship of associated objects, and represents that there can be three relationships, for example, A and / or B can represent that A exists alone, A and B exist together, and B exists alone. In addition, in the description of the embodiments of the application, "multiple" means two or more than two.

[0029] Hereinafter, the terms "first", "second", and "third" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", and "third" can explicitly or implicitly include one or more of the features.

[0030] For the purpose of illustration and not for limitation, specific details such as specific system structures, technologies, and the like are presented in order to thoroughly understand the embodiments of the application. However, it should be clear to those skilled in the art that the application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the application.

[0031] High impact polystyrene is usually obtained by bulk polymerization of un-crosslinked polybutadiene and styrene, and has different chemical molecular structures, aggregate structures, molecular weights, and molecular weight distributions according to the grade of the material used, which also endows different grades of HIPS with different mechanical properties.

[0032] With the expansion of the application scenarios of home appliance products, as the main material of the inner liner of the refrigerator, the processing temperature of HIPS is generally 160-200℃, the working temperature during service is usually-30~-40℃, and the working temperature in a specific deep-freezing refrigerator can be as low as-80℃. Therefore, it is extremely difficult to characterize the mechanical properties of HIPS under such extreme working conditions.

[0033] Therefore, in the current HIPS performance test, the mechanical performance characterization under extreme conditions generally adopts a outsourcing test mode. Since the conditions of-80℃ deep cooling and 200℃ high temperature have high requirements on equipment, and the enterprise's own equipment is difficult to cover, resulting in high test cost, and the result accuracy depends on the technical level of the third-party operator, and the data consistency is difficult to guarantee. In addition, the physical test is difficult to realize the precise control of the extreme test environment, therefore, limited by the test environment conditions, the accuracy of the test result is limited.

[0034] Therefore, in order to improve the accuracy of the test result of the HIPS material, an embodiment of the present application provides a high impact polystyrene test method, which can be applied to electronic devices such as notebook computers, ultra-mobile personal computers (UMPC), netbooks, etc. The specific type of electronic device is not limited in the embodiment of the present application.

[0035] Please refer to Figure 1 , Figure 1 The implementation flowchart of the high impact polystyrene test method provided by the embodiment of the present application is shown, and the method comprises the following steps:

[0036] S101, a full-branched polybutadiene model is constructed by using butadiene as a monomer.

[0037] The above-mentioned polybutadiene model is composed of a complete branch structure formed by a main chain and a plurality of side chains extending from the main chain.

[0038] In an embodiment, the full name of butadiene is 1,3-butadiene, which is a simple conjugated diene (chemical molecular formula: C4H6), containing two unsaturated carbon-carbon double bonds (-CH2=CH-CH=CH2) in the molecular structure, and belongs to polymer monomers. Among them, butadiene is the basic building unit of synthetic polybutadiene, and a plurality of butadiene molecules can form long-chain macromolecules (polybutadiene) by opening double bonds and connecting with each other (polymerization reaction).

[0039] Among them, monomer refers to a small molecular compound that can be repeatedly connected to form a polymer macromolecule through polymerization reaction (such as polycondensation). In the embodiment, butadiene is the monomer of polybutadiene, and a plurality of butadiene monomers are built into polybutadiene macromolecules through polymerization.

[0040] The above-mentioned polybutadiene is a high molecular polymer (macromolecule) formed by polycondensation reaction of butadiene monomers, and contains a large number of repeated butadiene units (-CH2-CH=CH-CH2-) in the molecular structure. Among them, polybutadiene is an elastomer (rubbery substance), which exists as a toughening phase in HIPS, absorbs impact energy by being dispersed in the rigid polystyrene matrix, and solves the problem of brittleness of pure polystyrene.

[0041] The above full branched polybutadiene model refers to the complete branched structure of the polybutadiene macromolecular structure, in which, in addition to the main chain, there are multiple levels of side chains extending from the main chain, forming a complete network / tree structure of skeleton and branches. The polybutadiene model refers to a digital representation of the microstructure (not a real physical object) constructed in a computer for molecular dynamics simulation.

[0042] It should be noted that the linear polybutadiene model is commonly used in simplified simulation in the related art, but the polybutadiene in the real HIPS is mostly fully branched due to the polymerization process (such as the use of branched initiators). This structure directly affects the dispersibility of polybutadiene in polystyrene, and further determines the impact resistance of HIPS, so the full branched model is the key to restoring the structure of the real material.

[0043] The main chain is the longest and continuous carbon chain skeleton in the branched polymer macromolecule, which is the backbone of the whole molecule. The multiple levels of side chains refer to shorter polybutadiene segments extending from specific carbon atoms (or repeating units) on the main chain; the multiple levels refer to the further extension of shorter secondary side chains (for example, the main chain extends a primary side chain, and the primary side chain extends a secondary side chain) to form a multi-level branched structure.

[0044] It should be noted that the number, length and distribution (multi-level structure) of the side chains increase the steric hindrance of the polybutadiene molecule, making it more likely to form a uniformly dispersed island structure when mixed with polystyrene subsequently, which is an important structural basis for the toughening of HIPS. In this embodiment, the number of side chains is not limited.

[0045] The above complete branched structure refers to the branched morphology formed by the main chain and the multiple levels of side chains in the polybutadiene model, which conforms to the real polymerization rule without omission. Among them, the main chain is continuous, and the side chains (including multiple levels) are reasonably distributed, which can restore the molecular topological structure of the real polybutadiene.

[0046] In an embodiment, the electronic device can digitize the process of polymerizing butadiene monomers to form a fully branched polybutadiene by molecular simulation software to generate a microstructure model (including atomic coordinates, bond lengths, bond angles, etc.) that can be operated subsequently. Among them, the molecular simulation software includes but is not limited to Materials Studio (MS, Materials Studio), VASP (Vienna Ab initio Simulation Package), which is not limited.

[0047] As an example, the electronic device can draw the molecular structure of butadiene by the pre-MS software, and determine the position and configuration of the carbon-carbon double bond (such as cis or trans structure) as a repeating unit of polybutadiene. Then, the BuildPolymers tool in the MS is called to import the drawn butadiene repeating unit, set the degree of polymerization (i.e. the number of repeating units, which determines the chain length), select the linear chain construction mode (to ensure no branched chain is generated), and automatically connect the repeating units in sequence by covalent bonds to form a continuous and unbranched polybutadiene backbone. Finally, according to the set degree of polymerization and other parameters, side chains can be grown on the polybutadiene backbone to obtain a polybutadiene model.

[0048] S102, initiate polymerization of styrene monomers with the first active site in the polybutadiene model as a seed to obtain cross-linked phase molecular chains of polybutadiene and polystyrene.

[0049] wherein the first active site is a double bond site in the polybutadiene model that initiates polymerization of styrene monomers to grow a polystyrene chain.

[0050] In an embodiment, the active site refers to a specific position in a molecule that has chemical reactivity and can initiate polymerization of other monomers. The descriptions of “first”, “second”, etc. in this embodiment are only for differentiation. In this step, the first active site specifically refers to the position of the carbon-carbon double bond (C=C) contained in the polybutadiene molecular chain. The double bond is easy to undergo addition reaction due to high electron cloud density, and is the reaction starting point for initiating polymerization of styrene monomers.

[0051] wherein the initiation of polymerization of styrene monomers with the first active site as a seed refers to starting from the first active site, activating the polymerization reaction through chemical action (such as opening of the double bond), and allowing the styrene monomers to start connecting to form a long chain at this site.

[0052] The above-mentioned styrene (chemical formula: C8H8) is an unsaturated monomer containing a benzene ring, and contains a carbon-carbon double bond in the molecule, which is the basic unit for synthesizing polystyrene (PS).

[0053] The above-mentioned polymerization refers to a chemical reaction in which monomers (styrene) are connected by chemical bonds to form a high molecular chain. In this step, the double bond of the styrene monomer is opened, and the polymerization is initiated from the first active site to form a polystyrene chain segment.

[0054] The cross-linked phase molecular chain of polybutadiene and polystyrene refers to a copolymer chain segment formed by chemical covalent bonding of polybutadiene (PB) and polystyrene (PS), rather than simple physical mixing. The PB segment and the PS segment are connected as a whole by the polymerization reaction initiated by the first active site, forming the overall macromolecular morphology of the cross-linked phase. In high-impact polystyrene (HIPS), this cross-linked phase is the key to connecting the elastomer phase (PB) and the rigid matrix phase (PS), effectively transferring stress and improving the impact resistance of the material.

[0055] The double bond site is the position of the carbon-carbon double bond (C=C) in the polybutadiene molecular chain. Due to the unsaturation of the double bond (containing a breakable bond), it can be opened during polymerization and combined with the double bond of the styrene monomer to become a reactive center for initiating the growth of the polystyrene chain.

[0056] It should be noted that the above steps are key links in building the microstructure of HIPS (PB-PS cross-linked phase) and are used to simulate the chemical bonding process of polybutadiene and polystyrene in real HIPS in electronic devices. Specifically, the double bond site in the polybutadiene model is designated as the first active site, which accurately corresponds to the chemical properties of the double bond of PB as a reactive center in real polymerization, avoiding structural distortion caused by random initiation in simulation. Then, the styrene monomer is polymerized by the first active site as a seed, and the bond formation process is simulated by molecular simulation software, finally generating a cross-linked phase molecular chain covalently connected by PB segments and PS segments. This can reproduce the essence of the chemical bonding of elastomers and rigid phases in real HIPS (rather than simple physical mixing), and is the core structural basis for the rigidity and impact resistance of HIPS

[0057] The cross-linked phase molecular chain is a key component for subsequent mixing with pure polystyrene chains to build a HIPS chemical model. Only by forming a chemically cross-linked PB-PS segment can the complex phase structure of the cross-linked phase dispersed in the PS matrix in real HIPS be formed after mixing, providing a microstructure close to reality for subsequent performance simulation.

[0058] S103, mixing the cross-linked phase molecular chain with a plurality of pure polystyrene molecular chains to build a high-impact polystyrene chemical model.

