A process design method and system for alcoholysis recovery and re-preparation of epoxy resin curing

Abstract

This invention discloses a method and system for designing a curing process for the re-preparation of epoxy resin from alcoholysis, belonging to the field of solid insulating material preparation processes. It utilizes non-isothermal differential scanning calorimetry to measure the exothermic curve during the curing process of the re-prepared epoxy resin from alcoholysis; calculates the characteristic temperatures during the curing reaction process; linearly extrapolates the pre-curing temperature and post-curing temperature; establishes the curing kinetic equation using a model method; calculates the apparent activation energy, reaction order, and pre-exponential factor during the curing process; solves for the curing time using the method of separation of variables and variable activation energy; and determines the curing process of the re-prepared epoxy resin based on the combination of the above curing temperature and curing time, thereby achieving a high degree of curing and excellent performance of the re-prepared epoxy resin in a short time.

Description

Technical Field

[0001] This invention belongs to the field of solid insulating material preparation technology, specifically relating to a method and system for designing an alcoholysis recovery and re-preparation of epoxy resin curing process. Background Technology

[0002] In 2022, my country's epoxy resin production exceeded 2.2 million tons, accounting for 54% of the global total. The resulting environmental pollution and recycling pressures are significant. Electrical / electronic component insulation and encapsulation applications (accounting for 32% of total epoxy resin usage) are predominantly used. Anhydride-cured epoxy resins, with their excellent insulation properties, high mechanical strength, good thermal stability, and chemical corrosion resistance, are widely used in switchgear insulation components, GIS post / pot insulators, line composite insulator core rods, and dry-type transformer potting. However, after decommissioning, they are often disposed of through landfill, incineration, or high-temperature pyrolysis, resulting in severe resource waste and high energy consumption and secondary pollution, placing enormous pressure on the environment. Furthermore, the raw materials for traditional epoxy resins are mostly derived from petroleum refining, such as bisphenol A diglycidyl ether, which will face resource shortages in the future. Research indicates that chemical upgrading and recycling methods can not only degrade epoxy resins but also achieve high utilization rates and added value of the degradation products. For anhydride-cured epoxy resin systems, the key to degradation and recycling lies in breaking the cross-linked ester bonds.

[0003] Studies have shown that alcoholysis is suitable for the depolymerization and degradation of anhydride-cured epoxy systems. Furthermore, the degradation products can be used to prepare new epoxy resins after simple processing. However, because the formulation of the new resin is altered, its curing conditions differ from the original resin. Additionally, some epoxy resins require longer curing times and higher temperatures, with smaller increases in the degree of curing later, leading to significant heat waste. Therefore, it is necessary to conduct curing kinetic analysis on the alcoholysis-recycled epoxy resin to determine its curing process, thereby preparing high-performance regenerated epoxy resins and promoting the green and environmentally friendly development of insulation materials. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for designing an alcoholysis recovery and re-preparation curing process for epoxy resin, which addresses the shortcomings of the prior art and solves the technical problem of lack of guidance on the alcoholysis recovery and re-preparation curing process of anhydride-cured epoxy resin for electrical equipment.

[0005] The present invention adopts the following technical solution:

[0006] A method for designing a process for curing epoxy resin after alcoholysis recovery includes the following steps:

[0007] S1. Measure the exothermic curve during the curing process of alcoholysis recovery and re-preparation of epoxy resin;

[0008] S2. Calculate the characteristic temperature during the curing reaction process based on the exothermic curve obtained in step S1, and obtain the pre-curing temperature and post-curing temperature by linear extrapolation.

[0009] S3. Establish the curing kinetic equations using the autocatalytic model method;

[0010] S4. Based on the curing kinetic equation obtained in step S3, calculate the apparent activation energy, reaction order, and pre-exponential factor during the curing process to obtain the analytical expression of the sample curing rate.

[0011] S5. Separate α and t in the analytical expression of the sample curing rate obtained in step S4 by the method of separation of variables, and use the variable activation energy to solve for the curing time.

[0012] S6. Determine the curing process for preparing epoxy resin based on the curing temperature obtained in step S2 and the curing time obtained in step S5.

