A high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin

Abstract

This invention relates to a high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin. First, a surface cell model of the polyurethane to be tested is constructed using Material Studio software. Then, the LAMMPS module in Matclid+ is used to further optimize the constructed surface cell model of the polyurethane to be tested. Finally, the correspondence between the polyurethane structure and the glass transition temperature is quickly established, reducing unnecessary physical experiments and enabling targeted experimental research and development of polyurethane resin. Comparison with experimental values ​​shows that this high-throughput calculation method has good predictive accuracy. Through its unique high-throughput calculation method, it can also calculate the glass transition temperature of polyurethane systems with various raw material components, greatly saving experimental time and costs.

Description

Technical Field

[0001] This invention belongs to the field of polymer material simulation technology, specifically relating to a high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin. Background Technology

[0002] The excellent performance of polyurethane resin depends on its complex chemical structure. Traditional experimental methods such as FTIR, XPS, and SEM are difficult to accurately characterize its molecular structure, arrangement, and cross-linking structure. Establishing the correspondence between resin matrix structure and performance using experimental methods has the disadvantages of long cycle time, low efficiency, and high cost.

[0003] Glass transition temperature (GVT) is a crucial thermodynamic property of polyurethane resins, especially important in the development of low-temperature curing polyurethane resins. It's essential to systematically study the low-temperature film-forming effect of resins starting from the GVT. Therefore, accurate calculation of the GVT is significant for exploring the relationship between molecular structure and macroscopic properties. Currently, the testing of polyurethane resin GVT often involves physical experiments on multiple resins followed by testing with equipment such as thermal analyzers. This approach fails to allow for rapid screening of different resin structures simultaneously. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that it provides a high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin, which can solve the technical problems of high raw material cost and inability to prepare multiple polyurethane resins and efficiently complete the glass transition temperature test in a short time in the experimental analysis method of polyurethane resin.

[0005] The technical solution adopted by this invention to solve its technical problem is: a high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin, comprising the following steps:

[0006] Step 1: Use Materials Studio software to build a polyurethane surface cell model;

[0007] 1.1. A polyurethane molecular chain with a molar ratio of hydroxyl component to isocyanate component of 1:1 was constructed using the 3D Atomistic component of Materials Studio.

[0008] 1.2. The polyurethane surface model was constructed using the Amorphous Cell module in Materials Studio. The density was set to 1.05, the precision to Ultra-fine, the force field to Dreiding, the charge configuration to Change using Gasteiger, the structure optimization algorithm to Conjugate gradient, the energy convergence criterion to 0.00002, the force field convergence criterion to 0.001, and no cell optimization was selected. Five polyurethane molecular chains were used for filling. The resulting polyurethane surface cell model was then saved as a CIF file.

[0009] Step 2: Input the completed polyurethane surface cell model into the LAMMPS module in Matcloud+, and use the LAMMPS module to further optimize the completed polyurethane surface cell model.

[0010] 2.1. Using the LAMMPS module in Matcloud+, a high-throughput glass transition temperature calculation workflow was employed, and then different polyurethane surface cell models were imported.

[0011] 2.2 Force field assignment for the polyurethane surface cell model; wherein, the force field type is selected as Molecular, the Gasteiger method is used to calculate the charge, the cutoff distance of the van der Waals interaction is set to 12, and AutoAssign is selected.

[0012] 2.3 Optimize the structure of the polyurethane surface cell model with the force field assigned in 2.2;

[0013] 2.4. The polyurethane surface cell model with optimized structure in 2.3 was subjected to multiple heating and annealing processes;

[0014] 2.5. Based on the heating and annealing process described in 2.4, further dynamic simulations were performed on the polyurethane surface cell model;

[0015] Step 3: Calculate the glass transition temperature of the optimized polyurethane surface cell model in the LAMMPS module;

[0016] 3.1 Based on the kinetic calculations in 2.5, the glass transition temperature of the polyurethane surface cell model is calculated;

[0017] 3.2 After calculating the glass transition temperature, the numerical values ​​of the volume of the polyurethane surface cell model with different structures at different temperatures were obtained;

[0018] 3.3. Plot a scatter plot with volume as the vertical axis and temperature as the horizontal axis. Then, perform piecewise linear fitting on the points on both sides of the inflection point in the scatter plot to obtain two intersecting straight lines. The temperature at the intersection of the two straight lines is the glass transition temperature of the polyurethane resin.

