Method for constructing resin-based material curing kinetic model based on Fourier transform infrared spectroscopy

Abstract

The invention discloses a method for constructing a resin-based material curing kinetic model based on Fourier transform infrared spectroscopy, which comprises the following steps of: 1, constructing a resin-based material curing kinetic model containing unknown parameters by using an autocatalytic reaction kinetic model; 2, carrying out curing tests at different curing temperatures for different curing times to obtain a resin-based material sample; step 3, carrying out Fourier transform infrared spectrum testing on each resin-based material sample; and 4, determining a resin-based material curing kinetic model. According to the method, Fourier infrared spectrograms of resin samples at different curing temperatures and time are tested, the area of characteristic peaks participating in the reaction is calculated, curing degree data of the resin material is obtained, and a curing kinetic model of the resin material is constructed according to the curing degree and the curing time, namely curing speed data. The method can reflect the macroscopic curing dynamic performance of the resin material in bridge deck pavement, and can better guide the construction of the resin-based bridge deck pavement material.

Description

Technical Field

[0001] The invention relates to the technical field of prediction and characterization of curing characteristics of resin-based materials, and in particular to a method for constructing a curing kinetics model of resin-based materials based on Fourier transform infrared spectroscopy. Background Art

[0002] The mechanical properties of thermosetting resin-based materials show a strong dependence on the degree of curing. Once the curing reaction is completed, it is irreversible, and an infusible spatial network structure is formed inside the material. In addition, thermosetting resin-based materials have excellent mechanical properties, good temperature stability, and excellent fatigue resistance. Therefore, the bridge deck paving field attempts to use resin materials as binders in bridge deck paving concrete. Unlike traditional bridge deck paving materials such as asphalt, the strength formation of thermosetting resin-based materials depends on their own curing reaction. During the curing process, the resin material often undergoes a transition from liquid to rubber state and finally to solid state. Therefore, mastering the curing reaction behavior of the resin material is crucial to determining the curing time and traffic conditions of the resin-based bridge deck pavement.

[0003] The curing behavior of thermosetting resin materials can be characterized by thermodynamics, spectroscopy, chemistry, electricity, mechanics and other methods. Among them, the differential scanning calorimetry test in the thermodynamic method has the advantages of fast test speed and high data accuracy, and is often used to study the curing behavior of resin materials. However, due to the limitations of the test method and equipment, the sample mass used in the differential scanning calorimetry test is generally at the 10mg level, and the curing behavior described has obvious microscopic scale characteristics, which makes it difficult to accurately reflect the curing reaction characteristics of resin-based materials on a macroscopic scale. In actual resin-based bridge deck pavement, the curing environment of the resin material is often several grams or tens of grams, and its curing reaction behavior is quite different from the microscopic scale.

[0004] Therefore, it is necessary to develop a method that can characterize the macroscopic curing behavior of resin-based materials. Summary of the invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and to provide a method for constructing a curing kinetic model of resin-based materials based on Fourier transform infrared spectroscopy. The method for constructing a curing kinetic model of resin-based materials based on Fourier transform infrared spectroscopy can achieve gram-level curing rate testing of actual resin-based materials to be paved without reducing the measurement accuracy of curing reactions, and is further used to guide the curing time and traffic conditions of actual resin-based material bridge deck paving.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy comprises the following steps.

[0008] Step 1: Construct a curing kinetic model for resin-based materials: Use the autocatalytic reaction kinetic model to construct the curing reaction rate of resin-based materials. The kinetic model of curing temperature T is as follows:

[0009]

[0010] In the formula, A is the pre-exponential factor of the model, and is the parameter to be solved;

[0011] E is the reaction activation energy, which is the parameter to be solved;

[0012] R is the universal gas constant, a known quantity;

[0013] α is the degree of curing;

[0014] t is the curing time;

[0015] Both m and n are reaction orders, and are parameters to be solved.