[0059] The above pure polystyrene molecular chain is a homopolymer chain segment formed by polymerization of styrene monomers without chemical cross-linking with PB (molecular structure: repeated styrene units: -C6H5-CH-CH2-). In HIPS, pure PS chains constitute a continuous phase, providing basic properties such as rigidity and processing flowability of the material.

[0060] In the context of molecular simulation, mixing is not simply physical stirring, but placing the crosslinked phase molecular chains and pure PS molecular chains in a periodic simulation box according to the component ratio of the real HIPS (for example, the PB phase accounts for 5%-15%), and through energy minimization, molecular relaxation and other operations, the two chain segments are uniformly distributed in space to form a complex phase system without obvious phase separation and in accordance with thermodynamic equilibrium.

[0061] The above high-impact polystyrene chemical model refers to a digital HIPS microstructure model constructed by the above mixing operation, and the core feature is that the chemical composition and structure are close to the real HIPS, which includes a PB-PS crosslinked phase (dispersed phase) and a pure PS phase (continuous phase), and the two phases form a stable complex phase structure through chemical or physical action. Among them, the chemical model not only reflects the spatial arrangement of molecules, but also accurately restores the core chemical characteristics of HIPS (the ratio of PB to PS, the connection mode of chemical bonds (covalent bonds of the crosslinked phase), etc.), which is different from the physical model which only reflects the physical form.

[0062] Among them, the number of the above pure polystyrene molecular chains can be set in advance, and there is no limitation. And,

[0063] As an example, the electronic device can mix the first preset number of pure polystyrene molecular chains with a second preset polymerization degree and the second preset number of pure polystyrene molecular chains with a third preset polymerization degree with the crosslinked phase molecular chains to obtain a high-impact polystyrene chemical model.

[0064] In an embodiment, the preset number refers to the number of the two kinds of pure polystyrene molecular chains preset according to the content and distribution characteristics of the polystyrene phase in the real HIPS before constructing the HIPS model. The first preset number corresponds to the number of the first kind of pure PS chain, and the second preset number corresponds to the number of the second kind of pure PS chain.

[0065] The above polymerization degree refers to the number of repeating units in the polymer molecular chain (for example, the polymerization degree is 10, that is, the molecular chain is connected by 10 styrene monomers), which directly determines the length of the molecular chain and the molecular weight (the higher the polymerization degree, the longer the chain and the larger the molecular weight). The second preset polymerization degree is the polymerization degree of the first kind of pure PS chain (for example, 5), and the third preset polymerization degree is the polymerization degree of the second kind of pure PS chain (for example, 10).

[0066] It should be noted that the purpose of the preset is to simulate the molecular weight distribution of the PS phase in the real HIPS, and the length of the molecular chain in the actual polymer is not completely consistent (but there is a certain distribution, such as short chains and long chains), and the setting of two different polymerization degrees can restore this distribution characteristic, avoid the simplification caused by a single polymerization degree (such as overestimating the rigidity of the material by using only long chains, and underestimating by using only short chains), and reflect the molecular weight distribution characteristics of the real PS phase.

[0067] The high-impact polystyrene chemical model refers to a digital HIPS microstructure model constructed through the above-mentioned mixing operation. Its core feature is that it contains two kinds of pure PS chains (constituting the continuous phase) and cross-linked molecular chains (constituting the dispersed phase) with different quantities and lengths, and the three are evenly distributed in a preset ratio. The chemical composition, molecular chain length distribution and phase morphology are close to the real HIPS, and it can be used for subsequent structural optimization and performance simulation.

[0068] The above mixing processes can all be implemented using the aforementioned molecular simulation software, which will not be described in detail here.

[0069] In this embodiment, two types of pure polystyrene molecular chains, with a first preset quantity and a second preset degree of polymerization, and a second preset quantity and a third preset degree of polymerization, are mixed with cross-linked phase molecular chains to construct a high-impact polystyrene chemical model. This avoids the performance simulation deviations caused by traditional single-degree-of-polymerization PS chain models. By adjusting the preset quantities of the two types of pure PS chains, the component ratio of polybutadiene (PB) phase (containing cross-linked phase) and PS phase in real HIPS is accurately matched, ensuring the authenticity of the model's chemical composition. Furthermore, the quantity and degree of polymerization of the two PS chains are adjustable preset parameters, allowing for rapid iterative testing of the performance of different structures without repeatedly preparing physical samples, thus improving the R&D efficiency of HIPS optimization.

[0070] As an example, the first preset quantity is less than the second preset quantity, and the second preset aggregation degree is less than the third preset aggregation degree.

[0071] For example, the first preset quantity can be 7, the second preset quantity can be 16, the second aggregation degree can be 10, and the third aggregation degree can be 15.

[0072] In this embodiment, since the second preset quantity is greater than the first preset quantity and the third preset degree of polymerization is greater than the second preset degree of polymerization, it can be considered that long-chain PS as the main component (the second preset quantity is larger) can fully simulate its supporting role in material rigidity and tear resistance, which meets the core performance requirements of HIPS as a structural material; a small amount of short-chain PS (the first preset quantity is even smaller) can specifically simulate its effect on improving processing fluidity, avoiding simulation deviations caused by excessive short chains leading to a decrease in rigidity.

[0073] S104. Optimize the molecular chain spatial structure of the chemical model of high-impact polystyrene based on the principle of molecular dynamics simulation to obtain a high-impact polystyrene material model that meets the preset physical properties of high-impact polystyrene material.

[0074] In an embodiment, the above-mentioned molecular dynamics simulation principle refers to a theoretical method based on classical Newtonian mechanics (such as Newton's equation of motion) to simulate the motion trajectory (position, velocity change over time) of atoms in a molecular chain through a computer to calculate intermolecular interaction energy (such as van der Waals force, covalent bond force), total energy of the system and other parameters. The core logic is: by simulating the thermal motion of atoms (such as vibration, rotation, chain segment creep), the spatial configuration change of the molecular chain under different environments is captured, and ultimately the prediction of the correlation between the microstructure and the macroscopic performance of the material is realized.

[0075] The above-mentioned spatial structure of the molecular chain refers to the arrangement form of the molecular chain in three-dimensional space, including: the entanglement degree of the molecular chain (such as the entanglement density of long-chain PS and cross-linked phase), the chain segment spacing (such as the average distance between PS chains, the uniformity of dispersion of cross-linked phase particles), the distribution of bond angles and dihedral angles (such as whether the angle of carbon-carbon bond conforms to the thermodynamic stable state) and the like. The spatial structure directly affects the macroscopic performance of the material (such as the tighter the chain entanglement, the higher the rigidity of the material).

[0076] Among them, optimization refers to adjusting the spatial structure of the molecular chain through the principle of molecular dynamics simulation (such as energy minimization, molecular relaxation calculation, annealing simulation) to eliminate non-physical defects (such as excessive repulsive energy caused by atomic overlap, uneven distribution of chain segments) in the initial model, so that the total energy of the system reaches the minimum (thermodynamic stable state), and finally a spatial configuration closer to the real material is obtained.

[0077] The above-mentioned preset physical properties refer to the basic physical parameters of the real HIPS, which are the target benchmark of the optimization process, and usually include but are not limited to: density (such as 1.02-1.05 g / cm 3 , matching the density range of the real HIPS), glass transition temperature (PS phase about 100℃, PB phase about -80℃), average value of bond length and bond angle (such as carbon-carbon single bond length about 0.154 nm) and the like. The parameters corresponding to the above-mentioned preset physical properties can be determined by experiment, and are the core indicators for judging whether the HIPS material model is real and reliable.

[0078] As an example, the electronic device can use mean square displacement (MSD) and radial distribution function (RDF) to determine whether the molecular chain structure reaches a relaxation state to determine whether the high-impact polystyrene material model meets the preset physical properties.

[0079] Specifically, the mean square displacement can describe the square average value of the motion trajectory of the molecular chain (or atom) deviating from the initial position within the simulation time, which is a key indicator for measuring the internal motion ability of the molecular chain. The trend of MSD value change over time can reflect whether the chain segment enters a free motion equilibrium state from an initial restricted state (such as excessive entanglement, rigid fixation). If the MSD curve tends to be flat (stable slope) in the later period, it means that the internal chain segment motion of the molecular chain reaches stability, that is, the internal structure of the molecular chain is relaxed.

[0080] The radial distribution function described above can describe the distribution probability of other atoms (or chain segments) at different distances from a certain atom (or chain segment) as the center, and can reflect the spatial arrangement relationship between the molecular chains (such as the average distance between the chains, the degree of close packing). If the RDF curve has a stable peak value and reduced fluctuation at a specific distance (such as the van der Waals interaction distance between PS chain segments), it indicates that the relative position between the molecular chains no longer changes dramatically, that is, the structure relaxation between the molecular chains.

[0081] The relaxation state described above refers to the thermodynamic stable state reached by the molecular chains after adjusting the spatial structure through thermal motion (vibration, rotation, chain segment creep). At this time, there is no excessive entanglement in the molecular chain, no abnormal crowding between the chains, the total energy of the system is the lowest, and the molecular motion and spatial arrangement are balanced, which is a symbol that the physical properties (such as density and glass transition temperature) of the model meet the real HIPS.

[0082] Among them, the electronic equipment can extract the MSD curve of the PS chain segment and the PB crosslinking phase chain segment in the simulation process. If the slope of the curve is stable in the later stage (such as the MSD of the long chain PS does not rise rapidly after 1000 ps), it indicates that the chain segment motion enters a stable balance from the initial rapid adjustment, and there is no residual stress or rigid constraint in the molecular chain, that is, the internal structure is relaxed; if the curve still continues to rise rapidly, it indicates that the chain segment motion has not reached balance (such as the chain segment is excessively fixed in the initial model), and the simulation time needs to be prolonged or the temperature parameter needs to be adjusted for further optimization.

[0083] Alternatively, the RDF curve between PS chain segments and between PS and crosslinking phase can be calculated. If the curve has a clear and stable peak value (the peak height and peak position no longer change significantly) at a characteristic distance (such as 0.3-0.5 nm, corresponding to the van der Waals interaction range), it indicates that the degree of close packing between the chains tends to be stable, and there is no local excessive aggregation or looseness, that is, the interchain structure is relaxed; if the peak value continues to fluctuate or has no obvious regularity, it indicates that the chain arrangement is still in a non-equilibrium state (such as local aggregation of the crosslinking phase), and further optimization needs to be performed by adjusting the simulation box size or applying an external force (such as a constant pressure condition).

