High polymer material safety test system and method

Abstract

The invention discloses a high polymer material safety test system and method, and belongs to the technical field of chemical detection. The temperature sensor, the gas concentration detection device and the timer are used for acquiring the temperature, the gas concentration and the aging time in the treatment bin filled with the sample, and the analysis module is used for processing data detected by the temperature sensor, the timer and the gas concentration detection device; the real-time concentration change rate of the target gas in each treatment bin at different temperatures is calculated, and whether the real-time concentration change rate of the target gas reaches the preset change rate threshold value is judged, so that the test process is simplified, frequent bin opening and sampling are avoided in the test process, the test efficiency is improved, and the test cost is reduced. And the safety test results of various easily-decomposed high polymer materials are more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical testing, and particularly relates to a safety testing system and method for polymer materials. Background Art

[0002] Polymer materials have many advantages such as high strength, low density, and easy processing. However, during the processing, storage, and use of polymer materials, when affected by environmental factors (such as light, heat, medium, microorganisms, etc.), their physical and chemical properties decline, thereby affecting safety. In particular, polymer materials such as nitrocellulose that are prone to decomposition are likely to undergo decomposition reactions during storage and use, resulting in potential safety hazards. Therefore, studying the aging behavior of polymer materials is of great significance for ensuring their safe use. Currently, during the safety testing of polymer materials, manual operation is usually relied on to control the aging time and temperature, which not only increases the complexity of the testing but also easily introduces human errors, leading to inconsistent results. Therefore, improving the automation level of the testing system, reducing manual intervention, and enhancing the accuracy and consistency of experiments are important directions for future technological development.

[0003] Activation energy is an important parameter characterizing the chemical reaction activity of materials. In the prior art, materials are generally placed in an aging test chamber for aging tests, samples are taken out of the chamber to test the mechanical properties of the materials, decay data of the mechanical properties of the materials are obtained, and then the activation energy and lifespan of the materials are calculated using the Arrhenius formula. During testing, it is necessary to frequently take samples out of the chamber, resulting in temperature fluctuations inside the chamber and affecting the accuracy of the testing. More importantly, although the mechanical properties of materials are closely related to the aging behavior of materials, they cannot fully represent the changes in the chemical properties of materials. Therefore, the method for evaluating the safety of materials based on mechanical properties in the prior art is not suitable for evaluating the safety of polymer materials such as nitrocellulose that are prone to decomposition.

[0004] Therefore, it is highly necessary to develop a testing system and method suitable for evaluating the safety of polymer materials prone to decomposition. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a safety testing system and method for polymer materials.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In the first aspect, the present invention provides a polymer material safety testing system, including a sample processing device, a control module, an analysis module, a storage module, a computing module and an evaluation module, wherein the sample processing device includes a casing, wherein a plurality of processing chambers are arranged in the casing, and the processing chambers are equipped with chamber doors, heating devices, temperature sensors, gas concentration detection devices and timers, wherein the temperature sensors, gas concentration detection devices and timers are respectively connected to the control module, and the control module, analysis module, storage module, computing module and evaluation module are connected in sequence.

[0008] Preferably, the gas concentration detection device includes at least one of a nitrogen oxide concentration sensor, a carbon monoxide concentration sensor, a methane concentration sensor, a carbon dioxide concentration sensor, an oxygen concentration sensor, and a sulfur dioxide concentration sensor.

[0009] Preferably, the polymer material safety testing system further comprises a display module, and the evaluation module is connected to the display module.

[0010] Preferably, the heating device includes a heating table, a temperature control device and a control panel, the heating table is arranged in the processing chamber, a heating tube is arranged in the heating table, the temperature sensor is arranged on the heating table, the control panel is arranged on the outer wall of the casing, a heating switch and a temperature adjustment knob are arranged on the control panel, the temperature adjustment knob is connected to the temperature control device, the heating switch is used to control the on and off of the power supply of the heating tube, the temperature adjustment knob is used to set the temperature of the heating tube, and the timer is arranged on the control panel.

[0011] Preferably, the inner wall of the casing is provided with an insulation layer, and a plurality of transverse insulation partitions and a plurality of longitudinal insulation partitions are provided inside the casing. The transverse insulation partitions and the longitudinal insulation partitions are staggered to divide the internal space of the casing into a plurality of processing chambers.

