Accelerated experiment method for evaluating influence of ultraviolet radiation on aging of silicone rubber material

Abstract

The invention discloses an accelerated experiment method for evaluating the influence of ultraviolet radiation on the aging of a silicone rubber material, which comprises the following steps: acquiring a silicone rubber material sample, carrying out an ultraviolet radiation aging accelerated experiment on the silicone rubber material, and carrying out aging characterization analysis on the accelerated aging silicone rubber material sample in each experiment process at each time node, generating sample aging characterization data; performing aging characterization analysis on the obtained natural aging silicone rubber material sample in the high-altitude area to generate aging characterization data of a control group; comparing the aging characterization data of the sample with the aging characterization data of the control group, and evaluating the influence of ultraviolet radiation on the aging of the silicone rubber material. The accelerated experiment method is effective and rapid, and the performance evaluation conclusion is high in practicability.

Description

Technical Field

[0001] This invention belongs to the technical field of insulation materials for high-voltage power equipment, specifically involving an accelerated experimental method for evaluating the effects of ultraviolet radiation on the aging of silicone rubber materials. Background Technology

[0002] Silicone rubber is widely used in the insulation systems of high-voltage power equipment due to its excellent resistance to high and low temperatures, electrical insulation, and aging resistance. It is particularly important as an insulating material for critical facilities such as high-voltage power cables, switchgear, and substations.

[0003] During the long-term operation of power equipment, the electrical properties, mechanical properties, and surface morphology of silicone rubber materials will change significantly due to ultraviolet radiation. In high-altitude areas (such as those above 3000 meters), the aging rate of silicone rubber materials is much higher than in other low-altitude areas due to the strong ultraviolet radiation.

[0004] Currently, experimental results regarding the specific effects of different ultraviolet bands on the aging of silicone rubber materials are limited, and corresponding performance evaluation methods are lacking. In the current work of material selection and life assessment for power equipment in high-altitude areas, there is an urgent need for technical solutions that can accurately assess the impact of ultraviolet radiation on the aging of silicone rubber. Summary of the Invention

[0005] In view of this, the present invention provides an accelerated experimental method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials, aiming to solve the technical problem that it is difficult to accurately evaluate the effect of ultraviolet radiation on the aging of silicone rubber in the prior art.

[0006] This invention provides an accelerated experimental method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials, comprising:

[0007] Silicone rubber material samples were obtained, and accelerated aging tests under ultraviolet radiation were conducted.

[0008] At each time point, the accelerated aging silicone rubber material samples in each experimental process were subjected to aging characterization analysis to generate sample aging characterization data.

[0009] Aging characterization analysis was performed on the naturally aged silicone rubber material samples obtained from high-altitude areas to generate aging characterization data for the control group.

[0010] By comparing the aging characterization data of the sample with those of the control group, the effect of ultraviolet radiation on the aging of silicone rubber materials was evaluated.

[0011] Furthermore, the process of obtaining silicone rubber material samples and conducting accelerated aging tests using ultraviolet radiation includes:

[0012] Two silicone rubber material samples were prepared. The first sample was used to receive UVB light source radiation, and the second sample was used to receive UVC light source radiation.

[0013] Set up an ultraviolet radiation environment;

[0014] Starting from hour 0, increase the exposure time of the two silicone rubber material samples in the ultraviolet radiation environment until any time point is reached;

[0015] After reaching any time point, the two silicone rubber material samples are taken out from the ultraviolet radiation environment, and the accelerated aging silicone rubber material samples in each experimental process are subjected to aging characterization analysis.

[0016] Furthermore, the setting of the ultraviolet radiation environment includes:

[0017] The wavelength of the UVB light source is controlled to be between 280 and 320 nm;

[0018] The wavelength of the UVC light source is controlled to be between 200 and 280 nm;

[0019] The irradiance of the light source is controlled at 1.2 W / m². 2 ;

[0020] The distance between the sample and the light source is controlled to be 45 mm to 55 mm.

[0021] Furthermore, the preparation of two silicone rubber material samples includes:

[0022] The thickness of the silicone rubber material sample was controlled to be between 0.2 cm and 0.25 cm.

[0023] Furthermore, the step of increasing the exposure time of the two silicone rubber material samples in the ultraviolet radiation environment from hour 0 until any time point is reached includes:

[0024] The temperature and humidity of the ultraviolet radiation environment are controlled according to the temperature and relative humidity corresponding to each time point, wherein,

[0025] Any time point includes: 25 hours, 50 hours, 75 hours, 100 hours, 200 hours, 300 hours, and 400 hours. Each time point is used to indicate the experimental progress of accelerated aging.

[0026] The temperature corresponding to each time point is a set value between 17 and 23°C;

[0027] The relative humidity at each time point is a set value between 10% and 27%.

[0028] Furthermore, the aging characterization analysis of the accelerated-aging silicone rubber material samples at each experimental stage includes:

[0029] The surface morphology of accelerated aging silicone rubber material samples was observed using scanning electron microscopy.

[0030] The chemical structure of accelerated aging silicone rubber material samples was analyzed using infrared spectroscopy and Raman spectroscopy.

[0031] By comprehensively analyzing the surface morphology and chemical structure changes of accelerated-aging silicone rubber material samples at various experimental stages, sample aging characterization data are generated.

[0032] Furthermore, the aging characterization analysis of the obtained naturally aged silicone rubber material samples from high-altitude areas, and the generation of aging characterization data for the control group, includes:

[0033] The surface morphology of naturally aged silicone rubber material samples from high-altitude areas with known service time was observed using scanning electron microscopy.

