A method for predicting the decomposition temperature of self-reactants and organic peroxides and control

Abstract

The present invention provides a method for predicting the decomposition temperature of self-reactants and organic peroxides and control, which relates to the technical field of testing of dangerous chemicals and dangerous goods, and solves the technical problems of high testing risk and long testing time. The steps for predicting the self-decomposition temperature include: testing the sample by differential scanning calorimetry, then performing differential scanning calorimetry testing after applying heat stress, comparing the test results, judging whether the sample is stable below 60°C, and if not, repeating the testing according to the temperature reduction gradient to determine the self-accelerating decomposition temperature. After obtaining the self-accelerating decomposition temperatures of the self-reactants and organic peroxides, it is judged whether temperature control is required based on the test data and spectra. The amount of sample required for testing in this method is small, thus greatly reducing the risk in the test process. It only takes a few hours for one test, shortening the testing time of the self-accelerating decomposition temperature; in addition, it also has the advantages of high safety and wide application range, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of testing hazardous chemicals and dangerous goods, and in particular to a method for predicting the decomposition temperature of self-reactive substances and organic peroxides, and determining whether self-reactive substances and organic peroxides need to be controlled at critical temperatures. Background Art

[0002] Self-reactive substances are thermally unstable substances that easily undergo intense exothermic decomposition even without oxygen (air). Organic peroxides easily decompose exothermically at normal or high temperatures, and the decomposition can be caused by heating, contact with impurities, friction or collision; therefore, both of these two types of substances have the characteristic of thermal instability.

[0003] In the field of hazardous chemicals / dangerous goods, these two types of substances are classified into 7 categories from type A to type G according to the degree of danger. Among them, the self-accelerating decomposition temperature (SADT) is an important parameter for their classification and critical temperature control.

[0004] In the international and domestic fields of dangerous goods and hazardous chemicals, the following classification explanations for self-reactive substances and mixtures are as follows: "Any self-reactive substance or mixture should be classified into this category, unless the self-accelerating decomposition temperature (SADT) of a 50 kg package is greater than 75 °C". The self-accelerating decomposition temperature is used as an important determination parameter for self-reactive substances and mixtures. For a single organic substance or a homogeneous mixture of organic substances, if the estimated self-accelerating decomposition temperature is greater than 75 °C, then relevant classification tests for self-reactive substances and mixtures are not required. The following classification explanations for organic peroxides are as follows: "The following organic peroxides require temperature control: a) Type B and Type C organic peroxides with SADT (self-accelerating decomposition temperature) ≤ 50 °C; b) Type D organic peroxides that show medium effects when heated under closed conditions and SADT ≤ 50 °C, or show weak or no effects when heated under closed conditions and SADT ≤ 45 °C; and c) Type E and Type F organic peroxides with SADT ≤ 45 °C", and the self-accelerating temperature is used as an important parameter for whether to conduct temperature control.

[0005] Currently, the existing self-accelerating decomposition temperature test methods are 4 test methods in Series H of the "Recommendations on the Transport of Dangerous Goods - Manual of Tests and Criteria" of the United Nations (hereinafter referred to as the "Manual of Tests and Criteria"). For Test H.1, the sample usage amount for the US self-accelerating decomposition temperature test is 25 kg, for H.2 adiabatic storage test and H.4 heat accumulation storage test, the sample usage amount is 1 kg, and for H.4 isothermal storage test, the sample usage amount is 20 g. All four test methods use a large amount of samples and have a high degree of danger during the test process; in addition, the existing sample test methods have a long test cycle. To obtain the final self-accelerating decomposition temperature, the test time is at least more than 7 days.

[0006] The self-accelerating decomposition temperature (SADT) is an important parameter for evaluating the thermal hazard characteristics of self-reactive chemical substances. The main components of a differential scanning calorimeter include a crucible, a temperature control system, and a liquid nitrogen system, which are used to measure the relationship between temperature and heat flow related to internal thermal transitions of materials, as well as for material research and development, performance testing, and quality control. Characteristics of materials such as glass transition temperature, cold crystallization, phase transition, melting, crystallization, product stability, curing / crosslinking, oxidation induction period, etc.