[0016] Step 2, curing test: the resin-based material is placed at different curing temperatures T for different curing times t to obtain N resin-based material samples; wherein N ≥ 10; the mass of each cured resin-based material sample is not less than 5g.

[0017] Step 3: Fourier transform infrared spectroscopy test: Each resin-based material sample is subjected to Fourier transform infrared spectroscopy test to obtain the curing degree α and curing reaction speed of each resin-based material sample.

[0018] Step 4: Determine the curing kinetics model of the resin-based material: Substitute them into the curing kinetic model of the resin-based material constructed in step 1 to obtain N curing kinetic equations of the resin-based material and fit and solve them, thereby obtaining a curing kinetic model of the resin-based material in which A, E, m and n are all determined quantities.

[0019] In step 2, the curing temperature T ranges from 35° C. to 80° C., and the curing time t is set to 0 h to 20 d.

[0020] In step 2, N ≥ 40.

[0021] In step 2, the curing temperatures T are 35° C., 50° C., 65° C. and 80° C., respectively, and the number of resin-based material samples corresponding to each curing temperature T is not less than 10.

[0022] In step 3, the curing reaction rate of each resin-based material sample is The method for obtaining comprises the following steps:

[0023] Step 3-1, obtaining a Fourier transform infrared spectrum: each resin-based material sample is subjected to a Fourier transform infrared spectrum test to obtain a Fourier transform infrared spectrum of the corresponding resin-based material sample.

[0024] Step 3-2, calculate the degree of cure α: calculate the peak area of ​​the maximum functional group characteristic peak involved in the curing reaction, and determine the degree of cure α of each resin-based material sample by combining the peak areas at the initial and final states of the reaction.

[0025] Step 3-3: Calculate the curing reaction rate Derivative the curing degree α with respect to the curing time t, we can obtain

[0026] In step 3-2, before calculating the peak area of ​​the largest functional group characteristic peak, the Fourier transform infrared spectrum needs to be baseline corrected.

[0027] In step 3, the scanning range of the Fourier transform infrared spectrum is in the mid-infrared region, with a wave number of 4000-400cm -1 , scanning resolution is 4 to 8cm -1 .

[0028] The number of FTIR spectroscopy scans for each resin-based material sample ranged from 16 to 32.

[0029] A=631338, E=45993, m=0.437, n=1.452.

[0030] Also includes step 5, calculating the curing reaction speed of the actual resin-based material Substitute the actual curing temperature T of the resin-based material to be paved into the curing kinetics model of the resin-based material determined in step 4 to obtain the curing reaction rate of the actual resin-based material It can then be used to guide the actual curing time and traffic conditions of resin-based bridge deck pavement.

[0031] The present invention has the following beneficial effects: the present invention utilizes an autocatalytic reaction kinetic model to construct a curing kinetic model for resin-based materials, and utilizes Fourier transform infrared spectroscopy testing to obtain the degree of curing and curing reaction rate of each resin-based material sample, thereby solving the parameters of the curing kinetic model.

[0032] The curing degree change of the resin-based binder under the actual curing time and curing temperature in the bridge deck pavement can be obtained, so as to construct its curing kinetic model and understand the curing behavior. Based on the content of the invention, it can provide important guidance for determining the curing time and traffic opening node after the resin-based bridge deck pavement is paved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1This is the Fourier transform infrared spectrum without baseline correction.

[0034] Figure 2 This is the Fourier transform infrared spectrum after baseline correction.

[0035] Figure 3 This is a graph showing the change in curing degree of the resin material after curing at 50°C for 480 hours.

[0036] Figure 4 This is a graph showing the curing speed change of the resin material at 50°C within 480 hours of curing. DETAILED DESCRIPTION

[0037] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0038] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0039] A method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy comprises the following steps.

[0040] Step 1: Construct a curing kinetic model for resin-based materials: Use the autocatalytic reaction kinetic model to construct the curing reaction rate of resin-based materials. The kinetic model of curing temperature T is as follows:

[0041]

[0042] Where A is the pre-exponential factor of the model and is the parameter to be solved.

