CN-117890423-B - Method for constructing thermosetting adhesive curing dynamics model for precise instrument

CN117890423BCN 117890423 BCN117890423 BCN 117890423BCN-117890423-B

Abstract

The invention discloses a method for constructing a thermosetting adhesive curing kinetic model for a precision instrument, which comprises the steps of firstly, carrying out a differential scanning calorimetric analysis (DSC) experiment to obtain corresponding heat flow density curves, secondly, carrying out peak-splitting fitting on each heat flow density curve to obtain a plurality of heat release peak curves, thirdly, obtaining a heat release curve, a curing degree curve and a curing rate curve of each heat release peak, thirdly, obtaining kinetic model parameters of each heat release peak by adopting self-catalytic model fitting, thirdly, calculating the percentage of heat release quantity corresponding to each heat release peak to the total heat release quantity of the adhesive curing, and finally, obtaining the real-time curing rate of each heat release peak according to the corresponding kinetic model, multiplying the real-time curing rate by the corresponding percentage and then carrying out linear superposition to obtain the real-time curing rate of the adhesive.

Inventors

JIANG CHAO
LIAO WENHAO
YAO ZHONGYANG
LI CHUNYANG

Assignees

湖南大学

Dates

Publication Date: 20260512
Application Date: 20240120

Claims (7)

1. The method for constructing the thermosetting adhesive curing kinetic model for the precise instrument is characterized by comprising the following steps of: Carrying out DSC experiments of uncured adhesive liquid drops at different heating rates to obtain corresponding heat flow density curves; Step two, carrying out peak-splitting fitting on the heat flow density curves of each group of experiments by adopting a Gaussian distribution model to obtain a plurality of exothermic peak curves; Sequentially integrating the heat flow density of each exothermic peak with respect to a time curve to obtain a heat release amount with respect to the time curve, a curing degree with respect to the time curve and a curing rate with respect to the time curve of each exothermic peak; Fitting by adopting an autocatalysis model to obtain kinetic model parameters of each exothermic peak, wherein the kinetic model parameters comprise a pre-finger factor, activation energy and a reaction progression; calculating the percentage of the total heat release amount corresponding to each heat release peak to the total heat release amount of the adhesive curing; And step six, calculating to obtain the real-time curing rate of each exothermic peak according to the corresponding dynamic model, multiplying the real-time curing rate by the corresponding percentage, and then linearly superposing the real-time curing rate of the adhesive.
2. The method for constructing a thermosetting adhesive curing kinetic model for precision instruments according to claim 1, wherein the first step comprises the following steps: (1) Developing uncured adhesive drops at N different heating rates DSC experiments under N, i=1, 2; (2) Recording time in the heating process of the adhesive Corresponding temperature And heat flux density Data; (3) Plotting the corresponding heat flux density versus time Curve of heat flux density versus temperature 。
3. The method for constructing a thermosetting adhesive curing kinetic model for precision instruments according to claim 1, wherein the second step comprises the following steps: (1) For a pair of Analyzing the slope of the curve to find out the point with obvious slope change, wherein each point corresponds to one exothermic peak; (2) For each set of experiments using a gaussian distribution model Carrying out peak-splitting fitting treatment on the curves to obtain a plurality of exothermic peak curves; (3) Each exothermic peak curve was recorded as peak 1, peak 2, peak 3, peak j, peak in the order in which the peak points appear 。
4. The method for constructing a thermosetting adhesive curing kinetic model for precision instruments according to claim 3, wherein the third step comprises the following steps: (1) At a rate of temperature rise of The heat flux density corresponding to peak 1 in the experiment of (2) is plotted against time Integrating the time to obtain the curve of the heat release quantity of the solar energy collector with respect to the time And total amount of exotherm ; (2) Will be Divided by the total amount of exotherm Obtaining a curve of the curing degree of the epoxy resin with respect to time ; (3) Will be Differentiating the time to obtain a curve of the curing rate of the material relative to the time ; (4) For each exothermic peak under each set of experiments, peak 1, peak 2, peak 3,..once, peak j,..once, peak were tested according to steps (1) to (3) above And processing the curve to obtain a corresponding curve of the heat release amount and the time, a curve of the curing degree and the curing rate and a curve of the curing rate and the time.
5. The method for constructing a thermosetting adhesive curing kinetic model for precision instruments according to claim 3, wherein the fourth step comprises the following steps: (1) Heat flux density versus temperature curve for peak 1 in each set of experiments was plotted Obtaining the peak temperature of peak 1 at each heating rate by taking the extremum ; (2) Solving for activation energy in kinetic model parameters using the Kissinger equation (1) Wherein, the The rate of temperature rise for each set of experiments; Indicating a temperature rise rate of Peak temperature at time, which is given as kelvin; Is the activation energy; is molar gas constant, its value is equal to ; Is a constant to be solved; Drawing With respect to Is subjected to a linear fit with a slope of Further, the activation energy of peak 1 can be obtained ; (3) Solving pre-finger factors and reaction progression in kinetic model parameters by autocatalysis model (2) Wherein, the Is the degree of solidification; is the curing rate; Is a pre-finger factor; representing temperature; Is the reaction level number; In combination with the previously solved activation energy Rate of cure Degree of solidification At a heating rate of Temperature of time peak 1 The fitting temperature rise rate of (2) is applied to The curing rate of time peak 1 is related to the temperature curve to obtain the corresponding parameters of the factor before finger Reaction progression Is a value of (2); (4) Taking average value of each parameter of peak 1 obtained at each group of heating rate, and respectively recording as And as a pre-finger factor and reaction progression in the kinetic model parameters of peak 1 (3) (4) (5) The kinetic model of peak 1 can be expressed as (6) Wherein, the As the degree of cure for peak 1, Cure rate for peak 1; (5) Similarly, other exothermic peaks, peak 2, peak 3, peak j, peak were subjected to the steps (1) to (4) above Processing the curve to obtain a corresponding dynamics model (7) Where j=2, 3, M; Respectively indicating a pre-finger factor, activation energy and a reaction progression in the dynamic model parameters of the peak j; As the degree of cure of the peak j, The cure rate for peak j.
6. The method for constructing a thermosetting adhesive curing kinetic model for precision instruments according to claim 3, wherein the fifth step comprises the following steps: (1) Total amount of exotherm for peak j under each set of experiments Taking an average value and recording as ; (8) (2) Average total heat release amount corresponding to each heat release peak The total amount of heat released during the curing process of the adhesive is obtained by linear addition and is recorded as ; (9) (3) Average value of total exothermic amount of each exothermic peak Total amount of heat released from curing the adhesive The ratio of the peak to the curing process is recorded as a percentage ; (10) (11)。
7. The method for constructing a thermosetting adhesive curing kinetic model for precision instruments according to claim 1, wherein the sixth step comprises the following steps: (1) The real-time curing rate of each exothermic peak of the adhesive can be solved under any condition by the corresponding dynamic model ; (2) Real-time cure rate for each exothermic peak Multiplying the peak by the percentage of the curing process And linearly adding to obtain the real-time curing rate of the adhesive under the condition (12)。