[0013] Preferably, in step S1, the heat flow during the sample curing process is measured using a non-isothermal differential scanning calorimetry method, with nitrogen atmosphere, heating rate of 2.5 to 20 °C / min, and temperature of 30 to 300 °C.

[0014] Preferably, in step S2, the intersection of the baseline of the exothermic curve at different heating rates β and the tangent of the rising edge is defined as the initial curing temperature T. i The peak value of the exothermic curve is defined as the peak curing temperature T. p Using linear fitting, T is obtained when β = 0. i and T p As the pre-curing temperature and post-curing temperature.

[0015] Preferably, in step S3, the curing kinetic equation is as follows:

[0016]

[0017] Where α is the degree of curing; t is the reaction time; A is the pre-exponential factor; E a is the apparent activation energy; R is the gas constant; T is the Kelvin temperature; m and n are the reaction orders.

[0018] More preferably, m and n are determined using shape factor functions y(α) and z(α), and the degree of curing corresponding to the maximum values ​​of y(α) and z(α) is defined as α, respectively. m and α p ∞ , there is ln(exp(x)dα / dt)=lnA+nln[α p (1-α)], nln[α] pUsing the term [1-α] as the abscissa and ln(exp(x)dα / dt) as the ordinate, a linear fit is obtained to obtain A and n, and E a Substitute the average value, m, and n into the fitting calculation A.

[0019] More preferably, m and n are determined based on the shape factor functions y(α) and z(α), and the temperature integral term π(x) in z(α) is approximated by the Senum equation, let x = E a / RT, then y(α) and z(α):

[0020]

[0021] Among them, e x It is the x-th power of a natural number.

[0022] Preferably, in step S4, E is calculated using linear fitting of the Kissinger, Ozawa, and Starink equations. a The average values ​​are as follows:

[0023]

[0024] Among them, T α Here, β represents the temperature corresponding to different degrees of curing, A is the pre-exponential factor, R is the gas constant, and E is the temperature. a As the apparent activation energy, T p This represents the peak curing temperature.

[0025] Preferably, in step S5, the curing time is calculated as follows:

[0026]

[0027] Where, α m The degree of curing is raised to the power of m, α is the degree of curing, R is the gas constant, T is the Kelvin temperature, and E is the curing temperature. a (α) is the activation energy function for the degree of curing.

[0028] Preferably, in step S6, the epoxy resin is prepared again using a two-stage curing method, and the curing process is determined by the α-Tt diagram.

[0029] Secondly, embodiments of the present invention provide a system for designing a process for curing epoxy resin after alcoholysis recovery, characterized in that it includes:

[0030] The measurement module measures the exothermic curve during the curing process of alcoholysis recovery and reprocessing of epoxy resin;

[0031] The extrapolation module calculates the characteristic temperatures during the curing reaction process based on the exothermic curve obtained from the measurement module, and linearly extrapolates to obtain the pre-curing temperature and post-curing temperature.

[0032] The equation module uses the autocatalytic model method to establish the curing kinetic equations.

[0033] The calculation module calculates the apparent activation energy, reaction order, and pre-exponential factor during the curing process based on the curing kinetic equation obtained from the equation module, and obtains the analytical expression of the sample curing rate.

[0034] The separation module separates α and t in the analytical expression of the sample curing rate using the method of separation of variables, and uses the variable activation energy to solve for the curing time.

[0035] The design module determines the curing process for the prepared epoxy resin based on the curing temperature and curing time.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] A method for designing a curing process for epoxy resin reprocessing after alcoholysis is presented, addressing the lack of guidance in this process. This method measures the heat release and heating of small-sized samples, and extrapolates the required curing temperature based on characteristic curing temperature values. A widely applicable and highly accurate autocatalytic model is selected for curing kinetic analysis. The parameters in the calculation equation are fitted to establish the curing kinetic equation, yielding analytical expressions for the curing rate in relation to temperature and time. Furthermore, the relationship between the degree of curing, temperature, and time can be solved using the separation of variables integral method on the curing kinetic differential equation. This provides guidance for the curing process of epoxy resin reprocessing after alcoholysis, saving significant time and raw materials compared to traditional orthogonal experiments. Moreover, it allows for the establishment of a database of curing kinetic equations corresponding one-to-one with each sample, laying a crucial foundation for epoxy resin curing analysis.