[0084] Specifically, refer to Figure 2 and Figure 3 , Figure 2 is a HIPS density simulation curve diagram in a B control method provided by an embodiment of the application; Figure 3 is a HIPS mean square displacement simulation curve diagram in a B control method provided by an embodiment of the application.

[0085] Among them, Figure 2The abscissa in the figure is simulation time (unit: ps), and the ordinate is material density (unit: g / cm^3). The curve shows a trend of rapid rise and then tends to be stable. The initial stage has a low density, which is due to the non-physical defects of the initial HIPS material model in the simulation, such as excessively loose molecular chains and large interatomic gaps; as the molecular dynamics simulation progresses, the molecular chains adjust their spatial arrangement through thermal motion, and the packing gradually becomes compact, and the density rapidly rises; the final density stabilizes between 1-1.05, indicating that the system has reached a stable structure of thermodynamic equilibrium, verifying the conversion of the HIPS material model from chemical reasonableness to physical reality (the density matches the experimental value of real HIPS, providing a reliable structural basis for subsequent performance simulation).

[0086] Figure 3 The abscissa in the figure is simulation time, and the ordinate is mean square displacement (MSD, unit: angstrom square), reflecting the motion ability and diffusion behavior of molecular chains (or atoms): the MSD curve increases with time, reflecting the position movement of molecular chains in the simulation; the MSD curve (curve 1) rises rapidly at the initial stage, because the molecular chains are released from the limited initial structure and begin to adjust freely; the subsequent speed-up slows down and tends to be stable, indicating that the molecular chain motion enters a stable state after the system reaches equilibrium; curve 2 is a linear fit of the MSD curve, which can be used to calculate the molecular diffusion coefficient (the slope of the fitted straight line is directly related to the diffusion coefficient), and then reflect the fluidity of the molecular chains in HIPS (such as chain segment motion ability, which is a core micro factor affecting material glass transition and mechanical relaxation).

[0087] The high-impact polystyrene material model refers to the optimized digital model, and its core feature is that not only the chemical composition and complex phase structure are reasonable, but also the molecular chain spatial structure reaches a thermodynamic stable state, and the basic physical properties (density, glass transition temperature, etc.) are consistent with the preset values (experimental data of real HIPS). The model can be directly used for subsequent mechanical performance simulation under extreme environments.

[0088] It should be noted that the high-impact polystyrene chemical model can be optimized by molecular dynamics simulation principle to adjust the position of the chain segment and stretch the excessively entangled molecular chains, so that the system energy is minimized to obtain a thermodynamically stable spatial structure. Moreover, the density, glass transition temperature and other physical properties of the model need to be simulated and calculated during the optimization process, and compared with the preset experimental data of real HIPS, which can ensure that the physical properties of the high-impact polystyrene material model are similar to the preset physical properties of real HIPS, solving the problem of apparent structural reasonableness but physical property disconnection in traditional simulation.

[0089] S105, simulating the mechanical property change rule of the high-impact polystyrene material model in the preset extreme test environment to obtain the test result.

[0090] In an embodiment, the preset extreme test environment refers to an environment parameter that is set in advance in simulation software according to an actual application scenario (such as low-temperature refrigeration packaging or high-temperature industrial components) of the HIPS and exceeds a conventional service condition.

[0091] Generally, the extreme test environment includes three types of conditions, extreme temperature: such as a deep cold environment of -80°C to -60°C (simulating the stress of HIPS packaging in cold chain transportation), a high-temperature environment of 150°C to 200°C (simulating the service state of HIPS in injection molding processing or components close to a heat source); extreme mechanical load: such as a high impact velocity (10 to 100 m / s, simulating the scene of HIPS products being impacted by external force), a constant high pressure (5 to 10 MPa, simulating the stress of HIPS components in deep sea or high-pressure equipment); extreme medium environment: such as contact with a strong solvent (such as toluene) or a high-humidity environment, simulating the performance change of HIPS in the chemical industry or a humid environment.

[0092] The mechanical property refers to an index of the mechanical behavior of a material under the action of external force, and generally includes impact strength (the impact ability of a material to resist fracture), tensile modulus / tensile strength (the ability of a material to resist tensile deformation, reflecting rigidity), elongation at break (the maximum elongation ratio of a material before fracture, reflecting toughness), storage modulus / loss factor (obtained through dynamic mechanical analysis, reflecting the motion of molecular chains and the energy dissipation ability, which is not limited).

[0093] The change rule refers to the change trend of the mechanical property with the extreme environment parameter, for example, under a deep cold environment of -80°C, the impact strength of HIPS decreases with the decrease of temperature (because the motion of PS segments is limited, brittleness is enhanced), and under a high-temperature environment of 200°C, the tensile modulus significantly decreases with the increase of temperature (because the PS phase is softened, rigidity decreases).

[0094] The test result refers to quantitative extreme environment parameter-mechanical property correlation data obtained through simulation calculation, and the form includes: numerical data (such as impact strength of 2.5 kJ / m 2 at -80°C and 5.0 kJ / m 2 at 25°C); a change curve (such as a temperature-impact strength curve, an impact velocity-elongation at break curve, and a stress-strain curve), which is not limited.

[0095] The extreme test environment can be input by a user in a molecular simulation software in an electronic device, so as to ensure that the extreme test environment matches the real service condition. That is, the test process can be implemented in the molecular simulation software, which is not described in detail.

[0096] In the embodiment, by constructing a full-branched polybutadiene model with a main chain and multiple levels of side chains, and by initiating the polymerization of styrene monomers to grow the polybutadiene model double bond site to grow the polystyrene chain, the PB-PS crosslinking phase molecular chain (i.e., the crosslinking phase molecular chain of polybutadiene and polystyrene) is generated, and the crosslinking phase molecular chain is mixed with multiple pure polystyrene (PS) molecular chains to construct a chemical model that fits the real HIPS, which can truly reproduce the crosslinking process of PB-PS, ensure that the molecular structure of the high-impact polystyrene chemical model generated finally is consistent with the molecular structure of the actual HIPS, and avoid performance simulation distortion caused by model simplification. Then, based on the molecular dynamics simulation, the molecular chain space structure of the HIPS chemical model is optimized, which not only can effectively correct the non-real defect molecular chain space structure of the HIPS chemical model, such as molecular chain overlap and space conflict, so that the molecular chain arrangement is more consistent with the complex phase structure of the real HIPS, and through optimization, the HIPS chemical model satisfies the preset physical characteristics of the HIPS material, providing a basis for subsequent mechanical property simulation under extreme conditions, and solving the problem that the HIPS material model in the traditional simulation is disconnected with the real material characteristics. Finally, based on the principle of molecular dynamics simulation, the mechanical property change law under the preset extreme test environment is simulated to obtain the test results, which can be tested without relying on outsourcing, and can be free from the adjustment restrictions of the extreme test environment, not only can reduce the test cost, but also can avoid the deviation caused by environmental interference in the traditional test, and improve the accuracy of the test results.

[0097] In another embodiment, the electronic device can also construct a polybutadiene model according to steps S401-S404 as shown in Figure 4 The details are as follows:

[0098] S401, construct a polybutadiene main chain with butadiene as a monomer.

[0099] In an embodiment, the polybutadiene and main chain have been explained in S101 above, and in the embodiment, the way of constructing a polybutadiene main chain with butadiene as a monomer will not be described.

[0100] As a specific example, the electronic device can use butadiene as a monomer, and simultaneously enable a first polymerization mode of connecting polymerization through the 1st carbon atom and the 2nd carbon atom, and a second polymerization mode of connecting polymerization through the 1st carbon atom and the 4th carbon atom to generate a polybutadiene main chain with a first preset polymerization degree.

[0101] In an embodiment, the structure of the butadiene monomer is In the above formula, the carbon atoms are numbered in the order from left to right: the 1st carbon atom (C1): the first carbon in the left double bond (CH2=); the 2nd carbon atom (C2): the second carbon in the left double bond (=CH-); and the 4th carbon atom (C4): the fourth carbon in the right double bond (-CH2=). The three carbon atoms are the reaction sites when butadiene is polymerized, and the connection mode thereof usually directly determines the structure of the polybutadiene main chain.

[0102] The first polymerization mode refers to that, in the polymerization reaction of butadiene monomers, the double bond (C1=C2) between the 1st carbon atom (C1) and the adjacent 2nd carbon atom (C2) is opened, and meanwhile connected with the corresponding site of another butadiene monomer, to form a structural unit of -CH2-CH=CH-CH2- (in which C2 and C3 remain a double bond). This mode is called 1,2-polymerization, and in the generated chain segment, there is one hydrogen atom (or substituent) not involved in the connection remaining on C2, and the main chain side chain structure is relatively complex.

[0103] The second polymerization mode refers to that, in the polymerization reaction of butadiene monomers, the 1st carbon atom (C1) is connected with the terminal 4th carbon atom (C4) through double bond electron cloud recombination (i.e., after the opening of two double bonds, C1 and C4 form a single bond, and a double bond remains between C2 and C3), to form a structural unit of -CH4-CH=CH-CH4- (C1 and C4 are directly connected, and the main chain is continuous and linear). This mode is called 1,4-polymerization, and the generated chain segment has a more regular main chain, and the double bond is located on the main chain.

[0104] The above polymerization reaction refers to a chemical reaction in which butadiene monomers are connected through covalent bonds to form long-chain macromolecules through the above two polymerization modes. In the polymerization reaction, the double bonds of the monomers are opened and recombined to form the repeating units of the polybutadiene main chain.

[0105] In an embodiment, the first preset polymerization degree refers to a value (such as a polymerization degree of 10, i.e., the main chain is composed of one butadiene unit connected through the two modes) preset according to the molecular weight requirement (such as chain length and mechanical property) of the target polybutadiene. The polymerization degree directly determines the main chain length and molecular weight (the higher the polymerization degree, the longer the main chain).