[0007] In order to further reduce the test hazard of the self-accelerating decomposition temperature and shorten the test time, it is necessary to improve the existing test methods and judgment methods. Summary of the Invention

[0008] In order to estimate the decomposition temperature of self-reactants and organic peroxides, shorten the test time, improve the safety performance of the test, and determine whether critical temperature control is required, the present invention provides a method for estimating the decomposition temperature of self-reactants and organic peroxides and control, and the specific technical solution is as follows.

[0009] A method for estimating the self-accelerating decomposition temperature, the steps include:

[0010] A. Take a sample and test the sample using differential scanning calorimetry;

[0011] B. Test the sample subjected to heat stress using differential scanning calorimetry;

[0012] C. Compare the test results in steps A and B to estimate the self-accelerating decomposition temperature of the sample.

[0013] Preferably, differential scanning calorimetry specifically measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0014] Preferably, the sample taken is 1 - 50 mg.

[0015] Preferably, in step A, the sample is placed in a sealed crucible of a differential scanning calorimeter, filled with nitrogen, and heated at a heating rate of 2 - 5 k / min under a nitrogen atmosphere, and the test results are saved.

[0016] Preferably, in step B, the sample is placed in a sealed crucible of a differential scanning calorimeter, kept at a constant temperature for 24 h under the action of a set temperature, and under a nitrogen atmosphere, the heating rate is adjusted to be the same as that in step A, and the test results are saved.

[0017] Further preferably, the test results include test parameters and DSC graph curves.

[0018] More preferably, in step C, first determine whether the self-accelerating decomposition temperature of the sample is greater than 60°C. When the self-accelerating decomposition temperature of the sample is less than 60°C, repeat steps B and C with a temperature reduction gradient of 10°C until the decomposition behavior of the sample remains stable, and then take this temperature as the self-accelerating decomposition temperature of the sample.

[0019] More preferably, when comparing the test results in step C with those in step A and step B, specifically, compare the test parameters and DSC spectrum curves in the test results, and judge the differences in the onset decomposition temperature, the shape of the spectrum, and the magnitude of exothermic or endothermic energy.

[0020] A method for predicting the self-accelerating decomposition temperature of a self-reactant, using the above method for predicting the self-accelerating decomposition temperature, and the sample is a self-reactant.

[0021] Even more preferably, when comparing the test results, if the differences in the onset decomposition temperature, the shape of the spectrum, and the magnitude of exothermic or endothermic energy are within 10%, it is determined that the decomposition behavior of the sample remains stable.

[0022] A method for judging the critical temperature control of a self-reactant, using the above method for predicting the self-accelerating decomposition temperature of a self-reactant. When it is determined that the temperature at which the self-reactant starts to decompose is greater than or equal to 60°C, it is judged that the self-reactant does not perform critical temperature control; when it is determined that the temperature at which the self-reactant starts to decompose is less than 60°C, judge the decomposition behavior of the self-reactant at the set temperature.

[0023] A method for predicting the self-accelerating decomposition temperature of an organic peroxide, using the above method for predicting the self-accelerating decomposition temperature, and the sample is an organic peroxide.

[0024] Even more preferably, when comparing the test results, if the differences in the onset decomposition temperature, the shape of the spectrum, and the magnitude of exothermic or endothermic energy are within 10%, it is determined that the decomposition behavior of the sample remains stable.

[0025] A method for judging the critical temperature control of an organic peroxide, characterized in that it uses the above method for predicting the self-accelerating decomposition temperature of an organic peroxide. When it is determined that the temperature at which the organic peroxide starts to decompose is greater than or equal to 60°C, it is judged that the organic peroxide does not perform critical temperature control; when it is determined that the temperature at which the organic peroxide starts to decompose is less than 60°C, judge the decomposition behavior of the organic peroxide at the set temperature.

[0026] The method for predicting the decomposition temperature and control of a self-reactant and an organic peroxide provided by the present invention has the following beneficial effects:

[0027] (1) Method for predicting the self-accelerating decomposition temperature. By using differential scanning calorimetry to test the sample, this test can use less sample, thus ensuring the safety of the test. In addition, the self-accelerating decomposition temperature can be determined through comparison. By repeating the test with a cooling gradient, the approximate range of the self-accelerating decomposition temperature can be directly predicted.

