Plastic compatibilization recovery simulation method and system based on dissipative particle dynamics

Abstract

The invention relates to the technical field of molecular simulation, and discloses a plastic compatibilization recovery simulation method and system based on dissipative particle dynamics, and the method simulates the blending process of a PE polymer and a PP polymer in a molten state from the perspective of mesoscale dissipative particle dynamics simulation. The melt blending diffusion movement process of the molecular chain under the melting condition is more truly reflected; different simulation systems are regulated and controlled by changing the molecular mass, molecular proportion, block distribution and the like of the added PE-PP compatilizer; the interface distribution mechanism of the compatilizer is clarified, and the influence of the spatial conformation distribution of the copolymer on the interfacial tension is defined; the mass transfer characteristics of the compatibilizer are analyzed, the mass transfer process of a system is regulated and controlled in combination with the micelle structure evolution rule of the compatibilizer, the universal and applicable compatibilizer structure accurate design mechanism is explored, a guiding effect is achieved on formulation of a waste PE / PP melt blending recycling process, and the purposes of stabilizing a phase interface and improving the physical performance of a recycled material are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular simulation, and in particular to a plastic volume expansion and recycling simulation method and system based on dissipative particle dynamics. Background Art

[0002] Physical recycling refers to a method of directly granulating and molding waste plastics after cleaning and crushing without destroying the polymer structure of the plastic. However, the physical recycling process can only recycle waste plastics of a single component. If you want to recycle multi-component plastics, you need to melt and blend two or more plastics during the physical recycling process. However, due to the different structures of different plastic polymers, the recycled products do not meet the requirements of industrial production. One solution is to add a compatibilizer, which allows multiple resins and different waste plastic waste to be mixed for reuse.

[0003] At present, the two types of waste plastics with the largest amount are PE (polyethylene) and PP (polypropylene). If PE and PP can be physically blended and recycled, it will be of great significance for green and sustainable development. However, PE and PP are thermodynamically incompatible. The polymer products after blending have high interfacial tension, poor interfacial adhesion, and poor mechanical properties. The economic benefits of direct mixed recycling are low. Enterprises have found that adding PE-PP compatibilizers with the same chemical composition can reduce the interfacial tension between PE and PP, improve the interfacial properties of the two phases, and make the recycled products have a stable form and high physical and mechanical properties, thereby increasing the recycling value. The molecular structure of the PE-PP compatibilizer is crucial to the melt blending of PE and PP, but there is currently a lack of methods to rationally design the molecular structure of the PE-PP compatibilizer.

[0004] Therefore, a plastic volume expansion and recycling simulation method based on dissipative particle dynamics is urgently needed to provide reliable reference data for designing a suitable PE-PP compatibilizer molecular structure. Summary of the invention

[0005] The present invention provides a plastic volume expansion and recovery simulation method and system based on dissipative particle dynamics, which is used to solve the defect that a method for comprehensive analysis of the melt blending process of PE and PP is lacking, resulting in an inability to design a suitable PE-PP compatibilizer molecular structure.

[0006] The present invention provides a plastic volume expansion and recycling simulation method based on dissipative particle dynamics, comprising:

[0007] Based on the atomic species of the target PE and the target PP, a full-atom molecular chain model of the target PE and the target PP is established, and full-atom molecular dynamics simulation parameters are set for the full-atom molecular chain model of the target PE and the target PP;

[0008] Through the full-atom molecular chain model of the target PE and the target PP, the blend of the target PE and the target PP is relaxed to the target equilibrium structure by using the relaxation method to obtain the target temperature and the target pressure;

[0009] Through the full-atom molecular chain model of the target PE and the target PP, the melt blending of the target PE and the target PP is simulated at the target temperature and the target pressure, and the dissipative particle dynamics data of the target PE and the target PP are obtained;

[0010] According to the dissipative particle dynamics data of target PE and target PP, a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics was established;

[0011] Through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, the two-phase diffusion and two-phase separation of the target PE and target PP in the melt blending process are simulated at the target temperature and target pressure, and the interfacial tension of the PE / PP melt blending system reaching equilibrium is obtained;

[0012] PE-PP compatibilizers with different molecular structures were added to the PE / PP melt blending system to simulate the effects of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and the interfacial tension of the PE / PP melt blending system reached equilibrium after the PE-PP compatibilizers with different molecular structures were added.

[0013] The interfacial tension of the PE / PP melt blending system reached equilibrium before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures was analyzed, and the PE-PP compatibilizer that met the melt blending requirements of the target PE and target PP was screened.

[0014] According to an embodiment provided by the present invention, the all-atom molecular dynamics simulation parameters include the potential function of the all-atom molecular dynamics simulation, the ensemble of the simulation system, and the boundary conditions of the simulation system.

[0015] According to an embodiment provided by the present invention, the relaxation method is a 21-step annealing method.

[0016] According to an embodiment provided by the present invention, the dissipative particle dynamics data of the target PE and the target PP include repulsive force parameters of the dissipative particle dynamics simulation and the length of the bead chain model of the dissipative particle dynamics simulation.

[0017] According to an embodiment provided by the present invention, the melt blending of the target PE and the target PP is simulated at the target temperature and the target pressure by using the full-atom molecular chain model of the target PE and the target PP, and the dissipative particle dynamics data of the target PE and the target PP are obtained, including:

[0018] The full-atom molecular chain model of the target PE and the target PP is obtained to simulate the cohesive energy of the melt blending process of the target PE and the target PP at the target temperature and the target pressure;

[0019] According to the full-atom molecular chain model of the target PE and the target PP, the cohesive energy of the melt blending process of the target PE and the target PP is simulated at the target temperature and the target pressure, and the repulsive force parameters of the dissipative particle dynamics simulation are obtained;

[0020] The number average degree of polymerization and characteristic ratio of the target PE and the target PP are obtained, and the length of the bead chain model for dissipative particle dynamics simulation is obtained according to the number average degree of polymerization and characteristic ratio of the target PE and the target PP.