[0019] Furthermore, the hydroxyl component is one or more of 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, polyether glycol, polycaprolactone glycol, polyester glycol, and polycarbonate glycol.

[0020] Furthermore, the isocyanate component is one or more of isoflurane diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4-toluene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate.

[0021] Furthermore, the polyurethane surface cell model is heated and annealed three times.

[0022] Furthermore, the specific parameters for the structural optimization are as follows: the structural optimization algorithm is selected as Conjugate gradient, the energy convergence criterion is selected as 0.0001, the force field convergence criterion is selected as 0.000001, the maximum number of iterations for structural optimization is 1000, the maximum number of energy / force calculations is 10000, the optimized cell parameters are selected, the maximum allowable volume change value in a single iteration is set to 0.0005, and the applied pressure is selected as Isostatic Pressure.

[0023] Furthermore, the parameters set during the heating process are as follows: the kinetic simulation ensemble is NPT, the initial temperature is set to 200K, the final temperature is set to 800K, the temperature control method is Nose-Hoover temperature control, the temperature control frequency is set to 100, the initial pressure and the final pressure are both set to 1 atmosphere, the pressure control method is Nose-Hoover pressure control, the pressure control frequency is set to 1000, the time step is 1fs, the total simulation time is 200,000fs, the total number of simulation steps is 200,000, the initial velocity is set to Random, and the temperature is 298K; the annealing process is based on the parameters of the heating process, with the temperature reduced from 800K to 200K.

[0024] Furthermore, the parameters for the dynamic simulation are as follows: ensemble selection is NVE, time step is 1fs, total simulation time is 200,000fs, total simulation steps are 200,000, initial velocity is set to Random, and temperature is 298K.

[0025] Furthermore, the parameters for calculating the glass transition temperature are as follows: the target starting temperature is set to 450K, the target ending temperature is set to 100K, the temperature interval is set to 25K, the equilibrium time at each temperature is 100ps, and the output quantities during the glass transition temperature calculation are selected as Temperature and Volume.

[0026] The beneficial effects of this invention are:

[0027] This invention discloses a high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin. First, a surface cell model of the polyurethane to be tested is constructed using MaterialsStudio software. Then, the LAMMPS module in Matcloud+ is used to further optimize the constructed surface cell model of the polyurethane to be tested. Finally, the correspondence between the polyurethane structure and the glass transition temperature is quickly established. This not only reduces unnecessary physical experiments but also allows for targeted experimental research and development of polyurethane resin. Furthermore, comparison with experimental values ​​shows that this high-throughput calculation method has good predictive accuracy. Through its unique high-throughput calculation method, it can also calculate polyurethane resins with various raw material composition systems, greatly saving experimental time and costs. Attached Figure Description

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Figure 1 The results are for the glass transition temperature test of PU-1;

[0030] Figure 2 The glass transition temperature test results for PU-1A;

[0031] Figure 3 The glass transition temperature test results for PU-2;

[0032] Figure 4 The glass transition temperature test results for PU-2A are shown.

[0033] Figure 5 The results are for the glass transition temperature test of PU-3;

[0034] Figure 6 The glass transition temperature test results for PU-3A are shown.

[0035] Figure 7 The results are for the glass transition temperature test of PU-4;

[0036] Figure 8 The results are for the glass transition temperature test of PU-4A. Detailed Implementation

[0037] The computer simulation software used in this invention includes MaterialsStudio developed by Accelrys Inc. in the United States and the MatCloud+ intelligent big data cloud platform for materials developed by Beijing Maigaocai Cloud Technology Co., Ltd. MaterialsStudio can efficiently model polymer structures, while the MatCloud+ intelligent big data cloud platform integrates LAMMPS software. LAMMPS can perform molecular dynamics calculations on the structural model built by MaterialsStudio at different system temperatures, based on the structural model built by MaterialsStudio, and finally obtain the changes in the characteristic volume and temperature curve of the structural model built by MaterialsStudio.

[0038] The present invention provides a high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin, comprising the following steps:

[0039] Step 1: Use Materials Studio software to build a polyurethane surface cell model;

[0040] 1.1. Using the 3D Atomistic component of Materials Studio, a polyurethane molecular chain with a molar ratio of hydroxyl component to isocyanate component of 1:1 is constructed; wherein the hydroxyl component can be one or more of 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, polyether glycol, polycaprolactone glycol, polyester glycol, and polycarbonate glycol; and the isocyanate component can be one or more of isoflurane diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4-toluene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate.

