Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge
Silicone rubber is widely used as an insulating material. In this article, silicone rubber samples were prepared by varying the content of crosslinker (2,5-bis(tert-butyl-peroxy)-2,5-dimethylhexane, DBPMH), and the free volume holes in the samples were investigated by means of positron annihilation...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-10-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/15/19/6833 |
| _version_ | 1797478331781742592 |
|---|---|
| author | Yue Yang Zheng Wang Xiangyang Peng Zhen Huang Pengfei Fang |
| author_facet | Yue Yang Zheng Wang Xiangyang Peng Zhen Huang Pengfei Fang |
| author_sort | Yue Yang |
| collection | DOAJ |
| description | Silicone rubber is widely used as an insulating material. In this article, silicone rubber samples were prepared by varying the content of crosslinker (2,5-bis(tert-butyl-peroxy)-2,5-dimethylhexane, DBPMH), and the free volume holes in the samples were investigated by means of positron annihilation lifetime spectroscopy (PALS) measurement. The surface chemical structure, surface micromorphology and water diffusion of the samples after corona discharge treatment were studied by FTIR, SEM and EIS measurements, respectively. As the crosslinker weight ratio increased from 0.2 wt.% to 1.5 wt.%, the mean free volume hole size first decreased and then remained unchanged. However, the concentration of free volume holes did not vary as the crosslinker weight ratio increased. SEM morphologies show that surface cracks were produced on samples having high crosslinking levels after corona treatment. The water diffusion coefficient of samples after corona treatment increased from 3.13 × 10<sup>−10</sup> cm<sup>2</sup> s<sup>−1</sup> to 17.68 × 10<sup>−10</sup> cm<sup>2</sup> s<sup>−1</sup> in the initial immersion period, as the crosslinker weight ratio increased from 0.2 wt.% to 3.0 wt.%. The results indicated that deterioration of samples with high crosslinking levels were more serious and water repellency more easily lost. The corona resistance ability of low crosslinking level silicone rubber stems from internal low molecular weight molecules. |
| first_indexed | 2024-03-09T21:30:24Z |
| format | Article |
| id | doaj.art-597ac79c7a824bf2a0bdfba52dc71ffc |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T21:30:24Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-597ac79c7a824bf2a0bdfba52dc71ffc2023-11-23T20:57:31ZengMDPI AGMaterials1996-19442022-10-011519683310.3390/ma15196833Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona DischargeYue Yang0Zheng Wang1Xiangyang Peng2Zhen Huang3Pengfei Fang4School of Physics and Technology, Wuhan University, Wuhan 430072, ChinaSchool of Physics and Technology, Wuhan University, Wuhan 430072, ChinaGuangdong Key Laboratory of Electric Power Equipment Reliability, Electric Power Research Institute of Guangdong Power Grid Co., Ltd., Guangzhou 510080, ChinaGuangdong Key Laboratory of Electric Power Equipment Reliability, Electric Power Research Institute of Guangdong Power Grid Co., Ltd., Guangzhou 510080, ChinaSchool of Physics and Technology, Wuhan University, Wuhan 430072, ChinaSilicone rubber is widely used as an insulating material. In this article, silicone rubber samples were prepared by varying the content of crosslinker (2,5-bis(tert-butyl-peroxy)-2,5-dimethylhexane, DBPMH), and the free volume holes in the samples were investigated by means of positron annihilation lifetime spectroscopy (PALS) measurement. The surface chemical structure, surface micromorphology and water diffusion of the samples after corona discharge treatment were studied by FTIR, SEM and EIS measurements, respectively. As the crosslinker weight ratio increased from 0.2 wt.% to 1.5 wt.%, the mean free volume hole size first decreased and then remained unchanged. However, the concentration of free volume holes did not vary as the crosslinker weight ratio increased. SEM morphologies show that surface cracks were produced on samples having high crosslinking levels after corona treatment. The water diffusion coefficient of samples after corona treatment increased from 3.13 × 10<sup>−10</sup> cm<sup>2</sup> s<sup>−1</sup> to 17.68 × 10<sup>−10</sup> cm<sup>2</sup> s<sup>−1</sup> in the initial immersion period, as the crosslinker weight ratio increased from 0.2 wt.% to 3.0 wt.%. The results indicated that deterioration of samples with high crosslinking levels were more serious and water repellency more easily lost. The corona resistance ability of low crosslinking level silicone rubber stems from internal low molecular weight molecules.https://www.mdpi.com/1996-1944/15/19/6833silicone rubbercrosslinking levelcorona dischargeelectrochemical impedancewater diffusion |
| spellingShingle | Yue Yang Zheng Wang Xiangyang Peng Zhen Huang Pengfei Fang Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge Materials silicone rubber crosslinking level corona discharge electrochemical impedance water diffusion |
| title | Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge |
| title_full | Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge |
| title_fullStr | Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge |
| title_full_unstemmed | Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge |
| title_short | Influence of Crosslinking Extent on Free Volumes of Silicone Rubber and Water Diffusion after Corona Discharge |
| title_sort | influence of crosslinking extent on free volumes of silicone rubber and water diffusion after corona discharge |
| topic | silicone rubber crosslinking level corona discharge electrochemical impedance water diffusion |
| url | https://www.mdpi.com/1996-1944/15/19/6833 |
| work_keys_str_mv | AT yueyang influenceofcrosslinkingextentonfreevolumesofsiliconerubberandwaterdiffusionaftercoronadischarge AT zhengwang influenceofcrosslinkingextentonfreevolumesofsiliconerubberandwaterdiffusionaftercoronadischarge AT xiangyangpeng influenceofcrosslinkingextentonfreevolumesofsiliconerubberandwaterdiffusionaftercoronadischarge AT zhenhuang influenceofcrosslinkingextentonfreevolumesofsiliconerubberandwaterdiffusionaftercoronadischarge AT pengfeifang influenceofcrosslinkingextentonfreevolumesofsiliconerubberandwaterdiffusionaftercoronadischarge |