[0012] Preferably, the processing chamber is provided with an air intake pipe and an exhaust pipe, the exhaust pipe is connected to a fan and an exhaust gas purification device in sequence, the air intake pipe is provided with an air intake valve, and the exhaust pipe is provided with an exhaust valve. The fan, air intake valve and exhaust valve are respectively connected to the control module.

[0013] In a second aspect, the present invention provides a polymer material safety testing method, which is tested using the polymer material safety testing system as described in the first aspect.

[0014] Preferably, the polymer material safety testing method comprises the following steps:

[0015] S1. Weigh n samples of the same mass and place them in n sample slots. Place the sample slots with samples in the treatment chamber, and use a gas concentration detection device to detect the initial concentration C0 of the target gas corresponding to the samples in the treatment chamber.

[0016] S2. Heat the n treatment chambers to different preset temperatures T within a preset time and then keep them warm. Start timing from when the temperature reaches T, and use a gas concentration detection device to detect the concentration of the target gas corresponding to the samples in the treatment chamber at a preset period to obtain the real-time concentration C of the target gas t , and record the time t of each detection.

[0017] S3. Calculate the change rate Δ of the real-time concentration of the target gas in each treatment chamber at different temperatures according to the following formula (1) t :

[0018]

[0019] S4. Compare the change rate Δ of the real-time concentration of the target gas t with a preset change rate threshold Δ0; if Δ t = Δ0, input the real-time concentration C of the target gas t and its corresponding detection time t and temperature T into the storage module for storage, and go to step S6; if Δ t < Δ0, repeat step S2; if Δ t > Δ0, control the reminder module to issue a warning.

[0020] S5. According to n groups of real-time concentrations C of the target gas t and their corresponding detection times t and temperatures T, use the Arrhenius formula to calculate the reaction activation energy of the samples.

[0021] S6. Evaluate the safety level of the samples according to the reaction activation energy of the samples.

[0022] Further preferably, in step S5, the calculation process of the reaction activation energy of the samples is as follows:

[0023] According to the Arrhenius formula, we know that:

[0024] Among them, k is the reaction rate constant at temperature T i , T i is the temperature in the i-th treatment chamber, t i is the detection time when Δ i = Δ0 under the condition of T t in the i-th treatment chamber, A is the pre-exponential factor, E is the reaction activation energy, R is the molar gas constant, and i is a positive integer not greater than n;

[0025] Taking t i as the reaction rate constant, we get:

[0026] Then lnt i and show a linear relationship;

[0027] Fitting the linear function of lnt i and and calculating through the slope of the linear function, the reaction activation energy E of the sample is obtained.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The present invention obtains the temperature, gas concentration and aging time in the treatment chamber containing the sample through the temperature sensor, gas concentration detection device and timer, processes the data detected by the temperature sensor, timer and gas concentration detection device through the analysis module, calculates the real-time change rate of the target gas concentration in each treatment chamber at different temperatures, and determines whether the real-time change rate of the target gas concentration reaches the preset change rate threshold, simplifies the test process, has no frequent opening of the chamber for sampling during the test process, improves the test efficiency, and makes the safety test results of various easily decomposable polymer materials more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of the polymer material safety testing system provided by the present invention;

[0031] Figure 2 is a top view of the sample treatment device provided by the present invention;

[0032] Figure 3 is a cross-sectional view of the treatment chamber provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the first aspect, the present invention provides a polymer material safety testing system, the structure of which is as Figures 1 to 3 shown.

[0035] The safety testing system for the polymer material includes a sample processing device, a control module, an analysis module, a storage module, a calculation module, and an evaluation module. The sample processing device includes a casing 1, and several processing chambers 2 are arranged inside the casing 1. Each processing chamber 2 is equipped with a chamber door 3, a heating device, a temperature sensor, a gas concentration detection device 4, and a timer 5. The temperature sensor, the gas concentration detection device 4, and the timer 5 are respectively connected to the control module, and the control module, the analysis module, the storage module, the calculation module, and the evaluation module are connected in sequence.