[0041] 1.2. The polyurethane surface model was constructed using the Amorphous Cell module in Materials Studio. The settings were: density: 1.05, precision: Ultra-fine, force field: Dreiding, charge configuration: Change using Gasteiger, structure optimization algorithm: Conjugate gradient, energy convergence criterion: 0.00002, force field convergence criterion: 0.001, no cell optimization was selected, and five polyurethane molecular chains were used for filling. The resulting polyurethane surface cell model was then saved as a CIF file.

[0042] Step 2: Input the completed polyurethane surface cell model into the LAMMPS module in Matcloud+, and use the LAMMPS module to further optimize the completed polyurethane surface cell model.

[0043] 2.1. Using the LAMMPS module in Matcloud+, a high-throughput glass transition temperature calculation workflow was employed, and then different polyurethane surface cell models were imported.

[0044] 2.2 Force field assignment for the polyurethane surface cell model; wherein, the force field type is selected as Molecular, the Gasteiger method is used to calculate the charge, the cutoff distance of the van der Waals interaction is set to 12, and Auto Assign is selected.

[0045] 2.3. Perform structural optimization on the polyurethane surface cell model with force fields assigned in 2.2. The structural optimization algorithm selected is Conjugate gradient, the energy convergence criterion is 0.0001, the force field convergence criterion is 0.000001, the maximum number of iterations for structural optimization is 1000, the maximum number of energy / force calculations is 10000, the cell parameters are optimized, the maximum allowable volume change per iteration is set to 0.0005, and the applied pressure is Isostatic Pressure. Structural optimization ensures that the polyurethane surface cell model reaches its most stable state before dynamic simulation.

[0046] 2.4. The polyurethane surface cell model optimized in section 2.3 underwent three heating and annealing processes. The parameters set during the heating process were as follows: NPT was selected for the kinetic simulation ensemble; the initial temperature was set to 200K and the final temperature to 800K; Nose-Hoover temperature control was selected as the temperature control method; the temperature control frequency was set to 100; both the initial and final pressures were set to one atmosphere; Nose-Hoover pressure control was selected as the pressure control method; the pressure control frequency was set to 1000; the time step was 1 fs; the total simulation time was 200,000 fs; the total number of simulation steps was 200,000; the initial velocity was set to Random; and the temperature was 298K. The annealing process involved reducing the temperature from 800K to 200K based on the heating parameters. Through these three heating and annealing processes, localized high-energy points within the polyurethane surface cell model were eliminated, resulting in a more rational molecular configuration.

[0047] 2.5. Based on the heating and annealing in 2.4, the dynamic simulation of the polyurethane surface cell model is continued; where the ensemble is NVE, the time step is 1fs, the total simulation time is 200000fs, the total number of simulation steps is 200000, the initial velocity is set to Random, and the temperature is 298K.

[0048] Step 3: Calculate the glass transition temperature of the optimized polyurethane surface cell model in the LAMMPS module;

[0049] 3.1 Based on the kinetic calculations in 2.5, the glass transition temperature of the polyurethane surface cell model is calculated; the target initial temperature is set to 450K, the target final temperature is set to 100K, the temperature interval is set to 25K, the equilibrium time at each temperature is 100ps, and the output quantities during the glass transition temperature calculation are selected as Temperature and Volume.

[0050] 3.2 After calculating the glass transition temperature, the numerical values ​​of the volume of the polyurethane surface cell model with different structures at different temperatures were obtained;

[0051] 3.3 Using the values ​​obtained in 3.2, plot a scatter plot with volume as the ordinate and temperature as the abscissa. Then, perform piecewise linear fitting on the points on both sides of the inflection point in the scatter plot to obtain two intersecting straight lines. The temperature at the intersection of the two straight lines is the glass transition temperature of the polyurethane resin.

[0052] Example

[0053] A polyurethane molecular chain with a molar ratio of 3:1:2 of 2,4-toluene diisocyanate, polycarbonate diol (relative molecular mass of 983) and 1,2-propanediol was constructed using the 3D Atomistic component of Materials Studio and named 1# polyurethane molecular chain.

[0054] Similarly, a polyurethane molecular chain with a molar ratio of isoflurone diisocyanate, polybutylene adipate diol (relative molecular mass of 1091) and 1,4-butanediol of 4:1:3 was established and named polyurethane molecular chain #2.

[0055] Similarly, a polyurethane molecular chain with a molar ratio of hexamethylene diisocyanate, polycarbonate diol (relative molecular mass of 983) and 1,4-butanediol of 4:1:3 was established and named polyurethane molecular chain #3.