[0106] The above first preset polymerization degree can be set according to actual conditions, and no limitation is made thereto. For example, the above first preset polymerization degree can be 10.

[0107] Further, the polybutadiene main chain refers to a continuous carbon chain formed by the two polymerization modes described above, which is the main structure of the polybutadiene molecule and is the basis for the subsequent extension of the side chain. Due to the presence of the repeating units polymerized by the first polymerization mode and the second polymerization mode, there are both main chain double bonds (from the second polymerization mode) and side chain related structures (from the first polymerization mode) in the main chain, and this mixed structure will affect the elasticity, crosslinking activity and other properties of the polybutadiene.

[0108] It should be noted that in real industrial production, the polymerization of butadiene is not a single polymerization mode, but two modes coexist. Further, when the second polymerization mode is dominant, the main chain is more regular, which gives the material elasticity; the side chain related structure introduced by the first polymerization mode can enhance the entanglement of the chain segment and the crosslinking activity. Further, by simultaneously enabling the two modes, the mixed structure can be accurately reproduced, and the deviation between the model and the real material performance caused by a single polymerization mode can be avoided.

[0109] S402, growing a primary polybutadiene side chain with the second active site of the polybutadiene main chain as a seed.

[0110] The second active site is a double bond site in the polybutadiene main chain that initiates the polymerization of butadiene monomers to grow a primary polybutadiene side chain.

[0111] In an embodiment, the second active site is similar to the first active site, and the only difference is that the second active site is a double bond position on the polybutadiene main chain.

[0112] The primary polybutadiene side chain is a polybutadiene branch chain (primary indicates the first generation of side chains directly extended from the main chain) directly connected to the main chain, which is grown by the polymerization of butadiene monomers with the second active site of the polybutadiene main chain as a starting point.

[0113] It should be noted that the butadiene monomers are polymerized around the second active site of the polybutadiene main chain, which is used as a seed. The conjugated double bond of butadiene is opened and connected to the active double bond of the main chain through a chemical bond, and the chain segment of the side chain begins to form. As the butadiene monomers continue to polymerize at the active site, the chain segment gradually lengthens, and finally branches out from the polybutadiene main chain to grow into a primary polybutadiene side chain. Through the above steps, branched structures can be introduced to the polybutadiene main chain, increasing the entanglement ability of the molecular chain and the subsequent reaction sites, and providing a structural basis for constructing a fully branched polybutadiene model.

[0114] As a specific example, the electronic device can use the second active site of the polybutadiene main chain as a seed to perform a polymerization reaction through the first polymerization mode and the second polymerization mode, and generate a primary polybutadiene side chain with a first preset polymerization degree.

[0115] The first polymerization mode, the second polymerization mode, the polymerization reaction, and the first preset polymerization degree have been explained above, and will not be described in detail.

[0116] It should be noted that the double bond of the butadiene monomer is covalently combined with the second active site on the polybutadiene main chain through the first polymerization mode and the second polymerization mode, and the side chain growth is formally started; then, the butadiene monomer is continuously connected to the end of the side chain through the two polymerization modes, so that the side chain is continuously extended, and finally the side chain contains structural units corresponding to the first polymerization mode and the second polymerization mode, respectively, to form a segment similar to the polybutadiene main chain structure, which has regularity and side group activity; when the number of butadiene units in the side chain reaches the first preset polymerization degree, the polymerization reaction stops, and a primary polybutadiene side chain directly connected to the polybutadiene main chain is finally generated. Through the design of the two polymerization modes and the first preset polymerization degree control, not only can the primary polybutadiene side chain inherit the mixed structure characteristics of the polybutadiene main chain, providing a structural basis for subsequent cross-linking reaction and material toughening performance, but also the length of the side chain can be accurately controlled to avoid the problem of insufficient branching caused by too short side chain or segment entanglement caused by too long side chain.

[0117] S403, growing a secondary polybutadiene side chain with the third active site of the primary polybutadiene side chain as a seed.

[0118] The third active site is a double bond site in the primary polybutadiene side chain that initiates the polymerization of butadiene monomers to grow a secondary polybutadiene side chain.

[0119] In an embodiment, the third active site is similar to the first active site, and the way of generating the secondary polybutadiene side chain is similar to the way of growing the primary polybutadiene side chain, which will not be described in detail.

[0120] For example, the electronic device can generate a secondary polybutadiene side chain with a first preset polymerization degree by performing a polymerization reaction through the first polymerization mode and the second polymerization mode with the third active site of the primary polybutadiene side chain as a seed.

[0121] It should be noted that the ratio of the number of structural units formed by the first polymerization mode to the number of structural units formed by the second polymerization mode is 1:N1 when generating the polybutadiene main chain. The ratio of the number of structural units formed by the first polymerization mode to the number of structural units formed by the second polymerization mode is 1:N2 when generating the primary polybutadiene side chain. And the ratio of the number of structural units formed by the first polymerization mode to the number of structural units formed by the second polymerization mode is 1:N3 when generating the secondary polybutadiene side chain. Wherein, N1, N2, N3 are integers greater than 1, and N1

[0122] In an embodiment, the structural unit refers to a basic unit that constitutes a polybutadiene chain segment (main chain or side chain) after the butadiene monomer is connected by a specific polymerization method (first polymerization method or second polymerization method).

[0123] The structural unit formed by the first polymerization method is a unit formed by connecting the butadiene monomer through the first and second carbon atoms (the structure is -CH2-CH=CH-CH2-, wherein the second carbon has a side group active site), which has high reactivity due to the side group and is beneficial for subsequent branch chain growth or crosslinking reaction; the structural unit formed by the second polymerization method is a unit formed by connecting the butadiene monomer through the first and fourth carbon atoms (the structure is -CH4-CH=CH-CH4-, and the double bond is located in the polybutadiene main chain), which has a more regular main chain and good flexibility, and endows the polybutadiene with elastic properties.

[0124] In the above ratios, “1” represents the number of structural units corresponding to the first polymerization method, and N, N2, and N3 represent the number of structural units corresponding to the second polymerization method. Generally, the larger the ratio, the higher the proportion of structural units corresponding to the second polymerization method in the chain segment (the more regular and elastic), and the lower the proportion of structural units corresponding to the second polymerization method (the fewer side group active sites).

[0125] It should be noted that N1

[0126] In addition, in the primary polybutadiene side chain, the proportion of polymerization units corresponding to the second polymerization method is increased (N2>N1), which can enhance the elasticity of the side chain by increasing the proportion of structural units corresponding to the second polymerization method while retaining part of the structural units corresponding to the first polymerization method (providing active sites for secondary side chains), thereby balancing the branching activity and basic elasticity.

[0127] In addition, in the secondary polybutadiene side chain, since there is no need to grow higher-level side chains, the proportion of structural units corresponding to the second polymerization method is maximized (N3 is the maximum), which can enhance the flexibility and elasticity of the overall chain segment and improve the toughening ability of polybutadiene as an elastomer phase in HIPS.

[0128] As an example, the electronic device can draw a butadiene monomer through molecular simulation, and explicitly identify the positions of the 1st, 2nd, 3rd, and 4th carbon atoms; then, taking butadiene as a monomer, while enabling a first polymerization mode of connecting the 1st and 2nd carbon atoms and a second polymerization mode of connecting the 1st and 4th carbon atoms, the number ratio of the structural units formed by the two modes is controlled to be 1:3, to generate a polybutadiene main chain with a first preset polymerization degree of 10; then, taking the side group double bond (second active site) of the polybutadiene main chain as a seed, still through the first polymerization mode and the second polymerization mode, the number ratio of the structural units is controlled to be 1:5, to generate a first-level polybutadiene side chain with a first preset polymerization degree of 10; finally, taking the side group double bond (third active site) of the first-level polybutadiene side chain as a seed, continuing to react through the two polymerization modes, the number ratio of the structural units is controlled to be 1:8, to generate a second-level polybutadiene side chain with a first preset polymerization degree of 10, and finally complete the construction of the fully branched polybutadiene model.

[0129] In the present embodiment, by setting N1

[0130] S404, determining the polybutadiene main chain, the first-level polybutadiene side chain, and the second-level polybutadiene side chain as the polybutadiene model.

[0131] In an embodiment, the complete branched structure of the polybutadiene model composed of a main chain and multiple levels of side chains extending from the main chain has been described in S101 above. Therefore, the polybutadiene main chain, the first-level polybutadiene side chain, and the second-level polybutadiene side chain can be directly determined as the polybutadiene model.

[0132] In this embodiment, by the design of main chain-based and side chain hierarchical growth, a clear multi-level branched structure is formed, which can significantly increase the entanglement density between molecular chains, avoid the defects of brittle and insufficient elasticity of linear polybutadiene, and lay a structural foundation for subsequent materials with excellent toughness and deformation absorption capacity. Moreover, the double bond initiating side chain polymerization is explicitly defined as the second active site and the third active site, which can precisely control the starting point of the growth of each polybutadiene side chain, avoid structural chaos caused by random polymerization (such as uneven distribution of side chains and uncontrollable branching degree), and flexibly optimize the model structure by adjusting the number of active sites or the length of side chains to adapt to different impact resistance requirements of HIPS.

[0133] In another embodiment, when generating a high-impact polystyrene material model, the electronic device optimizes the molecular chain space structure based on the principle of molecular dynamics simulation in a simulation container. The optimization process can be as shown in steps S501-S507, as follows: Figure 5

[0134] S501, simulate a first constant temperature and constant volume environment, and perform a first preset time length of relaxation calculation on the high-impact polystyrene chemical model to obtain a first simulation model.

[0135] Among them, the temperature in the above-mentioned first constant temperature and constant volume environment is a first preset temperature; the relaxation calculation refers to a calculation process of making a non-equilibrium molecular system reach a thermodynamic equilibrium state.