[0036] The system provided by the present invention obtains the temperature, gas concentration, and aging time in the processing chamber 2 through the temperature sensor, the gas concentration detection device 4, and the timer 5. The analysis module processes the data detected by the temperature sensor, the gas concentration detection device 4, and the timer 5, calculates the real-time change rate of the target gas concentration in each processing chamber 2 at different temperatures, and determines whether the real-time change rate of the target gas concentration reaches the preset change rate threshold. The calculation module performs linear fitting on the temperature and aging time when the real-time change rate of the target gas concentration reaches the preset change rate threshold, and obtains the reaction activation energy of the sample through the calculation of the slope of the linear function. The evaluation module divides the safety level of the sample according to the reaction activation energy of the sample.

[0037] Using the system provided by the present invention to test the safety of polymer materials, there is no frequent opening of the chamber for sampling during the test process, which can improve the test efficiency and make the safety test results of various easily decomposable polymer materials more reliable.

[0038] In one embodiment, the gas concentration detection device 4 includes at least one of a nitrogen oxide concentration sensor, a carbon monoxide concentration sensor, a methane concentration sensor, a carbon dioxide concentration sensor, an oxygen concentration sensor, and a sulfur dioxide concentration sensor.

[0039] In one embodiment, the safety testing system for the polymer material further includes a display module, and the evaluation module is connected to the display module.

[0040] In one embodiment, the heating device includes a heating table 12, a temperature control device, and a control panel 6. The heating table 12 is arranged inside the processing chamber 2, and a heating tube is arranged inside the heating table 12. The temperature sensor is arranged on the heating table. A heating switch and a temperature adjustment knob are arranged on the control panel 6. The control panel 6 is arranged on the outer wall of the casing 1. The temperature adjustment knob is connected to the temperature control device. The heating switch is used to control the on-off of the power supply of the heating tube, and the temperature adjustment knob is used to set the temperature of the heating tube. The timer 5 is arranged on the control panel 6.

[0041] In one embodiment, an inner wall of the casing 1 is provided with a heat-insulating layer 7, and a plurality of horizontal heat-insulating partitions 8 and a plurality of vertical heat-insulating partitions 9 are arranged in the casing 1. The horizontal heat-insulating partitions 8 and the vertical heat-insulating partitions 9 are arranged alternately to divide the internal space of the casing 1 into a plurality of processing chambers 2.

[0042] In one embodiment, the processing chamber 1 is provided with an intake pipe 10 and an exhaust pipe 11. The exhaust pipe 11 is sequentially connected with a fan and an exhaust gas purification device (not shown in the figure). The intake pipe 10 is provided with an intake valve (not shown in the figure), and the exhaust pipe 11 is provided with an exhaust valve.

[0043] After the test is completed, the exhaust valve, the intake valve and the fan can be opened to extract the exhaust gas in the processing chamber 2 for purification treatment, so as to avoid direct discharge of the exhaust gas and pollute the environment.

[0044] In a second aspect, a method for testing the safety of a polymer material provided by the present invention is to perform a test by using the polymer material safety testing system described in the first aspect.

[0045] The method for testing the safety of the polymer material includes the following steps:

[0046] S1. Weigh n samples of the same mass and place them in n sample slots. Place the sample slots containing the samples in the processing chamber 2, and use the gas concentration detection device 5 to detect the initial concentration C0 of the target gas corresponding to the samples in the processing chamber 2.

[0047] S2. Heat the n processing chambers 2 to different preset temperatures T within a preset time and then keep them warm. Start timing from the time when the temperature rises to T, and use the gas concentration detection device 5 to detect the concentration of the target gas corresponding to the samples in the processing chamber 2 according to a preset period to obtain the real-time concentration C t of the target gas, and record the time t of each detection.

[0048] S3. Calculate the change rate Δ t of the real-time concentration of the target gas in each processing chamber 2 at different temperatures according to the following formula (1):

[0049]

[0050] S4. Compare the change rate Δ t of the real-time concentration of the target gas with a preset change rate threshold Δ0; if Δ t = Δ0, input the real-time concentration C t of the target gas, its corresponding detection time t and temperature T into the storage module for storage, and turn to step S5; if Δ t < Δ0, repeat step S2; if Δ t > Δ0, control the reminder module to issue a warning.