[0038] Furthermore, in step S1, the curing exothermic curve of the alcoholysis recovery and re-preparation of epoxy resin was obtained by non-isothermal differential scanning calorimetry. The heating rate was 2.5 to 20 °C / min, and the test temperature range was 30 to 300 °C. The experimental operation was simple and the test could be completed in a short time. At the same time, the required sample mass was small, saving raw materials.

[0039] Furthermore, in step S2, the required curing temperature for the sample is obtained by linear extrapolation based on the curing temperature characteristic value, and the initial curing temperature T at different heating rates β is calculated. i and peak curing temperature T p Perform linear fitting and extrapolate to obtain T when β = 0. i and T p This temperature is used as the temperature value required for the second-stage curing, and the process for determining the curing temperature is clear and simple.

[0040] Furthermore, in step S3, a universal autocatalytic model method is used to establish the curing kinetic equation, which can be used for the analysis and modeling of most epoxy resins. The model has a high degree of fit and is close to the experimental values, thus reflecting the true curing condition of epoxy resins.

[0041] Furthermore, in step S5, α and t in the curing kinetic equation are separated by the method of separation of variables integration. Since the activation energy function reflects the ease with which the crosslinking reaction occurs during the curing process, it is more accurate to use the variable activation energy to solve for the curing time.

[0042] Furthermore, step S6 can determine the time required for the alcoholysis recovery and re-preparation of epoxy resin to reach different degrees of curing based on the curing temperature value in step S2. The curing schemes are diverse and easy to screen.

[0043] It is understandable that the beneficial effects of the second aspect mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0044] In summary, this invention measured the curing exothermic curve of the sample using non-isothermal differential scanning calorimetry (DSC), and linearly extrapolated the characteristic temperatures during the curing reaction to obtain the pre-curing and post-curing temperatures. Simultaneously, a curing kinetic equation was established using an autocatalytic model to characterize the curing rate of the sample, and the curing time was solved using the separation of variables method and variable activation energy. Based on the curing temperature and time, curing schemes for different degrees of epoxy resin curing were realized. The entire testing process is simple, saving time and a large amount of raw materials compared to traditional trial-and-error methods. It plays an important role in guiding the analysis of curing processes for the recovery and reprocessing of epoxy resins after alcoholysis.

[0045] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0046] Figure 1 Flowchart for curing kinetics analysis of alcoholysis recovery and reprocessing of epoxy resin;

[0047] Figure 2 Non-isothermal DSC results for the preparation of epoxy resin from alcoholysis recovery;

[0048] Figure 3 The graph shows the linear fitting results for the curing characteristic temperature.

[0049] Figure 4 This is a graph showing the relationship between the degree of curing and temperature.

[0050] Figure 5 The figure shows the fitting results for the apparent activation energy Ea;

[0051] Figure 6 The graph shows the shape factors y(α) and z(α).

[0052] Figure 7 This is a graph showing the relationship between the degree of curing and time at different temperatures;

[0053] Figure 8 A schematic diagram of a computer device provided in an embodiment of the present invention;

[0054] Figure 9 This is a block diagram of a chip provided according to an embodiment of the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0057] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0058] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0059] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0060] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0061] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0062] This invention provides a method for designing a curing process for the re-prepared epoxy resin from alcoholysis. The method involves measuring the exothermic curve during the curing process using non-isothermal differential scanning calorimetry (DSC); calculating the characteristic temperatures during the curing reaction; linearly extrapolating the pre-curing and post-curing temperatures; establishing curing kinetic equations using a modeling method; calculating the apparent activation energy, reaction order, and pre-exponential factor during the curing process; solving for the curing time using the method of separation of variables and variable activation energy; and determining the curing process for the re-prepared epoxy resin based on the combination of the above curing temperatures and curing times. This method aims to achieve a high degree of curing and excellent performance of the re-prepared epoxy resin in a short time.

