A method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction

Abstract

The present invention discloses a method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction. By collecting samples at different time points and quantitatively analyzing the characteristic absorption peak of the carbamate C-O bond using Fourier transform infrared spectroscopy (FTIR), the conversion rate of hydroxyl groups in the polyol is calculated. Furthermore, by monitoring the total volume expansion of the system during the reaction and combining it with an analysis of the volume expansion of the physical blowing agent, the conversion rate of water is derived. Based on the conversion rates of the polyol and water, the conversion rate of the isocyanate (NCO) group can be calculated. This method effectively solves the problem of difficult real-time monitoring of reactant conversion rates in complex polyurethane foaming reaction systems and provides a reliable basis for controlling the polyurethane foaming reaction process.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane polymers, in particular to a method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process. Background Art

[0002] In recent years, polymer grouting, a new engineering repair technology, has been widely used in infrastructure repair projects due to its advantages such as rapid expansion, high early strength, waterproofness, durability, and environmental friendliness. For example, in underground projects such as mines and tunnels, flood control, foundation reinforcement, and road maintenance, polymer grouting has become a distinctive development direction in geotechnical engineering.

[0003] The main components of polymer slurry include isocyanate, polyol, blowing agent, and catalyst. These ingredients primarily comprise two raw materials, Material A and Material B. Material A primarily consists of isocyanate, while Material B contains polyol, catalyst, blowing agent, and foam stabilizer. After Material A and Material B are thoroughly stirred and mixed, gelation and foaming reactions primarily occur. At the beginning of the reaction, the slurry is a reddish-brown, viscous liquid. As the reaction proceeds, a large number of bubble nuclei are gradually generated, rapidly increasing in size and volume, ultimately solidifying to form a high-molecular-weight solid polymer with a certain strength.

[0004] During this reaction process, the conversion rate of reactants directly affects the curing rate and final performance of the polyurethane slurry. The physical properties of polyurethane slurry, such as hardness, viscoelasticity, durability, and water resistance, mainly depend on the degree of reaction between isocyanate and polyol in the slurry. Therefore, accurately measuring the conversion rate of each reactant is key to ensuring that the slurry achieves the expected reaction efficiency during the construction process, thereby ensuring the final material performance and construction quality. In addition, by studying the conversion rate of reactants, it is possible to discover key factors affecting the slurry reaction, such as reaction temperature, catalyst type, component ratio, etc. These data can be used to optimize the formulation of polyurethane slurry, improve its reaction speed and curing characteristics, and make it more suitable for specific engineering needs.

[0005] Currently, the most commonly used measurement method is titration, which has relatively low accuracy and is susceptible to interference from side reactions or other chemicals. Furthermore, titration is a destructive test, consuming a large amount of sample per measurement, resulting in sample waste and increased experimental costs. Furthermore, the method is complex and susceptible to human error, limiting its application in more precise applications. Summary of the Invention

[0006] The purpose of the invention is to provide a method for determining the conversion rate of reactants during the reaction process of a two-component polyurethane polymer slurry, which solves the problem that the measurement method in the prior art is a destructive detection method, which consumes a large amount of sample each time, resulting in sample waste and increased experimental costs. Secondly, the operation is complicated and is susceptible to human error, which limits the application of this method in more precise situations.

[0007] The present invention is achieved by providing a method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction process, wherein the two components include a component A and a component B, wherein the component A includes an isocyanate, and the component B includes a polyol, water, and a physical foaming agent; the method comprises the following steps:

[0008] S1. Mix component A and component B, start timing after mixing evenly, use a pre-cooled sampling cup to sample at the time point to be tested, then place the sample in a low-temperature environment, and add an organic solvent to the sample to fully react;

[0009] S2. Perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of the CO bond of the carbamate. By comparing the relative changes of the CO bond absorption peak and the internal standard absorption peak at different time points, the formation rate of the carbamate during the reaction process is quantitatively calculated to obtain the conversion rate of the hydroxyl group in the reactant polyol;

[0010] S3, heating the B component, and recording the volume expansion curve V of the B component as it changes with temperature during the heating process. B =f(T);

[0011] S4. Mix components A and B and record the temperature T(t) and total volume expansion V at each time point t. 总 (t), according to the volume expansion curve V B =f(T), the conversion rate of water in the reaction process is obtained; the conversion rate of isocyanate (NCO) groups is obtained based on the conversion rate of hydroxyl groups and the conversion rate of water.