[0051] S5. According to the real-time concentrations C of n groups of target gases t and their corresponding detection times t and temperatures T, use the Arrhenius formula to calculate the reaction activation energy of the sample;

[0052] S6. Evaluate the safety level of the sample according to the reaction activation energy of the sample.

[0053] In the present invention, the aging time required for the change rate of the real-time gas concentration in the treatment chamber 2 containing the same sample under different temperature conditions to reach the preset change rate threshold is used as the reaction rate at different temperatures, and lnt is fitted i and to obtain a linear function, and the reaction activation energy of the sample is obtained by calculating the slope of the linear function, and then the safety level of the sample is evaluated according to the reaction activation energy.

[0054] In the present invention, n is a positive integer, preferably a positive integer not less than 3.

[0055] In the present invention, in step S1, the sample is a polymer material that is easily decomposed, such as a nitrocellulose film.

[0056] In an embodiment, in step S5, the calculation process of the reaction activation energy of the sample is as follows:

[0057] According to the Arrhenius formula, it can be known that:

[0058] where k is the reaction rate constant at temperature T i when, T i is the temperature in the i-th treatment chamber, t i is the detection time when Δ i =Δ0 in the i-th treatment chamber under the condition of T t , A is the pre-exponential factor, E is the reaction activation energy, R is the molar gas constant, and i is a positive integer not greater than n;

[0059] Taking t i as the reaction rate constant, we get:

[0060] Then there is a linear relationship between lnt i and ;

[0061] Fit a linear function of lnt i and , and obtain the reaction activation energy E of the sample by calculating the slope of the linear function.

[0062] In the present invention, the threshold of the target gas concentration in the treatment chamber 2 is set to C m, the preset change rate threshold Δ0 is calculated by the following formula (4):

[0063]

[0064] For example, if the target gas is a flammable gas, the threshold C of the target gas concentration in the treatment chamber 2 m can be 10-15% of the lower explosion limit of the target gas concentration.

[0065] In a practical application scenario, the present invention uses the above-mentioned polymer material safety testing system to perform safety testing on nitrocellulose membranes, and the testing steps are as follows:

[0066] S1. Weigh 4 nitrocellulose membrane samples of the same mass, place them in 4 sample slots respectively, place the 4 sample slots containing the samples in 4 treatment chambers 2 respectively, close the chamber doors, and use a nitrogen oxide sensor to detect the initial concentration C0 of nitrogen oxide gas in each treatment chamber;

[0067] S2. Heat the four treatment chambers 2 to different preset temperatures within a preset time, then keep them warm and start timing. The temperatures in the four treatment chambers are: T1 = 150 °C, T2 = 140 °C, T3 = 130 °C, T4 = 120 °C. Use a nitrogen oxide sensor to detect the concentration of nitrogen oxide gas in each treatment chamber according to a preset period to obtain the real-time concentration C t of nitrogen oxide gas, and record the time t of each detection;

[0068] S3. Calculate the real-time concentration change rate Δ t of nitrogen oxide gas in each treatment chamber at different temperatures according to the following formula (1);

[0069]

[0070] S4. Compare the real-time concentration change rate Δ t of the target gas with the preset change rate threshold Δ0, and Δ0 is 5%; if Δ t = Δ0, input the real-time concentration C t of the target gas, its corresponding detection time and temperature into the storage module for storage, and go to step S6; if Δ t < Δ0, repeat step S2; if Δ t > Δ0, control the reminder module to issue a warning;

[0071] S5. The detection times are t1 = 30 min, t2 = 50 min, t3 = 80 min, t4 = 110 min respectively, and then the corresponding A linear function is obtained through linear fitting, and the reaction activation energy E of the sample is calculated through the slope calculation of the linear function; finally, the safety level of the sample is divided according to the reaction activation energy of the sample.

[0072] The larger the value of the reaction activation energy E, the higher the safety of the sample. Specifically, in step S5, if 150 kJ / mol ≤ E ≤ 160 kJ / mol, the safety level of the sample is rated as first level; if 160 kJ / mol < E ≤ 170 kJ / mol, the safety level of the sample is rated as second level; if 170 kJ / mol < E ≤ 180 kJ / mol, the safety level of the sample is rated as third level.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polymer material safety testing system, characterized in that: The invention comprises a sample processing device, a control module, an analysis module, a storage module, a calculation module and an evaluation module. The sample processing device comprises a casing, a plurality of processing chambers are arranged in the casing, the processing chambers are equipped with chamber doors, a heating device, a temperature sensor, a gas concentration detection device and a timer, the temperature sensor, the gas concentration detection device and the timer are respectively connected to the control module, and the control module, the analysis module, the storage module, the calculation module and the evaluation module are connected in sequence.