[0043] E is the activation energy of the reaction and is the parameter to be solved.

[0044] R is the universal gas constant, a known quantity.

[0045] α is the degree of curing; t is the curing time.

[0046] Both m and n are reaction orders, and are parameters to be solved.

[0047] Step 2, curing test: placing the resin-based material at different curing temperatures T for different curing times t to obtain N resin-based material samples; wherein N ≥ 10, and further, N ≥ 40.

[0048] The mass of each sample of the resin-based material after curing is not less than 5 g, and further not less than 10 g.

[0049] The preferred value range of the above-mentioned curing temperature T is 35°C to 80°C, and the curing time t is set to 0h to 20d. In this embodiment, the curing temperatures T are 35°C, 50°C, 65°C and 80°C respectively, and the number of resin-based material samples corresponding to each curing temperature T is not less than 10.

[0050] Step 3: Fourier transform infrared spectroscopy test: Each resin-based material sample is subjected to Fourier transform infrared spectroscopy test to obtain the curing degree α and curing reaction speed of each resin-based material sample.

[0051] The curing reaction rate of each resin-based material sample The method for obtaining preferably includes the following steps.

[0052] Step 3-1, obtaining a Fourier transform infrared spectrum: each resin-based material sample is subjected to a Fourier transform infrared spectrum test to obtain a Fourier transform infrared spectrum of the corresponding resin-based material sample.

[0053] The scanning range of the above Fourier transform infrared spectrum is in the mid-infrared region, with a wave number of 4000-400cm -1 , the scanning resolution is preferably 4 to 8 cm -1 The number of Fourier transform infrared spectroscopy scans for each resin-based material sample is preferably 16 to 32. In this embodiment, the scanning resolution is preferably 4 cm -1 The number of scans for each specimen is preferably 32 times.

[0054] Figure 1 Shows the Fourier transform infrared spectrum of the resin-based material sample cured at 50°C.

[0055] Next, the original Fourier transform infrared spectrum is baseline corrected to eliminate the influence of external factors such as scanning background noise and dust on the test results during the test. The baseline corrected Fourier transform infrared spectrum is as follows: Figure 2 shown.

[0056] Step 3-2: Calculate the degree of curing α

[0057] Preferably, in the baseline-corrected Fourier transform infrared spectrum, the peak area of ​​the maximum functional group characteristic peak involved in the curing reaction is calculated, and the curing degree α of each resin-based material sample is determined by combining the peak areas at the initial and final states of the reaction. Figure 3 The change in the degree of cure of the resin sample after curing at 50°C for 480 hours is shown.

[0058] Step 3-3: Calculate the curing reaction rate Derivative the curing degree α with respect to the curing time t, we can obtain

[0059] according to Figure 3 The change of curing degree with different curing time can be used to obtain the change data of curing speed with curing time, such as Figure 4 shown.

[0060] Step 4: Determine the curing kinetics model of the resin-based material: Substitute them into the curing kinetic model of the resin-based material constructed in step 1 to obtain N curing kinetic equations of the resin-based material and fit and solve them, so as to obtain a curing kinetic model of the resin-based material in which A, E, m and n are all determined quantities, as shown in Table 1.

[0061] Table 1 Main properties of aggregate

[0062] parameter A E m n Value 631338 45993 0.437 1.452

[0063] Step 5: Calculate the curing reaction rate of the actual resin-based material Substitute the actual curing temperature T of the resin-based material to be paved into the curing kinetics model of the resin-based material determined in step 4 to obtain the curing reaction rate of the actual resin-based material It is then used to guide the curing time and traffic conditions of actual resin-based bridge deck pavement. When solving, the curing degree α in the curing kinetics model of the resin-based material needs to be expressed as the integral of the curing reaction rate over the curing time. Therefore, the curing kinetics model of the resin-based material only includes one unknown variable to be solved:

[0064]

[0065] The present invention obtains the curing degree data of the resin material by testing the Fourier infrared spectra of the resin sample at different curing temperatures and times, calculating the characteristic peak area involved in the reaction, and constructs a curing kinetic model of the resin material according to the curing degree and curing time, that is, the curing speed data. The method can reflect the curing kinetic performance of the resin material on a macro scale in bridge deck paving, can better guide the construction of resin-based bridge deck paving materials, and can reflect the actual service status of the material, so it has significant practical value and guiding significance.