[0012] The present invention collects samples at different time points and uses infrared spectroscopy to quantitatively analyze the characteristic absorption peak of the carbamate CO group to calculate the conversion rate of the hydroxyl group in the polyol. The water conversion rate is then derived by monitoring the total volume expansion of the system during the reaction, combined with analysis of the volume expansion of the physical blowing agent. Based on the conversion rates of the polyol and water, the conversion rate of the isocyanate (NCO) group can be calculated. This effectively solves the problem of real-time monitoring of reactant conversion rates in complex polyurethane foaming reaction systems and provides a reliable basis for controlling the polyurethane foaming reaction process.

[0013] After mixing components A and B, the following gelling and foaming reactions mainly occur:

[0014]

[0015] A further technical solution of the present invention is as follows: in step S1, components A and B are added in equal proportions to an insulated reaction vessel, stirred for 5 seconds, and then a timer is started. A sample is taken at the desired time using a pre-cooled aluminum sampling cup, and the sample is then quickly placed in an ice-water mixture to maintain a low temperature. The aluminum sampling cup has excellent thermal conductivity, and using the pre-cooled aluminum sampling cup allows for rapid cooling of the sample. Since the polyurethane polymer slurry has difficulty reacting at low temperatures, the sample is then placed in the ice-water mixture to maintain a low temperature, further inhibiting its reaction.

[0016] A further technical solution of the present invention is that the organic solvent in step S1 is di-n-butylamine, and the volume of di-n-butylamine is 2-3 times that of the sample. Di-n-butylamine reacts specifically with isocyanate (-NCO) and maintains high reactivity even at low temperatures, rapidly consuming the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0017] A further technical solution of the present invention is: in infrared spectroscopy, according to the Beer-Lambert law, the area of ​​the absorption peak is generally proportional to the concentration of the substance. Its form is:

[0018] A=ε·c·l

[0019] Where A is absorbance, ε is the molar absorptivity (characteristic of a material at a specific wavelength), c is the concentration of the substance, and l is the optical path length of the sample. Under normal conditions, there is a linear relationship between concentration and absorbance (i.e., peak area). Therefore, the conversion rate can be calculated using Equation 1.

[0020] The (CO) bond in the carbamate group described in step S2 is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0021]

[0022] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0023] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0024] In the present invention, the internal standard peak is the CH stretching vibration peak of the methylene group (-CH2-) in the isocyanate. The CH stretching vibration peak of the methylene group (-CH2-) does not chemically react with reactants such as isocyanate, polyol, and water, and does not overlap with the characteristic absorption peaks of other reactants. Therefore, it is not interfered with by other substances in the reaction. By using a stable internal standard substance, its peak area does not change much during the reaction process. As a reference benchmark, it can compensate for changes caused by experimental conditions (such as changes in sample concentration, instrument fluctuations, etc.).

[0025] A further technical solution of the present invention is: in step S3, component B containing a physical foaming agent is separately injected into a cylindrical container with a scale, and the cylindrical container is placed on a heating device for heating; the temperature of component B in the cylindrical container is collected, and during the gradual heating process, the volume expansion curve V of the physical foaming agent of component B as it changes with temperature is recorded. B =f(T).

[0026] A further technical solution of the present invention is: the volume expansion curve formula of the physical foaming agent of component B as it changes with temperature is formula 2:

[0027]

[0028] Where R is the radius of the container, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0029] A further technical solution of the present invention is: in step S4, components A and B are injected into a cylindrical container with a scale for mixing and reacting, and the temperature T(t) and the total volume expansion V of the system are recorded. 总 (t), during the reaction process, at each time point t at the temperature T(t), according to the physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point The molar number of CO2 is obtained according to the ideal gas equation. The molar number of CO2 generated by the reaction is equal to the molar number of water converted, and the water conversion rate is calculated. The conversion rate of the isocyanate (NCO) group can be calculated based on the conversion rate of the hydroxyl group and the conversion rate of water.

[0030] A further technical solution of the present invention is: converting the volume expansion of CO2 described in the ideal gas equation into moles, in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0031] A further technical solution of the present invention is that the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0032]

[0033] According to the foaming reaction equation, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water in the reaction process can be calculated based on the number of moles of CO2.