[0034] Chemical structure of naturally aged silicone rubber material samples from high-altitude areas with known service time obtained by infrared spectroscopy and Raman spectroscopy analysis;

[0035] By comprehensively analyzing the surface morphology and chemical structure changes of naturally aged silicone rubber material samples at different service times, sample aging characterization data are generated. The service time ranges from 1 year to 10 years, with 1-year intervals.

[0036] Furthermore, the surface morphology of the silicone rubber material sample was observed at a magnification of 200x or higher, and the surface morphology included any of the following: cracks, pores, and particle boundaries.

[0037] Furthermore, the chemical structure of the silicone rubber material sample was analyzed by infrared spectroscopy, wherein the chemical structure of the silicone rubber material sample includes: CH bonds, Si-CH3 bonds, and C=O oxidation products.

[0038] Furthermore, Raman spectroscopy was used to analyze the chemical structure of the silicone rubber material sample, wherein the chemical structure of the silicone rubber material sample includes: CH bonds, Si-CH3 bonds, and Si-O-Si bonds.

[0039] The accelerated aging test method provided by this invention for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials simulates ultraviolet radiation in the UVB and UVC bands respectively, and conducts accelerated aging tests on silicone rubber materials to evaluate the effects of UVB and UVC ultraviolet radiation in high-altitude areas on the surface morphology and chemical structure of silicone rubber materials. This accelerated test method is effective and rapid, and the performance evaluation conclusions are highly practical.

[0040] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0042] Figure 1 This is a schematic flowchart of an accelerated experimental method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials according to an embodiment of the present invention.

[0043] Figure 2 Comparison of microstructure of sample No. 1 during UVB radiation aging from 0 to 400 hours (200x magnification);

[0044] Figure 3 Comparison of microstructure of sample No. 1 during UVC radiation aging from 0 to 400 hours (200x magnification);

[0045] Figure 4 Infrared spectra of sample No. 1 after UVB radiation aging from 0 to 400 hours;

[0046] Figure 5 Infrared spectra of sample No. 1 after UVC radiation aging from 0 to 400 hours;

[0047] Figure 6 Raman spectra of sample 1 after UVB irradiation aging from 0 to 400 hours;

[0048] Figure 7 Raman spectra of sample No. 1 after UVC radiation aging from 0 to 400 hours. Detailed Implementation

[0049] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are illustrated in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, the embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0050] Silicone rubber materials possess good stability and anti-aging properties, enabling them to be used for extended periods in harsh environments. On the other hand, ultraviolet radiation can cause cross-linking breakage, changes in molecular structure, and surface crack formation in silicone rubber. These changes directly affect its electrical insulation and mechanical strength, and in the long run, can impact the reliability and safety of electrical equipment.

[0051] Silicone rubber materials are widely used in power equipment, especially power transmission and transformation equipment, in high-altitude areas due to their excellent electrical insulation properties, weather resistance, and flexibility. However, in high-altitude areas, strong ultraviolet radiation, especially short-wave ultraviolet (UVC) radiation, significantly accelerates the aging of silicone rubber materials, leading to decreased equipment reliability and shortened service life. Therefore, clarifying the specific effects and aging mechanisms of different wavelengths of ultraviolet radiation on silicone rubber materials is of significant practical importance.

[0052] In high-altitude areas (above 3000 meters), the aging rate of silicone rubber materials is much higher than in other low-altitude areas due to the strong influence of ultraviolet radiation. The UVB (wavelength 280-320nm) and UVC (wavelength 200-280nm) radiation in high-altitude regions are particularly intense, with UVC radiation intensity far exceeding that in normal environments. This may accelerate the chemical degradation and physical property decline of silicone rubber, thereby affecting the long-term stable operation of electrical equipment.

[0053] Existing experimental results on the effects of ultraviolet radiation on the aging of silicone rubber mostly focus on changes in the surface morphology, chemical structure, and mechanical properties of the material. There are also some analyses on the effects of UVB radiation on the aging of silicone rubber, but the effects of UVC radiation are rarely discussed.

[0054] Existing accelerated aging methods for ultraviolet radiation primarily focus on simulating UVB radiation, neglecting the accelerating effect of UVC radiation and lacking a comprehensive analysis of the combined impact of UVB and UVC radiation on silicone rubber properties. Furthermore, current methods cannot fully simulate the real-world ultraviolet radiation environment at high altitudes. Therefore, there is a need to develop a more accurate and effective accelerated aging method for ultraviolet radiation, particularly one that can simultaneously consider the effects of UVB and UVC radiation on the aging of silicone rubber materials. This would provide a reliable scientific basis for the selection and lifespan assessment of silicone rubber materials for power equipment in high-altitude areas.

[0055] The accelerated aging test method provided by this invention for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials simulates ultraviolet radiation in the UVB and UVC bands respectively, and conducts accelerated aging tests on silicone rubber materials to evaluate the effects of UVB and UVC ultraviolet radiation in high-altitude areas on the surface morphology and chemical structure of silicone rubber materials. This accelerated test and performance evaluation method is effective, rapid and the conclusions are reliable.

[0056] This accelerated experimental and performance evaluation method can accurately simulate the ultraviolet radiation environment (including UVB and UVC bands), systematically evaluate the impact of ultraviolet radiation on the surface morphology and chemical structure of silicone rubber, and deeply reveal the mechanism of ultraviolet radiation, especially the UVC band, in the aging process of silicone rubber. This will further provide a scientific basis for the selection, life assessment, and ultraviolet aging effect of silicone rubber materials in power equipment in high-altitude areas.