[0066] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for constructing a curing kinetics model of resin-based materials based on Fourier transform infrared spectroscopy, characterized in that: The steps include: Step 1: Construct a curing kinetic model for resin-based materials: Use the autocatalytic reaction kinetic model to construct the curing reaction rate of resin-based materials. The kinetic model of curing temperature T is as follows: In the formula, A is the pre-exponential factor of the model, and is the parameter to be solved; E is the activation energy of the reaction, which is the parameter to be solved; R is the universal gas constant, a known quantity; α is the degree of curing; t is the curing time; Both m and n are reaction orders, and are parameters to be solved; Step 2, curing test: the resin-based material is placed at different curing temperatures T for different curing times t to obtain N resin-based material samples; wherein N ≥ 10; the mass of each cured resin-based material sample is not less than 5g; Step 3: Fourier transform infrared spectroscopy test: Each resin-based material sample is subjected to Fourier transform infrared spectroscopy test to obtain the curing degree α and curing reaction speed of each resin-based material sample. Step 4: Determine the curing kinetics model of the resin-based material: Substitute them into the curing kinetic model of the resin-based material constructed in step 1 to obtain N curing kinetic equations of the resin-based material and fit and solve them, thereby obtaining a curing kinetic model of the resin-based material in which A, E, m and n are all determined quantities.

2. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 1, characterized in that: In step 2, the curing temperature T ranges from 35° C. to 80° C., and the curing time t is set to 0 h to 20 d.

3. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 2, characterized in that: In step 2, N ≥ 40.

4. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 3, characterized in that: In step 2, the curing temperatures T are 35° C., 50° C., 65° C. and 80° C., respectively, and the number of resin-based material samples corresponding to each curing temperature T is not less than 10.

5. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 1, characterized in that: In step 3, the curing reaction rate of each resin-based material sample is The method for obtaining comprises the following steps: Step 3-1, obtaining a Fourier transform infrared spectrum: performing a Fourier transform infrared spectrum test on each resin-based material sample to obtain a Fourier transform infrared spectrum of the corresponding resin-based material sample; Step 3-2, calculate the degree of curing α: calculate the peak area of ​​the maximum functional group characteristic peak involved in the curing reaction, and determine the degree of curing α of each resin-based material sample by combining the peak areas at the initial and final states of the reaction; Step 3-3: Calculate the curing reaction rate Derivative the curing degree α with respect to the curing time t, we can obtain 6. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 5, characterized in that: In step 3-2, before calculating the peak area of ​​the largest functional group characteristic peak, the Fourier transform infrared spectrum needs to be baseline corrected.

7. The method for constructing a curing kinetic model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 1 or 5, characterized in that: In step 3, the scanning range of the Fourier transform infrared spectrum is in the mid-infrared region, with a wave number of 4000-400cm -1 , scanning resolution is 4 to 8cm -1 .

8. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 7, characterized in that: The number of FTIR spectroscopy scans for each resin-based material sample ranged from 16 to 32.

9. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 8, characterized in that: A=631338, E=45993, m=0.437, n=1.

452.

10. The method for constructing a curing kinetics model of a resin-based material based on Fourier transform infrared spectroscopy according to claim 1, characterized in that: Also includes step 5, calculating the curing reaction speed of the actual resin-based material Substitute the actual curing temperature T of the resin-based material to be paved into the curing kinetics model of the resin-based material determined in step 4 to obtain the curing reaction rate of the actual resin-based material It can then be used to guide the actual curing time and traffic conditions of resin-based bridge deck pavement.

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