Method for measuring reactant conversion rate in reaction process of double-component polyurethane high polymer slurry

Abstract

The invention discloses a method for determining the reactant conversion rate in the reaction process of two-component polyurethane polymer slurry, which comprises the following steps: collecting samples at different time points, and quantitatively analyzing the characteristic absorption peak of a carbamate C-O bond by using Fourier transform infrared spectroscopy (FTIR) to calculate the conversion rate of hydroxyl in polyol. And the conversion rate of the water is deduced by monitoring the total volume expansion amount of the system in the reaction process and combining with the analysis of the volume expansion of the physical foaming agent. According to the conversion rate of the polyol and the water, the conversion rate of the isocyanate (NCO) group can be calculated, the problem that the reactant conversion rate in a complex polyurethane foaming reaction system is difficult to monitor in real time is effectively solved, and a reliable basis is provided 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, as a new type of engineering repair technology, has been widely used in infrastructure repair projects due to its advantages such as fast expansion, high early strength, waterproofness, durability, and environmental protection. For example, in water hazard prevention, foundation reinforcement, road maintenance, etc. in underground projects such as mines and tunnels, polymer grouting has become a distinctive development direction in the field of geotechnical engineering.

[0003] The main components of polymer slurry include isocyanate, polyol, foaming agent and catalyst, etc. These components mainly constitute two raw materials A and B. Among them, A is mainly composed of isocyanate, while B contains polyol, catalyst, foaming agent, foam stabilizer, etc. When A and B are fully stirred and mixed, gel reaction and foaming reaction mainly 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, the bubbles rapidly increase in size, and the volume expands, and finally solidifies to form a high molecular solid polymer with a certain strength.

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

[0005] At present, the commonly used measurement method is titration, which has relatively low measurement accuracy and is easily interfered by side reactions or other chemical substances. In addition, titration is a destructive test, and each measurement consumes a large amount of sample, resulting in sample waste and increased experimental costs. Secondly, the operation is complicated and susceptible to human errors, which limits the application of this method in more precise occasions. Summary of the invention

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

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

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

[0009] S2. Perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of the CO bond of the carbamate, and quantitatively calculate the formation rate of the carbamate during the reaction by comparing the relative changes of the CO bond absorption peak and the internal standard absorption peak at different time points, so as 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) group is obtained according to the conversion rate of hydroxyl group and the conversion rate of water.

[0012] The invention collects samples at different time points and uses infrared spectroscopy to quantitatively analyze the characteristic absorption peak of carbamate CO group, calculates the conversion rate of hydroxyl in polyol, and derives the conversion rate of water by monitoring the total volume expansion of the system during the reaction process and combining the analysis of the volume expansion of the physical foaming agent. According to the conversion rates of polyol and water, the conversion rate of isocyanate (NCO) group can be calculated, effectively solving the problem that the conversion rate of reactants in a complex polyurethane foaming reaction system is difficult to monitor in real time, and providing a reliable basis for controlling the polyurethane foaming reaction process.

[0013] After component A and component B are mixed, the following gelling reaction and foaming reaction mainly occur:

[0014]

[0015] A further technical solution of the present invention is: in the step S1, components A and B are added in equal proportions to an insulated reaction vessel, and the timing is started after stirring for 5 seconds, and a pre-cooled aluminum sampling cup is used to sample at the time point to be tested, and then the sample is quickly placed in an ice-water mixture to maintain a low temperature. The aluminum sampling cup has excellent thermal conductivity, and the use of a pre-cooled aluminum sampling cup can quickly cool the sample. The polyurethane polymer slurry is difficult to react at a low temperature, and then the sample is placed in an 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 the di-n-butylamine is 2-3 times that of the sample. Di-n-butylamine can react exclusively with isocyanate (-NCO), and has high reactivity even at low temperatures, and can quickly consume 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 spectrum, according to the Beer-Lambert law, the area of ​​the absorption peak is usually 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 (material characteristic at a specific wavelength), c is the substance concentration, 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 Formula 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -1 .

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

[0025] A further technical solution of the present invention is: in the step S3, the component B containing the 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 the 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 the 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 as follows:

[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 scales for mixed reaction, and the temperature T(t) and total volume expansion V of the system are recorded. 总 (t), during the reaction, 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 volume expansion of CO2 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 conversion rate of water 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: the volume expansion of CO2 described in the ideal gas equation is converted 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: according to the conversion rate of hydroxyl group and the conversion rate of water at the same time, the conversion rate of isocyanate (NCO) group at that time can be calculated by formula 4:

[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] Beneficial effects of the present invention: The present invention collects samples at different time points and uses Fourier transform infrared spectroscopy (FTIR) to quantitatively analyze the characteristic absorption peak of the carbamate CO group, calculates the conversion rate of the hydroxyl group in the polyol, and derives the water conversion rate by monitoring the total volume expansion of the system during the reaction, combined with the analysis of the volume expansion of the physical foaming agent. According to the conversion rates of the polyol and water, the conversion rate of the isocyanate (NCO) group can be calculated, which effectively solves the problem that the conversion rate of the reactants in the complex polyurethane foaming reaction system is difficult to monitor in real time, 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 This is a 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 It is a graph showing changes in infrared characteristic peaks at different times during the reaction process of the present invention;

