An environmental stress testing device and method based on the transmittance variation of a polymer reference material

Abstract

This invention discloses an environmental stress testing device and method based on the change in transmittance of a polymer reference material. The testing device includes a transparent polymer reference material sample, a high-transparency glass sample, a shell, a first sensor, and a second sensor. The transparent polymer reference material sample and the high-transparency glass sample have the same thickness and are located on the same plane. The first sensor is positioned directly below the transparent polymer reference material sample, and the second sensor is positioned directly below the high-transparency glass sample. The shell is integrally connected to the transparent polymer reference material sample and the high-transparency glass sample, enclosing the first and second sensors inside the shell. The first and second sensors are identical sensors. This invention can measure the change in transmittance of polymer materials to quantitatively assess environmental stress.

Description

Technical Field

[0001] This invention relates to the field of material aging and environmental testing, specifically to an environmental stress testing device and method based on the change in transmittance of a polymer reference material. Background Art

[0002] Environmental stress reflects the impact of environmental factors on products. The combined effect of environmental factors such as solar radiation, temperature, and humidity in different regions on products constitutes the comprehensive environmental stress. For the field of materials aging, accurate quantitative measurement of comprehensive environmental stress is the prerequisite and foundation for conducting environmental testing and designing material and product performance. Existing technologies contain numerous evaluation methods for the aging behavior of commonly used polymer materials in different climates. For example, Chinese patent application number 201811181744.2, "A Method for Quantitatively Comparing the Aging Damage of Polymer Materials to Different Climate Environments," assesses the aging behavior of polymer materials in different climates by utilizing changes in the yellow index of the polymer material. However, these existing evaluation methods are time-consuming, requiring at least one year, and are based on periodic sampling tests of polymer materials. The data obtained is discontinuous, failing to achieve the goal of precise control over the testing time. Summary of the Invention

[0003] One of the objectives of this invention is to provide an environmental stress testing device based on the change in transmittance of a polymer reference material, used to measure the change in transmittance of the polymer material, thereby quantifying and assessing environmental stress.

[0004] An environmental stress testing device based on the transmittance variation of a polymer reference material includes a transparent polymer reference material sample, a high-transparency glass material sample, a shell, a first sensor, and a second sensor. The transparent polymer reference material sample and the high-transparency glass material sample have the same thickness and are located on the same plane. The first sensor is located directly below the transparent polymer reference material sample, and the second sensor is located directly below the high-transparency glass material sample. The shell is integrated with the transparent polymer reference material sample and the high-transparency glass material sample, and encloses the first sensor and the second sensor inside the shell. The shell is mainly used to prevent dust from entering the device and affecting the accuracy of the transmittance measurement. The first sensor and the second sensor are the same sensor.

[0005] The device of this invention is particularly suitable for comparing environmental stresses at different locations of large test samples used in outdoor environments. For example, when conducting outdoor exposure tests on whole vehicles, the device can be installed at different locations on the vehicle, such as the plane below the bumper, the dashboard, and the door trim panel. Based on the characteristics of the light transmittance change of a transparent polymer reference material after its aging performance deteriorates under a certain environment, the device calculates the light transmittance change of the transparent polymer reference material in real time by measuring the comparison of the natural irradiation received by the transparent polymer reference material and a high-transmittance glass material. This reflects the effect of environmental stress accumulation at the measurement location and quantifies the environmental stress experienced by different parts.

[0006] The present invention also has the following preferred designs:

[0007] Both the first sensor and the second sensor in this invention are light sensors.

[0008] Alternatively, both the first and second sensors may be radiation sensors.

[0009] Preferably, the first sensor and the second sensor are calibrated, and the measurement error of the two sensors is within 2%.

[0010] The present invention also includes a measurement storage circuit board connected to the first sensor and the second sensor for recording and storing the measurement signals of the first sensor and the second sensor. The measurement storage circuit board can also be replaced by an external measurement recording instrument, which can measure, record and calculate in real time and summarize the data through transmission methods such as networks.

[0011] Furthermore, the outer shell of the device described in this invention is made of opaque material, and the internal surfaces of the outer shell are made of a material with a reflectance coefficient of <30%, thereby avoiding the impact of edge light leakage or internal reflection on measurement accuracy.

[0012] The second objective of this invention is to provide a test method using the aforementioned environmental stress testing device based on the transmittance variation of a polymer reference material, comprising the following steps:

[0013] (a) Install the test apparatus on the target test plane;

[0014] (b) Natural light illuminating the test plane passes through a transparent polymer reference material sample and its irradiance or illuminance is measured by the first sensor.