[0028] (2) The method for predicting the self-accelerating decomposition temperature can be applied to the measurement of the decomposition temperature of self-reactants and organic oxides. The comparison and determination method greatly shortens the measurement time period, thus providing a simple and rapid determination method, which is more conducive to the effective control of dangerous goods and hazardous chemicals.

[0029] (3) By using the method for predicting the self-accelerating decomposition temperature of self-reactants and organic oxides, it can be judged whether the self-reactant or organic oxide needs to be controlled at a critical temperature. By comparing the test results, it can be judged whether the decomposition behavior of the self-reactant or organic oxide is stable at the set temperature, thus achieving accurate judgment.

[0030] This method also has the advantages of simple operation, wide application range, time saving, and safety guarantee. Description of the Drawings

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1 is the flow chart for predicting the self-accelerating decomposition temperature;

[0033] Figure 2 is the test result diagram of test sample 1;

[0034] Figure 3 is the test result diagram of test sample 2;

[0035] Figure 4 is the shape comparison diagram of the spectra;

[0036] Figure 5 is the exothermic comparison diagram

[0037] Figure 6 is the schematic diagram of the differential scanning calorimeter;

[0038] Figure 7 is the schematic diagram of the principle of the differential scanning calorimeter;

[0039] Figure 8It is a flow chart of the method for predicting the self-accelerating decomposition temperature and controlling the critical temperature.

[0040] In the figure: 1 - crucible, 2 - lid, 3 - furnace, 4 - thermocouple. Specific implementation mode

[0041] Combined Figures 1 to 8 As shown, the specific implementation mode of a method for predicting the decomposition temperature of self-reactants and organic peroxides and control provided by the present invention is described in detail.

[0042] Example 1

[0043] A method for predicting the self-accelerating decomposition temperature, as Figure 1 shown, the specific steps include:

[0044] Step A.

[0045] Take a sample and test the sample by differential scanning calorimetry.

[0046] The amount of the sample taken is 1 - 50 mg, and the amount used for sample testing is 1 - 50 mg, which greatly reduces the danger during the test process. It only takes a few hours for one test, and also shortens the test time of the self-accelerating decomposition temperature.

[0047] Differential scanning calorimetry (DSC) is specifically to measure the relationship between the heat flow rate and time or temperature under controlled temperature conditions. Differential scanning calorimetry (DSC) is a thermal analysis method. Under programmed temperature control, the relationship between the power difference (such as in the form of heat) input to the sample and the reference is measured. The curve recorded by the differential scanning calorimeter is called the DSC curve. It takes the heat absorption or heat release rate of the sample, that is, the heat flow rate dH / dt (unit: millijoule / second) as the ordinate, and the temperature T or time t as the abscissa, and can measure a variety of thermodynamic and kinetic parameters, such as specific heat capacity, reaction heat, transition heat, phase diagram, reaction rate, crystallization rate, crystallinity of polymers, sample purity, etc.

[0048] When there is a temperature difference ΔT between the sample and the reference during the heating process of the sample, through the differential thermal amplification circuit and the differential heat compensation amplifier, the current flowing into the compensation heating wire changes. When the sample absorbs heat, the compensation amplifier immediately increases the current on the sample side; conversely, when the sample releases heat, it increases the current on the reference side until the heat on both sides is balanced and the temperature difference ΔT disappears. That is to say, the heat change that occurs during the thermal reaction of the sample is compensated by timely input of electric power, so what is actually recorded is the change relationship of the difference in the thermal power of the two electric heat compensations under the sample and the reference with time t. If the heating rate is constant, what is recorded is also the change relationship of the difference in thermal power with temperature T.

[0049] In this step, specifically, the sample is placed in a sealed crucible of a differential scanning calorimeter, filled with nitrogen, and heated at a heating rate of 2 - 5 K / min under a nitrogen atmosphere, and the test results are saved.

[0050] Among them, the adjustment of the heating rate is within the range of 2 - 5 K / min, that is, the temperature rises by 2 - 5 °C per minute, so that stable heating can be achieved, and the test time can also be saved.

[0051] Step B.

[0052] The differential scanning calorimetry can be used to test the sample subjected to thermal stress.