[0021] According to an embodiment provided by the present invention, the all-atom molecular chain model of the target PE and the target PP is obtained to simulate the cohesive energy of the melt blending process of the target PE and the target PP at the target temperature and the target pressure, comprising:

[0022] The full-atom molecular chain model of the target PE and the target PP is obtained. The melt blending process of the target PE and the target PP is simulated at the target temperature and the target pressure, and the intramolecular interaction energy E in the simulated system is intra and the total potential energy E of all molecules in the simulation system total ;

[0023] The intramolecular interaction energy E in the simulated system intra and the total potential energy E of all molecules in the simulation system total Subtract the cohesive energy E of the target PE and target PP melt blending process under the target temperature and target pressure. coh .

[0024] According to an embodiment provided by the present invention, the cohesive energy of the melt blending process of the target PE and the target PP is simulated at the target temperature and the target pressure according to the full-atom molecular chain model of the target PE and the target PP to obtain the repulsive force parameters of the dissipative particle dynamics simulation, including:

[0025] The cohesive energy E of the melt blending process of target PE and target PP is simulated at the target temperature and target pressure according to the full-atom molecular chain model of target PE and target PP. coh , and the solubility parameter δ and the Flory-Huggins parameter χ ij ;

[0026] According to the solubility parameter δ and Flory-Huggins parameter χ ij , combined with the density of the simulation system, the repulsive force parameters of the dissipative particle dynamics simulation are obtained.

[0027] According to an embodiment provided by the present invention, the method of obtaining the number average degree of polymerization and characteristic ratio of the target PE and the target PP, and obtaining the length of the bead chain model for dissipative particle dynamics simulation according to the number average degree of polymerization and characteristic ratio of the target PE and the target PP, comprises:

[0028] The number average degree of polymerization of the target PE and the target PP is divided by the characteristic ratio of the target PE and the target PP to obtain the length of the bead chain model for the dissipative particle dynamics simulation.

[0029] According to an embodiment provided by the present invention, the expression of interfacial tension is:

[0030]

[0031] In the expression of interfacial tension, γ represents interfacial tension, L Z represents the simulation box size parameter, P zz represents the component of pressure in the z direction, P xx represents the component of pressure in the x direction, P yy Represents the component of pressure in the y direction.

[0032] According to an embodiment provided by the present invention, the PE-PP compatibilizers with different molecular structures include a linear multi-block copolymer type PE-PP compatibilizer and a graft copolymer type PE-PP compatibilizer.

[0033] According to an embodiment provided by the present invention, the interfacial tension of the PE / PP melt blending system is analyzed to reach equilibrium before and after the addition of the PE-PP compatibilizer and after the addition of the PE-PP compatibilizers with different molecular structures, and the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP is screened and obtained, comprising:

[0034] According to the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of different molecular structures, the compatibility efficiency of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of different molecular structures are obtained, and the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP is screened.

[0035] According to an embodiment provided by the present invention, it also includes:

[0036] Different concentrations of PE-PP compatibilizers were added to the PE / PP melt blending system to simulate the effects of different concentrations of PE-PP compatibilizers on the melt blending process of target PE and target PP, and the interfacial tensions of the PE / PP melt blending system at different concentrations of PE-PP compatibilizers were obtained;

[0037] After analyzing the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures, combined with the equilibrium interfacial tension of the PE / PP melt blending system at different concentrations of PE-PP compatibilizer, we further screened out the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP.

[0038] According to an embodiment provided by the present invention, it also includes:

[0039] After adding PE-PP compatibilizer to the PE / PP melt blending system, the diffusion and distribution of the PE-PP compatibilizer at the interface and bulk of the PE / PP melt blending system are obtained to obtain the relationship between the conformation of the PE-PP compatibilizer and the interfacial tension.

[0040] According to an embodiment provided by the present invention, it also includes:

[0041] Using molten polypropylene as solvent and molten PE-PP copolymer molecules as solute, a PP / PE-PP polymer melt blending model was established, and the micelle formation process of PE-PP copolymer molecules in a single polymer phase was studied.

[0042] The present invention also provides a plastic volume expansion and recycling simulation system based on dissipative particle dynamics, comprising:

[0043] The first establishment module is used to: establish a full-atom molecular chain model of the target PE and the target PP based on the atomic species of the target PE and the target PP, and set full-atom molecular dynamics simulation parameters for the full-atom molecular chain model of the target PE and the target PP;

[0044] A relaxation module is used to: relax the blend of the target PE and the target PP to the target equilibrium structure by using the full-atom molecular chain model of the target PE and the target PP and the relaxation method to obtain the target temperature and the target pressure;

[0045] The first simulation module is used to: simulate the melt blending of the target PE and the target PP at the target temperature and the target pressure through the full-atom molecular chain model of the target PE and the target PP, and obtain the dissipative particle dynamics data of the target PE and the target PP;

[0046] The second establishment module is used to: establish a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics according to the dissipative particle dynamics data of the target PE and the target PP;

[0047] The second simulation module is used to: simulate the two-phase diffusion and two-phase separation of target PE and target PP in the melt blending process at the target temperature and target pressure through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, and obtain the interfacial tension of the PE / PP melt blending system to reach equilibrium;

[0048] The third simulation module is used to: respectively add PE-PP compatibilizers with different molecular structures into the PE / PP melt blending system, simulate the influence of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and obtain the interfacial tension of the PE / PP melt blending system reaching equilibrium after the PE-PP compatibilizers with different molecular structures are respectively added;

[0049] The analysis module is used to analyze the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures, and screen out PE-PP compatibilizers that meet the melt blending requirements of the target PE and the target PP.