[0015] (c) Natural light illuminating the test plane passes through a high-transmittance glass sample and its irradiance or illuminance is measured by a second sensor.

[0016] (d) During the test, the ratio of irradiance or illuminance measured by the first sensor and the second sensor reflects the ratio of light transmittance of the transparent polymer reference material sample to that of the high-transmittance glass material sample.

[0017] This invention can accurately measure the transmittance variation curve of a transparent polymer reference material at different locations, thereby enabling a comparison of environmental stress at different locations.

[0018] The light transmittance of the transparent polymer reference material sample described in this invention is calculated as follows:

[0019] (1) Assuming that in the initial state, the irradiance or illuminance of the natural light illuminating the test plane at a certain moment is S0, and the transmittance of the transparent polymer reference material sample and the high-transparency glass material sample are T, respectively. 10 With T 20 The irradiance or illuminance measured by the first sensor and the second sensor are S, respectively. 10 and S 20 If the ratio of the two is D0, then we have

[0020]

[0021] (2) Similarly, after a certain period of measurement, the irradiance or illuminance of the natural light illuminating the test plane at a certain moment is S. t At this moment, the transmittance of the transparent polymer reference material sample drops to T. 1t The light transmittance of the high-transmittance glass material sample changes to T. 2t The first and second sensors measured the irradiance or illuminance at that moment as S, respectively. 1t and S 2t The ratio of the two is D. t Then there is

[0022]

[0023] Because the high-transmittance glass material sample has good aging resistance, its light transmittance change is negligible, making T... 2t ≈T 20 Then there is

[0024]

[0025] That is, the change in the ratio of irradiance or illuminance measured by the first sensor and the second sensor is equivalent to the change in the transmittance of the polymer reference material sample.

[0026] The transmittance of the transparent polymer reference material sample described in this invention is calculated using the instantaneous method, i.e., D t The ratio of the irradiance or illuminance measured by the first sensor and the second sensor at a certain time t is used.

[0027] The transmittance of the transparent polymer reference material sample described in this invention can also be calculated using the daily cumulative value method, that is, for step (2), D is calculated in the following way. t :

[0028] After a certain period of measurement, the transmittance of the transparent polymer reference material sample decreased to T. 1t The light transmittance of the high-transmittance glass material sample changes to T. 2t The irradiance or illuminance of natural light illuminating the test plane at a certain time on that day is S. t The irradiance or illuminance measured by the first sensor and the second sensor at that moment are S, respectively. 1t and S 2t Then S 1t =S t ×T 1t The total daily radiation R is obtained by integrating the irradiance or illuminance measured by the first sensor over a daily period. 1D ,have

[0029] R 1D =∫S 1t =∫S t ·T 1t

[0030] Due to light transmittance T 1t There will not be significant changes in the short term, therefore T on that day 1t For constant calculations, we have

[0031] R 1D =∫S 1t =∫S t ·T 1t =T 1t ·∫S t

[0032] Similarly, the total daily radiation or total daily solar radiation R is obtained by integrating the irradiance or illuminance measured by the second sensor over a daily period. 2D ,have

[0033] R 2D =∫S 2t =∫S t ·T 2t =T 2t ·∫S t

[0034] Then take the ratio of the two as D for that day. t If the value is true, then we have

[0035]

[0036] To avoid the impact of water accumulation on rainy days and the weak light before and after sunrise and sunset, the irradiance or illuminance S involved in the integration for the daily accumulation method is... 1t and S 2t S must be satisfied 1t >50W / m 2 S 2t >10000lm / m 2 .

[0037] The beneficial effects of the present invention are:

[0038] 1. This invention is based on the transmittance change characteristics of a polymer reference material after its performance deteriorates under certain environmental conditions. By measuring the natural irradiation received by the transparent polymer reference material and a high-transmittance glass material, the transmittance change of the transparent polymer reference material is calculated in real time, and this is used to quantitatively assess environmental stress. This method can be used to compare environmental stress at different locations or in different parts of large test samples, and is particularly suitable for comparing environmental stress in different parts of large test samples used in outdoor environments. For example, when conducting outdoor exposure tests on whole vehicles, different locations on the vehicle, such as the plane below the bumper, the horizontal plane of the dashboard, and the horizontal plane of the door trim, can be used. Furthermore, the transmittance change of the transparent polymer reference material can be continuously and quantitatively measured, serving as a benchmark for aging test control, thereby achieving precise control of the test.

[0039] 2. This invention can be used to quantitatively evaluate the comprehensive environmental effects of materials or products at their service location or region, which helps in product design and material selection improvement, and can save production costs and improve production efficiency for enterprises.