[0034] A further technical solution of the present invention is that the conversion rate of the isocyanate (NCO) group at that moment can be calculated by formula 4 based on the conversion rate of the hydroxyl group and the conversion rate of water at the same moment:

[0035]

[0036] Among them, n OH,初始 is the number of moles of polyol (-OH) at the initial moment, is the number of moles of water at the initial moment, n NCO,初始 is the number of moles of isocyanate (-NCO) groups at the initial moment.

[0037] The present invention has the following beneficial effects: By collecting samples at different time points and quantitatively analyzing the characteristic absorption peak of the carbamate CO group using Fourier transform infrared spectroscopy (FTIR), the conversion rate of hydroxyl groups in the polyol is calculated. Furthermore, by monitoring the total volume expansion of the system during the reaction and combining this with analysis of the volume expansion of the physical blowing agent, the water conversion rate is deduced. Based on the conversion rates of the polyol and water, the conversion rate of the isocyanate (NCO) group can be calculated. This effectively solves the problem of real-time monitoring of reactant conversion rates in complex polyurethane foaming reaction systems and provides a reliable basis for controlling the polyurethane foaming reaction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the operation for measuring the conversion rate of carbamate CO bonds;

[0039] Figure 2 Schematic diagram of the relationship between the volume expansion of component B and temperature;

[0040] Figure 3 To measure the temperature and volume change during the mixing process of component A and component B;

[0041] Figure 4 This is a comparison diagram of the infrared characteristic peak changes of the CO bond before and after the reaction in the present invention;

[0042] Figure 5 This is a graph showing changes in infrared characteristic peaks at different times during the reaction process of the present invention;

[0043] Figure 6 This is a graph of polyol (-OH) conversion rates at different times provided by the present invention;

[0044] Figure 7 This is the curve of the physical foaming agent of component B changing with temperature;

[0045] Figure 8 It is a graph showing the volume changes of components A and B after mixing at different times;

[0046] Figure 9 3 is a diagram of the molar component conversion rate of water at different times provided by the present invention. DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0048] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology, and are not used to limit the conditions for implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0049] A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process comprises the following steps:

[0050] S1. Add components A and B in equal proportions to an insulated reaction vessel and stir for 5 seconds before starting the timer. Use a pre-chilled aluminum sampling cup to collect samples at the desired time point and quickly place the sample in an ice-water mixture to maintain a low temperature. Add dibutylamine (2 to 3 times the sample volume) to the sampling cup and stir to allow for a complete reaction.

[0051] Among them, component A is isocyanate, and component B is polyol, water, physical foaming agent, catalyst and other additives. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0052]

[0053] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0054] S2. Use a Fourier transform infrared spectrometer (FTIR) to analyze the sample and determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at different time points, the formation rate of carbamate during the reaction can be quantitatively calculated, and the conversion rate of hydroxyl groups in the reactant polyol can be further estimated. In infrared spectroscopy, according to the Beer-Lambert law, the area of ​​the absorption peak is generally proportional to the concentration of the substance. Its form is:

[0055] A=ε·c·l

[0056] Where A is absorbance, ε is the molar absorptivity (characteristic of a material at a specific wavelength), c is the concentration of the substance, and l is the optical path length of the sample. Under normal conditions, there is a linear relationship between concentration and absorbance (i.e., peak area). Therefore, the conversion rate can be calculated using Equation 1.

[0057] The (CO) bond in the carbamate described in step S2 is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to formula 1:

[0058]

[0059] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0060] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0061] S3. Pour the mixed solution of component B containing the physical foaming agent into a graduated cylinder, and heat the cylinder on a heating device. Place a temperature acquisition instrument in the cylinder, immerse the probe of the temperature sensor in the mixed solution, gradually increase the temperature, and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0062] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0063] S4. Inject components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =(T), and then calculate the CO2 volume expansion at that time point

[0064] Convert the volume of CO2 to moles according to the ideal gas equation.

[0065] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0066] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0067]

[0068] Based on the conversion rate of hydroxyl groups and the conversion rate of water, the conversion rate of isocyanate (NCO) groups can be calculated using Formula 4:

[0069]

[0070] Among them, n OH , initial is the number of moles of polyol (-OH) at the initial moment, is the number of moles of water at the initial moment, n NCO , initial is the molar number of isocyanate (-NCO) groups at the initial moment.

[0071] Example 1:

[0072] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0073] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds and then starting the timer. Use a pre-chilled aluminum sampling cup to collect a sample at 5 seconds. Then, quickly place the sample in an ice-water mixture to maintain a low temperature. Add dibutylamine (2 times the sample volume) to the sampling cup and stir to allow for a complete reaction.