[0050] The present invention also provides an electronic device, comprising a processor and a memory storing a computer program, wherein when the processor executes the computer program, it implements any of the above-mentioned plastic volume expansion and recycling simulation methods based on dissipative particle dynamics.

[0051] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-mentioned plastic volume expansion and recycling simulation methods based on dissipative particle dynamics.

[0052] The present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute any of the above-mentioned plastic volume expansion and recycling simulation methods based on dissipative particle dynamics.

[0053] The present invention provides a plastic volume expansion and recycling simulation method and system based on dissipative particle dynamics. Combined with all-atom molecular dynamics, the blending process of PE polymer and PP polymer in a molten state is simulated from the perspective of dissipative particle dynamics simulation at a mesoscopic scale, so as to more realistically reflect the melt blending diffusion movement process of molecular chains under molten conditions; different simulation systems can be regulated by changing the molecular mass, molecular ratio, block distribution, etc. of the added PE-PP compatibilizer; the interface distribution mechanism of the compatibilizer is explained, and the influence of the spatial conformation distribution of the copolymer on the interfacial tension is clarified; the mass transfer characteristics of the compatibilizer are analyzed, and the mass transfer process of the system is regulated in combination with the evolution law of the micelle structure of the compatibilizer, so as to explore the generally applicable precise design mechanism of the compatibilizer structure, which has a guiding role in the formulation of the waste PE / PP melt blending recycling process, and finally achieves the purpose of stabilizing the phase interface and improving the physical properties of the recycled material. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1 A schematic flow chart of a plastic volume expansion and recycling simulation method based on dissipative particle dynamics provided by the present invention.

[0056] Figure 2 It is a schematic diagram of the PE / PP / PE-PP melt blending process based on dissipative particle dynamics simulation in a specific embodiment of the present invention.

[0057] Figure 3 It is a schematic diagram of the micelle formation process of PE / PP / PE-PP based on dissipative particle dynamics simulation in a specific embodiment of the present invention.

[0058] Figure 4 A schematic structural diagram of a plastic volume expansion and recycling simulation system based on dissipative particle dynamics provided by the present invention.

[0059] Figure 5 This is a schematic structural diagram of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments, and they should not be understood as limitations on the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the description of the present invention, it should be understood that the terms used are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0061] The present invention believes that the dissipative particle dynamics (DPD) simulation method can be used to intuitively observe the PE / PP polymer melt blending process and the diffusion movement process of the added PE-PP copolymer molecules (i.e., PE-PP compatibilizer) in the system, so as to better understand the thermodynamic related mechanisms in the polymer melt blending process. The present invention uses the DPD simulation method to study the variation law of the copolymer interfacial tension under different conditions, and explores a generally applicable method for the precise design of the compatibilizer structure, which has an important guiding role in polymer recycling and the preparation of high-performance composite polymer materials.

[0062] Combine the following Figure 1-Figure 5 The present invention describes a plastic volume expansion and recycling simulation method and system based on dissipative particle dynamics. It should be noted that the execution subject of the plastic volume expansion and recycling simulation method based on dissipative particle dynamics provided by the present invention can be any network-side device / terminal-side device that meets the technical requirements, such as a plastic volume expansion and recycling simulation device based on dissipative particle dynamics.

[0063] Figure 1 Schematic diagram of the process of the plastic volume expansion and recycling simulation method based on dissipative particle dynamics provided by the present invention. Figure 1 The present invention provides a plastic volume expansion and recycling simulation method based on dissipative particle dynamics, which may include the following steps:

[0064] S110 , based on the atomic species of the target PE and the target PP, establish a full-atom molecular chain model of the target PE and the target PP, and set full-atom molecular dynamics simulation parameters for the full-atom molecular chain model of the target PE and the target PP.

[0065] Specifically, the full-atom molecular chain model of the target PE and the target PP can be established by lammps software, or by other software with molecular dynamics properties, such as Gromacs, Material Studio, Charmm, Amber, Moltempalte, etc. Further, the full-atom molecular dynamics simulation parameters can be set for the full-atom molecular chain model of the target PE and the target PP based on the atomic species of the target PE and the target PP. In this embodiment, the potential function of the full-atom molecular chain model adopts OPLS-AA force field, and the potential function can be selected from one or more of the potential functions such as PCFF, CVFF, COMPASS, CHARMM, etc. The simulation can adopt one or more of the NVE, NVT, and NPT ensembles, and the temperature can be controlled by thermostats such as Noose-Hoover, Temp / rescale, Langevin, and Berendson. The pressure can be controlled by thermostats such as Noose-Hoover, Berendson, and Parrinello-Rahman. In this embodiment, the Noose-Hoover thermostat and barostat are used to control the temperature and pressure of the system. All simulations use periodic boundary conditions in the x, y, and z directions.

[0066] S120. Using the full-atom molecular chain model of the target PE and the target PP and the relaxation method, the blend of the target PE and the target PP is relaxed to a target equilibrium structure to obtain a target temperature and a target pressure.

[0067] Specifically, the relaxation method used in this embodiment is a 21-step annealing method. The purpose of relaxation is to eliminate the unreasonable internal stress of molecules in the initial structure of the target PE and the target PP, so that the molecular structure can be fully relaxed.