[0057] like Figure 1 As shown, the accelerated experimental method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials according to an embodiment of the present invention includes:

[0058] S100: Obtain silicone rubber material samples and conduct accelerated aging tests on silicone rubber materials under ultraviolet radiation.

[0059] At each time point, the accelerated aging silicone rubber material samples in each experimental process were subjected to aging characterization analysis to generate sample aging characterization data.

[0060] S200: Aging characterization analysis was performed on the naturally aged silicone rubber material samples obtained from high-altitude areas to generate aging characterization data for the control group.

[0061] S300: Compare the aging characterization data of the sample with the aging characterization data of the control group to evaluate the effect of ultraviolet radiation on the aging of silicone rubber materials.

[0062] Specifically, the process of obtaining silicone rubber material samples and conducting accelerated ultraviolet radiation aging tests on silicone rubber materials includes:

[0063] Two silicone rubber material samples were prepared. The first sample was used to receive UVB light source radiation, and the second sample was used to receive UVC light source radiation.

[0064] Set up an ultraviolet radiation environment;

[0065] Starting from hour 0, increase the exposure time of the two silicone rubber material samples in the ultraviolet radiation environment until any time point is reached;

[0066] After reaching any time point, the two silicone rubber material samples are taken out from the ultraviolet radiation environment, and the accelerated aging silicone rubber material samples in each experimental process are subjected to aging characterization analysis.

[0067] Specifically, the setting of the ultraviolet radiation environment includes:

[0068] The wavelength of the UVB light source is controlled to be between 280 and 320 nm;

[0069] The wavelength of the UVC light source is controlled to be between 200 and 280 nm;

[0070] The irradiance of the light source is controlled at 1.2 W / m². 2 ;

[0071] The distance between the sample and the light source is controlled to be 45 mm to 55 mm.

[0072] Specifically, the preparation of two silicone rubber material samples includes:

[0073] The thickness of the silicone rubber material sample was controlled to be between 0.2 cm and 0.25 cm.

[0074] Specifically, the step of increasing the exposure time of the two silicone rubber material samples in the ultraviolet radiation environment from hour 0 until any time point is reached includes:

[0075] The temperature and humidity of the ultraviolet radiation environment are controlled according to the temperature and relative humidity corresponding to each time point, wherein,

[0076] Any time point includes: 25 hours, 50 hours, 75 hours, 100 hours, 200 hours, 300 hours, and 400 hours. Each time point is used to indicate the experimental progress of accelerated aging.

[0077] The temperature corresponding to each time point is a set value between 17 and 23°C;

[0078] The relative humidity at each time point is a set value between 10% and 27%.

[0079] Specifically, the aging characterization analysis of the accelerated-aging silicone rubber material samples at each experimental stage includes:

[0080] The surface morphology of accelerated aging silicone rubber material samples was observed using scanning electron microscopy.

[0081] The chemical structure of accelerated aging silicone rubber material samples was analyzed using infrared spectroscopy and Raman spectroscopy.

[0082] By comprehensively analyzing the surface morphology and chemical structure changes of accelerated-aging silicone rubber material samples at various experimental stages, sample aging characterization data are generated.

[0083] Specifically, the aging characterization analysis of the obtained naturally aged silicone rubber material samples from high-altitude areas, and the generation of aging characterization data for a control group, includes:

[0084] The surface morphology of naturally aged silicone rubber material samples from high-altitude areas with known service time was observed using scanning electron microscopy.

[0085] Chemical structure of naturally aged silicone rubber material samples from high-altitude areas with known service time obtained by infrared spectroscopy and Raman spectroscopy analysis;

[0086] By comprehensively analyzing the surface morphology and chemical structure changes of naturally aged silicone rubber material samples at different service times, sample aging characterization data are generated. The service time ranges from 1 year to 10 years, with 1-year intervals.

[0087] Specifically, the surface morphology of the silicone rubber material sample was observed at a magnification of 200x or higher, and the surface morphology included any of the following: cracks, pores, and particle boundaries.

[0088] Specifically, the chemical structure of the silicone rubber material sample was analyzed by infrared spectroscopy. The chemical structure of the silicone rubber material sample includes: CH bonds, Si-CH3 bonds, and C=O oxidation products.

[0089] Specifically, Raman spectroscopy was used to analyze the chemical structure of the silicone rubber material sample, wherein the chemical structure of the silicone rubber material sample includes: CH bonds, Si-CH3 bonds, and Si-O-Si bonds.

[0090] The accelerated aging test method provided by this invention for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials simulates ultraviolet radiation in the UVB and UVC bands respectively, and conducts accelerated aging tests on silicone rubber materials to evaluate the effects of UVB and UVC ultraviolet radiation in high-altitude areas on the surface morphology and chemical structure of silicone rubber materials. This accelerated test method is effective and rapid, and the performance evaluation conclusions are highly practical.

[0091] Another embodiment of the present invention provides an accelerated experimental method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials, comprising the following steps S10 to S50.

[0092] S10: Design an accelerated aging experiment for silicone rubber materials under ultraviolet radiation;

[0093] S20: Determine the ultraviolet radiation aging characterization and analysis scheme for silicone rubber materials;

[0094] S30: Obtain silicone rubber material samples and conduct accelerated aging tests on the silicone rubber materials under ultraviolet radiation.

[0095] At each time point, the surface morphology and chemical structure changes of the accelerated aging silicone rubber material samples in each experimental process are determined by the aging characterization and analysis scheme described above.

[0096] S40: Using the obtained naturally aged silicone rubber material samples from high-altitude areas, determine the surface morphology and chemical structure changes of the naturally aged silicone rubber material samples through the aging characterization and analysis scheme described above.