[0043] Figure 6 It is a graph of polyol (-OH) conversion rate 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] Fig. 9 It 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, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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 people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the 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 the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the 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, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to sample at the time point to be tested, and then quickly place the sample in an ice-water mixture to keep it low temperature. Add di-n-butylamine in a volume 2 to 3 times the volume of the sample to the sampling cup, and stir to mix for full 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 Fourier transform infrared spectrometer (FTIR) to analyze the sample by infrared spectrum and determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes of CO absorption peaks at different time points, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl groups in the reactant polyol is inferred. In infrared spectroscopy, according to the Beer-Lambert law, the area of ​​the absorption peak is usually 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 (material characteristic at a specific wavelength), c is the substance concentration, 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 Formula 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 the hydroxyl group 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -1 .

[0061] S3. Pour the mixed solution of component B containing the physical foaming agent into a graduated cylinder, and place the cylinder on a heating device for heating; place a temperature acquisition instrument in the cylinder, and 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 for mixing and reaction, and record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0064] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0067]

[0068] According to the conversion rate of hydroxyl group and water, the conversion rate of isocyanate (NCO) group can be calculated by 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] Embodiment 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, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample when the timing reaches 5 seconds, and then quickly place the sample in an ice-water mixture to keep it low temperature. Add di-n-butylamine in a volume of twice the sample volume to the sampling cup, and stir to mix for full reaction.

[0074] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative change of the CO absorption peak at 5s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is deduced. The (CO) bond in the carbamate is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0085] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0088]

[0089] According to the conversion rate of hydroxyl group and water, the conversion rate of isocyanate (NCO) group can be calculated by 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] Embodiment 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, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample when the timing reaches 10 seconds, and then quickly place the sample in an ice-water mixture to keep it low. Add di-n-butylamine in a volume twice that of the sample to the sampling cup, and stir to mix for full reaction.

[0095] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes of the CO absorption peak at 10s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is deduced. The (CO) bond in the carbamate group is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0107] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0110]

[0111] In this embodiment, the ambient temperature is 32 degrees, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 10s, the volume of AB after mixing is 270.6 ml, and the corresponding temperature 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 into moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), at this time the molar number of CO2 is 0.00273 mol, according to the formula The conversion of available water was 8.2%.

[0112] According to the conversion rate of hydroxyl group and water, the conversion rate of isocyanate (NCO) group can be calculated by 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 group and the conversion rate of water at 10 seconds of reaction, the conversion rate of isocyanate (NCO) group at 10 seconds was calculated by formula 4 to be 3.19%.

[0116] Embodiment three:

[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 the insulated reaction vessel, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample at 18 seconds, and then quickly place the sample in an ice-water mixture to keep it low. Add di-n-butylamine in a volume 3 times the volume of the sample to the sampling cup, stir and mix to allow for full reaction.

[0119] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative change of the CO absorption peak at 18s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is deduced. The (CO) bond in the carbamate group is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0131] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0134]

[0135] In this embodiment, the ambient temperature is 32 degrees, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 20s, the volume of AB after mixing is 376.8 ml, and the corresponding temperature 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 into moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), at this time the molar number of CO2 is 0.0066 mol, according to formula 3 The conversion rate of available water was 19.8%.

[0136] Embodiment 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 the insulated reaction vessel, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample at 27 seconds, and then quickly place the sample in an ice-water mixture to keep it low. Add di-n-butylamine in a volume 3 times the volume of the sample to the sampling cup, and stir to mix for full reaction.

[0139] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes of the CO absorption peak at 27s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is deduced. The (CO) bond in the carbamate is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0151] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0154]

[0155] In this embodiment, the ambient temperature is 32 degrees, 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 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 into moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), at this time the molar number of CO2 is 0.01198 mol, according to formula 3 The conversion rate of available water was 19.8%.

[0156] Embodiment five:

[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 the insulated reaction vessel, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample at 36 seconds, and then quickly place the sample in an ice-water mixture to keep it low. Add di-n-butylamine in a volume 3 times the volume of the sample to the sampling cup, and stir to mix for full reaction.

[0159] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes of the CO absorption peak at 36s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is inferred. The (CO) bond in the carbamate is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0171] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0174]

[0175] In this embodiment, the ambient temperature is 32 degrees, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 39s, the volume of AB after mixing is 607.36 ml, and the corresponding temperature 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 into moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), at this time the molar number of CO2 is 0.01794 mol, according to formula 3 The conversion rate of available water was 35.93%.

[0176] Embodiment six:

[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 the insulated reaction vessel, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample at 45 seconds, and then quickly place the sample in an ice-water mixture to keep it low. Add di-n-butylamine in a volume 3 times the volume of the sample to the sampling cup, stir and mix to allow for full reaction.