[0063] Please see Figure 1 This invention discloses a method for designing a process for curing epoxy resin after alcoholysis recovery, comprising the following steps:

[0064] S1. Measure the exothermic curve during the curing process of alcoholysis recovery and re-preparation of epoxy resin;

[0065] The heat flow during the curing process of the sample was measured using non-isothermal differential scanning calorimetry (DSC) in a nitrogen atmosphere. The heating rate β was 2.5–20 °C / min, and the temperature test range was 30–300 °C.

[0066] S2. Calculate the characteristic temperatures during the curing reaction process, and obtain the pre-curing temperature and post-curing temperature by linear extrapolation.

[0067] The intersection of the baseline and the tangent of the rising edge of the exothermic curve at different β values ​​is defined as the initial curing temperature T. i The peak value of the exothermic curve is defined as the peak curing temperature T.p Using linear fitting, T is obtained when β = 0. i and T p As the pre-curing temperature and post-curing temperature.

[0068] S3. Use the model method to establish the curing kinetic equations;

[0069] The curing kinetic equations were established using the autocatalytic model method as follows:

[0070]

[0071] Where α is the degree of curing; t is the reaction time; A is the pre-exponential factor; E a is the apparent activation energy; R is the gas constant; T is the Kelvin temperature; m and n are the reaction orders.

[0072] S4. Calculate the apparent activation energy, reaction order, and pre-exponential factor during the curing process;

[0073] E was calculated using linear fitting of the Kissinger, Ozawa, and Starink equations. a The average value, the first two methods are based on 1 / T p ln(β / T) is the x-axis. p 2 ) and ln(β) are the ordinates used to fit and calculate E. a In the Starink method, the x-axis is 1 / T. α The ordinate is ln(β / T) α 1.92 The details are as follows:

[0074]

[0075] Among them, T α These represent the temperatures corresponding to different degrees of curing, and their corresponding relationships can be obtained by integrating and normalizing the DSC curves, such as... Figure 4 As shown. The expressions for the above three equations are shown in equation (2), and the fitting results are shown in [the figure]. Figure 5 .

[0076] m and n are determined using shape factor functions y(α) and z(α), where the temperature integral term π(x) in z(α) is approximated by the Senum equation, let x = E a If / RT, then y(α) and z(α) are as follows:

[0077]

[0078] Wherein, the degree of curing corresponding to the maximum values ​​of y(α) and z(α) are defined as α m and α p∞ Then p = m / n = α m / (1-α m Equation (1) can be transformed into ln(exp(x)dα / dt)=lnA+nln[α p (1-α)], nln[α] p Using the term [1-α] as the x-axis and ln(exp(x)dα / dt) as the y-axis, linear fitting can determine A and n, and E a Substitute the average value, m, and n into equation (1) to fit and calculate A.

[0079] S5. Separate α and t using the method of separation of variables, and use Starink E a (α) Solve for curing time by varying activation energy;

[0080] Based on the variable separation integration method, using Starink E a The (α) function is used to calculate the curing time, as follows:

[0081]

[0082] Substituting different values ​​of T, we obtain a definite α-E. a By finding the corresponding relationship, we can solve for t by integrating both sides of the equation.

[0083] S6. The curing process for preparing epoxy resin is determined by the above combination of curing temperature and curing time.

[0084] The epoxy resin was then prepared using a two-stage curing method, and the curing process was determined by the α-Tt diagram.

[0085] In another embodiment of the present invention, a method system for designing an alcoholysis recovery and reprocessing epoxy resin curing process is provided. This system can be used to implement the above-mentioned alcoholysis recovery and reprocessing epoxy resin curing process design method. Specifically, the alcoholysis recovery and reprocessing epoxy resin curing process design method system includes a measurement module, an extrapolation module, an equation module, a calculation module, a separation module, and a design module.

[0086] The measurement module measures the exothermic curve during the curing process of alcoholysis recovery and re-preparation of epoxy resin.