[0056] Similarly, a polyurethane molecular chain with a molar ratio of 6:1:5 of 2,4-toluene diisocyanate, polypropylene glycol (relative molecular mass of 1004) and 1,4-butanediol was established and named polyurethane molecular chain #4.

[0057] The polyurethane surface model was constructed using the Amorphous Cell module in Materials Studio, with the following settings: density set to 1.05, precision set to Ultra-fine, force field set to COMPASS, charge configuration set to Change using Gasteiger, optimization geometry selected, structure optimization algorithm set to smart, energy convergence criterion set to 0.00002, force field convergence criterion set to 0.001, and cell optimization not selected.

[0058] Five polyurethane molecular chains of type 1 were selected for filling, and the resulting cell structure was saved as a CIF file named PU-1.

[0059] Five polyurethane molecular chains of type 2 were selected for filling, and the resulting cell structure was saved as a CIF file named PU-2.

[0060] Five polyurethane molecular chains of type 3 were selected for filling, and the resulting cell structure was saved as a CIF file named PU-3.

[0061] Five polyurethane molecular chains of type 4 were selected for filling, and the resulting cell structure was saved as a CIF file named PU-4.

[0062] The LAMMPS module of the Matcloud+ materials intelligent computing big data cloud platform was used to import different polyurethane surface cell models using a high-throughput glass transition temperature calculation workflow.

[0063] Force fields were assigned to the polyurethane surface cell model. The force field type was selected as Molecular, and the Gasteiger method was used to calculate the charge, with the cutoff distance for van der Waals interactions set to 12. Auto Assign was selected to assign the force fields to the structure.

[0064] Structural optimization was performed on the model with the force field pre-assigned. The Conjugate gradient algorithm was selected for structural optimization, with an energy convergence criterion of 0.0001 and a force field convergence criterion of 0.000001. The maximum number of iterations for structural optimization was 1000, and the maximum number of energy / force calculations was 10000. Here, the cell parameters were optimized, the maximum allowable volume change per iteration was set to 0.0005, and Isostatic Pressure was selected for the applied pressure.

[0065] Based on structural optimization, the polyurethane surface model was heated and annealed. The kinetic simulation ensemble was NPT, with an initial temperature of 200K and a final temperature of 800K. Heating was carried out within this temperature range, using Nose-Hoover temperature control with a control frequency of 100. Both the initial and final pressures were set to one atmosphere, with Nose-Hoover pressure control used and a control frequency of 1000. The time step was 1 fs, the total simulation time was 200,000 fs, and the total number of simulation steps was 200,000. The initial velocity was set to Random, and the temperature was 298K. The temperature was then reduced from 800K to 200K in the same manner, i.e., the annealing process, and this cycle was repeated three times.

[0066] Based on multiple heating and annealing cycles, dynamic simulations were continued, with the NVE ensemble selected. The time step was 1 fs, the total simulation time was 200,000 fs, and the total number of simulation steps was 200,000. The initial velocity was set to Random, and the temperature was 298 K.

[0067] Based on the kinetic calculations, the glass transition temperature was calculated. The target initial temperature was set to 450K, the target final temperature to 100K, the temperature interval to 25K, and the equilibrium time at each temperature to 100ps. The output parameters selected during the glass transition temperature calculation were Temperature and Volume. Then, the volumes of the polyurethane surface cell models for PU-1, PU-2, PU-3, and PU-4 at different temperatures were obtained. Scatter plots were then created on the volume (ordinate) and temperature (abscissa) data for PU-1, PU-2, PU-3, and PU-4, as shown below. Figure 1 , Figure 3 , Figure 5 as well as Figure 7 As shown, the points on both sides of the inflection point in the scatter plot are then piecewise linearly fitted to obtain two intersecting straight lines. The temperature at the intersection of the two straight lines is the glass transition temperature of the polyurethane resin. The glass transition temperatures of PU-1, PU-2, PU-3 and PU-4 are 13.59℃, 24.68℃, -30.75℃ and 48.23℃, respectively.