[0040] 3. The environmental stress testing method based on the transmittance change of polymer reference material of the present invention, compared with the current environmental stress model calculated by environmental factors such as light intensity, temperature and humidity, originates from the performance change of polymer reference material, rather than deriving the parameters of the environmental stress model by the change of material performance, and its results are more direct. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the environmental stress testing device based on the transmittance variation of a polymer reference material according to the present invention.

[0042] Figure 2 The figures show the changes in illuminance and transmittance ratio of transparent polymer reference material PS and high-transparency glass material on a typical day in Guangzhou, my country, as measured in the examples.

[0043] Figure 3 This is the transmittance change curve of the transparent polymer reference material PS measured in the examples over a one-year period in Guangzhou, my country. Detailed Implementation

[0044] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments, so that those skilled in the art can better understand and implement the technical solution of the present invention.

[0045] An environmental stress testing device based on the transmittance variation of a polymer reference material, such as Figure 1 As shown, the device includes a transparent polymer reference material sample 1, a high-transparency glass material sample 2, a housing 3, a first sensor 4a, and a second sensor 4b. The transparent polymer reference material sample 1 and the high-transparency glass material sample 2 have the same thickness and are located on the same plane. The first sensor 4a is located directly below the transparent polymer reference material sample 1, and the second sensor 4b is located directly below the high-transparency glass material sample 2. The housing 3 is connected to the transparent polymer reference material sample 1 and the high-transparency glass material sample 2 as a whole, and encloses the first sensor 4a and the second sensor 4b inside the housing 3. The housing 3 has a side and a bottom surface. The two edges of the upper end of the side are connected to the transparent polymer reference material sample 1 and the high-transparency glass material sample 2 respectively. This is mainly used to prevent dust from entering the interior of the device and affecting the accuracy of the transmittance measurement. The first sensor 4a and the second sensor 4b are the same sensor.

[0046] As a preferred embodiment:

[0047] The outer shell 3 is made of opaque material, and the internal surfaces of the outer shell 3 are made of a material with a reflectance coefficient of less than 30%, thereby avoiding the impact of edge light leakage or internal reflection on measurement accuracy.

[0048] Both the first sensor 4a and the second sensor 4b are light sensors used to detect illuminance.

[0049] Alternatively, both the first sensor 4a and the second sensor 4b can be radiation sensors used to detect irradiance.

[0050] After metrological calibration, the measurement error of the first sensor 4a and the second sensor 4b is within 2%.

[0051] The device also includes a measurement and storage circuit board 5 connected to the first sensor 4a and the second sensor 4b, for recording and storing the measurement signals of the first sensor 4a and the second sensor 4b. The measurement and storage circuit board 5 can also be replaced by an external measurement and recording instrument, which can measure, record and calculate in real time and summarize the data through transmission methods such as networks.

[0052] The test method using the above-mentioned environmental stress testing device based on the transmittance variation of polymer reference materials includes the following steps:

[0053] (a) Install the test device on the target test plane, which may be different locations on the vehicle, such as the plane below the car bumper, the horizontal plane of the dashboard, or the horizontal plane of the door trim panel, when conducting outdoor exposure tests on the whole vehicle.

[0054] (b) Natural light illuminating the test plane passes through the transparent polymer reference material sample 1 and its irradiance or illuminance is measured by the first sensor 4a.

[0055] (c) Natural light illuminating the test plane passes through the high-transmittance glass material sample 2 and its irradiance or illuminance is measured by the second sensor 4b.

[0056] (d) During the test, the ratio of irradiance or illuminance measured by the first sensor 4a and the second sensor 4b reflects the ratio of light transmittance of the transparent polymer reference material sample 1 and the high-transmittance glass material sample 2.

[0057] The transmittance of the transparent polymer reference material sample 1 was calculated as follows:

[0058] (1) Assuming that in the initial state, the irradiance or illuminance of the natural light illuminating the test plane at a certain moment is S0, and the transmittance of the transparent polymer reference material sample and the high-transparency glass material sample are T, respectively. 10 With T 20 The irradiance or illuminance measured by the first sensor and the second sensor are S, respectively. 10 and S 20 If the ratio of the two is D0, then we have

[0059]

[0060] (2) Similarly, after a certain period of measurement, the irradiance or illuminance of the natural light illuminating the test plane at a certain moment is S. t At this moment, the transmittance of the transparent polymer reference material sample drops to T. 1t The light transmittance of the high-transmittance glass material sample changes to T. 2t The first and second sensors measured the irradiance or illuminance at that moment as S, respectively. 1t and S 2t The ratio of the two is D. t Then there is

[0061]

[0062] Because the high-transmittance glass material sample has good aging resistance, its light transmittance change is negligible, making T... 2t ≈T 20 Then there is

[0063]

[0064] That is, the change in the ratio of irradiance or illuminance measured by the first sensor and the second sensor is equivalent to the change in the transmittance of the polymer reference material sample.

