|
|
|
| Insulation Properties of Self-Healing Silicone Based on Dynamic Hindered Thiourea Bond |
| Ding Yiming1, Jiao Yuyang1, Zhai Hanjun2, Lü Zepeng2, Ma Xianwei1,3 |
1. State Grid Beijing Power Supply Company Beijing 100032 China;
2. State Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong University Xi’an 710049 China;
3. Beijing Zhuoyue Power Construction Co. Ltd Beijing 100027 China |
|
|
|
Abstract Silicone rubber is a kind of insulating material widely used in power system. However, due to its poor mechanical strength, it is easy to be damaged during use, which affects its service life. Self-healing materials can repair their own minor damages under certain conditions, and then restore certain original properties. Silicone containing dynamic hindered thiourea bonds is a new type of intelligent insulation material, which can be used in power equipment and electronic devices. At present, the research on self-healing materials mainly focuses on the repair efficiency of mechanical properties, and pays less attention to their insulation properties. In order to study the feasibility of self-healing materials in electrical field, dynamic thiourea bond was synthesized by p-phenyldiisothiocyanate and aminopropyl double-ended polydimethicone. Anhydrous piperazine provided steric hindrance structure, and tri(2-aminoethyl)amine was used to adjust the molecular chain structure. A kind of material with healing property and insulating property was developed.
In this study, the crosslinking degree is variable and the cross-linking degree of PDMS-1, PDMS-2 and PDMS-3 increased. Firstly, the structure of the sample was tested, and the successful synthesis of thiourea bond was verified by Fourier transform infrared spectroscopy. The cross-linked structure was verified by swelling experiment, and the glass transition temperature was obtained by differential scanning calorimetry. It was found that the glass transition temperature of the sample increased with the increase of the cross-linking degree. The mechanical tests show that the elongation at break of the sample is close to 55%~59%, and the elastic modulus decreases from 23.535 MPa to 5.707 MPa with the increase of crosslinking degree, and the tensile strength increases first and then decreases. Due to the introduction of dynamic bond, the relative permittivity of the sample increases compared with that of ordinary silicone rubber, ranging from 2.1~4.8. It is found that the activation energy of thiourea bond is lower than that of urea bond through relaxation peak. The results of space charge show that with the increase of cross-linking degree, the homo-charge injection increases. The insulation test results show that the DC resistivity and breakdown field strength increase with the increase of crosslinking degree.
The self-healing properties of the material were verified by scratch repair experiments. Scratches were made on the surface of self-healing PDMS and ordinary commercial PDMS samples with a clean utility knife, and the wounds were fixed with a long tail clip after the wound was split. The morphology of the samples before and after the repair was observed with a microscope. After two days of treatment at 90℃, the incision of ordinary silicone rubber had a weak trend of repair, and PDMS-1 after 24 h of heat treatment, the incision became significantly smaller. The healing efficiency of the sample was evaluated by tensile strength and insulation properties. The repair efficiency of PDMS-1 with linear structure and PDMS-2 with low crosslinking degree can reach more than 60% based on mechanical properties, while the repair efficiency of PDMS-3 is low due to the high cross-linking degree, which limits the movement of chain segments. The breakdown strength of PDMS-1 and the repair efficiency of PDMS-2 can reach 84.3% and 79.1% respectively.
Through the above experiments, the following conclusions are drawn: (1) The self-healing PDMS containing the dynamic hindered thiourea bond has good repair performance, and the repair efficiency based on the breakdown strength can recover up to 84.3%. Although the resistivity decreases before and after repair, it still has good insulation effect; The repair efficiency of PDMS-1 with linear structure and PDMS-2 with low crosslinking degree can reach more than 60%. (2) The cross-linked structure can improve the insulation performance by affecting the movement of carriers, including resistivity and breakdown strength, etc., while also weakening the repair efficiency of the material by hindering the movement of the molecular chain.
|
|
Received: 08 November 2024
|
|
|
|
|
|
[1] 李国倡, 郭孔英, 张家豪, 等. 电缆附件用硅橡胶力-热老化特性及电-热-力多物理场耦合仿真研究[J]. 物理学报, 2024, 73(7): 23-34.