Description

Method for constructing thermosetting adhesive curing dynamics model for precise instrument Technical Field The invention relates to the technical field of precision instruments, in particular to a construction method of a thermosetting adhesive curing kinetic model for a precision instrument. Background Along with the rapid development of modern science and technology, the precise instrument is widely applied to the fields of modern production, scientific research, medical diagnosis and the like, is used for measuring the ambient temperature, carrier displacement, body diagnosis and the like, has wide application, has important roles in improving the production efficiency, promoting scientific progress, improving the human living level and the like, is connected by adopting an adhesive, and is connected in an opaque environment, so that the precise instrument cannot be connected by using a photo-curing adhesive, and has the advantages of rapid curing at high temperature, high strength, good stability, good adhesive property and the like, and is widely applied to the connection of the precise instrument. In the manufacturing process of the precision instrument, the thermosetting adhesive is widely applied to the bonding and fixing of various parts, however, residual stress is inevitably generated in the adhesive in the curing process due to temperature change and chemical reaction, the important influence is generated on the performance of the precision instrument, meanwhile, the precision of a curing dynamic model constructed by adopting a traditional method is lower due to the fact that the curing process of the thermosetting adhesive is complex, the quality and the performance of the precision instrument are seriously influenced because the curing process of the thermosetting adhesive is difficult to accurately predict and control in the manufacturing process of the precision instrument, the deep research is needed in the curing process of the adhesive for reducing the residual stress after curing molding, the relation between the curing degree and technological parameters (temperature, time and the like) is analyzed by establishing a dynamic model of the adhesive from the curing mechanism, theoretical basis is provided for optimizing the curing process of the adhesive, the curing residual stress is reduced, the high-precision dynamic model is a basis for guaranteeing the accuracy of the analysis result of the curing process, however, the corresponding curing degree of each exothermic peak is considered to be equal to the curing degree of the adhesive in real time in the traditional curing dynamic model construction process of the thermosetting adhesive, the model fitting result is greatly deviated from the actual experimental result, the following analysis result is greatly influenced, the following analysis and the curing process of the adhesive is greatly influenced, the accuracy of the adhesive is greatly improved, the precision of the adhesive is greatly improved, and the precision is high in the accuracy is high, and the accuracy is can be greatly improved. Disclosure of Invention Aiming at the problems, the invention discloses a construction method of a thermosetting adhesive curing dynamics model for a precise instrument. The method comprises the steps of dividing a heat flow density curve in the adhesive curing process into a plurality of simple exothermic peak curves, analyzing and processing each exothermic peak curve according to the heat flow density curve, establishing a corresponding dynamic model, and finally combining the percentage of the exothermic amount of the peak to the total exothermic amount to obtain the real-time theoretical curing rate of the adhesive cured under any condition. The specific implementation steps of the invention are as follows: Carrying out DSC experiments of uncured adhesive liquid drops at different heating rates to obtain corresponding heat flow density curves; Step two, carrying out peak-splitting fitting on the heat flow density curves of each group of experiments by adopting a Gaussian distribution model to obtain a plurality of exothermic peak curves; Integrating the heat flow density of each exothermic peak with respect to a time curve to obtain a heat release amount with respect to the time curve, a curing degree with respect to the time curve and a curing rate with respect to the time curve of each exothermic peak; Fitting by adopting an autocatalysis model to obtain kinetic model parameters of each exothermic peak, wherein the kinetic model parameters comprise a pre-finger factor, activation energy and a reaction progression; calculating the percentage of the total heat release amount corresponding to each heat release peak to the total heat release amount of the adhesive curing; And step six, calculating to obtain the real-time curing rate of each exothermic peak according to the corresponding dynamic model, multiplying the real-time curing rate by