[0065] The transmittance of the transparent polymer reference material sample 1 was calculated using the instantaneous method, i.e., D. t The ratio of the irradiance or illuminance measured by the first sensor and the second sensor at a certain time t is used, as shown in Experimental Case 1.

[0066] Experimental Case 1:

[0067] The testing device was fabricated using polystyrene (PS) as a transparent polymer reference material and was fixedly installed outdoors at a 19° south (latitude) angle in Guangzhou, my country.

[0068] Before the experiment began, the transmittance of the transparent polymer reference material sample 1 and the high-transmittance glass material sample 2 on the apparatus were tested according to method B of standard GB / T 2410-2008. The transmittance T of the transparent polymer reference material sample 1 was measured. 10 =89.5, the light transmittance T of the high-transmittance glass material sample 2 20 =93.2.

[0069] By the following formula

[0070]

[0071]

[0072] The original transmittance ratio D0 was calculated to be 0.9603. The measured illuminance of the transparent polymer reference material sample PS and the high-transmittance glass material sample on a typical day in Guangzhou, my country, and the curves showing the change in their transmittance ratios are shown below. Figure 2 .

[0073] The transmittance of the transparent polymer reference material sample 1 can also be calculated using the daily cumulative value method. That is, for step (2), D is calculated as follows: t :

[0074] After a certain period of measurement, the transmittance of the transparent polymer reference material sample 1 decreased to T. 1t The light transmittance of high-transmittance glass material sample 2 changes to T 2t The irradiance or illuminance of natural light illuminating the test plane at a certain time on that day is S. t The irradiance or illuminance measured by the first sensor 4a and the second sensor 4b at this moment are S, respectively. 1t and S 2t Then S 1t =St ×T 1t The total daily radiation R is obtained by integrating the irradiance or illuminance measured by the first sensor over a daily period. 1D ,have

[0075] R 1D =∫S 1t =∫S t ·T 1t

[0076] Due to light transmittance T 1t There will not be significant changes in the short term, therefore T on that day 1t For constant calculations, we have

[0077] R 1D =∫S 1t =∫S t ·T 1t =T 1t ·∫S t

[0078] Similarly, the total daily radiation or total daily solar radiation R is obtained by integrating the irradiance or illuminance measured by the second sensor over a daily period. 2D ,have

[0079] R 2D =∫S 2t =∫S t ·T 2t =T 2t ·∫S t

[0080] Then take the ratio of the two as D for that day. t If the value is true, then we have

[0081]

[0082] To avoid the impact of water accumulation on rainy days and the weak light before and after sunrise and sunset, the irradiance or illuminance S involved in the integration for the daily accumulation method is... 1t and S 2t S must be satisfied 1t >50W / m 2 S 2t >10000lm / m 2 .

[0083] Test Case 2: Based on the ratio D of daily irradiance or illuminance measured by the testing device. t Calculate the transmittance T of the transparent polymer reference material 1t Plot the transmittance variation curve of transparent polymer reference material sample 1 with time t as the horizontal axis. The transmittance variation curve of transparent polymer reference material sample PS in Guangzhou, my country over one year is shown below. Figure 3 As shown.

[0084] This invention is based on the transmittance change characteristics of a polymer reference material after its performance deteriorates under certain environmental conditions. By measuring the difference in natural irradiation received between the transparent polymer reference material and a high-transmittance glass material, the transmittance change of the transparent polymer reference material is calculated in real time, allowing for a quantitative assessment of environmental stress. The transmittance change of the transparent polymer reference material can be continuously and quantitatively measured, serving as a benchmark for controlling aging tests, thereby achieving precise control of the test.

[0085] The above embodiments are merely preferred embodiments of the present invention, but should not be construed as limiting the invention. Any modifications and improvements made based on the concept of the present invention should fall within the protection scope of the present invention, and the specific protection scope is subject to the claims.

Claims

1. An environmental stress testing device based on the transmittance variation of a polymer reference material, characterized in that, The device includes a transparent polymer reference material sample, a high-transparency glass material sample, a housing, a first sensor, and a second sensor. The transparent polymer reference material sample and the high-transparency glass material sample have the same thickness and are located on the same plane. The first sensor is located directly below the transparent polymer reference material sample, and the second sensor is located directly below the high-transparency glass material sample. The housing is connected to the transparent polymer reference material sample and the high-transparency glass material sample as a whole, and encloses the first sensor and the second sensor inside the housing. The first sensor and the second sensor are the same sensor.