[0087] The extrapolation module calculates the characteristic temperatures during the curing reaction process based on the exothermic curve obtained from the measurement module, and linearly extrapolates to obtain the pre-curing temperature and post-curing temperature.

[0088] The equation module uses the autocatalytic model method to establish the curing kinetic equations.

[0089] The calculation module calculates the apparent activation energy, reaction order, and pre-exponential factor during the curing process based on the curing kinetic equation obtained from the equation module, and obtains the analytical expression of the sample curing rate.

[0090] The separation module separates α and t in the analytical expression of the sample curing rate using the method of separation of variables, and uses the variable activation energy to solve for the curing time.

[0091] The design module determines the curing process for the prepared epoxy resin based on the curing temperature and curing time.

[0092] In another embodiment of the present invention, a terminal device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to achieve a corresponding method flow or corresponding function. The processor described in this embodiment can be used in the operation of a process design method for alcoholysis recovery and subsequent epoxy resin curing, including:

[0093] The exothermic curves of the curing process of the epoxy resin recovered from alcoholysis were measured; the characteristic temperatures of the curing reaction were calculated based on the exothermic curves, and the pre-curing temperature and post-curing temperature were obtained by linear extrapolation; the curing kinetic equation was established using the autocatalytic model method; the apparent activation energy, reaction order, and pre-exponential factor of the curing process were calculated based on the curing kinetic equation to obtain the analytical expression of the sample curing rate; α and t in the analytical expression of the sample curing rate were separated by the method of separation of variables, and the curing time was solved using the variable activation energy; the curing process of the reconstituted epoxy resin was determined based on the curing temperature and curing time.

[0094] Please see Figure 8The terminal device is a computer device. In this embodiment, the computer device 60 includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When executed by the processor 61, the computer program 63 implements the fluid composition calculation method in the reservoir stimulation wellbore of this embodiment. To avoid repetition, details are omitted here. Alternatively, when executed by the processor 61, the computer program 63 implements the functions of each model / unit in the alcoholysis recovery and epoxy resin curing process design method system of this embodiment. To avoid repetition, details are omitted here.

[0095] Computer device 60 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. Computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will understand that... Figure 8 This is merely an example of computer device 60 and does not constitute a limitation on computer device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, computer device may also include input / output devices, network access devices, buses, etc.

[0096] The processor 61 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0097] The memory 62 can be an internal storage unit of the computer device 60, such as a hard disk or RAM of the computer device 60. The memory 62 can also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the computer device 60.

[0098] Furthermore, the memory 62 may include both internal storage units of the computer device 60 and external storage devices. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 can also be used to temporarily store data that has been output or will be output.

[0099] Please see Figure 9 The terminal device is a chip. In this embodiment, the chip 600 includes a processor 622, which may be one or more, and a memory 632 for storing computer programs executable by the processor 622. The computer program stored in the memory 632 may include one or more modules, each corresponding to a set of instructions. Furthermore, the processor 622 may be configured to execute the computer program to perform the above-described alcoholysis recovery and epoxy resin curing process design method.

[0100] Additionally, chip 600 may also include a power supply component 626 and a communication component 650. The power supply component 626 can be configured to perform power management of chip 600, and the communication component 650 can be configured to enable communication of chip 600, such as wired or wireless communication. Furthermore, chip 600 may also include an input / output (I / O) interface 658. Chip 600 can operate on an operating system stored in memory 632.

[0101] In another embodiment of the present invention, a storage medium is also provided, specifically a computer-readable storage medium (memory). This computer-readable storage medium is a memory device in a terminal device used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and extended storage media supported by the terminal device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, this storage space also stores one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device.

[0102] One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the alcoholysis recovery and epoxy resin curing process design method in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps:

[0103] The exothermic curves of the curing process of the epoxy resin recovered from alcoholysis were measured; the characteristic temperatures of the curing reaction were calculated based on the exothermic curves, and the pre-curing temperature and post-curing temperature were obtained by linear extrapolation; the curing kinetic equation was established using the autocatalytic model method; the apparent activation energy, reaction order, and pre-exponential factor of the curing process were calculated based on the curing kinetic equation to obtain the analytical expression of the sample curing rate; α and t in the analytical expression of the sample curing rate were separated by the method of separation of variables, and the curing time was solved using the variable activation energy; the curing process of the reconstituted epoxy resin was determined based on the curing temperature and curing time.