[0053] Among them, the sample consumption is 1 - 50 mg, which is the same as in Step A. The differential scanning calorimetry is specifically to measure the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0054] Specifically, the sample is placed in a sealed crucible of a differential scanning calorimeter, kept at a constant temperature for 24 h under the action of a set temperature, under a nitrogen atmosphere, the heating rate is adjusted to be the same as that in Step A, and the test results are saved.

[0055] Step C.

[0056] Compare the test results in Step A and Step B to estimate the self - accelerating decomposition temperature of the sample. The test results include test parameters and DSC graph curves.

[0057] First, judge whether the self - accelerating decomposition temperature of the sample is greater than 60 °C. When the self - accelerating decomposition temperature of the sample is less than 60 °C, repeat Step B and Step C with a temperature reduction gradient of 10 °C until the decomposition behavior of the sample remains stable, and then take this temperature as the self - accelerating decomposition temperature of the sample.

[0058] Among them, in Step C, comparing the test results in Step A and Step B specifically means comparing the test parameters and DSC graph curves in the test results, and judging the differences in the onset decomposition temperature, the shape of the graph, and the magnitude of exothermic or endothermic energy. If the measurement uncertainty range of the DSC test results of the original sample and the sample after applying thermal stress is less than 10%, it is considered that the sample has passed the test and no temperature control is required; since this test is carried out under the condition of 60 °C, when the sample fails the test, it is determined with a temperature reduction gradient of 10 °C.

[0059] Example 2

[0060] According to the classification process of self-reactive substances and organic peroxides in the "Test and Standard Manual", whether the self-accelerating decomposition temperature in a 50-kg package is less than 60 °C is an important parameter for classification. According to the "100K rule", the initial decomposition temperature of chemicals is screened by differential scanning calorimetry (DSC). If the initial decomposition temperature screened by DSC is greater than or equal to 60 °C, temperature control is not required, and it can be assumed that it has sufficient thermal stability. If the screened initial decomposition temperature is lower than 60 °C, it is necessary to judge whether the decomposition behavior changes under thermal stress for the sample within a specified time.

[0061] A method for predicting the self-accelerating decomposition temperature of a self-reactant, using the above method for predicting the self-accelerating decomposition temperature, and the sample is a self-reactant.

[0062] The method for predicting the self-accelerating decomposition temperature includes the following steps:

[0063] Step A. Take a self-reactant and test the sample by differential scanning calorimetry; the amount of the self-reactant taken is 1-50 mg. Specifically, differential scanning calorimetry measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0064] Specifically, put the self-reactant into a sealed crucible of a differential scanning calorimeter, fill it with nitrogen, heat it at a heating rate of 2-5 k / min under a nitrogen atmosphere, and save the test results.

[0065] Step B. Test the sample under thermal stress by differential scanning calorimetry; the amount of the self-reactant taken is 1-50 mg. Specifically, differential scanning calorimetry measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0066] Place the self-reactant in a sealed crucible of a differential scanning calorimeter, keep it at a constant temperature for 24 h under the action of a set temperature, adjust the heating rate to be the same as that in Step A under a nitrogen atmosphere, and save the test results.

[0067] Step C. Compare the test results in Step A and Step B to predict the self-accelerating decomposition temperature of the self-reactant. The test results include test parameters and DSC graph curves. First, judge whether the self-accelerating decomposition temperature of the self-reactant is greater than 60 °C. When the self-accelerating decomposition temperature of the self-reactant is less than 60 °C, repeat Step B and Step C with a temperature reduction gradient of 10 °C until the decomposition behavior of the self-reactant remains stable, and then take this temperature as the self-accelerating decomposition temperature of the sample.

[0068] Specifically, in Step C, comparing the test results in Step A and Step B is to compare the test parameters and DSC graph curves in the test results, and judge the differences in the initial decomposition temperature, the shape of the graph, and the magnitude of heat release or endothermic absorption.

[0069] In addition, when comparing test results, if the starting decomposition temperature, the shape of the spectrum, and the difference range of the exothermic or endothermic energy are within 10%, it is determined that the decomposition behavior of the sample remains stable.