[0097] S50: Compare the surface morphology and chemical structure changes of naturally aged silicone rubber material samples with those of accelerated-aged silicone rubber material samples at each experimental stage to determine the effectiveness of the accelerated aging experiment.

[0098] Further, step S10, designing an accelerated aging experiment for silicone rubber material under ultraviolet radiation, includes:

[0099] The ultraviolet light sources are defined as UVB sources with wavelengths of 280 to 320 nm and UVC sources with wavelengths of 200 to 280 nm.

[0100] The thickness of the silicone rubber material sample was determined to be 0.2 cm;

[0101] The experimental temperature was determined to be between 17 and 23°C, and the relative humidity was determined to be between 10% and 27%.

[0102] The radiation time was determined to be from 0 to 400 hours, including the following time points: 0 hours, 25 hours, 50 hours, 75 hours, 100 hours, 200 hours, 300 hours, and 400 hours. Each time point was used to indicate the experimental progress of accelerated aging.

[0103] Further, step S20, determining the ultraviolet radiation aging characterization and analysis scheme for silicone rubber materials, includes:

[0104] Scanning electron microscopy was used to observe the surface morphology of the silicone rubber material samples.

[0105] Infrared spectroscopy and Raman spectroscopy were used to analyze the chemical structural changes of silicone rubber material samples.

[0106] The performance changes of silicone rubber material samples were evaluated by comprehensively analyzing changes in surface morphology and chemical structure.

[0107] Further, step S30, obtaining a silicone rubber material sample and conducting an accelerated ultraviolet radiation aging test on the silicone rubber material, includes:

[0108] Two silicone rubber material samples were prepared from silicone rubber materials from different manufacturers. The first sample was used to receive UVB light source radiation, and the second sample was used to receive UVC light source radiation.

[0109] Control the ultraviolet radiation environment according to the temperature and relative humidity corresponding to each time point;

[0110] The distance between the sample and the light source was controlled at 50 mm to control the exposed area of ​​the sample in the ultraviolet radiation environment;

[0111] Starting from hour 0, increase the exposure time of the silicone rubber material sample in the ultraviolet radiation environment until any time point is reached;

[0112] After reaching any time point, two silicone rubber material samples are taken out, and the surface morphology and chemical structure changes of the accelerated aging samples in the accelerated aging experiment are determined by the aging characterization analysis scheme.

[0113] The accelerated UV aging test of the silicone rubber material was terminated when the upper limit of the irradiation time was reached.

[0114] Further, step S40, utilizing the obtained naturally aged silicone rubber material sample from a high-altitude region, includes:

[0115] Silicone rubber materials with known service time in high-altitude areas were obtained as natural aging samples.

[0116] Further, step S30, which determines the surface morphology and chemical structure changes of the accelerated aging sample during the accelerated aging experiment using the aging characterization analysis scheme, includes:

[0117] The surface morphology of silicone rubber material samples was observed using a scanning electron microscope. The surface morphology of accelerated aging samples at each time point was observed at a magnification of 20x or higher. The surface morphology included any of the following: cracks, pores, and particle boundaries.

[0118] Further, step S30, which determines the surface morphology and chemical structure changes of the accelerated aging sample during the accelerated aging experiment using the aging characterization analysis scheme, includes:

[0119] The chemical structure of the silicone rubber material sample was analyzed by infrared spectroscopy. The chemical structure of the silicone rubber material sample includes: CH bonds, Si-CH3 bonds, and C=O oxidation products.

[0120] Further, step S30, which determines the surface morphology and chemical structure changes of the accelerated aging sample during the accelerated aging experiment using the aging characterization analysis scheme, includes:

[0121] The chemical structure of the silicone rubber material sample was analyzed by Raman spectroscopy. The chemical structure of the silicone rubber material sample includes CH bonds, Si-CH3 bonds, and Si-O-Si bonds.

[0122] Further, step S30, which determines the surface morphology and chemical structure changes of the accelerated aging sample during the accelerated aging experiment using the aging characterization analysis scheme, includes:

[0123] The performance changes of silicone rubber material samples were determined by comprehensively analyzing changes in surface morphology and chemical structure. Among them, UVC ultraviolet light had a more significant aging effect on silicone rubber than UVB ultraviolet light. In the later stage of the aging process, a large number of cracks, holes and particle peeling appeared on the sample surface.

[0124] Further, step S40, comparing the surface morphology and chemical structure changes of naturally aged silicone rubber material samples with those of accelerated-aged silicone rubber material samples at each experimental stage, determines the effectiveness of the accelerated aging experiment, including:

[0125] The surface morphology and chemical structure changes of the naturally aged samples in Tibet with a service life of 10 years are consistent with the surface morphology and chemical structure changes of the silicone rubber material samples aged by UVC ultraviolet light acceleration.

[0126] The damage level of naturally aged samples with a service life of 10 years in Tibet ranged from UVB accelerated aging to 300 to 400 hours.

[0127] In some embodiments, when selecting silicone rubber material samples, multiple silicone rubber material samples from different manufacturers are selected, and the thickness of each sample is controlled to be 0.2 cm.

[0128] In some embodiments, multiple silicone rubber material samples from four different manufacturers are selected and numbered 1 to 4 respectively. Sample 1 is a silicone rubber material with a thickness of 0.2 cm produced by Company A, Sample 2 is a silicone rubber material with a thickness of 0.2 cm produced by Company B, Sample 3 is a silicone rubber material with a thickness of 0.2 cm produced by Company C, and Sample 4 is a silicone rubber material with a thickness of 0.25 cm produced by Company D.