[0104] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0105] 1) Anhydride-cured epoxy resin, anhydrous ethanol, and potassium phosphate were placed in a sealed container and heated at 120°C for 3 hours. After the heating was completed, the potassium phosphate was filtered out and heated at 80°C for 1 hour to obtain degraded epoxy resin. This degraded epoxy resin was then mixed with E-51 epoxy resin and methyltetrahydrophthalic anhydride was added. The mass ratio of the three components was 3:1:2.816. The mixture was placed in an aluminum crucible, and the heat flux during the curing process was measured using differential scanning calorimetry (DSC) in a nitrogen atmosphere. The heating rates β were 5, 10, 15, and 20°C / min, respectively. The temperature range was 30–300°C. The test results are as follows: Figure 2 As shown.

[0106] 2) Draw the baseline and the tangent of the rising edge of the exothermic curves under different β values, and take the intersection point as the initial curing temperature T. i The peak value of the exothermic curve is taken as the peak curing temperature T. p Using a first-order linear function for T under different β i and T p By fitting the data and substituting β = 0, we obtain T. i and T p As the pre-curing temperature and post-curing temperature, the results are as follows Figure 3 As shown.

[0107] 3) The curing kinetic equation was established using the autocatalytic SB(m,n) two-parameter model method.

[0108] 4) E was calculated using linear fitting of the Kissinger, Ozawa, and Starink equations. a The average value, the first two methods are based on 1 / T p ln(β / T) is the x-axis. p 2 ) and ln(β) are the ordinates used to fit and calculate E. a In the Starink method, the x-axis is 1 / T. α The ordinate is ln(β / T) α 1.92 ), where T α These represent the temperatures corresponding to different degrees of curing, and their corresponding relationships can be obtained by integrating and normalizing the DSC exothermic curves, such as... Figure 4 As shown.

[0109] 5) Use shape factor functions y(α) and z(α) to determine m and n, such as... Figure 6 As shown.

[0110] 6) Separate α and t based on the variable separation integration method, and use Starink E a The (α) function is used to solve for the curing time;

[0111] 7) Please refer to Figure 7 If the degree of curing of the prepared epoxy resin is to reach 90%, it is cured at 115℃ for 130 min in the first stage, and then cured at 160℃ for 10 min in the second stage.

[0112] Based on the above analysis, the curing process for alcoholysis recovery and re-preparation of epoxy resin was determined, and epoxy resin samples with a diameter of 90 mm and a thickness of 1 mm were prepared under this condition. The electrical performance parameters are shown in Table 1.

[0113] Table 1 Electrical performance parameters of epoxy resin

[0114]

[0115]

[0116] The resistivity decreased and the relative permittivity increased, but it still meets the relevant standard requirements.

[0117] In summary, this invention provides a method for designing a curing process for the reprocessing of epoxy resin after alcoholysis, offering theoretical guidance and technical experience for the curing conditions of the reprocessed epoxy resin. When determining the curing temperature, linear fitting is used for extrapolation to obtain the pre-curing and post-curing temperatures of the reprocessed resin. After obtaining the curing kinetic equation, Starink variable activation energy separation and integral methods are used to solve for the curing time, ultimately yielding the α-Tt diagram. The establishment of this model and the determination of the curing process lay the foundation for the future reprocessing of high-performance epoxy resins through alcoholysis, and are of great significance for its industrial-scale production.