[0074] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0075]

[0076] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0077] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 5s and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0078]

[0079] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0080] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0081] like Figure 4-6 As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 5s, the infrared absorption peak area of ​​the CO bond is 0.125, and the internal standard absorption peak area is 1.925. According to formula 1, the conversion rate of the polyol hydroxyl group is 2.11%.

[0082] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0083] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0084] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0085] Convert the volume of CO2 to moles according to the ideal gas equation.

[0086] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0087] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0088]

[0089] Based on the conversion rate of hydroxyl groups and the conversion rate of water, the conversion rate of isocyanate (NCO) groups can be calculated using Formula 4:

[0090]

[0091] Among them, n OH,初始 is the number of moles of polyol (-OH) at the initial moment, is the number of moles of water at the initial moment, n NCO,初始 is the number of moles of isocyanate (-NCO) groups at the initial moment.

[0092] Example 2:

[0093] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0094] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds, and then start the timer. Use a pre-cooled aluminum sampling cup to collect a sample at 10 seconds. Then, quickly place the sample in an ice-water mixture to maintain a low temperature. Add twice the volume of di-n-butylamine to the sampling cup and stir to allow for a complete reaction.

[0095] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0096]

[0097] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0098] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 10s and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate group is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0099]

[0100] Among them, A C-O The CO peak area during the reaction, AC-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0101] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0102] like Figure 4-6 As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 10s, the infrared absorption peak area of ​​the CO bond is 0.356, and the internal standard absorption peak area is 1.954. According to formula 1, the conversion rate of the polyol hydroxyl group is 6.1%.

[0103] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0104] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0105] Figure 7 The curve showing the change of physical foaming agent of component B with temperature shows that when the heating temperature is greater than 67°C, the volume begins to expand.

[0106] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0107] Convert the volume of CO2 to moles according to the ideal gas equation.

[0108] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0109] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0110]

[0111] In this example, the ambient temperature is 32 degrees Celsius, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol. At t = 10s, the volume of AB after mixing is 270.6 ml, and the corresponding temperature at this time is 41.34°C. The physical foaming agent has not yet foamed, and the volume expansion is due to the carbon dioxide generated by the chemical reaction. According to the ideal gas equation, the volume of CO2 is converted to moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), the molar number of CO2 is 0.00273 mol, according to formula 3 The conversion of available water was 8.2%.

[0112] Based on the conversion rate of hydroxyl groups and the conversion rate of water, the conversion rate of isocyanate (NCO) groups can be calculated using Formula 4:

[0113]

[0114] Among them, n OH,初始 is the number of moles of polyol (-OH) at the initial moment, is the number of moles of water at the initial moment, n NCO,初始 is the number of moles of isocyanate (-NCO) groups at the initial moment.

[0115] In this embodiment, according to the conversion rate of hydroxyl groups and the conversion rate of water at 10 seconds of reaction, the conversion rate of isocyanate (NCO) groups at 10 seconds was calculated to be 3.19% by formula 4.

[0116] Example 3:

[0117] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0118] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds, and then start the timer. Use a pre-cooled aluminum sampling cup to collect a sample at 18 seconds. Then, quickly place the sample in an ice-water mixture to maintain a low temperature. Add three times the volume of di-n-butylamine to the sampling cup and stir to allow for a complete reaction.

[0119] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0120]

[0121] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0122] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 18s and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate group is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0123]

[0124] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0125] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0126] like Figure 4-6As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 18s, the infrared absorption peak area of ​​the CO bond is 0.838, and the internal standard absorption peak area is 1.935. According to formula 1, the conversion rate of the polyol hydroxyl group is 14.22%.

[0127] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0128] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0129] Figure 7 The curve showing the change of physical foaming agent of component B with temperature shows that when the heating temperature is greater than 67°C, the volume begins to expand.

[0130] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0131] Convert the volume of CO2 to moles according to the ideal gas equation.

[0132] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0133] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0134]

[0135] In this example, the ambient temperature is 32 degrees Celsius, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol. At t = 20s, the volume of AB after mixing is 376.8 ml, and the corresponding temperature at this time is 53.07°C. The physical foaming agent has not yet foamed, and the volume expansion is due to the carbon dioxide generated by the chemical reaction. According to the ideal gas equation, the volume of CO2 is converted to moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), the molar number of CO2 is 0.0066 mol, according to formula 3 The conversion of available water was 19.8%.