[0129] In summary, the thickness of all samples was controlled at 0.2 cm, which helps to ensure that the exposure area of ​​each sample in the radiation environment is consistent and avoids deviations in experimental conditions.

[0130] In some embodiments, an accelerated ultraviolet (UV) weathering test chamber, model HYJ-1020UV, is used. This equipment provides a stable UV radiation environment, such as eight 40W UV fluorescent lamps, distributed on both sides of the central axis, four on each side. The UV light sources include two types: UVB313 (wavelength 280-320nm) and UVC254 (wavelength 200-280nm). The main emission peak of the UVB313 light source is concentrated around 313nm, effectively simulating the UVB band radiation characteristics in natural environments; the main emission peak of the UVC254 light source is concentrated around 254nm, accurately simulating the intense UVC radiation environment at high altitudes.

[0131] In some embodiments, when setting experimental conditions, two silicone rubber material samples from each of the four manufacturers were placed in UVB and UVC radiation environments in numerical order for aging experiments. The radiation time gradient was precisely controlled between 0 and 400 hours, specifically divided into nine time points: 0 hours (which can serve as an initial control group), 25 hours, 50 hours, 75 hours, 100 hours, 200 hours, 300 hours, and 400 hours, to simulate the ultraviolet radiation aging effect of silicone rubber under different service years.

[0132] During the experiment, the distance between the sample and the ultraviolet light source (radiation distance) was controlled at 50 mm. The experimental temperature range was controlled between 17℃ and 23℃, and the relative humidity (RH) range was controlled between 10% and 27%.

[0133] During the experiment, the experimental variables included the ultraviolet light band, such as UVB or UVC, and the irradiation time. Other experimental conditions, such as sample thickness, irradiation distance, temperature, and humidity, were kept consistent to ensure that the experimental conditions for each sample were consistent and to ensure the comparability of the experimental results. In this way, the experimental results were accurate and highly repeatable.

[0134] During the experiment, accelerated aging samples were taken out at various time points for performance analysis.

[0135] In some embodiments, a high-resolution scanning electron microscope (SEM) is used to observe the surface morphology of the sample. Specifically, the surface morphology of the sample is systematically observed at a magnification of 200x or higher, including microscopic features such as cracks, pores, and particle boundaries; and the observed surface morphology features are recorded.

[0136] Therefore, observing the surface morphology of silicone rubber samples at various time points during the aging process using scanning electron microscopy (SEM) can clearly demonstrate the influence of ultraviolet radiation on the surface morphology of silicone rubber. It can record the formation process of surface defects such as cracks and pores in real time, effectively assess changes in sample surface morphology, and provide intuitive evidence for the aging assessment of silicone rubber. After the accelerated experiment, the surface morphology of the samples at each time point is compared to determine the changes, differences, and trends in surface morphology.

[0137] Experimental results show that UVC radiation (or UVC radiation conditions) causes the most severe damage to the silicone rubber surface. As the radiation time increases, cracks and pores gradually expand significantly, and at least one independent crack or pore merges into a larger area pore or a longer crack. The surface morphology changes of silicone rubber caused by UVB radiation (UVB radiation conditions) are mainly manifested as surface roughening, gradual blurring of particle boundaries, and the appearance of fine cracks.

[0138] Experimental results show that UVC radiation has the most significant destructive effect on silicone rubber, with obvious cracks and holes appearing on the sample surface; while UVB radiation mainly causes surface roughening and blurring of particle boundaries.

[0139] In some embodiments, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy are used to quantitatively analyze the chemical structure of the samples to clarify the changes in the internal chemical bonds of silicone rubber under ultraviolet radiation. FTIR spectroscopy analysis revealed that under ultraviolet radiation, the Si-O, Si-CH3, and CH bonds in the silicone rubber material underwent significant breakage. The oxidation reaction under UVC radiation was particularly intense, leading to a significant increase in the absorption peak intensity of the C=O oxidation product, indicating that the chemical degradation of silicone rubber material under UVC radiation is more rapid and severe.

[0140] Thus, by using Fourier transform infrared (FTIR) and Raman spectroscopy to quantitatively analyze changes in the chemical structure of the samples, the breaking process of chemical bonds and the formation process of oxidation products in silicone rubber during ultraviolet (UV) irradiation were revealed. Experimental results showed that UVC irradiation significantly increased the formation of C=O oxidation products, while UVB irradiation had a greater impact on the breaking of organic side chains (Si-CH3 and CH) in silicone rubber. FTIR and Raman spectroscopy not only revealed the chemical structural changes of silicone rubber under UV irradiation but also provided quantitative support for assessing the UV aging mechanism.

[0141] In some embodiments, to verify the ability of accelerated testing to simulate real-world environments, naturally aged silicone rubber material samples from actual high-altitude regions (such as the Qinghai-Tibet Plateau and Tibet) were selected for comparison with the accelerated test samples. For the naturally aged samples, the same analytical methods as for the experimental samples were used to observe the sample surface morphology and analyze the sample chemical structure.

[0142] The comparative results show that the aging effect under simulated ultraviolet radiation conditions has a high degree of agreement with the actual natural aging effect in high-altitude areas. Specifically, the surface morphology and chemical structure changes of the naturally aged samples from Tibet with a service life of 10 years are remarkably similar to those after 300 to 400 hours of cumulative UVB radiation. This result strongly demonstrates that the accelerated experimental method proposed in this invention has an accurate and efficient simulation capability for actual high-altitude ultraviolet radiation environments.