Li Guochang, Guo Kongying, Zhang Jiahao, et al.Stress-thermal aging properties of silicone rubber used for cable accessories and electric-thermal-stress multiple fields coupling simulation[J]. Acta Physica Sinica, 2024, 73(7): 23-34.
[2] 赵明伟, 马天祥, 李丹, 等. 硅橡胶绝缘材料温度及场强依赖特性对XLPE绝缘直流电缆预制接头内电场分布的影响[J]. 绝缘材料, 2024, 57(1): 74-79.
Zhao Mingwei, Ma Tianxiang, Li Dan, et al.Effects of temperature and field strength dependence characteristics of silicone rubber insulating material on electric field distribution in prefabricated joints of XLPE insulated DC cables[J]. Insulating Materials, 2024, 57(1): 74-79.
[3] 景巍巍, 谢坤, 李鸿泽, 等. 硅橡胶绝缘高压电缆附件的老化特性研究[J]. 高压电器, 2023, 59(11): 201-210, 223.
Jing Weiwei, Xie Kun, Li Hongze, et al.Research on aging characteristics of silicone rubber insulated high voltage cable accessories[J]. High Voltage Apparatus, 2023, 59(11): 201-210, 223.
[4] 梁琛, 司马文霞, 孙魄韬, 等. 单组分光敏微胶囊/纳米SiO2/环氧树脂复合绝缘介质的自修复特性[J]. 电工技术学报, 2022, 37(6): 1564-1571.
Liang Chen, Sima Wenxia, Sun Potao, et al.Self-healing property of one-component photosensitive microcapsule/nano-SiO2/epoxy composite dielectric[J]. Transactions of China Electrotechnical Society, 2022, 37(6): 1564-1571.
[5] 杜伯学, 张莹, 孔晓晓, 等. 环氧树脂绝缘电树枝劣化研究进展[J]. 电工技术学报, 2022, 37(5): 1128-1135, 1157.
Du Boxue, Zhang Ying, Kong Xiaoxiao, et al.Research progress on electrical tree in epoxy resin insulation[J]. Transactions of China Electrotechnical Society, 2022, 37(5): 1128-1135, 1157.
[6] 王凡, 李猛, 宋芳, 等. 自修复弹性体材料的研究进展及应用[J]. 特种橡胶制品, 2024, 45(1): 72-78.
Wang Fan, Li Meng, Song Fang, et al.Research and application of self-healing elastomer materials[J]. Special Purpose Rubber Products, 2024, 45(1): 72-78.
[7] 尹志颖, 赵方, 马宇琪, 等. 本征型自修复有机硅弹性体的研究进展[J]. 有机硅材料, 2022, 36(6): 62-69.
Yin Zhiying, Zhao Fang, Ma Yuqi, et al.Research progress of intrinsic self-healing silicone elastomers[J]. Silicone Material, 2022, 36(6): 62-69.
[8] 查俊伟, 高婧涵, 万宝全, 等. 自修复聚硅氧烷研究进展[J]. 高电压技术, 2023, 49(1): 279-293.
Zha Junwei, Gao Jinghan, Wan Baoquan, et al.Research progress in self-healing polysiloxane[J]. High Voltage Engineering, 2023, 49(1): 279-293.
[9] Yanagisawa Y, Nan Yiling, Okuro K, et al.Mecha-nically robust, readily repairable polymers via tailored noncovalent cross-linking[J]. Science, 2018, 359(6371): 72-76.
[10] 孙文杰, 张磊, 毛佳乐, 等. 电力设备绝缘损伤形式及自修复材料研究进展[J]. 电工技术学报, 2022, 37(8): 2107-2116.
Sun Wenjie, Zhang Lei, Mao Jiale, et al.Types of insulation damage and self-healing materials of power equipment: a review[J]. Transactions of China Electrotechnical Society, 2022, 37(8): 2107-2116.