[0068] Specifically, the 21-step annealing method is implemented as follows: a total of seven cycles, each cycle has three molecular dynamics simulation steps: (1) the highest temperature T max NVT simulation under (2) final temperature T final NVT simulation under (3)T final NPT simulations at 37 °C. In longer simulations (100 ps per step), the pressure applied during the NPT step was gradually increased to a maximum pressure P in the first three cycles (steps 1–9). max , to allow the molecular structure to fully deform and relax, the NPT ensemble pressure in the first three cycles was 0.02P max , 0.6P max , P max Then, in a shorter simulation (10 ps per step), the pressure is gradually decreased over the next four cycles (steps 10–20) to a final pressure P final, using a larger pressure change to eliminate the abnormal stress in the system, the NPT ensemble pressure in the last four cycles was 0.5P max , 0.1P max , 0.01P max , P max The simulation time of the last step (step 21) NPT relaxation process can be appropriately increased, such as 1 ns. max , T final , P max , P final They are 600K, 300K, 50000Bar and 1Bar respectively.

[0069] After preliminary relaxation of the initial structure, the model temperature and pressure after relaxation are set to the target temperature and target pressure, and the relaxation time is set to simulate the state of the polymer PE / PP after melt blending.

[0070] S130. Using a full-atom molecular chain model of the target PE and the target PP, at a target temperature and a target pressure, simulate the melt blending of the target PE and the target PP, and obtain dissipative particle dynamics data of the target PE and the target PP.

[0071] Specifically, S130 can first obtain the full-atom molecular chain model of the target PE and the target PP, simulate the melt blending process of the target PE and the target PP at the target temperature and the target pressure, and simulate the intramolecular interaction energy E in the system. intra and the total potential energy E of all molecules in the simulation system total ; Then the intramolecular interaction energy E in the simulation system intra and the total potential energy E of all molecules in the simulation system total Subtract the cohesive energy E of the target PE and target PP melt blending process under the target temperature and target pressure. coh Then, according to the full-atom molecular chain model of the target PE and the target PP, the cohesive energy E of the melt blending process of the target PE and the target PP is simulated at the target temperature and the target pressure. coh , and the solubility parameter δ and Flory-Huggins parameter χ ij ; Then according to the solubility parameter δ and Flory-Huggins parameter χ ij , combined with the density of the simulation system, the repulsive force parameters of the dissipative particle dynamics simulation are obtained; and the number average degree of polymerization of the target PE and the target PP are divided by the characteristic ratio of the target PE and the target PP to obtain the bead chain model length of the dissipative particle dynamics simulation; the above-obtained data are used as the dissipative particle dynamics data of the target PE and the target PP.

[0072] S140. According to the dissipative particle dynamics data of the target PE and the target PP, a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics is established.

[0073] In this embodiment, S140 simulates the polymer blending process under melt blending by establishing a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics. The number density of the system is set to 3, and the simulation is performed using the NVE ensemble. The energy unit of the system is K B T, mass unit m, length unit r c Both are set to 1. The PE / PP polymer melt blending bead chain model uses the Harmonic potential with a coefficient of 4.0. The dissipation factor and noise intensity are set to 4.5 and 3 respectively. The simulation box size is: L x ×L y ×L z =30×30×60r c 3 , the total number of DPD beads in the system remained unchanged at 162,000.

[0074] S150. Through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, at the target temperature and target pressure, the two-phase diffusion and two-phase separation of the target PE and the target PP in the melt blending process are simulated to obtain the interfacial tension of the PE / PP melt blending system to reach equilibrium.

[0075] S160. PE-PP compatibilizers with different molecular structures are added to the PE / PP melt blending system respectively, and the influence of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP is simulated to obtain the interfacial tension of the PE / PP melt blending system reaching equilibrium after the PE-PP compatibilizers with different molecular structures are added respectively.

[0076] The expression of interfacial tension is:

[0077]

[0078] In the expression of interfacial tension, γ represents interfacial tension, and the interfacial tension value is recorded as γ 0 , L z represents the simulation box size parameter, P zz represents the component of pressure in the z direction, P xx represents the component of pressure in the x direction, P yy Represents the component of pressure in the y direction.

[0079] When performing DPD simulation in steps S150 and S160, simulation data can be collected in real time to obtain the components of pressure in the x, y, and z directions during the simulation process, and then the interfacial tension expression is used to obtain the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures.

[0080] In addition, Ovito software or VMD software can be used to visualize the DPD polymer melt blending process.

[0081] S170. Analyze the interfacial tension of the PE / PP melt blending system to reach equilibrium before and after adding the PE-PP compatibilizer and after adding PE-PP compatibilizers with different molecular structures, and screen out the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP.

[0082] When adding PE-PP compatibilizers with different molecular structures to the PE / PP melt blending system, the concentrations of the PE-PP compatibilizers with different molecular structures can be made the same first to quantitatively explore the effects of the PE-PP compatibilizers with different molecular structures on the PE / PP melt blending. The molecular structures of the added PE-PP compatibilizers can be as follows: Figure 2 To quantitatively compare the differences in PE-PP copolymer compatibilizer molecules, all copolymer DPD chain lengths were equal and kept constant.