[0068] Comparative Example

[0069] The glass transition temperatures of the polyurethane resins numbered PU-1, PU-2, PU-3, and PU-4 in the examples were tested using experimental methods, as shown in the following steps:

[0070] Step 1: Polyurethane resins numbered PU-1, PU-2, PU-3 and PU-4 were synthesized using experimental methods;

[0071] In a four-necked flask equipped with a spherical condenser, a nitrogen inlet tube, and a stirrer, 140 g of polycarbonate diol (molecular weight 900-1100, model UH100, manufacturer: Ube Industries, Ltd., Japan), 73.08 g of 2,4-toluene diisocyanate, 42.28 g of butyl acetate, and 0.04 g of dibutyltin dilaurate were added. The mixture was reacted at 80°C for 3 h, then cooled to 40°C, and 21.28 g of 1,2-propanediol was added. The mixture was stirred for 5 min and then baked in an oven at 85°C for 12 h to obtain polyurethane resin, named PU-1A.

[0072] In a four-necked flask equipped with a spherical condenser, a nitrogen inlet tube, and a stirrer, 140g of polybutylene adipate diol (molecular weight 900-1100, model POL3112T, manufacturer: Qingdao Xinyutian Chemical Co., Ltd.), 124.32g of isoflurane diisocyanate, and 0.04g of dibutyltin dilaurate were added. The mixture was reacted at 80℃ for 3 hours, then cooled to 40℃, and 37.8g of 1,4-butanediol was added. The mixture was stirred for 5 minutes and then baked in an oven at 85℃ for 12 hours to obtain polyurethane resin, named PU-2A.

[0073] In a four-necked flask equipped with a spherical condenser, a nitrogen inlet tube, and a stirrer, 140g of polycarbonate diol (molecular weight 900-1100, model UH100, manufacturer: Ube Industries, Ltd., Japan), 94.08g of hexamethylene diisocyanate, 80g of butyl acetate, and 0.04g of dibutyltin dilaurate were added. The mixture was reacted at 80℃ for 3 hours, then cooled to 50℃, and 37.8g of 1,4-butanediol was added. The mixture was stirred for 5 minutes and then baked in an oven at 85℃ for 12 hours to obtain polyurethane resin, named PU-3A.

[0074] In a four-necked flask equipped with a spherical condenser, a nitrogen inlet tube, and a stirrer, 100g of polypropylene glycol (molecular weight 900-1100, model PPG-1000, manufacturer: Jiangsu Haian Petrochemical Plant), 104.4g of 2,4-toluene diisocyanate, and 0.04g of dibutyltin dilaurate were added. The mixture was reacted at 80℃ for 3 hours, then cooled to 40℃, and 38g of 1,2-propanediol was added. The mixture was stirred for 5 minutes and then baked in an oven at 85℃ for 12 hours to obtain polyurethane resin, named PU-4A.

[0075] Step 2: The glass transition temperatures of PU-1A, PU-2A, PU-3A, and PU-4A were determined using a DuPont 1090B thermal analyzer. The parameters were: nitrogen atmosphere, heating rate 10℃ / min, temperature range -80~100℃. The calculated glass transition temperatures of PU-1A, PU-2A, PU-3A, and PU-4A from the thermal analyzer are as follows: Figure 2 , Figure 4 , Figure 6 as well as Figure 8 As shown, the glass transition temperatures of PU-1A, PU-2A, PU-3A and PU-4A are 11.44℃, 24.6℃, -33.89℃ and 47.35℃, respectively.

[0076] From the above, we can see that the glass transition temperature (GTH) of PU-1 is 13.59℃, and that of PU-1A is 11.44℃; the GTH of PU-2 is 24.68℃, and that of PU-2A is 24.6℃; the GTH of PU-3 is -33.89℃, and that of PU-3A is -30.75℃; the GTH of PU-4 is 48.23℃, and that of PU-4A is 47.35℃. For different polyurethane resin systems, the GTH calculated using the high-throughput calculation method developed above is roughly the same as the GTH measured by the thermal analyzer in the experiment. Both methods indicate that the more linear structures in the polyurethane resin, the lower the GTH. For example, the GTH of polyurethane prepared with cyclic isocyanates (such as those containing 2,4-toluene diisocyanate or isoflurane diisocyanate) is higher than that of resins prepared with linear isocyanates (such as hexamethylene diisocyanate).

[0077] Comparison with experimental values ​​revealed that this high-throughput calculation method has good prediction accuracy, thus proving the rationality of the polyurethane surface model design and the reliability of the theoretical calculation. This method provides an efficient way to calculate the glass transition temperature of polyurethane resin. Through its unique high-throughput calculation method, it can calculate polyurethane resins with various raw material composition systems, greatly saving experimental time and costs.