2. The polymer material safety testing system according to claim 1, characterized in that: The gas concentration detection device includes at least one of a nitrogen oxide concentration sensor, a carbon monoxide concentration sensor, a methane concentration sensor, a carbon dioxide concentration sensor, an oxygen concentration sensor, and a sulfur dioxide concentration sensor.

3. The polymer material safety testing system according to claim 1, characterized in that: It also includes a display module, and the evaluation module is connected to the display module.

4. The polymer material safety testing system according to claim 1, characterized in that: The heating device includes a heating platform, a temperature control device and a control panel. The heating platform is arranged in the processing chamber. A heating tube is arranged in the heating platform. The temperature sensor is arranged on the heating platform. The control panel is arranged on the outer wall of the casing. A heating switch and a temperature adjustment knob are arranged on the control panel. The temperature adjustment knob is connected to the temperature control device. The heating switch is used to control the on and off of the power supply of the heating tube. The temperature adjustment knob is used to set the temperature of the heating tube. The timer is arranged on the control panel.

5. The polymer material safety testing system according to claim 1, characterized in that: The inner wall of the casing is provided with a heat-insulating layer, and a plurality of transverse heat-insulating partitions and a plurality of longitudinal heat-insulating partitions are provided in the casing. The transverse heat-insulating partitions and the longitudinal heat-insulating partitions are staggered to divide the inner space of the casing into a plurality of processing chambers.

6. The polymer material safety testing system according to claim 1, characterized in that: The processing chamber is provided with an air intake pipe and an exhaust pipe, the exhaust pipe is connected with a fan and an exhaust gas purification device in sequence, the air intake pipe is provided with an air intake valve, and the exhaust pipe is provided with an exhaust valve. The fan, the air intake valve and the exhaust valve are respectively connected with the control module.

7. A polymer material safety testing method, characterized in that: The test is performed using the polymer material safety testing system as described in any one of claims 1 to 6.

8. The polymer material safety testing method according to claim 7, characterized in that: The steps include: S1. Weigh n samples of the same mass and place them in n sample slots. Place the sample slots containing the samples in a processing chamber, and use a gas concentration detection device to detect the initial concentration C0 of the target gas corresponding to the samples in the processing chamber; S2, heating the n processing chambers to different preset temperatures T within a preset time and then keeping them warm, starting the timing from when the temperature reaches T, using the gas concentration detection device to detect the target gas concentration corresponding to the sample in the processing chamber according to the preset cycle, and obtaining the real-time concentration C of the target gas t , and record the time t of each detection; S3. Calculate the real-time concentration change rate Δ of the target gas in each processing chamber at different temperatures according to the following formula (1): t : S4, the target gas real-time concentration change rate Δ t Compare with the preset change rate threshold Δ0; if Δ t =Δ0, the real-time concentration of the target gas C t and its corresponding detection time t and temperature T are input into the storage module for storage, and then go to step S6; if Δ t <Δ0, repeat step S2; if Δ t >Δ0, control the reminder module to issue an alarm; S5, according to the real-time concentration C of n groups of target gases t And its corresponding detection time t and temperature T, using the Arrhenius formula, calculate the reaction activation energy of the sample; S6. Evaluate the safety level of the sample based on the reaction activation energy of the sample.

9. The polymer material safety testing method according to claim 8, characterized in that: In step S5, the calculation process of the reaction activation energy of the sample is as follows: According to the Arrhenius formula: Where k is the temperature T i The reaction rate constant, T i is the temperature in the i-th processing chamber, t i For the i-th processing bin in T i Under the condition Δ t = Δ0, A is the pre-exponential factor, E is the reaction activation energy, R is the molar gas constant, and i is a positive integer not greater than n; will be t i As the reaction rate constant, we obtain: lnt i and There is a linear relationship between them; Fitting lnt i and The linear function of the reaction activation energy E of the sample is calculated by calculating the slope of the linear function.

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