[0083] After obtaining the interfacial tension of the PE / PP melt blend system when PE-PP compatibilizers with different molecular structures are added respectively to reach equilibrium, the compatibility efficiency of various PE-PP compatibilizers can be obtained accordingly: 1-γ / γ 0 (γ, γ 0 They represent the interfacial tension of the PE / PP melt blend system before and after the addition of the PE-PP compatibilizer or after the addition of PE-PP compatibilizers with different molecular structures, that is, the interfacial tension of the PE / PP melt blend system before and after the change, and the compatibilization efficiency is taken as the molecular block number n of the PE-PP compatibilizer. b The function of can be used to compare the effects of differences in molecular structure of compatibilizers on PE / PP melt blending at the same concentration, so as to screen PE-PP compatibilizers with suitable molecular structures that meet the melt blending requirements of target PE and target PP (for example, the compatibility efficiency reaches a certain preset range).

[0084] Furthermore, this embodiment also explores the addition of different concentrations of PE-PP compatibilizers to the PE / PP melt blending system, simulates the influence of different concentrations of PE-PP compatibilizers on the melt blending process of the target PE and the target PP, and obtains the equilibrium interfacial tension of the PE / PP melt blending system under different concentrations of PE-PP compatibilizers; and when analyzing the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures, combined with the equilibrium interfacial tension of the PE / PP melt blending system under different concentrations of PE-PP compatibilizers, further screens out PE-PP compatibilizers that meet the melt blending requirements of the target PE and the target PP.

[0085] Because the PE-PP compatibilizer added in the DPD simulation moves for a long time at a low concentration, the molecules tend to be distributed at the interface. Therefore, when discussing its concentration, the interface concentration can better describe its content in the system. The interface concentration is defined as: φ = (n c l c ) / I CS , where n c is the number of copolymer molecules at the interface, l c For its chain length, I cs The cross-sectional area of ​​the simulated box can be changed by changing the number of added compatibilizer molecules to change the size of the interface concentration φ. The effect of the compatibilizer molecule concentration on the interfacial tension of the system was investigated. In this example, the number of PE-PP molecules added was 36, 180, and 360.

[0086] In one embodiment, after adding the PE-PP compatibilizer to the PE / PP melt blending system, the diffusion and distribution of the PE-PP compatibilizer at the interface and bulk of the PE / PP melt blending system can be obtained to obtain the relationship between the conformation of the PE-PP compatibilizer and the interfacial tension. That is, based on step S110-170, the PE-PP compatibilizer added to the PE / PP melt blending system is further analyzed to calculate the interface distribution and mean square gyration radius ratio of the PE-PP compatibilizer in the PE / PP melt blending system, explore the thermodynamic mechanism model of the PE / PP / PE-PP system, and analyze the mechanism of the volume expansion process.

[0087] Specifically, the density distribution of PE-PP compatibilizer (copolymer molecules) in the PE / PP melt blend system can be realized by calculating the number distribution of PE-PP compatibilizer perpendicular to the interface direction. The mean square gyration radius of the polymer chain can reflect the changes in the symmetry of the copolymer molecular structure and the chain conformation, which is calculated by the formula: where r j iis the coordinate of the jth bead in the ith copolymer molecule, r cm i is the coordinate of the mass center of the ith copolymer. To characterize the stretching of the copolymer molecular chain along the x, y, and z directions, the three components of the square of the radius of gyration R are calculated. g,x 2 , R g,y 2 and R g,z 2 You can use R g,z 2 Indicates the extension degree of the molecular chain in the direction perpendicular to the interface, and R g,xy 2 Indicates the extension degree of the molecular chain in the direction parallel to the interface, where R g,xy 2 The calculation formula is: To understand the unfavorable repulsive interaction between PE and PP polymer molecules, the radial distribution function g ab (r) is used to characterize the probability of finding bead b near bead a. At the same time, by integrating it, the coordination number distribution of the polymer molecule can be obtained: Quantitative characterization of unfavorable contacts between polymers.

[0088] In one embodiment, this embodiment can also use molten polypropylene as solvent and molten PE-PP copolymer molecules as solute to establish a PP / PE-PP polymer melt blending model to study the micelle formation process of PE-PP copolymer molecules in a single polymer phase. That is, on the basis of step S110-170, PE-PP copolymer molecules are added to the PP phase to establish a simulation system for the micelle formation of PE-PP copolymer molecules in the PP bulk phase, and by exploring the mechanism of micelle formation of multi-block copolymer molecules and grafted copolymer molecules, the mass transfer process of the PE-PP copolymer compatibilizer molecules in the system is studied to regulate the structure evolution law of the system.

[0089] Specifically, in order to reduce the amount of calculation, the PP and PE-PP polymer melt mixing model can be remodeled, using only half of the aforementioned box size, the box size is L x ×L y ×L z =30×30×30r c 3 The total number of beads in the system remained unchanged at 81,000. The other simulation steps were consistent with the above steps. The concentration of PE-PP copolymer in the PP bulk phase was changed by changing the number of added PE-PP copolymer molecules. Figure 3 This is a diagram of the process of PE-PP copolymer molecules forming micelles in the PP phase.

[0090] The process of waste plastic blend expansion is a complex interface distribution and mass transfer diffusion process that occurs in the blend medium. Existing copolymer compatibilizer design research is often based only on the change of interfacial tension at interface equilibrium. The obtained high-quality compatibilizer may aggregate to form micelles during mass transfer diffusion, which cannot achieve the expected effect. How to comprehensively consider the competition and coupling relationship between the two processes of interface distribution and mass transfer diffusion is particularly important. To this end, the present invention analyzes the law of change in the properties of the blend system under the action of multiple factors and multiple processes, and uses this to explain the mechanism of change in the interfacial mixing free energy of the system, and to explain the thermodynamic nature of the interface distribution and mass transfer diffusion involved in the process of blend expansion, and then clarify the copolymer block structure design and regulation mechanism with high compatibility efficiency as the goal. Combined with thermodynamic analysis, the structural optimization mechanism of the compatibilizer with strong interface distribution ability and low micelle formation tendency is explained, which ultimately provides a theoretical basis for the development and creation of transformative and subversive compatibilizers for high-value recovery of plastics.