[0143] The above comparison of accelerated-aged samples and naturally aged samples from high-altitude regions (Tibetan Plateau) further verifies the influence of ultraviolet radiation on the aging of silicone rubber. Experimental results show that the aging degree of naturally aged samples from the Tibetan Plateau falls between that of UVB-radiated and UVC-radiated aged samples, and their surface morphology and chemical structure changes are closer to the 300-400 hour state of UVB-band radiation aging. This comparative experimental result demonstrates that the ultraviolet aging experimental method of this invention can effectively simulate the ultraviolet radiation environment in high-altitude regions and provide accurate material lifetime assessment data.

[0144] In summary, the accelerated testing and performance evaluation method of this invention, through systematic experimental design, explored the effects of ultraviolet light (UVB and UVC) on the aging of silicone rubber materials. It also provided a detailed analysis of the surface morphology, chemical structure, and electrical properties of the aged samples. This method can accurately and efficiently simulate the aging process of silicone rubber in actual ultraviolet radiation environments, providing a reliable scientific basis for material selection and service life assessment of power equipment in high-altitude areas. Furthermore, the experimental method of this invention can be further extended to the aging test results of other high-voltage insulating materials, demonstrating broad application potential and significant theoretical and practical guiding significance.

[0145] The accelerated testing and performance evaluation method of this invention, through the design of reasonable experimental schemes and sample preparation methods, can precisely control the influence of different wavelengths of ultraviolet radiation (UVB and UVC) on silicone rubber material samples. By controlling conditions such as ultraviolet radiation time, temperature, and humidity, the ultraviolet aging effect under different wavelengths and conditions is simulated, thereby achieving comprehensive experimental results on the ultraviolet aging process of silicone rubber materials.

[0146] The accelerated experiment and performance evaluation method of this invention, through systematic and detailed experimental design and analysis, is conducive to comprehensively revealing the aging mechanism of silicone rubber materials by UVB and UVC ultraviolet light, and clarifying the differential influence of different ultraviolet bands on the surface morphology, chemical structure and comprehensive performance of silicone rubber materials.

[0147] The accelerated testing and performance evaluation method of this invention, through precise control of the ultraviolet aging accelerated test, makes the experimental results highly repeatable and reliable, and can provide a theoretical basis for the use of silicone rubber materials in high-altitude areas.

[0148] The following section provides a more detailed explanation of the aging experiment process, the aging experiment data analysis process, and the experimental conclusions.

[0149] Four different silicone rubber samples from various manufacturers were used in the experiment, numbered 1, 2, 3, and 4. The thicknesses of the four samples were 0.2 cm for sample 1, 0.2 cm for sample 2, 0.2 cm for sample 3, and 0.25 cm for sample 4, and all samples showed no obvious defects in appearance. The thickness of the aging samples was 0.2 cm to ensure the accuracy of the experimental data. Two samples of each type were prepared: one for UVB radiation aging and the other for UVC radiation aging.

[0150] Specifically, UVB313 (wavelength 280-320nm) and UVC254 (wavelength 200-280nm) light sources were selected for accelerated aging of the samples under ultraviolet radiation. The emission spectrum of UVB313 covers the wavelength range from 280nm to 378nm, mainly concentrated at 313nm; the spectrum of UVC254 is narrower, concentrated at 254nm, covering the wavelength range of 230nm to 290nm.

[0151] Environmental factors such as temperature and humidity, radiation distance, and radiation time were used as accelerated aging conditions to conduct accelerated aging experiments on silicone rubber in the laboratory, simulating different environmental factors. Specifically, during the aging experiment, the distance between the sample and the UV light source was maintained at 50 mm. The aging time points for the two samples under UVB and UVC irradiation were set to 25 hours, 50 hours, 75 hours, 100 hours, 200 hours, 300 hours, and 400 hours, respectively. The specific aging temperature and humidity are listed in Table 1.

[0152] Table 1 UV Accelerated Aging Conditions

[0153] light source Aging time (h) Temperature (°C) Humidity (%RH) UVB 0 to 25 20.9 10 UVB 25 to 50 20.9 19 UVB 50 to 75 22.5 13 UVB 75 to 100 21.8 15 UVB 100 to 200 18.1 13 UVB 200 to 300 19.8 17 UVB 300 to 400 17.1 11 UVC 0 to 25 19.2 10 UVC 25 to 50 19.1 10 UVC 50 to 75 18.8 10 UVC 75 to 100 19.6 11 UVC 100 to 200 19.9 15 UVC 200 to 300 20.2 27 UVC 300 to 400 20.8 16

[0154] During the accelerated aging experiment, samples were removed at each time point for appearance and performance testing, including surface morphology and chemical structure analysis. After performance testing, the samples were returned to continue the experiment. Throughout the experiment, the same surface (front or back) of each sample was exposed to UVB and UVC ultraviolet light. In this way, different stages of the ultraviolet aging process can be simulated by controlling the irradiation time.

[0155] Specifically, during surface morphology analysis, scanning electron microscopy (SEM) was used to observe the surface morphology of each sample under different UV irradiation times. In the early stage of UV aging (0-100 hours), the sample surface was relatively smooth, with uniform particles and no obvious cracks. As the UV irradiation time increased, especially under the influence of the UVC band, cracks, pores, and surface roughening gradually appeared on the sample surface. UVB band radiation was relatively mild, and the surface only showed minor roughening changes.