[0118] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0119] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0120] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0121] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0122] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0123] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0124] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random-access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0125] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0126] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0127] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0128] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for designing a process for curing epoxy resin after alcoholysis recovery, characterized in that, Includes the following steps: S1. Measure the exothermic curve during the curing process of alcoholysis recovery and re-preparation of epoxy resin; S2. Calculate the characteristic temperature during the curing reaction process based on the exothermic curve obtained in step S1, and obtain the pre-curing temperature and post-curing temperature by linear extrapolation. S3. Establish the curing kinetic equations using the autocatalytic model method; S4. Based on the curing kinetic equation obtained in step S3, calculate the apparent activation energy, reaction order, and pre-exponential factor during the curing process to obtain the analytical expression of the sample curing rate. S5. Using the separation of variables method, analyze the sample curing rate in the formula obtained in step S4. α and t Separation, To indicate the degree of curing. t The curing time is calculated using the variable activation energy, and the curing time is obtained as follows: in, For the degree of curing m Power of 1 The gas constant is Kelvin temperature, The activation energy function represents the degree of curing. S6. Determine the curing process for preparing epoxy resin based on the curing temperature obtained in step S2 and the curing time obtained in step S5.

2. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 1, characterized in that, In step S1, the heat flow during the sample curing process is measured using non-isothermal differential scanning calorimetry. The gas atmosphere is nitrogen, the heating rate is 2.5~20 ℃ / min, and the temperature is 30~300 ℃.

3. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 1, characterized in that, In step S2, different heating rates β The intersection of the baseline of the exothermic curve and the tangent at the rising edge is defined as the initial curing temperature. T i The peak value of the exothermic curve is defined as the peak curing temperature. T p Using linear fitting, we obtain β =0 T i and T p As the pre-curing temperature and post-curing temperature.

4. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 1, characterized in that, In step S3, the curing kinetic equation is as follows: in, α This refers to the degree of curing. t Reaction time; A Pre-exponential factors; E a It is the apparent activation energy; R It is the gas constant; T Kelvin temperature; m and n denoted as the reaction order.

5. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 4, characterized in that, Use the shape factor function y ( α )and z ( α )Sure m and n , y ( α )and z ( α The degree of curing corresponding to the maximum value is defined as follows: α m and α p ∞ , has ln(exp( x ) dα / dt )=ln A + n ln[ α p (1- α )],Will n ln[ α p (1- α The term is used as the x-axis, ln(exp( x ) dα / dt ) as the ordinate linear fitting to obtain A and n ,Will E a average value, m and n Substitute into the fitting calculation A ,make x = E a / RT .

6. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 5, characterized in that, According to the shape factor function y ( α )and z ( α ) to determine m and n , z ( α The temperature integral term π( x Approximated by the Senum equation, let x = E a / RT ,but y ( α )and z ( α ): in, For natural numbers x Power of 1.

7. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 1, characterized in that, In step S4, use , and The equation was obtained through linear fitting calculation. E a The average values ​​are as follows: in, T α These are the temperatures corresponding to different degrees of curing. For the heating rate, Pre-exponential factor, The gas constant is As the apparent activation energy, This represents the peak curing temperature.

8. The method for designing a process for curing epoxy resin after alcoholysis recovery according to claim 1, characterized in that, In step S6, epoxy resin is prepared again using a two-stage curing method. The curing process is as follows: α-Tt The diagram is confirmed.

9. A system for designing a process to recover and cure epoxy resin through alcoholysis, characterized in that, include: The measurement module measures the exothermic curve during the curing process of alcoholysis recovery and reprocessing of epoxy resin; The extrapolation module calculates the characteristic temperatures during the curing reaction process based on the exothermic curve obtained from the measurement module, and linearly extrapolates to obtain the pre-curing temperature and post-curing temperature. The equation module uses the autocatalytic model method to establish the curing kinetic equations. The calculation module calculates the apparent activation energy, reaction order, and pre-exponential factor during the curing process based on the curing kinetic equation obtained from the equation module, and obtains the analytical expression of the sample curing rate. The separation module uses the separation of variables method to analyze the curing rate of the sample. α and t Separate the curing time using variable activation energy. To indicate the degree of curing. t The curing time is calculated using the variable activation energy, and the curing time is obtained as follows: in, For the degree of curing m Power of 1 The gas constant is Kelvin temperature, The activation energy function represents the degree of curing. The design module determines the curing process for the prepared epoxy resin based on the curing temperature and curing time.

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