[0091] The plastic volume expansion and recycling simulation method based on dissipative particle dynamics provided by the present invention has the following advantages:

[0092] (1) Compared with all-atom molecular dynamics, this method can describe the process of polymer melt blending on a larger time and space scale, and clearly show the changes in molecular structure and system interface during polymer melt blending, which is beyond the reach of all-atom molecular dynamics simulation.

[0093] (2) This method proposes a universal design method for adding copolymer compatibilizer molecules during the recycling process of blended polymers, which can greatly shorten the development cycle of new compatibilizer molecules and provide a new method for the design and development of compatibilizers.

[0094] (3) This method uses DPD simulation to accurately design the structure of the copolymer compatibilizer and conducts research on the volume expansion and recovery of PE / PP blends. It can clarify the influence mechanism of PE / PP blend components and PE-PP copolymer structure on the distribution of interfacial equilibrium spatial conformation and provide a basis for the distribution of copolymer molecules at the interface.

[0095] (4) The DPD simulation method used in this method can analyze the deep evolution of the copolymer block structure and clarify the micelle formation law to enhance mass transfer. At the same time, it can intuitively study the spatial conformation of the copolymer and, combined with the enthalpy-entropy change of the copolymer, regulate the interfacial distribution process of the compatibilizer.

[0096] The following is a description of the plastic volume expansion and recycling simulation system based on dissipative particle dynamics provided by the present invention. The plastic volume expansion and recycling simulation system based on dissipative particle dynamics described below and the plastic volume expansion and recycling simulation method based on dissipative particle dynamics described above can be referenced to each other.

[0097] Reference Figure 3The present invention provides a plastic volume expansion and recycling simulation system based on dissipative particle dynamics, which may include:

[0098] The first establishment module is used to: establish a full-atom molecular chain model of the target PE and the target PP based on the atomic species of the target PE and the target PP, and set full-atom molecular dynamics simulation parameters for the full-atom molecular chain model of the target PE and the target PP;

[0099] A relaxation module is used to: relax the blend of the target PE and the target PP to the target equilibrium structure by using the full-atom molecular chain model of the target PE and the target PP and the relaxation method to obtain the target temperature and the target pressure;

[0100] The first simulation module is used to: simulate the melt blending of the target PE and the target PP at the target temperature and the target pressure through the full-atom molecular chain model of the target PE and the target PP, and obtain the dissipative particle dynamics data of the target PE and the target PP;

[0101] The second establishment module is used to: establish a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics according to the dissipative particle dynamics data of the target PE and the target PP;

[0102] The second simulation module is used to: simulate the two-phase diffusion and two-phase separation of target PE and target PP in the melt blending process at the target temperature and target pressure through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, and obtain the interfacial tension of the PE / PP melt blending system to reach equilibrium;

[0103] The third simulation module is used to: respectively add PE-PP compatibilizers with different molecular structures into the PE / PP melt blending system, simulate the influence of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and obtain the interfacial tension of the PE / PP melt blending system reaching equilibrium after the PE-PP compatibilizers with different molecular structures are respectively added;

[0104] The analysis module is used to analyze the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures, and screen out PE-PP compatibilizers that meet the melt blending requirements of the target PE and the target PP.

[0105] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the plastic volume expansion recycling simulation method based on dissipative particle dynamics, and the method includes:

[0106] Based on the atomic species of the target PE and the target PP, a full-atom molecular chain model of the target PE and the target PP is established, and full-atom molecular dynamics simulation parameters are set for the full-atom molecular chain model of the target PE and the target PP;

[0107] Through the full-atom molecular chain model of the target PE and the target PP, the blend of the target PE and the target PP is relaxed to the target equilibrium structure by using the relaxation method to obtain the target temperature and the target pressure;

[0108] Through the full-atom molecular chain model of the target PE and the target PP, the melt blending of the target PE and the target PP is simulated at the target temperature and the target pressure, and the dissipative particle dynamics data of the target PE and the target PP are obtained;

[0109] According to the dissipative particle dynamics data of target PE and target PP, a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics was established;

[0110] Through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, the two-phase diffusion and two-phase separation of the target PE and target PP in the melt blending process are simulated at the target temperature and target pressure, and the interfacial tension of the PE / PP melt blending system reaching equilibrium is obtained;

[0111] PE-PP compatibilizers with different molecular structures were added to the PE / PP melt blending system to simulate the effects of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and the interfacial tension of the PE / PP melt blending system reached equilibrium after the PE-PP compatibilizers with different molecular structures were added.

[0112] The interfacial tension of the PE / PP melt blending system reached equilibrium before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures was analyzed, and the PE-PP compatibilizer that met the melt blending requirements of the target PE and target PP was screened.