[0136] Example 4:

[0137] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0138] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds, and then start the timer. Use a pre-chilled aluminum sampling cup to collect a sample at 27 seconds. Immediately place the sample in an ice-water mixture to maintain a low temperature. Add three times the volume of di-n-butylamine to the sampling cup and stir to allow for a complete reaction.

[0139] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0140]

[0141] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0142] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 27s and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0143]

[0144] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0145] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0146] like Figure 4-6 As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 27s, the infrared absorption peak area of ​​the CO bond is 1.809, and the internal standard absorption peak area is 1.915. According to the formula, the conversion rate of the polyol hydroxyl group is 39.39%.

[0147] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0148] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0149] Figure 7 The curve showing the change of physical foaming agent of component B with temperature shows that when the heating temperature is greater than 67°C, the volume begins to expand.

[0150] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0151] Convert the volume of CO2 to moles according to the ideal gas equation.

[0152] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0153] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0154]

[0155] In this example, the ambient temperature is 32 degrees Celsius, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 30s, the volume of AB after mixing is 536.74 ml, and the corresponding temperature at this time is 67.31 ° C. The volume of component B changes by 2 ml. After deducting the volume change caused by the physical foaming agent of component B, the volume of carbon dioxide generated only by the chemical reaction is 334.74 ml. According to the ideal gas equation, the volume of CO2 is converted to moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), the molar number of CO2 is 0.01198 mol, according to formula 3 The conversion of available water was 19.8%.

[0156] Embodiment 5:

[0157] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0158] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds, and then start timing. Use a pre-chilled aluminum sampling cup to collect a sample at 36 seconds. Then, quickly place the sample in an ice-water mixture to maintain a low temperature. Add three times the volume of dibutylamine to the sampling cup and stir to allow for a complete reaction.

[0159] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0160]

[0161] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0162] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 36 seconds and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0163]

[0164] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0165] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0166] like Figure 4-6As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 36s, the infrared absorption peak area of ​​the CO bond is 2.693, and the internal standard absorption peak area is 1.939. According to the formula, the conversion rate of the polyol hydroxyl group is 45.81%.

[0167] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0168] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0169] Figure 7 The curve showing the change of physical foaming agent of component B with temperature shows that when the heating temperature is greater than 67°C, the volume begins to expand.

[0170] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0171] Convert the volume of CO2 to moles according to the ideal gas equation.

[0172] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0173] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0174]

[0175] In this example, the ambient temperature is 32 degrees Celsius, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 39 s, the volume of AB after mixing is 607.36 ml, and the corresponding temperature at this time is 81.23 ° C. The volume of component B changes by 5 ml. After deducting the volume change caused by the physical foaming agent of component B, the volume of carbon dioxide generated only by the chemical reaction is 402.36 ml. According to the ideal gas equation, the volume of CO2 is converted to moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), the molar number of CO2 is 0.01794 mol, according to formula 3 The conversion rate of available water was 35.93%.

[0176] Example 6:

[0177] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0178] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds, and then start the timer. Use a pre-cooled aluminum sampling cup to collect a sample at 45 seconds. Then, quickly place the sample in an ice-water mixture to maintain a low temperature. Add three times the volume of di-n-butylamine to the sampling cup and stir to allow for a complete reaction.

[0179] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0180]

[0181] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0182] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 45 seconds and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0183]

[0184] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0185] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0186] like Figure 4-6 As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 45s, the infrared absorption peak area of ​​the CO bond is 3.596, and the internal standard absorption peak area is 1.936. According to the formula, the conversion rate of the polyol hydroxyl group is 61.08%.

[0187] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0188] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0189] Figure 7 The curve showing the change of physical foaming agent of component B with temperature shows that when the heating temperature is greater than 67°C, the volume begins to expand.

[0190] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0191] Convert the volume of CO2 to moles according to the ideal gas equation.

[0192] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0193] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0194]

[0195] In this example, the ambient temperature is 32 degrees Celsius, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol. At t = 47 s, the volume of AB after mixing is 907.49 ml, which corresponds to a temperature of 92.38 ° C. The volume of component B changes by 10 ml. After deducting the volume change caused by the physical foaming agent of component B, the volume of carbon dioxide generated only by the chemical reaction is 697.49 ml. The volume of CO2 is converted to moles according to the ideal gas equation. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), the molar number of CO2 is 0.02324 mol, according to formula 3 The conversion rate of available water was 69.73%.