[0156] Specifically, the morphology of sample 1 observed by SEM under 200x magnification during the UVB aging process from 0 to 400 hours is as follows. Figure 2 As shown. Figure 2 The aging process is illustrated below: as the aging time increases, the surface particles gradually become uneven, and slight cracks appear. At the 400-hour mark, the surface becomes even rougher, with significant granulation, and the material structure begins to loosen. Specifically, the morphology of sample 1 during UVC aging from 0 to 400 hours, observed by SEM under 200x magnification, is as follows. Figure 3 As shown. Figure 3 The following aging process was demonstrated: the cracks gradually developed from small cracks in the early stage to large-area cracks in the later stage. Especially after 300 hours, the cracks expanded significantly, the surface structure was severely degraded, and the particle peeling phenomenon was obvious.

[0157] Specifically, in the chemical structure analysis, the Fourier Transform Infrared (FTIR) spectra of samples 1 to 4 were analyzed to observe the changes in the chemical structure of silicone rubber materials during UV aging. The functional group assignments of the silicone rubber materials in the FTIR spectra are shown in Table 2. FTIR analysis showed that with the extension of aging time, the absorption peaks of the CH bonds and Si-CH3 bonds in silicone rubber gradually weakened, while the absorption peaks of the C=O oxidation products significantly increased under UVC aging conditions.

[0158] Table 2. Functional Group Assignments in Infrared Spectra of Silicone Rubber Materials

[0159]

[0160] Specifically, during the UVB aging process of sample No. 1 from 0 to 400 hours, the infrared spectrum of sample No. 1 silicone rubber material is as follows: Figure 4 As shown. Figure 4 The following characteristics were observed: the intensity of the Si-CH3 and CH characteristic peaks decreased slightly, but the peak of C=O oxidation products did not show a significant increase, indicating that the sample has good anti-aging properties under UVB conditions.

[0161] Specifically, during the UVC aging process of sample No. 1 from 0 to 400 hours, the infrared spectrum of sample No. 1 silicone rubber material is as follows: Figure 5 As shown. Figure 5 The following characteristics were observed: the C=O characteristic peak was significantly enhanced, and the Si-CH3 and CH peak intensities decreased significantly, indicating that the material underwent a violent oxidation reaction, especially after aging for more than 300 hours, the accumulation of C=O oxidation products was more obvious.

[0162] Specifically, during chemical structure analysis, Raman spectroscopy was performed on the four samples to further reveal the structural changes of the silicone rubber material samples during UV aging. Table 3 shows the identification of functional groups and peak positions in the Raman spectra of the silicone rubber materials. Analysis of the Raman spectra revealed that the characteristic peaks of CH and Si-O-Si decreased significantly with increasing UVC irradiation time, indicating accelerated degradation of the organic side chains and main chain. Compared to UVB aging, UVC aging caused more severe damage.

[0163] Table 3. Functional group assignments in Raman spectra of silicone rubber materials

[0164]

[0165] Specifically, during the UVB aging process of sample 1 from 0 to 400 hours, the Raman spectrum of sample 1 (silicone rubber material) is as follows: Figure 6 As shown. Figure 6 The following characteristics were observed: the characteristic peaks of CH and Si-CH3 gradually weakened, but in the later stage of aging (300 to 400 hours), the change in the main chain structure Si-O-Si was small, indicating that the main chain of the material maintained high stability and exhibited good resistance to ultraviolet aging.

[0166] Specifically, during the UVC aging process of sample 1 from 0 to 400 hours, the Raman spectrum of sample 1 (silicone rubber material) is as follows: Figure 7 As shown. Figure 7 The following characteristics were observed: the characteristic peaks of CH and Si-CH3 were significantly attenuated, and the peaks of the Si-O-Si main chain structure also decreased significantly, indicating that under the action of UVC radiation, both the main chain and side chain of the material underwent obvious oxidation and degradation reactions, and the structural damage was relatively severe.

[0167] Based on the above experimental results, the following conclusions can be drawn: UVC ultraviolet light has a more severe aging effect on silicone rubber than UVB, especially in the later stages of aging (300 to 400 hours). Numerous cracks, pores, and particle peeling appear on the sample surface, leading to comprehensive degradation of the material structure. The experimental results further indicate that silicone rubber materials from different manufacturers exhibit significant differences in their resistance to ultraviolet aging. Sample 1 showed the strongest anti-aging ability, while sample 2 showed the most severe aging.

[0168] Furthermore, composite insulator silicone rubber material that has been naturally aged for 10 years in high-altitude areas of Tibet was selected as a natural aging sample and systematically compared with samples that have undergone accelerated aging treatment in the UVB and UVC bands from 0 to 400 hours in the experiment to verify the practical adaptability and predictive ability of the accelerated experimental method.

[0169] According to SEM observations, the naturally aged sample exhibits moderate surface roughness at 200x magnification, with obvious local granulation, accompanied by a small number of pores and surface undulations. At 1000x magnification, the particle boundaries are blurred and the bonding force is weakened, but no through cracks are observed. Compared with the state of complete structural collapse of the sample after 400 hours of UVC aging, its degree of damage is between 300 and 400 hours of UVB aging.

[0170] FTIR spectral analysis showed that naturally aged samples generally exhibited Si-CH3 and CH peaks (such as 1259, 1413, and 2962 cm⁻¹). -1 The attenuation reflects significant aging of the organic side chains, and the Si-O-Si backbone peak (1008 cm⁻¹) in some samples is also observed. -1 The strength decreased, and at 1720cm -1 A peak of C=O oxidation product appears at [location], and OH absorption occurs (3300-3650 cm⁻¹). -1 The enhanced hygroscopicity indicates a significant oxidation reaction accompanied by increased hygroscopicity and decreased hydrophobicity. Compared with the experimental samples, the C=O peak intensity of the naturally aged samples was generally higher than that of the UVB-aged samples, but slightly lower than that of the UVC-aged group, indicating that natural environmental aging triggered a more complex synergistic oxidation process.