[0070] Example 3

[0071] According to the classification process of self-reactive substances and organic peroxides, whether the self-accelerating decomposition temperature in a 50-kg package is less than 60°C is an important parameter for classification. According to the "100K rule", the initial decomposition temperature of chemicals is screened by differential scanning calorimetry (DSC). If the initial decomposition temperature screened by DSC is greater than or equal to 60°C, temperature control is not required, and it can be assumed that it has sufficient thermal stability. If the screened initial decomposition temperature is lower than 60°C, it is necessary to judge whether the decomposition behavior changes under thermal stress for the sample within a specified time.

[0072] A method for predicting the self-accelerating decomposition temperature of an organic peroxide, using the above method for predicting the self-accelerating decomposition temperature, and the sample is an organic peroxide.

[0073] The method for predicting the self-accelerating decomposition temperature includes the following steps:

[0074] Step A. Take an organic peroxide and test the sample by differential scanning calorimetry; the dosage of the organic peroxide is 1-50 mg. Specifically, differential scanning calorimetry measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0075] Specifically, put the organic peroxide into a sealed crucible of a differential scanning calorimeter, fill it with nitrogen, and heat it at a heating rate of 2-5 k / min under a nitrogen atmosphere, and save the test results.

[0076] Step B. Test the organic peroxide under thermal stress by differential scanning calorimetry; the dosage of the organic peroxide is 1-50 mg. Specifically, differential scanning calorimetry measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0077] Place the organic peroxide in a sealed crucible of a differential scanning calorimeter, keep it at a constant temperature for 24 h under the action of a set temperature, adjust the heating rate to be the same as that in Step A under a nitrogen atmosphere, and save the test results.

[0078] Step C. Compare the test results in Step A and Step B to estimate the self-accelerating decomposition temperature of the organic peroxide. The test results include test parameters and DSC curve. First, determine whether the self-accelerating decomposition temperature of the organic peroxide is greater than 60°C. When the self-accelerating decomposition temperature of the sample is less than 60°C, repeat Step B and Step C with a temperature reduction gradient of 10°C until the decomposition behavior of the organic peroxide remains stable, and then take this temperature as the self-accelerating decomposition temperature of the sample.

[0079] Among them, in Step C, comparing the test results in Step A and Step B specifically means comparing the test parameters and DSC curve in the test results, and judging the differences in the onset decomposition temperature, the shape of the curve, and the magnitude of exothermic or endothermic energy.

[0080] In addition, when comparing the test results, if the differences in the onset decomposition temperature, the shape of the curve, and the magnitude of exothermic or endothermic energy are within 10%, it is determined that the decomposition behavior of the sample remains stable.

[0081] Example 4

[0082] Based on Example 2, a method for judging critical temperature control of the self-reactant according to the test results is provided, which is as follows.

[0083] A method for judging critical temperature control of the self-reactant uses the above method for estimating the self-accelerating decomposition temperature of the self-reactant. The method for estimating the self-accelerating decomposition temperature of the self-reactant uses the above method for estimating the self-accelerating decomposition temperature, and the sample is the self-reactant.

[0084] Among them, the steps of the method for estimating the self-accelerating decomposition temperature include:

[0085] Step A. Take the self-reactant and test the sample by differential scanning calorimetry; the amount of the self-reactant taken is 1 - 50 mg. Among them, differential scanning calorimetry specifically measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0086] Specifically, put the self-reactant into a sealed crucible of the differential scanning calorimeter, fill it with nitrogen, heat it at a heating rate of 2 - 5 k / min under a nitrogen atmosphere, and save the test results.

[0087] Step B. Use differential scanning calorimetry to test the self-reactant under heat stress; the amount of the self-reactant taken is 1 - 50 mg. Among them, differential scanning calorimetry specifically measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0088] Place the self-reactant in a sealed crucible of the differential scanning calorimeter, keep it at a constant temperature for 24 h under the action of a set temperature, under a nitrogen atmosphere, adjust the heating rate to be the same as that in Step A, and save the test results.