[0196] Embodiment seven:

[0197] like Figure 1-9 A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process is shown, comprising the following steps:

[0198] S1. Add 20 mL of component A and 20 mL of component B to an insulated reaction vessel, stirring for 5 seconds, and then start timing. Use a pre-chilled aluminum sampling cup to collect a sample at 54 seconds. Then, quickly place the sample in an ice-water mixture to maintain a low temperature. Add three times the volume of di-n-butylamine to the sampling cup and stir to allow for complete reaction.

[0199] Component A is isocyanate, and the initial molar number of isocyanate (-NCO) groups is 0.08384; component B is polyol, water, physical blowing agent, catalyst and other additives, and the initial molar number of polyol is 0.04291. After mixing, the following gelation reaction and foaming reaction mainly occur:

[0200]

[0201] Among them, di-n-butylamine can react specifically with isocyanate (-NCO) and has high reactivity even at low temperatures. It can quickly consume the isocyanate in the reaction system without interfering with other components in the system, thereby effectively terminating the reaction.

[0202] S2. Use a Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample and measure the characteristic absorption peak of polyurethane CO. By comparing the relative changes in the CO absorption peak at 54s and the CH stretching vibration peak of the methylene group in the isocyanate, the formation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is deduced. The (CO) bond in the carbamate is formed by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the amount of CO bond generated can be directly related to the consumption of (-OH). The conversion rate of hydroxyl groups in the polyol is calculated according to Formula 1:

[0203]

[0204] Among them, A C-O The CO peak area during the reaction, A C-O,max is the maximum area of ​​the CO peak when the reaction is complete, A C-H is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

[0205] Among them, the infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923 cm -1 .

[0206] like Figure 4-6As shown, after the reaction is complete (t = 90s), the maximum integral area of ​​the infrared absorption peak of the polyurethane CO bond is 5.921, and the integral area of ​​the internal standard CH stretching vibration peak is 1.943; at t = 54s, the infrared absorption peak area of ​​the CO bond is 4.165, and the internal standard absorption peak area is 1.935. According to the formula, the conversion rate of the polyol hydroxyl group is 70.71%.

[0207] S3. Pour 100 mL of the mixed solution of component B containing the physical foaming agent into a graduated cylinder. Place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder so that the probe of the temperature sensor is immersed in the mixed solution. Gradually increase the temperature and record the volume expansion data V of the foaming agent of component B as it changes with temperature. B =f(T)

[0208] The volume expansion formula is R is the radius, h(t) is the height from the bottom to the highest point of the liquid surface at time t, and h1(t) is the height from the bottom to the lowest point of the liquid surface at time t.

[0209] Figure 7 The curve showing the change of physical foaming agent of component B with temperature shows that when the heating temperature is greater than 67°C, the volume begins to expand.

[0210] S4. Pour 100 mL of each of components A and B into a graduated cylinder and mix them. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at the temperature T(t), according to the previously obtained physical foaming agent expansion curve V B =f(T), calculate the volume expansion V of the physical foaming agent B =T(t), and then calculate the CO2 volume expansion at that time point

[0211] Convert the volume of CO2 to moles according to the ideal gas equation.

[0212] in, is the number of moles of CO2, P is the atmospheric pressure, is the volume expansion of CO2, R is the ideal gas constant, and T is the temperature.

[0213] According to the foaming reaction equation shown in step S1, the number of moles of CO2 generated by the reaction is equal to the number of moles of water converted. Therefore, the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0214]

[0215] In this example, the ambient temperature is 32 degrees Celsius, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol. At t = 64 s, the volume of AB after mixing is 1186.69 ml, which corresponds to a temperature of 106.13 ° C. The volume of component B changes by 40 ml. After deducting the volume change caused by the physical foaming agent of component B, the volume of carbon dioxide generated only by the chemical reaction is 946.69 ml. The volume of CO2 is converted to moles according to the ideal gas equation. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), the molar number of CO2 is 0.0304 mol, according to formula 3 The conversion rate of available water was 91.22%.

[0216] Based on the conversion rate of hydroxyl groups and water at the same time, the conversion rate of isocyanate (NCO) groups can be calculated using Formula 4:

[0217]

[0218] Among them, n OH,初始 is the number of moles of polyol (-OH) at the initial moment, is the number of moles of water at the initial moment, n NCO,初始 is the number of moles of isocyanate (-NCO) groups at the initial moment.