[0179] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes of the CO absorption peak at 45s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is deduced. The (CO) bond in the carbamate is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0191] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0194]

[0195] In this embodiment, the ambient temperature is 32 degrees, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 47s, the volume of AB after mixing is 907.49 ml, and the corresponding temperature is 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. According to the ideal gas equation, the volume of CO2 is converted into moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), at this time 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 the insulated reaction vessel, stir for 5 seconds and then start timing. Use a pre-cooled aluminum sampling cup to take a sample at 54 seconds, and then quickly place the sample in an ice-water mixture to keep it low. Add di-n-butylamine in a volume 3 times the volume of the sample to the sampling cup, stir and mix to allow for full reaction.

[0199] Among them, component A is isocyanate, and the initial molar number of isocyanate (-NCO) group is 0.08384; component B is polyol, water, physical foaming agent, catalyst and other additives, and the initial molar number of polyol is 0.04291; after mixing, the following gel 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 Fourier transform infrared spectrometer (FTIR) to perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of polyurethane CO. By comparing the relative changes of the CO absorption peak at 54s and the CH stretching vibration peak of the methylene group in the isocyanate, the generation rate of carbamate during the reaction process is quantitatively calculated, and then the conversion rate of hydroxyl in the reactant polyol is inferred. The (CO) bond in the carbamate is generated by the reaction of the polyol (-OH) group and the isocyanate (-NCO) group. Therefore, the generation amount of the CO bond can be directly related to the consumption of (-OH), and the conversion rate of hydroxyl 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] The infrared characteristic absorption peak of CO bond is located at 1225cm -1 The infrared vibration peak of CH is located at 2923cm -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; when 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, and place the cylinder on a heating device to heat it. Place a temperature acquisition instrument in the cylinder, and 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)

[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 component A and B into a graduated cylinder for mixing and reaction. Record the temperature T(t) and total volume expansion V of the system. 总 (t), during the reaction, at each time point t at 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 volume expansion of CO2 at that time point

[0211] Convert the volume of CO2 to moles using 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, so the conversion rate of water during the reaction can be calculated according to the following formula 3:

[0214]

[0215] In this embodiment, the ambient temperature is 32 degrees, 100 ml of each component A and B are mixed, and the molar number of water is 0.03333 mol; t = 64s, the volume of AB after mixing is 1186.69 ml, and the corresponding temperature is 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. According to the ideal gas equation, the volume of CO2 is converted into moles. P is atmospheric pressure (1 atm), R is the ideal gas constant (0.0821 Latmmol -1 K -1 ), at this time the molar number of CO2 is 0.0304 mol, according to formula 3 The conversion rate of available water was 91.22%.

[0216] According to the conversion rate of hydroxyl group and water at the same time, the conversion rate of isocyanate (NCO) group can be calculated by 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 and the peak area change;

[0220] Initial stage of reaction: In the initial stage of reaction, the hydroxyl group (-OH) of polyol reacts with the isocyanate group (-NCO) of isocyanate to form an amide group (-NHCO-) ​​and an ether bond (-O-). At this time, 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 nearly completed, most of the polyols have been converted into polyurethanes, and the area of ​​the CO peak reaches a maximum value. The above description is only 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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process, wherein the two components include component A and component B, wherein component A includes isocyanate, and component B includes polyol, water and a physical foaming 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 take samples at the time point to be tested, then put the samples in a low temperature environment, and add an organic solvent to the samples for full reaction; S2. Perform infrared spectroscopy analysis on the sample to determine the characteristic absorption peak of the CO bond of the polyurethane, and quantitatively calculate the formation rate of carbamate during the reaction by comparing the relative changes of the characteristic absorption peak of the CO bond at different time points with the internal standard absorption peak, so as to obtain the conversion rate of the hydroxyl group in the reactant polyol; 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); S4. Mix components A and B and record the temperature at each time point t. T (t) and the total volume expansion V 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) group is obtained according to the conversion rate of hydroxyl group and the conversion rate of water.

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

3. The method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process according to claim 1, characterized in that: 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, characterized in that: In step S2, the conversion rate of hydroxyl groups in the polyol is calculated according to formula 1: 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.

5. The method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process according to claim 1, characterized in that: 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).

6. The method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process according to claim 5, characterized in that: The volume expansion curve formula of the physical foaming agent of component B as it changes with temperature is as follows: 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.

7. The method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process according to claim 1, characterized in that: In step S4, components A and B are injected into a cylindrical container with scales for mixing and reaction, and the temperature T(t) and total volume expansion V of the system are recorded. 总 (t), during the reaction, 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 volume expansion of CO2 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 conversion rate of water 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.

8. The method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process according to claim 7, characterized in that: The volume expansion of CO2 described by the ideal gas equation is converted 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.

9. The method for determining the conversion rate of reactants during a two-component polyurethane polymer slurry reaction according to claim 7, characterized in 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:

10. The method for determining the conversion rate of reactants in a two-component polyurethane polymer slurry reaction process according to claim 7, characterized in that: 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: 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.

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