[0171] Raman spectroscopy further verified the above conclusions. The CH signal of the naturally aged samples was severely attenuated, and the Si-O-Si main chain signal of some samples was slightly blurred, with enhanced or drifted mid-frequency impurity peaks, indicating the accumulation of by-products and increased structural impurities. In comparison with the experimental samples, the main chain intensity of the naturally aged samples was close to that of the UVB group, but its side chain breakage was higher; the CH peaks in the UVC samples were still identifiable, while those in the naturally aged samples almost completely disappeared, and significant baseline drift and impurity peaks appeared in the mid-frequency region. This can be considered a comprehensive manifestation of the synergistic aging caused by outdoor oxygen, moisture, and temperature cycling.

[0172] In summary, the naturally aged samples from Tibet that have been in service for 10 years show a trend of high consistency with the UVC accelerated aging results in terms of microstructure, chemical structure, and spectral response. This further proves that the UV accelerated aging experimental method established in this invention has good practical simulation effect and can provide theoretical basis and experimental support for the life assessment and aging mechanism experimental results of silicone rubber materials for power equipment in plateau environments.

[0173] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if any adjustments and variations of this invention fall within the scope of the claims of this invention and their equivalents, this invention is also intended to include those modifications and variations.

Claims

1. An accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials, characterized in that, include: Silicone rubber material samples were obtained, and accelerated aging tests under ultraviolet radiation were conducted. At each time point, the accelerated aging silicone rubber material samples in each experimental process were subjected to aging characterization analysis to generate sample aging characterization data. Aging characterization analysis was performed on the naturally aged silicone rubber material samples obtained from high-altitude areas to generate aging characterization data for the control group. By comparing the aging characterization data of the sample with those of the control group, the effect of ultraviolet radiation on the aging of silicone rubber materials was evaluated.

2. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 1, characterized in that, The process of obtaining silicone rubber material samples and conducting accelerated ultraviolet radiation aging tests on silicone rubber materials includes: Two silicone rubber material samples were prepared. The first sample was used to receive UVB light source radiation, and the second sample was used to receive UVC light source radiation. Set up an ultraviolet radiation environment; Starting from hour 0, increase the exposure time of the two silicone rubber material samples in the ultraviolet radiation environment until any time point is reached; After reaching any time point, the two silicone rubber material samples are taken out from the ultraviolet radiation environment, and the accelerated aging silicone rubber material samples in each experimental process are subjected to aging characterization analysis.

3. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 2, characterized in that, The setting of the ultraviolet radiation environment includes: The wavelength of the UVB light source is controlled to be between 280 and 320 nm; The wavelength of the UVC light source is controlled to be between 200 and 280 nm; The irradiance of the light source is controlled at 1.2 W / m². 2 ; The distance between the sample and the light source is controlled to be 45 mm to 55 mm.

4. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 2, characterized in that, The preparation of two silicone rubber material samples includes: The thickness of the silicone rubber material sample was controlled to be between 0.2 cm and 0.25 cm.

5. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 2, characterized in that, Starting from hour 0, the exposure time of the two silicone rubber material samples in the ultraviolet radiation environment is increased until any time point is reached, including: The temperature and humidity of the ultraviolet radiation environment are controlled according to the temperature and relative humidity corresponding to each time point, wherein, Any time point includes: 25 hours, 50 hours, 75 hours, 100 hours, 200 hours, 300 hours, and 400 hours. Each time point is used to indicate the experimental progress of accelerated aging. The temperature corresponding to each time point is a set value between 17 and 23°C; The relative humidity at each time point is a set value between 10% and 27%.

6. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 2, characterized in that, The aging characterization analysis of accelerated-aging silicone rubber material samples at each experimental stage includes: The surface morphology of accelerated aging silicone rubber material samples was observed using scanning electron microscopy. The chemical structure of accelerated aging silicone rubber material samples was analyzed using infrared spectroscopy and Raman spectroscopy. By comprehensively analyzing the surface morphology and chemical structure changes of accelerated-aging silicone rubber material samples at various experimental stages, sample aging characterization data are generated.

7. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 1, characterized in that, The aging characterization analysis of the naturally aged silicone rubber material samples obtained from high-altitude areas was performed to generate aging characterization data for a control group, including: The surface morphology of naturally aged silicone rubber material samples from high-altitude areas with known service time was observed using scanning electron microscopy. Chemical structure of naturally aged silicone rubber material samples from high-altitude areas with known service time obtained by infrared spectroscopy and Raman spectroscopy analysis; By comprehensively analyzing the surface morphology and chemical structure changes of naturally aged silicone rubber material samples at different service times, sample aging characterization data are generated. The service time ranges from 1 year to 10 years, with 1-year intervals.

8. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 6 or 7, characterized in that, The surface morphology of the silicone rubber material sample was observed at a magnification of 200x or higher. The surface morphology included any of the following: cracks, pores, and particle boundaries.

9. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 6 or 7, characterized in that, The chemical structure of the silicone rubber material sample was analyzed by infrared spectroscopy. The chemical structure of the silicone rubber material sample includes: CH bonds, Si-CH3 bonds, and C=O oxidation products.

10. The accelerated testing method for evaluating the effect of ultraviolet radiation on the aging of silicone rubber materials as described in claim 6 or 7, characterized in that, The chemical structure of the silicone rubber material sample was analyzed by Raman spectroscopy. The chemical structure of the silicone rubber material sample includes CH bonds, Si-CH3 bonds, and Si-O-Si bonds.

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