[0113] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0114] On the other hand, the present invention further provides a computer program product, the computer program product comprising a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the plastic volume expansion and recycling simulation method based on dissipative particle dynamics provided by the above methods, the method comprising:

[0115] Based on the atomic species of the target PE and the target PP, a full-atom molecular chain model of the target PE and the target PP is established, and full-atom molecular dynamics simulation parameters are set for the full-atom molecular chain model of the target PE and the target PP;

[0116] Through the full-atom molecular chain model of the target PE and the target PP, the blend of the target PE and the target PP is relaxed to the target equilibrium structure by using the relaxation method to obtain the target temperature and the target pressure;

[0117] Through the full-atom molecular chain model of the target PE and the target PP, the melt blending of the target PE and the target PP is simulated at the target temperature and the target pressure, and the dissipative particle dynamics data of the target PE and the target PP are obtained;

[0118] According to the dissipative particle dynamics data of target PE and target PP, a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics was established;

[0119] Through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, the two-phase diffusion and two-phase separation of the target PE and target PP in the melt blending process are simulated at the target temperature and target pressure, and the interfacial tension of the PE / PP melt blending system reaching equilibrium is obtained;

[0120] PE-PP compatibilizers with different molecular structures were added to the PE / PP melt blending system to simulate the effects of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and the interfacial tension of the PE / PP melt blending system reached equilibrium after the PE-PP compatibilizers with different molecular structures were added.

[0121] The interfacial tension of the PE / PP melt blending system reached equilibrium before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures was analyzed, and the PE-PP compatibilizer that met the melt blending requirements of the target PE and target PP was screened.

[0122] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the plastic volume expansion and recycling simulation method based on dissipative particle dynamics provided by the above methods, the method comprising:

[0123] Based on the atomic species of the target PE and the target PP, a full-atom molecular chain model of the target PE and the target PP is established, and full-atom molecular dynamics simulation parameters are set for the full-atom molecular chain model of the target PE and the target PP;

[0124] Through the full-atom molecular chain model of the target PE and the target PP, the blend of the target PE and the target PP is relaxed to the target equilibrium structure by using the relaxation method to obtain the target temperature and the target pressure;

[0125] Through the full-atom molecular chain model of the target PE and the target PP, the melt blending of the target PE and the target PP is simulated at the target temperature and the target pressure, and the dissipative particle dynamics data of the target PE and the target PP are obtained;

[0126] According to the dissipative particle dynamics data of target PE and target PP, a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics was established;

[0127] Through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, the two-phase diffusion and two-phase separation of the target PE and target PP in the melt blending process are simulated at the target temperature and target pressure, and the interfacial tension of the PE / PP melt blending system reaching equilibrium is obtained;

[0128] PE-PP compatibilizers with different molecular structures were added to the PE / PP melt blending system to simulate the effects of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and the interfacial tension of the PE / PP melt blending system reached equilibrium after the PE-PP compatibilizers with different molecular structures were added.

[0129] The interfacial tension of the PE / PP melt blending system reached equilibrium before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures was analyzed, and the PE-PP compatibilizer that met the melt blending requirements of the target PE and target PP was screened.

[0130] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0131] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A plastic volume expansion and recycling simulation method based on dissipative particle dynamics, characterized in that: include: Based on the atomic species of the target PE and the target PP, a full-atom molecular chain model of the target PE and the target PP is established, and full-atom molecular dynamics simulation parameters are set for the full-atom molecular chain model of the target PE and the target PP; Through the full-atom molecular chain model of the target PE and the target PP, the blend of the target PE and the target PP is relaxed to the target equilibrium structure by using the relaxation method to obtain the target temperature and the target pressure; Through the full-atom molecular chain model of the target PE and the target PP, the melt blending of the target PE and the target PP is simulated at the target temperature and the target pressure, and the dissipative particle dynamics data of the target PE and the target PP are obtained; According to the dissipative particle dynamics data of target PE and target PP, a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics was established; Through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, the two-phase diffusion and two-phase separation of the target PE and target PP in the melt blending process are simulated at the target temperature and target pressure, and the interfacial tension of the PE / PP melt blending system reaching equilibrium is obtained; PE-PP compatibilizers with different molecular structures were added to the PE / PP melt blending system to simulate the effects of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and the interfacial tension of the PE / PP melt blending system reached equilibrium after the PE-PP compatibilizers with different molecular structures were added. The interfacial tension of the PE / PP melt blending system reached equilibrium before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures was analyzed, and the PE-PP compatibilizer that met the melt blending requirements of the target PE and target PP was screened.

2. The plastic volume expansion and recycling simulation method based on dissipative particle dynamics according to claim 1 is characterized in that: The method simulates the melt blending of the target PE and the target PP at the target temperature and the target pressure through the full-atom molecular chain model of the target PE and the target PP, and obtains the dissipative particle dynamics data of the target PE and the target PP, including: The full-atom molecular chain model of the target PE and the target PP is obtained to simulate the cohesive energy of the melt blending process of the target PE and the target PP at the target temperature and the target pressure; According to the full-atom molecular chain model of the target PE and the target PP, the cohesive energy of the melt blending process of the target PE and the target PP is simulated at the target temperature and the target pressure, and the repulsive force parameters of the dissipative particle dynamics simulation are obtained; The number average degree of polymerization and characteristic ratio of the target PE and the target PP are obtained, and the length of the bead chain model for dissipative particle dynamics simulation is obtained according to the number average degree of polymerization and characteristic ratio of the target PE and the target PP.

3. The plastic volume expansion and recycling simulation method based on dissipative particle dynamics according to claim 2 is characterized in that: The method of obtaining the full-atom molecular chain model of the target PE and the target PP and simulating the cohesive energy of the melt blending process of the target PE and the target PP at the target temperature and the target pressure includes: The full-atom molecular chain model of the target PE and the target PP is obtained. The melt blending process of the target PE and the target PP is simulated at the target temperature and the target pressure, and the intramolecular interaction energy E in the simulated system is intra and the total potential energy E of all molecules in the simulation system total ; The intramolecular interaction energy E in the simulated system intra and the total potential energy E of all molecules in the simulation system total Subtract the cohesive energy E of the target PE and target PP melt blending process at the target temperature and target pressure. coh .