[0219] like Figure 5 It can be seen that the reaction process is related to the change of peak area;

[0220] Initial reaction phase: In the initial reaction phase, the hydroxyl group (-OH) of the polyol reacts with the isocyanate group (-NCO) of the isocyanate to form an amide group (-NHCO-) ​​and an ether bond (-O-). At this point, the CO peak begins to appear in the infrared spectrum, and its intensity is relatively weak.

[0221] Reaction in progress: As the reaction proceeds, the area of ​​the CO peak will gradually increase, and the degree of conversion of the polyol in the reaction will increase.

[0222] At the end of the reaction: When the reaction is nearing completion, most of the polyol has been converted into polyurethane, and the CO peak area reaches its maximum value. The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction, wherein the two components include component A and component B, wherein component A includes isocyanate, and component B includes polyol, water, and a physical blowing agent; characterized in that: The method comprises the following steps: S1. Mix component A and component B, start timing after mixing evenly, use a pre-cooled sampling cup to sample at the time point to be tested, then place the sample in a low-temperature environment, and add an organic solvent to the sample to fully react; S2. Perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of the CO bond of the polyurethane. By comparing the relative changes of the characteristic absorption peak of the CO bond at different time points with the internal standard absorption peak, the formation rate of carbamate during the reaction process is quantitatively calculated to obtain the conversion rate of the hydroxyl group in the reactant polyol; S3, heating the B component, and recording the volume expansion curve of the B component as it changes with temperature during the heating process In step S3, the B component containing the physical foaming agent is injected into a cylindrical container with a scale, and the cylindrical container is placed on a heating device for heating; the temperature of the B component in the cylindrical container is collected, and the volume expansion curve of the physical foaming agent of the B component with temperature changes is recorded during the gradual heating process. ; The volume expansion curve formula of the physical foaming agent of component B as it changes with temperature is as follows: Formula 2 Where R is the radius of the container, is the height from the bottom to the highest point of the liquid surface at time t, is the height from the bottom to the lowest point of the liquid surface at time t; S4. Mix components A and B and record the temperature at each time point t. and total volume expansion In step S4, components A and B are injected into a cylindrical container with scales for mixing and reaction, and the temperature of the system is recorded. and total volume expansion , during the reaction, the temperature at each time point t According to the expansion curve of the physical foaming agent , calculate the volume expansion of the physical foaming agent , and then calculate the time point Volume expansion , according to the ideal gas equation, we can get The number of moles of The number of moles is equal to the number of moles of water converted, and the conversion rate of water is calculated; the conversion rate of isocyanate (NCO) groups can be calculated based on the conversion rate of hydroxyl groups and the conversion rate of water; The conversion of isocyanate (NCO) groups was obtained based on the conversion of hydroxyl groups and the conversion of water.

2. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 1, wherein: In step S1, components A and B are added in equal proportions to an insulated reaction vessel, stirred for 5 seconds, and then timing is started. A pre-cooled aluminum sampling cup is used to take a sample at the time point to be tested, and then the sample is placed in an ice-water mixture to maintain a low temperature.

3. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 1, wherein: In step S1, the organic solvent is di-n-butylamine, and the volume of the di-n-butylamine is 2-3 times that of the sample.

4. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 1, wherein: In step S2, the conversion rate of hydroxyl groups in the polyol is calculated according to formula 1: Formula 1 in, The CO peak area during the reaction is is the maximum area of ​​the CO peak when the reaction is complete, is the area of ​​the internal standard peak, which is the CH stretching vibration peak of the methylene group in isocyanate.

5. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 1, wherein: According to the ideal gas equation The volume expansion is converted into moles, ,in, for The number of moles, P is the atmospheric pressure, for The volume expansion of a gas is R, the ideal gas constant, and T the temperature.

6. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 1, wherein: The reaction generates The number of moles is equal to the number of moles of water converted, so the conversion rate of water during the reaction can be calculated according to the following formula 3: Formula 3.

7. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 1, wherein: According to the conversion rate of hydroxyl group and water at the same time, the conversion rate of isocyanate (NCO) group at that time can be calculated by formula 4: Formula 4 in, is the number of moles of polyol (-OH) at the initial moment, is the number of moles of water at the initial moment, is the number of moles of isocyanate (-NCO) groups at the initial moment.

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