[11] 刘云鹏, 黎馨阳, 刘贺晨, 等. 基于亚胺键的香草醛基可降解环氧树脂综合性能研究[J/OL]. 电工技术学报, 2024: 1-16[2024-11-23]. https://doi.org/10.19595/j.cnki.1000-6753.tces.240564.
Liu Yunpeng, Li Xinyang, Liu Hechen, et al. Comprehensive performance study of vanillin-based degradable epoxy resin based on imine bonding [J/OL]. Transactions of China Electrotechnical Society, 2024: 1-16[2024-11-23]. https://doi.org/10.19595/j.cnki.1000-6753.tces.240564.
[12] 伍云健, 丁大霖, 林慧, 等. 基于动态双硫键的本征自修复环氧绝缘材料性能研究[J]. 电工技术学报, 2024, 39(3): 836-843.
Wu Yunjian, Ding Dalin, Lin Hui, et al.Properties of intrinsic self-healing epoxy insulating materials based on dynamic disulfide bond[J]. Transactions of China Electrotechnical Society, 2024, 39(3): 836-843.
[13] Sun Jiawen, Liu Chao, Duan Jizhou, et al.Facile fabrication of self-healing silicone-based poly(urea-thiourea)/ tannic acid composite for anti-biofouling[J]. Journal of Materials Science & Technology, 2022, 124: 1-13.
[14] Li Yanmei, Zhang Zeping, Rong Minzhi, et al.Tailored modular assembly derived self-healing polythioureas with largely tunable properties covering plastics, elastomers and fibers[J]. Nature Commun-ications, 2022, 13(1): 2633.
[15] Sun Wenjie, Luo Jiaming, Zhang Lei, et al.Insulating silicones based on dynamic hindered urea bonds with high dielectric healability and recyclability[J]. ACS Applied Polymer Materials, 2021, 3(11): 5622-5631.
[16] Ying Hanze, Zhang Yanfeng, Cheng Jianjun.Dynamic urea bond for the design of reversible and self-healing polymers[J]. Nature Communications, 2014, 5: 3218.
[17] Sun Wenjie, Zhang Lei, Wang Shuang, et al.Mechanically enhanced healable and recyclable silicone with dynamic hindered urea bond for flexible electronics[J]. Journal of Materials Chemistry C, 2021, 9(27): 8579-8588.
[18] Carpi F, Anderson I, Bauer S, et al.Standards for dielectric elastomer transducers[J]. Smart Materials and Structures, 2015, 24(10): 105025.
[19] Ogliani E, Yu L, Javakhishvili I, et al.A thermo-reversible silicone elastomer with remotely controlled self-healing[J]. RSC Advances, 2018, 8(15): 8285-8291.
[20] Du Ke, Basuki J, Glattauer V, et al.Digital light processing 3D printing of PDMS-based soft and elastic materials with tunable mechanical properties[J]. ACS Applied Polymer Materials, 2021, 3(6): 3049-3059.
[21] Shivashankar H, Kevin A M, Manohar S B S, et al. Investigation on dielectric properties of PDMS based nanocomposites[J]. Physica B: Condensed Matter, 2021, 602: 412357.
[22] Min Daomin, Yan Chenyu, Huang Yin, et al.Dielectric and carrier transport properties of silicone rubber degraded by gamma irradiation[J]. Polymers, 2017, 9(10): 533.
[23] Huang Yin, Min Daomin, Li Shengtao, et al.Dielectric relaxation and carrier transport in epoxy resin and its microcomposite[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2017, 24(5): 3083-3091.
[24] Sun Wenjie, Luo Jiaming, Zhang Lei, et al.Insulating silicones based on dynamic hindered urea bonds with high dielectric healability and recyclability[J]. ACS Applied Polymer Materials, 2021, 3(11): 5622-5631.
[25] Zakaria S, Morshuis P H F, Benslimane M Y, et al. The electrical breakdown strength of pre-stretched elastomers, with and without sample volume conservation[J]. Smart Materials and Structures, 2015, 24(5): 055009. |
|
|
|
2024, Vol. 39 