[0136] In an embodiment, the above-mentioned first constant temperature and constant volume environment refers to a virtual environment with constant temperature and volume pre-set in molecular dynamics simulation, corresponding to the NVT (Number of particles, Volume, Temperature) ensemble in thermodynamics, where N is the number of molecules, V is the volume, and T is the temperature. Among them, the constant temperature is maintained by a temperature control algorithm (such as Berendsen thermostat), and the constant volume fixes the volume of the simulation container (avoids system expansion or contraction), which provides a stable environmental boundary for relaxation calculation.

[0137] Among them, the simulation container refers to a "virtual boundary" used to define the spatial range of the research system (such as HIPS molecular chain, atomic collection), which is essentially a three-dimensional space region defined in molecular simulation software, not a real physical container, and its core function is to provide a controllable spatial environment and calculation boundary for simulation.

[0138] The above-mentioned first preset time length refers to the pre-set duration of relaxation calculation (unit: ps or ns, such as 500 ps), which needs to meet the requirement of adjusting the non-equilibrium system to the equilibrium state. If the time length is too short, the system may not reach equilibrium, and if it is too long, the calculation cost will increase. ​

[0139] wherein, relaxation calculation as defined, refers to the process of adjusting the spatial structure of a non-equilibrium molecular system (such as a HIPS chemical model) through the thermal motion of molecular chains (vibration, rotation, chain segment slip) by molecular dynamics simulation algorithm (such as solving Newton's equation of motion), and finally making the total energy of the system (potential energy + kinetic energy) tend to be stable, and the molecular motion state reaches statistical equilibrium. The core role is to eliminate the non-physical defects (such as atomic overlap, local stress concentration) of the initial model, so that the molecular arrangement conforms to the thermodynamic stable state.

[0140] The first simulation model refers to the HIPS model obtained after the first preset time length relaxation calculation under the first constant temperature and constant volume environment, and is characterized by that the spatial structure of the molecular chain reaches a preliminary thermodynamic equilibrium (energy convergence, density stability), which can be used as a basic model for subsequent higher precision simulation (such as extreme environment performance test).

[0141] The first preset temperature refers to the temperature value (such as 800K) set in the first constant temperature and constant volume environment. The setting of temperature directly affects the movement ability of molecular chain (the higher the temperature, the more intense the chain segment movement, the faster the relaxation speed), which is a key parameter to control the relaxation efficiency.

[0142] It should be noted that although the HIPS chemical model constructed by the above steps ensures the correct chemical composition and connection relationship of PB and PS, it may have problems such as excessive crowding of molecular chains (such as local overlap of PS chains and PB) and local high energy (such as too large repulsive force between chain segments) due to manual construction. These defects will lead to distorted simulation results (such as incorrect prediction of density or elasticity) in subsequent performance simulation. Through relaxation calculation, the molecular chain can move freely (such as PS long chain stretching, PB side chain adjusting angle) in a constant temperature and constant volume environment, gradually eliminating defects and minimizing system energy.

[0143] Wherein, the first preset temperature of constant temperature can ensure the activity stability of molecular chain movement, that is, it will not be too slow due to too low temperature, nor will it be disordered due to too high temperature, and the constant volume of the fixed simulation container can avoid the interference of volume change to molecular packing (such as density calculation), so that the equilibrium process is more controllable. The combination of the two can efficiently promote the transition of the system to the thermodynamic equilibrium state.

[0144] S502, adjusting the relaxation calculation of the first simulation model for the first preset time length in the constant temperature environment, obtaining a second simulation model consistent with the preset real density of the high impact polystyrene material.

[0145] Wherein, the temperature in the constant temperature environment is the first preset temperature.

[0146] In an embodiment, the constant-temperature environment refers to a virtual environment in which the temperature is maintained constant by a temperature control algorithm during simulation, and the temperature value is a first preset temperature (consistent with the temperature in the first constant-temperature constant-volume environment), which ensures that the system is only affected by pressure regulation and avoids temperature fluctuations that interfere with density calibration. The core is to provide stable thermodynamic conditions for the correlation of pressure and density.

[0147] Adjusting the pressure in the constant-temperature environment means that under the premise of constant temperature, the pressure value (unit: bar) of the system is adjusted by a pressure control algorithm (such as the Parrinello-Rahman algorithm) in molecular simulation. The purpose is to drive the volume adjustment of the system through pressure change: when the pressure rises, the volume of the simulation container decreases, the molecular chains are more tightly packed, and the density increases; when the pressure decreases, the volume expands, and the density decreases, ultimately making the model density approach the preset real density.

[0148] The preset real density of the high-impact polystyrene material refers to the density value of the real HIPS material obtained by experimental measurement (usually 1.02-1.05 g / cm 3 ), which is the core benchmark for judging the physical reality of the simulation model. It can be considered that only when the density of the simulation model is consistent with this value (the deviation is usually required to be <5%), can the subsequent mechanical property (such as rigidity, impact resistance) simulation results match the real material.

[0149] The second simulation model refers to the HIPS material model obtained after constant-temperature pressure regulation and relaxation calculation for a first preset length of time, and its core feature is that the density is completely consistent with the preset real density, and the molecular chains reach a new thermodynamic equilibrium (energy convergence, volume stability) under the target pressure.

[0150] It should be noted that the first simulation model is the HIPS equilibrium model obtained after relaxation calculation in the above steps, and the molecular chains have eliminated the initial non-physical defects (such as atomic overlap, local energy too high), but because the volume is fixed in the NVT environment, the model density may deviate from the experimental density of the real HIPS (such as only 1.00 g / cm 3 , lower than the real value 1.04-1.06 g / cm 3 ), and needs to be further calibrated by pressure regulation. The above steps adjust the pressure (corresponding to the thermodynamic NPT ensemble, constant particle number N, pressure P, and temperature T) to make the system adapt to the pressure through volume change, and then adjust the density, from constant-volume equilibrium to density precision matching under constant pressure.

[0151] As an example, the pressure of the system is gradually adjusted by the pressure control algorithm (such as when the initial pressure is 1 bar, the density can be 1.00 g / cm 3 , the pressure can be increased to 5 bar, the volume is reduced, and the density is increased to 1.05 g / cm 3) while monitoring the density change; when the density reaches the preset real density, the pressure is maintained to continue relaxing for a first preset time length, to ensure that the molecular chains adapt to the new packing state (e.g., the spatial arrangement of PS chains and PB phases is stable), and to avoid volume rebound caused by chain segment movement after the density reaches the standard.

[0152] S503, simulate a plurality of annealing environments to obtain a third simulation model by reducing the first preset temperature.

[0153] In this embodiment, the simulation temperature of the annealing environment of each simulation can be set in advance, and the simulation temperature of the annealing environment of each adjacent simulation can be less than or equal to a preset temperature difference, to avoid local energy false equilibrium (e.g., chain segment freezing and residual stress) caused by rapid cooling.

[0154] The plurality of annealing environments refer to virtual environments constructed by multiple rounds of gradual cooling and constant temperature relaxation in the principle of molecular dynamics simulation. Each round of annealing corresponds to a fixed-temperature thermodynamic environment (usually a constant-temperature and constant-pressure NPT ensemble, to ensure that the volume / density of the system is stable). The plurality of annealing processes are performed in multiple stages rather than a single cooling process. The core of the annealing process is to allow the molecular chains to have sufficient time to adjust the spatial structure by slow cooling and sufficient relaxation, to avoid falling into local energy false equilibrium (e.g., chain segment freezing and residual stress) caused by rapid cooling.

[0155] In this step, the first preset temperature can be regarded as the initial temperature of the annealing.

[0156] The third simulation model refers to a final HIPS model obtained after multiple annealing environments, and the molecular chain structure of the final HIPS model reaches stable thermodynamic equilibrium at a target low temperature (e.g., 100K) and has no residual stress, energy convergence, and density matching the low-temperature physical properties of the real HIPS. Compared with the first simulation model and the second simulation model, the third simulation model is a model specially adapted to low-temperature extreme environments, and can be directly used for subsequent low-temperature mechanical property (e.g., deep cooling impact resistance) simulation.

[0157] The simulation temperature of the annealing environment of each simulation refers to a fixed temperature set in a round of the plurality of annealing (e.g., 500K in the second round), which is the target temperature of the system during the round of annealing. The simulation temperature of the annealing environment of each simulation should be less than the annealing temperature of the previous simulation, to ensure that each round of annealing achieves temperature reduction.

[0158] In another embodiment, the simulation temperature of the annealing environment of each simulation can be set in advance, and the simulation temperature of the annealing environment of each adjacent simulation can be less than or equal to a preset temperature difference, to avoid local energy false equilibrium (e.g., chain segment freezing and residual stress) caused by rapid cooling. The preset temperature difference can be set according to actual conditions, and is not limited in this regard.

[0159] As an example, the plurality of annealing environments described above can be 5 annealing cycles, and the temperature change gradient in each annealing cycle is 7, and the time is 100ps.

[0160] The simulation temperature of the annealing environment of the last simulation and the simulation temperature of the annealing environment of the current simulation are in a relative relationship, and details are not described.

[0161] It should be noted that the second simulation model obtained by the above steps is density-matched with the density of the real HIPS, but is only in a high-temperature equilibrium state. If it is directly placed in a low-temperature environment, the molecular chain will be quickly frozen due to the sudden weakening of thermal motion, and cannot adjust the spatial arrangement autonomously (such as the PS segment still maintaining loose winding at room temperature, rather than regular accumulation at low temperature), forming a false equilibrium structure. This structure will lead to distortion of subsequent low-temperature mechanical property simulation (such as misjudgment of impact strength, because the freezing degree of the segment does not match the real low temperature).

[0162] Therefore, through the annealing environment of multiple rounds of gradient cooling, the structure can be smoothly transitioned, and the molecular chain can fully adapt to the new temperature at each step, and finally the third simulation model is formed, which is completely consistent with the state of the real HIPS at low temperature in terms of segment arrangement and motion state.

[0163] S504, simulate a second isothermal-isochoric environment, perform relaxation calculation on the third simulation model for a second preset time length to obtain a fourth simulation model.

[0164] The second preset temperature in the second isothermal-isochoric environment is less than the first preset temperature, and the second preset time length is greater than the first preset time length.