[0078] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the scope of the present invention. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin, comprising the following steps: Step 1: Use Materials Studio software to build a polyurethane surface cell model; 1.

1. A polyurethane molecular chain with a molar ratio of hydroxyl component to isocyanate component of 1:1 was constructed using the 3D Atomistic component of Materials Studio. 1.2 The Amorphous Cell module in Materials Studio was used to construct the polyurethane surface model; The density was set to 1.05, the precision to Ultra-fine, the force field to Dreiding, the charge configuration to Change using Gasteiger, the structure optimization algorithm to Conjugate gradient, the energy convergence criterion to 0.00002, the force field convergence criterion to 0.001, and the cell optimization was not selected. Five polyurethane molecular chains were selected for filling, and the polyurethane surface cell model was finally saved as a CIF file. Step 2: Input the completed polyurethane surface cell model into the LAMMPS module in Matcloud+, and use the LAMMPS module to further optimize the completed polyurethane surface cell model. 2.

1. Using the LAMMPS module in Matcloud+, a high-throughput glass transition temperature calculation workflow was employed, and then different polyurethane surface cell models were imported. 2.2 Force field assignment for the polyurethane surface cell model; wherein, the force field type is selected as Molecular, the Gasteiger method is used to calculate the charge, the cutoff distance of the van der Waals interaction is set to 12, and Auto Assign is selected. 2.3 Optimize the structure of the polyurethane surface cell model with the force field assigned in 2.2; 2.

4. The polyurethane surface cell model with optimized structure in 2.3 was subjected to multiple heating and annealing processes; 2.

5. Based on the heating and annealing process described in 2.4, further dynamic simulations were performed on the polyurethane surface cell model; Step 3: Calculate the glass transition temperature of the optimized polyurethane surface cell model in the LAMMPS module; 3.1 Based on the kinetic calculations in 2.5, the glass transition temperature of the polyurethane surface cell model is calculated; 3.2 After calculating the glass transition temperature, the numerical values ​​of the volume of the polyurethane surface cell model with different structures at different temperatures were obtained; 3.

3. Plot a scatter plot with volume as the vertical axis and temperature as the horizontal axis. Then, perform piecewise linear fitting on the points on both sides of the inflection point in the scatter plot to obtain two intersecting straight lines. The temperature at the intersection of the two straight lines is the glass transition temperature of the polyurethane resin.

2. The high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, wherein the hydroxyl component is one or more of 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,2-propanediol, 1,3-propanediol, polyether glycol, polycaprolactone glycol, polyester glycol, and polycarbonate glycol.

3. The high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, wherein the isocyanate component is one or more of isoflurane diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4-toluene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate.

4. In the high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, the polyurethane surface cell model is subjected to heating and annealing three times.

5. The high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, wherein the parameters for structural optimization are as follows: the structural optimization algorithm is selected as Conjugate gradient, the energy convergence criterion is selected as 0.0001, the force field convergence criterion is selected as 0.000001, the maximum number of iterations for structural optimization is 1000, the maximum number of energy / force calculations is 10000, the optimized cell parameters are selected, the maximum allowable volume change value in a single iteration is set to 0.0005, and the applied pressure is selected as Isostatic Pressure.

6. A high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, wherein the parameters set during the heating process are as follows: the kinetic simulation ensemble is selected as NPT, the initial temperature is set to 200K, the final temperature is set to 800K, the temperature control method is selected as Nose-Hoover temperature control, the temperature control frequency is set to 100, the initial pressure and the final pressure are both set to 1 atmosphere, the pressure control method is selected as Nose-Hoover pressure control, the pressure control frequency is set to 1000, the time step is 1fs, the total simulation time is 200000fs, the total number of simulation steps is 200000, the initial velocity is set to Random, and the temperature is 298K; the annealing process is based on the parameters of the heating process, with the temperature reduced from 800K to 200K.

7. The high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, wherein the parameters of the kinetic simulation are: ensemble selection NVE, time step of 1fs, total simulation time of 200,000fs, total number of simulation steps of 200,000, initial velocity set to Random, and temperature of 298K.

8. The high-throughput calculation and analysis method for the glass transition temperature of polyurethane resin according to claim 1, wherein the parameters for calculating the glass transition temperature are: the target starting temperature is set to 450K, the target ending temperature is set to 100K, the temperature interval is set to 25K, the equilibrium time at each temperature is 100ps, and the output quantities during the glass transition temperature calculation are selected as: Temperature and Volume.

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