[0089] Step C. Compare the test results in Step A and Step B to estimate the self-accelerating decomposition temperature of the self-reactant. The test results include test parameters and DSC curve. First, determine whether the self-accelerating decomposition temperature of the sample is greater than 60°C. When the self-accelerating decomposition temperature of the self-reactant is less than 60°C, repeat Step B and Step C with a temperature reduction gradient of 10°C until the decomposition behavior of the self-reactant remains stable, and then take this temperature as the self-accelerating decomposition temperature of the sample.

[0090] Specifically, in Step C, comparing the test results in Step A and Step B means comparing the test parameters and DSC curve in the test results to determine the differences in the starting decomposition temperature, the shape of the curve, and the magnitude of exothermic or endothermic energy.

[0091] In addition, when comparing the test results, if the differences in the starting decomposition temperature, the shape of the curve, and the magnitude of exothermic or endothermic energy are within 10%, it is determined that the decomposition behavior of the self-reactant remains stable.

[0092] When it is determined that the temperature at which the self-reactant starts to decompose is greater than or equal to 60°C, it is determined that the self-reactant does not require critical temperature control; when it is determined that the temperature at which the self-reactant starts to decompose is less than 60°C, the decomposition behavior of the self-reactant at the set temperature is determined.

[0093] Example 5

[0094] Based on Example 3, a method for judging critical temperature control of organic peroxides according to test results is provided as follows.

[0095] A method for judging critical temperature control of organic peroxides uses the above method for estimating the self-accelerating decomposition temperature of organic peroxides. The method for estimating the self-accelerating decomposition temperature of organic peroxides uses the above method for estimating the self-accelerating decomposition temperature, and the sample is an organic peroxide.

[0096] The steps of the method for estimating the self-accelerating decomposition temperature include:

[0097] Step A. Take an organic peroxide and test the sample using differential scanning calorimetry; the amount of the organic peroxide taken is 1 - 50 mg. Specifically, differential scanning calorimetry measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0098] Specifically, put the organic peroxide into a sealed crucible of a differential scanning calorimeter, fill it with nitrogen, and heat it at a heating rate of 2 - 5 k / min under a nitrogen atmosphere, and save the test results.

[0099] Step B. Test the organic peroxide subjected to thermal stress by differential scanning calorimetry; the dosage of the organic peroxide is 1-50 mg. Specifically, differential scanning calorimetry measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

[0100] Place the organic peroxide in a sealed crucible of a differential scanning calorimeter, keep it at a constant temperature for 24 h under the action of a set temperature. Under a nitrogen atmosphere, adjust the heating rate to be the same as that in Step A, and save the test results.

[0101] Step C. Compare the test results in Step A and Step B to estimate the self-accelerating decomposition temperature of the organic peroxide. The test results include test parameters and DSC graph curves. First, determine whether the self-accelerating decomposition temperature of the organic peroxide is greater than 60 °C. When the self-accelerating decomposition temperature of the sample is less than 60 °C, repeat Step B and Step C with a temperature reduction gradient of 10 °C until the decomposition behavior of the sample remains stable, and then take this temperature as the self-accelerating decomposition temperature of the organic peroxide.

[0102] Specifically, in Step C, when comparing the test results in Step A and Step B, compare the test parameters and DSC graph curves in the test results, and judge the differences in the onset decomposition temperature, the shape of the graph, and the magnitude of exothermic or endothermic energy.

[0103] In addition, when comparing the test results, if the differences in the onset decomposition temperature, the shape of the graph, and the magnitude of exothermic or endothermic energy are within 10%, it is determined that the decomposition behavior of the organic peroxide remains stable.

[0104] When it is determined that the temperature at which the organic peroxide starts to decompose is greater than or equal to 60 °C, it is judged that the organic peroxide does not require critical temperature control; when it is determined that the temperature at which the organic peroxide starts to decompose is less than 60 °C, judge the decomposition behavior of the organic peroxide at the set temperature.

[0105] Example 6

[0106] On the basis of Examples 1 to 5, take Sample 1 and Sample 2 for specific tests, and thus obtain the test results as Figure 2 and Figure 3 shown.

[0107] Among them, Figure 2 for Sample 1, the shapes, positions, and endothermic / exothermic energy values of the DSC curves of the original sample and the sample after applying stress remain unchanged within the error range, and the melting endothermic peak also does not change. Therefore, the sample is stable and does not require temperature control.