[0165] In an embodiment, the second isothermal-isochoric environment is similar to the first isothermal-isochoric environment, and the difference between the two is that the temperature in the second isothermal-isochoric environment is fixed at the second preset temperature (a lower low temperature), and the volume is fixed at a specific value of the simulation container (which can match the equilibrium volume of the third simulation model at this temperature, or can be the same as the volume in the first isothermal-isochoric environment), and through the temperature control and constant volume boundary conditions, a stable space and temperature reference can be provided for relaxation at low temperature.

[0166] The second preset time length refers to the duration of the relaxation calculation in the second isothermal-isochoric environment (such as 500 ps), and is definitely greater than the first preset time length. It should be noted that due to the significant slowing down of molecular chain thermal motion at low temperature (second preset temperature < first preset temperature), the rate of segment adjusting spatial structure is reduced, and more time is needed to eliminate residual stress and reach stable equilibrium.

[0167] The fourth simulation model refers to the final HIPS model obtained after relaxation for a second preset time length under a second constant temperature and constant volume environment. It should be noted that under the condition of constant volume at the second preset temperature (low temperature), the spatial arrangement of molecular chains, the system energy (potential energy + kinetic energy) reaches a long-term stable thermodynamic equilibrium state (energy fluctuation < 0.5%), and there is no local structural defect (such as excessive crowding or loose of chain segments), which can be directly used for subsequent mechanical property testing (such as impact strength, tensile modulus calculation) in extreme low temperature environment.

[0168] The second preset temperature refers to a fixed temperature (such as 300K) set in the second constant temperature and constant volume environment, which is less than the first preset temperature.

[0169] It should be noted that the third simulation model has reached a preliminary low temperature equilibrium in the process of gradually reducing the temperature from the first preset temperature after multiple annealing environment treatments, but there may be a small structural fluctuation (such as local chain segment not completely stable) due to the constant pressure adjustment (volume changes with temperature) during the annealing process. Therefore, further optimization is needed under the second constant temperature and constant volume condition.

[0170] However, the second constant temperature and constant volume environment can eliminate volume fluctuation by fixing the volume, allowing the molecular chain to focus on adjusting the chain segment angle and eliminating local stress in a constant space, avoiding interference with the structure stability due to volume change. And at the second preset temperature (low temperature), the thermal motion of HIPS molecular chains (such as PB side chain rotation, PS chain segment peristalsis) is significantly slowed down, so the chain segment adjustment can be completed in a longer second preset time length, so that the molecular chain at low temperature has sufficient time to adjust and ensure its transition from the preliminary equilibrium after annealing to the deep equilibrium without energy fluctuation (such as the potential energy curve from small oscillation to complete flatness).

[0171] S505, obtaining the structure parameters corresponding to the structure index of the fourth simulation model.

[0172] The above structure index refers to the dimension / category used to describe the microstructure characteristics of the fourth simulation model, reflecting the spatial arrangement, interaction and aggregation state of HIPS molecular chains, which is the core dimension for judging the rationality of the model structure. For HIPS (PB branched phase + PS phase), the structure index includes but is not limited to: molecular chain packing characteristics (such as average interchain distance, packing tightness); intramolecular chain structure (such as average bond length, bond angle, and dihedral angle distribution of PB / PS chains); phase interface structure (such as interface thickness and interface atom distribution of PB phase and PS phase); chain segment motion related characteristics (such as rotation freedom of PB side chain and stretch degree of PS main chain); density and glass transition temperature.

[0173] The structure parameter is a quantified value / data corresponding to the structure index, which is used to convert the abstract structure characteristics into calculable and comparable specific parameters, and is used to directly verify the consistency of the model structure and the real HIPS.

[0174] For example, when the structure index is the packing tightness of the molecular chain, the corresponding structure parameters can be the model density, the first peak position of the RDF (reflecting the shortest average distance between chains), and the first peak height of the RDF (reflecting the atomic distribution probability at the distance, and the higher the value, the more concentrated the packing). In addition, when the structure index is the chain segment motion characteristic, the corresponding structure parameters can be the saturation value of MSD (mean square displacement) (reflecting the total motion amplitude of the chain segment) and the slope of the MSD curve (reflecting the motion rate of the chain segment).

[0175] Specifically, the structure index and the structure parameter can refer to the example description in the above Figure 2 and Figure 3 .

[0176] It should be noted that the structure parameter needs to be extracted from the molecular dynamics trajectory file (such as.xyz,.trr,.dcd format) of the fourth simulation model, which records the coordinates, energy and other dynamic data of all atoms in the simulation process. It can be obtained through the post-processing module of Materials Studio, LAMMPS, GROMACS and the like, and no detailed description is made.

[0177] S506, if the structure parameter meets the preset physical characteristic, the fourth simulation model is determined as a high-impact polystyrene material model.

[0178] In an embodiment, the above-mentioned preset physical characteristic refers to an index that can reflect the physical nature of HIPS, which is set in advance based on experimental data or authoritative literature reports of real high-impact polystyrene (HIPS) materials, and is a standard for judging whether the simulation model (such as the fourth simulation model) is close to the real material.

[0179] The index corresponding to the above-mentioned preset physical characteristic can be the same as the structure index in the above-mentioned S506 step.

[0180] As an example, the index corresponding to the above-mentioned preset physical characteristic can be density and glass transition temperature. The density characteristic refers to a static index reflecting the packing tightness of the molecular chain, and the preset values of the normal temperature and the target low temperature need to be distinguished. For example, the experimental density preset value of HIPS at room temperature can be 1.02-1.05 g / cm 3 ; the experimental density preset value of HIPS at low temperature: 1.04-1.06 g / cm 3 .

[0181] The glass transition temperature can reflect the dynamic index of the mutation of the chain segment movement ability, wherein the HIPS is a complex material, and the Tg of the PS phase and the PB phase needs to be preset respectively. For example, the experimental Tg preset value of the PS phase (rigid phase) can be 100-110°C; and the experimental Tg preset value of the PB phase (elastic phase) can be -90 to -80°C.

[0182] In an embodiment, the electronic device can extract the density structure parameter and the Tg-related structure parameter of the fourth simulation model, and calculate the deviation from the experimental value of the preset physical property. If the deviations are all within the preset reasonable range, it can be determined that the fourth simulation model meets the preset physical property, and then the fourth simulation model can be determined as the HIPS material model. Otherwise, if any deviation is not within the preset reasonable range, it can be determined that the fourth simulation model does not meet the preset physical property.

[0183] In another embodiment, whether the structure parameter meets the preset physical property can also refer to the example description in the above Figure 2 and Figure 3 . Specifically, taking the MSD and RDF as the structure parameters as an example, whether the structure parameter meets the preset physical property can be determined by judging whether the molecular chain structure reaches the relaxation state. For example, when it is determined that the molecular chain structure reaches the relaxation state, it is determined that the structure parameter meets the preset physical property; otherwise, when it is determined that the molecular chain structure does not reach the relaxation state, it is determined that the structure parameter does not meet the preset physical property.

[0184] wherein the relaxation state is that the spatial arrangement and movement state of the molecular chain of the fourth simulation model reach the thermodynamic equilibrium, there is no residual stress and the structure is stable, and the MSD and RDF are parameters for judging the state, and the results thereof usually directly correspond to the key structure parameters.

[0185] Generally, the RDF can reflect the distribution rule of the inter-chain atoms, and if the relaxation state is reached, the RDF curve needs to satisfy:

[0186] the curve has no obvious fluctuation, the peak position and peak height of the first peak (the shortest action distance between the chains) and the second peak (the next nearest neighbor distance) are stable (corresponding to the structure parameter RDF peak position / peak height without drift); the first peak position is consistent with the low-temperature inter-chain spacing of the real HIPS, indicating that the inter-chain packing is not excessively crowded / loose, and reaches the balance. If the RDF curve fluctuates greatly or the peak position deviates, it indicates that the inter-chain packing is not relaxed (such as local aggregation remaining after annealing).

[0187] In addition, the MSD can reflect the movement ability of the chain segment, and if the relaxation state is reached, the MSD curve needs to satisfy:

[0188] The curve tends to be flat (the slope tends to 0) after the second preset time period, corresponding to the stable saturation value of the structure parameter MSD, indicating that the chain segment motion enters the balance stage from the adjustment stage, and there is no additional stress release to cause the change of the motion amplitude; the MSD saturation value at low temperature is much smaller than that at room temperature, corresponding to the low-temperature chain segment motion amplitude that meets the standard, which is consistent with the characteristics of the real HIPS that the chain segment motion is limited at low temperature. If the MSD curve continues to rise (without saturation), it indicates that the chain segment is still adjusting and has not reached the relaxation state.

[0189] In this embodiment, the way of determining whether the structure parameter meets the preset physical characteristics is not limited.

[0190] S507, if the structure parameter does not meet the preset physical characteristics, adjust the environmental parameter in the simulation environment, and repeat the optimization process.

[0191] Based on the above S507 step, when the structure parameter does not meet the preset physical characteristics, it can be considered that the structure of the fourth simulation model deviates from the real HIPS, and thus cannot be used as a model for subsequent testing. Based on this, the electronic device can adjust the environmental parameter in the simulation environment and repeat the above S501-S507 steps until the structure parameter meets the preset physical characteristics.

[0192] Among them, the environmental parameter can be considered as a simulation condition that can affect the structure and motion of the molecular chain (can affect the structure of the fourth simulation model). The electronic device can adjust it according to the specific performance of the non-satisfaction, which is described in detail as follows:

[0193] For density deviation, if the density is too low (the accumulation is too loose), the electronic device can increase the environmental pressure in the NPT relaxation stage (such as when the second simulation model is constructed), compress the simulation container volume, force the molecular chain to be more tightly packed, and increase the density to the preset range. If the density is too high (the accumulation is too much), the environmental pressure can be reduced to allow the volume to expand moderately, relieve the crowding between the chains, and reduce the density to a reasonable value.