4. The plastic volume expansion and recycling simulation method based on dissipative particle dynamics according to claim 3 is characterized in that: The method of simulating the cohesive energy of the melt blending process of the target PE and the target PP at the target temperature and the target pressure according to the full-atom molecular chain model of the target PE and the target PP to obtain the repulsive force parameters of the dissipative particle dynamics simulation includes: The cohesive energy E of the melt blending process of target PE and target PP is simulated at the target temperature and target pressure according to the full-atom molecular chain model of target PE and target PP. coh , we get the solubility parameter δ and the Flory-Hukins parameter χ i j ; According to the solubility parameter δ and the Flory-Hukins parameter χ ij , combined with the density of the simulated system, to obtain the repulsive force parameters for the dissipative particle dynamics simulation; and / or, The step of obtaining the number average degree of polymerization and characteristic ratio of the target PE and the target PP, and obtaining the length of the bead chain model for dissipative particle dynamics simulation according to the number average degree of polymerization and characteristic ratio of the target PE and the target PP, comprises: The number average degree of polymerization of the target PE and the target PP is divided by the characteristic ratio of the target PE and the target PP to obtain the length of the bead chain model for the dissipative particle dynamics simulation.

5. The plastic volume expansion and recycling simulation method based on dissipative particle dynamics according to any one of claims 1 to 4, characterized in that: The expression of interfacial tension is: In the expression of interfacial tension, γ represents interfacial tension, L z represents the simulation box size parameter, P zz represents the component of pressure in the z direction, P xx represents the component of pressure in the x direction, P yy Represents the component of pressure in the y direction.

6. The plastic volume expansion and recycling simulation method based on dissipative particle dynamics according to claim 5 is characterized in that: The method of analyzing the interfacial tension of the PE / PP melt blending system before and after adding the PE-PP compatibilizer and after adding the PE-PP compatibilizers with different molecular structures to achieve equilibrium, and screening the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP, includes: According to the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of different molecular structures, the compatibility efficiency of the PE / PP melt blending system before and after the addition of the PE-PP compatibilizer and after the addition of different molecular structures are obtained, and the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP is screened.

7. The plastic volume expansion and recycling simulation method based on dissipative particle dynamics according to any one of claims 1 to 4, characterized in that: Also includes: Different concentrations of PE-PP compatibilizers were added to the PE / PP melt blending system to simulate the effects of different concentrations of PE-PP compatibilizers on the melt blending process of target PE and target PP, and the interfacial tensions of the PE / PP melt blending system at different concentrations of PE-PP compatibilizers were obtained; After analyzing the equilibrium interfacial tension of the PE / PP melt blending system before and after adding the PE-PP compatibilizer and after adding the PE-PP compatibilizers with different molecular structures, combined with the equilibrium interfacial tension of the PE / PP melt blending system at different concentrations of the PE-PP compatibilizer, the PE-PP compatibilizer that meets the melt blending requirements of the target PE and the target PP is further screened; and / or, Also includes: After adding a PE-PP compatibilizer to the PE / PP melt blending system, the diffusion and distribution of the PE-PP compatibilizer at the interface and bulk of the PE / PP melt blending system are obtained to obtain the relationship between the conformation of the PE-PP compatibilizer and the interfacial tension; and / or, Also includes: Using molten polypropylene as solvent and molten PE-PP copolymer molecules as solute, a PP / PE-PP polymer melt blending model was established, and the micelle formation process of PE-PP copolymer molecules in a single polymer phase was studied.

8. A plastic volume expansion and recycling simulation system based on dissipative particle dynamics, characterized in that: include: The first establishment module is used to: establish a full-atom molecular chain model of the target PE and the target PP based on the atomic species of the target PE and the target PP, and set full-atom molecular dynamics simulation parameters for the full-atom molecular chain model of the target PE and the target PP; A relaxation module is used to: relax the blend of the target PE and the target PP to the target equilibrium structure by using the full-atom molecular chain model of the target PE and the target PP and the relaxation method to obtain the target temperature and the target pressure; The first simulation module is used to: simulate the melt blending of the target PE and the target PP at the target temperature and the target pressure through the full-atom molecular chain model of the target PE and the target PP, and obtain the dissipative particle dynamics data of the target PE and the target PP; The second establishment module is used to: establish a PE / PP polymer melt blending bead chain model based on dissipative particle dynamics according to the dissipative particle dynamics data of the target PE and the target PP; The second simulation module is used to: simulate the two-phase diffusion and two-phase separation of target PE and target PP in the melt blending process at the target temperature and target pressure through the PE / PP polymer melt blending bead chain model based on dissipative particle dynamics, and obtain the interfacial tension of the PE / PP melt blending system to reach equilibrium; The third simulation module is used to: respectively add PE-PP compatibilizers with different molecular structures into the PE / PP melt blending system, simulate the influence of the PE-PP compatibilizers with different molecular structures on the melt blending process of the target PE and the target PP, and obtain the interfacial tension of the PE / PP melt blending system reaching equilibrium after the PE-PP compatibilizers with different molecular structures are respectively added; The analysis module is used to analyze the equilibrium interfacial tension of the PE / PP melt blending system before and after the addition of PE-PP compatibilizer and after the addition of PE-PP compatibilizers with different molecular structures, and screen out PE-PP compatibilizers that meet the melt blending requirements of the target PE and the target PP.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the plastic volume expansion and recycling simulation method based on dissipative particle dynamics as described in any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the plastic volume expansion and recycling simulation method based on dissipative particle dynamics as described in any one of claims 1 to 7 is implemented.

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