[0108] As Figures 3 to 5For the sample 2 shown, after applying thermal stress, the shape of the DSC test curve changed significantly. The first exothermic peak completely disappeared at around 100 °C, and the heat of decomposition decreased by about 20%. This indicates that the sample reacted under the condition of applying thermal stress, so it is necessary to control the temperature.

[0109] The present invention provides a method for predicting the self-accelerating decomposition temperature of self-reactive substances and organic peroxides, and also provides a method for determining whether critical temperature control is required. By comparing the DSC test results of the original sample and the sample after applying thermal stress, the self-accelerating decomposition temperature is predicted, which uses less amount than the existing self-accelerating decomposition temperature test methods, has higher safety during the test process, and shorter test time. It has important significance for the research on chemical hazards, as well as for hazardous chemical pipelines and testing institutions.

[0110] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for predicting the self-accelerating decomposition temperature, characterized in that The steps include: A. Take a sample and test the sample by differential scanning calorimetry; B. Test the sample subjected to thermal stress by differential scanning calorimetry; C. Compare the test results in steps A and B to estimate the self-accelerating decomposition temperature of the sample; In step C, first determine whether the self-accelerating decomposition temperature of the sample is greater than 60°C. When the self-accelerating decomposition temperature of the sample is less than 60°C, repeat steps B and C with a temperature reduction gradient of 10°C until the decomposition behavior of the sample remains stable, and then take this temperature as the self-accelerating decomposition temperature of the sample; In step C, comparing the test results in steps A and B specifically means comparing the test parameters and the DSC graph curves in the test results to judge the differences in the onset decomposition temperature, the shape of the graph, and the magnitude of exothermic or endothermic energy; When the sample is a self-reactant, when comparing the test results, if the differences in the onset decomposition temperature, the shape of the graph, and the magnitude of exothermic or endothermic energy are within 10%, it is judged that the decomposition behavior of the sample remains stable; When the sample is an organic peroxide, when comparing the test results, if the differences in the onset decomposition temperature, the shape of the graph, and the magnitude of exothermic or endothermic energy are within 10%, it is judged that the decomposition behavior of the sample remains stable.

2. The method for predicting the self-accelerating decomposition temperature according to claim 1, wherein The differential scanning calorimetry specifically measures the relationship between the heat flow rate and time or temperature under controlled temperature conditions.

3. The method for predicting the self-accelerating decomposition temperature according to claim 1, wherein The sample is taken in an amount of 1 - 50 mg.

4. The method for predicting the self-accelerating decomposition temperature according to claim 1, wherein, In step A, place the sample in a sealed crucible of a differential scanning calorimeter, fill it with nitrogen, and heat it at a heating rate of 2 - 5 k / min under a nitrogen atmosphere, and save the test results.

5. A method for predicting the self-accelerating decomposition temperature according to claim 1, characterized in that, In step B, place the sample in a sealed crucible of a differential scanning calorimeter, keep it at a constant temperature for 24 h under the action of a set temperature, under a nitrogen atmosphere, adjust the heating rate to be the same as that in step A, and save the test results.

6. A method for predicting the self-accelerating decomposition temperature according to claim 4 or 5, characterized in that The test results include test parameters and DSC graph curves.

7. A method for judging critical temperature control of self-reactants, characterized in that, Using the method for estimating the self-accelerating decomposition temperature according to any one of claims 1 - 6, when the sample is a self-reactant, if it is determined that the onset decomposition temperature of the self-reactant is greater than or equal to 60°C, it is judged that the self-reactant does not require critical temperature control; if it is determined that the onset decomposition temperature of the self-reactant is less than 60°C, judge the decomposition behavior of the self-reactant at the set temperature.

8. A method for judging critical temperature control of organic peroxides, characterized in that, Using the method for estimating the self-accelerating decomposition temperature according to any one of claims 1 - 6, when the sample is an organic peroxide, if it is determined that the onset decomposition temperature of the organic peroxide is greater than or equal to 60°C, it is judged that the organic peroxide does not require critical temperature control; if it is determined that the onset decomposition temperature of the organic peroxide is less than 60°C, judge the decomposition behavior of the organic peroxide at the set temperature.

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