[0194] For Tg deviation or chain segment motion abnormality, if the PB phase Tg is too high (the chain segment motion is insufficient), the low-temperature range can be widened in the multiple annealing stage, the low-temperature relaxation time can be extended, and the PB chain segment can be promoted to adjust at a lower temperature to reduce the Tg to the preset range. If the PS phase Tg is too low (the chain segment is too active), the starting temperature can be increased in the NVT relaxation stage (such as the first constant temperature and constant volume environment or the second constant temperature and constant volume environment), so that the PS chain segment can complete more complete rigid accumulation at a higher temperature to increase the Tg to the preset range.

[0195] In addition, for the structure that is not fully balanced, if the structure parameter fluctuates greatly (such as the density is high and low, and the MSD curve is not saturated), it indicates that the molecular chain has not reached a stable balance, and the relaxation time of each stage can be extended.

[0196] In this embodiment, the way of adjusting the environmental parameters in the simulation environment is not limited.

[0197] In this embodiment, the step-by-step optimization process includes eliminating initial non-physical defects by first isothermal constant-volume relaxation calculation, obtaining a first simulation model, matching the preset real density by isothermal pressure-density calibration, obtaining a second simulation model, smoothly transitioning to low temperature by multiple simulation annealing environmental gradient annealing, obtaining a third simulation model, and obtaining a fourth simulation model by second isothermal constant-volume deep balance for long-time relaxation calculation at low temperature. In combination with the closed-loop mechanism of structure parameter extraction, preset physical property verification, and iterative optimization of adjusting environmental parameters when not satisfied, not only can the transition of the HIPS chemical model from chemical reasonableness to thermodynamic equilibrium be realized, but also the spatial structure of the molecular chain can conform to the microstate of the real material. In addition, by benchmarking the structure parameters and the preset physical properties, the performance deviation between the model and the real HIPS can be eliminated. Further, the final HIPS material model can be consistent with the real HIPS in chemical structure and physical properties.

[0198] It should be noted that in the research of molecular dynamics simulation and mechanical property test of HIPS material, HIPS is often used in cold chain transportation (-40℃ to -80℃ deep cooling), high temperature processing (180℃ to 220℃) and other extreme scenarios. The demand for accurate simulation of the mechanical properties of HIPS under extreme environments (such as low-temperature impact resistance and high-temperature creep resistance) is increasingly urgent. However, if the mechanical property simulation of the constructed HIPS chemical model under extreme test environments (such as deep cooling, high temperature and high pressure) is directly carried out, the basic effectiveness of the HIPS chemical model cannot be verified, which may lead to difficulty in locating the abnormal performance source and reduce the accuracy of the test results.

[0199] Therefore, in order to provide the accuracy of the test results, the electronic device can generate the test results according to the steps S601-S602 as shown in FIG. 6. Figure 6 The details are as follows:

[0200] S601, simulate the mechanical property change rule of the high-impact polystyrene material model under the preset normal test environment, and obtain a target test result.

[0201] In an embodiment, the above-mentioned preset normal test environment refers to a typical environment preset for HIPS regular service and standard test, which simulates the daily use conditions of HIPS in the real world, and the core parameters need to conform to the industry standards (such as the environmental requirements of HIPS mechanical test in ISO and ASTM). That is, in the molecular simulation software, the environmental parameters of the normal test environment are input, and the HIPS material model is tested to obtain the target test result.

[0202] Specifically, the temperature in the normal test environment can be room temperature (298 K / 25 °C), and the pressure can be normal pressure (standard atmospheric pressure).

[0203] The target test result refers to the quantitative mechanical data and change curve finally output through the mechanical property simulation of the normal test environment, which is the core basis for verifying the effectiveness of the normal performance of the model. For example, the target test result can include but is not limited to the following information:

[0204] Tensile property data: elastic modulus 2.5-3.0 GPa, yield strength 25-30 MPa, elongation at break 15-20%; impact property data: Charpy impact strength 20-25 kJ / m 2 ; corresponding change curve: stress-strain curve, impact energy absorption curve, etc.

[0205] As an example, taking the stress-strain curve as an example, referring to Figure 7 , Figure 7 is a HIPS stress-strain curve provided by an embodiment of the present application in a B control method. Figure 7 The stress-strain curves of HIPS material model in different spatial directions (X, Y, Z) under molecular dynamics simulation are shown, which are used to present the anisotropy characteristics of its mechanical properties (i.e. the difference in mechanical properties of the material in different directions). The abscissa is the strain (dimensionless, reflecting the deformation degree of the material); the ordinate is the stress (unit: GPa, reflecting the strength of the force borne by the material).

[0206] Generally, in the X curve (curve in the X direction), the stress first rises rapidly to a peak value (about 0.035 GPa), and then gradually decreases, reflecting that the material in the X direction experiences the elastic / yield stage → softening / breaking stage, and the stress decreases with the increase of deformation. In the Y curve (curve in the Y direction), the stress peak is lower (about 0.025 GPa), and after rising, it quickly enters a flat decay stage, reflecting that the tensile strength of the Y direction is relatively weak, and the stress retention ability after deformation is poor. In the Z curve (curve in the Z direction), the stress peak is the highest (close to 0.04 GPa), and the subsequent downward trend is slower, indicating that the tensile strength of the Z direction is stronger, and the stress decay is slower during the deformation process.

[0207] It should be noted that HIPS is a blend of polystyrene (PS, rigid phase) and polybutadiene (PB, rubber toughening phase). The anisotropy of the curve is due to the difference in the orientation and packing of molecular chains in three-dimensional space in the simulation model, which directly reflects the distribution characteristics of the strength and toughness of HIPS in different directions, and can provide a basis for subsequent analysis of its actual service behavior (such as the effect of stress direction on performance).

[0208] The electronic device can adopt a Forcite calculation module and a COMPASS III (Condensed-phase Optimated Molecular Potentials for Atomistic Simulation Studies III) force field, apply a fixed stress to stretch the high-impact polystyrene material model, calculate the strain corresponding to the specific stress, and obtain the stress-strain curve.

[0209] In S602, if the target test result is consistent with the standard test result in the normal test environment, the electronic device simulates the mechanical property change rule of the high-impact polystyrene material model in the preset extreme test environment to obtain the test result.

[0210] In an embodiment, the electronic device can calculate the deviation of the numerical value of the HIPS normal mechanical key indicators such as elastic modulus, yield strength, and impact strength from the experimental standard value of the real HIPS in the normal environment, and determine that the target test result is consistent with the standard test result when the deviation is less than or equal to the preset allowable deviation. Otherwise, when the deviation is greater than the preset allowable deviation, it is determined that the target test result is inconsistent with the standard test result.

[0211] For the stress-strain and impact energy-time performance curves, if the overall change trend of the performance curve is consistent with the experimental curve, it can be determined that the target test result is consistent with the standard test result. Otherwise, if the overall change trend of the performance curve is inconsistent with the experimental curve, it can be determined that the target test result is inconsistent with the standard test result.

[0212] In an embodiment, the electronic device simulates the mechanical property change rule of the high-impact polystyrene material model in the preset extreme test environment to obtain the test result in a similar manner to the simulation of the mechanical property change rule of the high-impact polystyrene material model in the preset normal test environment to obtain the target test result, and no detailed description is made.

[0213] It should be noted that when the target test result is inconsistent with the standard test result, the electronic device can optimize the high-impact polystyrene material model according to the above-mentioned Figure 5 The high-impact polystyrene material model in the step is optimized, and the above-mentioned S601-S602 steps are performed again on the optimized high-impact polystyrene material model.

[0214] In the embodiment, first, the mechanical property change rule of the high impact polystyrene material model under the preset normal test environment is simulated to obtain a target test result, and when the target test result is consistent with a standard test result under the normal test environment, the mechanical property change rule of the high impact polystyrene material model under the preset extreme test environment is simulated to obtain a test result, so that it can be ensured that the performance change rule (such as low-temperature impact resistance drop and high-temperature modulus attenuation) obtained by subsequent extreme test environment (such as deep cold and high temperature) test is the real effect of the environment on the material, rather than a false result caused by defects of the high impact polystyrene material model, and the scientificity and accuracy of the test result under the extreme test environment are ensured.

[0215] It should be particularly pointed out that, in the execution of the above S501-S507 process, if the first preset temperature is less than the second preset temperature, for example, the first preset temperature is 300K, the second preset temperature is 800K, and the environmental parameters in the remaining simulation environment remain unchanged, it is easy to cause the final HIPS material model to have problems such as structural authenticity loss, thermodynamic equilibrium failure, and performance simulation foundation collapse.

[0216] Specifically, HIPS is composed of a rigid polystyrene phase and an elastic polybutadiene phase to form a complex system, and the thermal decomposition temperature is only about 623K-673K. If the temperature is raised to 800K in simulation, it is far beyond the threshold. When relaxed at 300K, the molecular chain should form a regular complex accumulation (PS rigid accumulation, PB elastic entanglement, and clear phase interface) conforming to the normal temperature, but the high temperature of 800K causes the carbon-carbon bond of the PS main chain and the double bond of the PB side chain to break, the long chain is decomposed into short chain or small molecule, and the long chain entanglement-complex dispersion structure is destroyed; at the same time, the PS / PB phase interface collapses due to excessive melting and mixing of the molecular chain, and the PB phase changes from dispersed granular to disordered dissolved state, and the model deviates from the real HIPS complex nature. Specifically, refer to Figure 8 , Figure 8 is a HIPS density simulation curve provided by another embodiment of the application in a high impact polystyrene test method. As shown in Figure 8 , the final model density is stabilized at about 1.0 g / cm 3 , which is significantly lower than the 1.02-1.05 g / cm 3 of the real HIPS, directly reflecting the problem of insufficient density caused by the failure of the molecular chain to tightly accumulate after high temperature and the collapse of the complex structure.