2. The environmental stress testing device based on the transmittance variation of a polymer reference material according to claim 1, characterized in that: Both the first sensor and the second sensor are light sensors.

3. The environmental stress testing device based on the transmittance variation of a polymer reference material according to claim 1, characterized in that: Both the first and second sensors are radiation sensors.

4. The environmental stress testing device based on the transmittance variation of a polymer reference material according to claim 1, characterized in that: The first and second sensors have been calibrated, and the measurement error of the two sensors is within 2%.

5. The environmental stress testing device based on the transmittance variation of a polymer reference material according to claim 1, characterized in that: It also includes a measurement storage circuit board connected to the first and second sensors for recording and storing the measurement signals of the first and second sensors.

6. The environmental stress testing device based on the transmittance variation of a polymer reference material according to claim 1, characterized in that: The outer shell is made of opaque material, and the reflectance of each internal surface of the outer shell is less than 30%.

7. A test method using an environmental stress testing device based on the transmittance variation of a polymer reference material as described in any one of claims 1 to 6, characterized in that, Includes the following steps: (a) Install the test apparatus on the target test plane; (b) Natural light illuminating the test plane passes through a transparent polymer reference material sample and its irradiance or illuminance is measured by the first sensor. (c) Natural light illuminating the test plane passes through a high-transmittance glass sample and its irradiance or illuminance is measured by a second sensor. (d) During the test, the ratio of irradiance or illuminance measured by the first sensor and the second sensor reflects the ratio of light transmittance of the transparent polymer reference material sample to that of the high-transmittance glass material sample.

8. The test method according to claim 7, characterized in that, The transmittance of the transparent polymer reference material sample is calculated as follows: (1) Assuming that in the initial state, the irradiance or illuminance of the natural light illuminating the test plane at a certain moment is S0, and the transmittance of the transparent polymer reference material sample and the high-transparency glass material sample are T, respectively. 10 With T 20 The irradiance or illuminance measured by the first sensor and the second sensor are S, respectively. 10 and S 20 If the ratio of the two is D0, then we have (2) Similarly, after a certain period of measurement, the irradiance or illuminance of the natural light illuminating the test plane at a certain moment is S. t At this moment, the transmittance of the transparent polymer reference material sample drops to T. 1t The light transmittance of the high-transmittance glass material sample changes to T. 2t The first and second sensors measured the irradiance or illuminance at that moment as S, respectively. 1t and S 2t The ratio of the two is D. t Then there is Because the high-transmittance glass material sample has good aging resistance, its light transmittance change is negligible, making T... 2t ≈T 20 Then there is That is, the change in the ratio of irradiance or illuminance measured by the first sensor and the second sensor is equivalent to the change in the transmittance of the polymer reference material sample.

9. The test method according to claim 8, characterized in that: The transmittance of the transparent polymer reference material sample was calculated using the instantaneous method, i.e., D t The ratio of the irradiance or illuminance measured by the first sensor and the second sensor at a certain time t is used.

10. The test method according to claim 8, characterized in that: The transmittance of the transparent polymer reference material sample was calculated using the daily cumulative value method, that is, for step (2), D was calculated in the following way. t : After a certain period of measurement, the transmittance of the transparent polymer reference material sample decreased to T. 1t The light transmittance of the high-transmittance glass material sample changes to T. 2t The irradiance or illuminance of natural light illuminating the test plane at a certain time on that day is S. t The irradiance or illuminance measured by the first sensor and the second sensor at that moment are S, respectively. 1t and S 2t Then S 1t =S t ×T 1t The total daily radiation R is obtained by integrating the irradiance or illuminance measured by the first sensor over a daily period. 1D ,have R 1D =∫S 1t =∫S t ·T 1t Due to light transmittance T 1t There will not be significant changes in the short term, therefore T on that day 1t For constant calculations, we have R 1D =∫S 1t =∫S t ·T 1t =T 1t ·∫S t Similarly, the total daily radiation or total daily solar radiation R is obtained by integrating the irradiance or illuminance measured by the second sensor over a daily period. 2D ,have R 2D =∫S 2t =∫S t ·T 2t =T 2t ·∫S t Then take the ratio of the two as D for that day. t If the value is true, then we have The daily cumulative value method is used. To avoid the impact of water accumulation on rainy days and the weak light before and after sunrise and sunset, the irradiance or illuminance S involved in the integration is... 1t and S 2t It must meet the following requirements: S 1t >50W / m 2 ,S 2t >10000lm / m 2 。

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