[0217] And, the molecular chain is in the normal temperature regular stacking state after the 300K relaxation, and is in the fragmentized and high activity state after the 800K high temperature damage, and the annealing cycle time of only the first preset time (100ps) in each round and the smaller temperature change gradient cannot support the chain segment to form a stable structure again. When the temperature is decreased from 800K to 300K, the molecular chain cannot be regularly stacked in a short time due to the violent movement under high temperature, is frozen in the disordered state of fragmentized winding and local excessive crowding / void, and is accompanied by a large amount of residual stress; the subsequent 500ps NVT relaxation at 300K cannot eliminate these defects, finally the model density deviates from the real density, and due to the slow release of residual stress, the density continues to fluctuate, and cannot reach the stable state of thermodynamic equilibrium. Specifically, refer to Figure 9 , Figure 9 is a HIPS mean square displacement simulation curve provided by another embodiment of the high impact polystyrene test method. As shown in Figure 9 , curve 1 continuously increases linearly with time, and does not show the characteristic of increasing and then stabilizing in the equilibrium state, proving that the molecular chain is still in the process of continuous disordered movement / relaxation, and the microstate of the model is seriously out of line with the stable state of the real HIPS at normal temperature, and the thermodynamic equilibrium fails.

[0218] And, when verified by the mean square displacement, the HIPS material model shows the non-relaxation characteristics due to the structural defects, and cannot reflect the chain segment movement characteristics of the rigid movement of the PS phase and the elastic creep of the PB phase of the real HIPS at 300K. On this basis, refer to Figure 10 , Figure 10 is a HIPS stress-strain curve provided by another embodiment of the high impact polystyrene test method. As shown in Figure 10 , the stress-strain curves of X, Y and Z directions fluctuate sharply and change irregularly, and even appear negative values, and completely do not have the clear mechanical stages such as elasticity, yield and fracture of the real HIPS. Therefore, it can be considered that the test results obtained by carrying out the mechanical property calculation based on the model with such structural damage and non-equilibrium are greatly deviated from the real HIPS, and lose the engineering reference value.

[0219] Figure 11 is a structural schematic diagram of an electronic device provided by an embodiment of the application. As shown in Figure 11 , the electronic device 1100 of the embodiment includes a processor 1110, a memory 1120, and a computer program 1130 stored in the memory 1120 and executable on the processor 1110, for example, a program of the high impact polystyrene test method. The processor 1110 implements the steps in each of the above-mentioned various embodiments of the high impact polystyrene test method when executing the computer program 1130, for example Figure 1S101 to S105. Alternatively, the processor 1110 implements the steps in the above-described various embodiments when executing the computer program 1130.

[0220] For example, the computer program 1130 can be divided into one or more modules, which are stored in the memory 1120 and executed by the processor 1110 to implement the high-impact polystyrene testing method provided by the embodiments of the present application. One or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program 1130 in the electronic device 1100. For example, the computer program 1130 can implement the high-impact polystyrene testing method provided by the embodiments of the present application.

[0221] The electronic device 1100 can include, but is not limited to, the processor 1110, the memory 1120. Those skilled in the art can understand that the electronic device 1100 can include more or fewer components than those shown, or can have different arrangements of the components, such as the electronic device also including an input / output device, a network access device, a bus, etc. Figure 11 The electronic device 1100 is only an example and does not constitute a limitation on the electronic device 1100, and can include more or fewer components than those shown, or combine certain components, or different components, for example, the electronic device can also include an input / output device, a network access device, a bus, etc.

[0222] The processor 1110 can be a central processing unit, and can also be other general-purpose processors, digital signal processors, application-specific integrated circuits, ready programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0223] The memory 1120 can be an internal storage unit of the electronic device 1100, such as a hard disk or a memory of the electronic device 1100. The memory 1120 can also be an external storage device of the electronic device 1100, such as a plug-in hard disk, a smart memory card, a flash memory card, etc. provided on the electronic device 1100. Further, the memory 1120 can include both the internal storage unit and the external storage device of the electronic device 1100.

[0224] The embodiments of the present application provide a computer readable storage medium, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the high-impact polystyrene testing method in the above-described various embodiments.

[0225] The embodiments of the present application provide a computer program product, when the computer program product is run on an electronic device, the electronic device executes the high-impact polystyrene testing method in the above-described various embodiments.

[0226] In this application, "at least one" means one or more, "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can mean: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple.

[0227] It should be understood that the size of the sequence number of the above-mentioned processes does not mean the order of execution in various embodiments of the present application. The execution order of the processes should be determined according to their functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0228] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A high impact polystyrene test method characterized by, The method comprises: constructing a full-branched polybutadiene model with butadiene as a monomer; the polybutadiene model comprises a complete branch structure formed by a main chain and multiple levels of side chains extending from the main chain; initiating polymerization of a styrene monomer with a first active site in the polybutadiene model as a seed to obtain cross-linked phase molecular chains of the polybutadiene and polystyrene; the first active site is a double bond site in the polybutadiene model that initiates polymerization of the styrene monomer to grow a polystyrene chain; mixing the cross-linked phase molecular chains with multiple pure polystyrene molecular chains to construct a high-impact polystyrene chemical model; optimizing the molecular chain spatial structure of the high-impact polystyrene chemical model based on the principle of molecular dynamics simulation to obtain a high-impact polystyrene material model that satisfies preset physical characteristics of a high-impact polystyrene material; simulating the mechanical property change rule of the high-impact polystyrene material model in a preset extreme test environment to obtain a test result.

2. The method of claim 1, wherein, The method of constructing a full-branched polybutadiene model with butadiene as a monomer comprises: constructing a polybutadiene main chain with the butadiene as a monomer; growing a first-level polybutadiene side chain with a second active site of the polybutadiene main chain as a seed; the second active site is a double bond site in the polybutadiene main chain that initiates polymerization of a butadiene monomer to grow the first-level polybutadiene side chain; growing a second-level polybutadiene side chain with a third active site of the first-level polybutadiene side chain as a seed; the third active site is a double bond site in the first-level polybutadiene side chain that initiates polymerization of the butadiene monomer to grow the second-level polybutadiene side chain; determining the polybutadiene main chain, the first-level polybutadiene side chain, and the second-level polybutadiene side chain as the polybutadiene model.

3. The method of claim 2, wherein, The method of constructing a full-branched polybutadiene model with butadiene as a monomer comprises: polymerizing the butadiene as a monomer by simultaneously enabling a first polymerization mode of polymerization through a first carbon atom and a second carbon atom and a second polymerization mode of polymerization through the first carbon atom and a fourth carbon atom to generate the polybutadiene main chain with a first preset polymerization degree; polymerizing the butadiene main chain by the first polymerization mode and the second polymerization mode with a second active site of the butadiene main chain as a seed to generate the first-level polybutadiene side chain with the first preset polymerization degree; polymerizing the first-level polybutadiene side chain by the first polymerization mode and the second polymerization mode with a third active site of the first-level polybutadiene side chain as a seed to generate the second-level polybutadiene side chain with the first preset polymerization degree.

4. The method of claim 3, wherein, When generating the polybutadiene main chain, the ratio of the number of structural units formed by the first polymerization mode to the number of structural units formed by the second polymerization mode is 1:N1; When generating the first-level polybutadiene side chain, the ratio of the number of structural units formed by the first polymerization mode to the number of structural units formed by the second polymerization mode is 1:N2; When generating the second-level polybutadiene side chain, the ratio of the number of structural units formed by the first polymerization mode to the number of structural units formed by the second polymerization mode is 1:N3; Wherein, N1, N2, N3 are all integers greater than 1, and N1 < N2 < N3.

5. The method of claim 1, wherein, The mixing of the cross-linking phase molecular chain with a plurality of pure polystyrene molecular chains to construct a high-impact polystyrene chemical model comprises: The first preset number of pure polystyrene molecular chains with a second preset degree of polymerization and the second preset number of pure polystyrene molecular chains with a third preset degree of polymerization are mixed with the cross-linking phase molecular chain to obtain the high-impact polystyrene chemical model.

6. The method of claim 5, wherein, The first preset number is less than the second preset number, and the second preset degree of polymerization is less than the third preset degree of polymerization.

7. The method according to any one of claims 1 to 6, characterized in that, The optimization of the molecular chain space structure of the high-impact polystyrene chemical model based on the principle of molecular dynamics simulation to obtain a high-impact polystyrene material model satisfying a preset physical property of the high-impact polystyrene material comprises: Based on the principle of molecular dynamics simulation, the molecular chain space structure is optimized in a simulation container under the following simulation environment, and the optimization process comprises: A first isothermal constant-volume environment is simulated, and a first preset time length of relaxation calculation is performed on the high-impact polystyrene chemical model to obtain a first simulation model; the temperature in the first isothermal constant-volume environment is a first preset temperature; the relaxation calculation refers to a calculation process of making a non-equilibrium molecular system reach a thermodynamic equilibrium state through calculation; Under a constant-temperature environment, the pressure in the constant-temperature environment is adjusted to perform the first preset time length of relaxation calculation on the first simulation model to obtain a second simulation model consistent with the preset real density of the high-impact polystyrene material; the temperature in the constant-temperature environment is the first preset temperature; A plurality of annealing environments are simulated, and the first preset temperature is lowered to obtain a third simulation model; the simulation temperature of the annealing environment of the current simulation is less than the simulation temperature of the annealing environment of the last simulation; A second isothermal constant-volume environment is simulated, and a second preset time length of relaxation calculation is performed on the third simulation model to obtain a fourth simulation model; the second preset temperature in the second isothermal constant-volume environment is less than the first preset temperature, and the second preset time length is greater than the first preset time length; A structure parameter corresponding to a structure index of the fourth simulation model is obtained; If the structure parameter satisfies the preset physical property, the fourth simulation model is determined as the high-impact polystyrene material model; If the structure parameter does not satisfy the preset physical property, the environmental parameter in the simulation environment is adjusted, and the optimization process is repeatedly executed.

8. The method according to any one of claims 1 to 6, characterized in that, The simulation of the mechanical property change rule of the high-impact polystyrene material model under a preset extreme test environment obtains a test result, which comprises: The simulation of the mechanical property change rule of the high-impact polystyrene material model under a preset normal test environment obtains a target test result; If the target test result is consistent with a standard test result under the normal test environment, the mechanical property change rule of the high-impact polystyrene material model under a preset extreme test environment is simulated to obtain a test result.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the method of any one of claims 1 to 8. The processor executes the computer program to implement the method of any one of claims 1 to 8.

10. A computer program product, characterized in that, When the computer program product is run on an electronic device, it causes the electronic device to perform a method as claimed in any of claims 1 to 8.

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