ACS Applied Polymer Materials
·
2024
·
IF 4.4
Yunjian Wu,Hui Lin,Yiran Hu,Fujin Cai,Xiaoxing Zhang
Epoxy is widely used as an insulating material for electric power and electronic equipment due to its excellent physicochemical properties and electrical performance. However, its stable 3D cross-linked structure makes it difficult to degrade and efficiently recycle. Epoxy insulation equipment is often incinerated or landfilled after decommissioning, resulting in environmental pollution and the waste of resources. Aimed at the demand of degradable epoxy insulating materials for power equipment, an epoxy with high insulation strength, low dielectric loss, and good thermal stability based on a Schiff base was designed and prepared in this paper. The vanillin and epichlorohydrin were etherized to produce an aldehyde-containing monocyclic oxide (VE), and the preparation process was optimized. After curing with a diamine curing agent at different temperatures, it was found that the content of Schiff base in epoxy first increased and then decreased with the curing temperature. The thermal, electrical, and degrading properties of epoxy vary with the Schiff base content. The maximum glass transition temperature is 121 °C, and the breakdown field strength gets its maximum of 45.4 kV mm–1, which is higher than that of conventional epoxy. The dielectric loss is comparable to that of conventional epoxy with the lowest of 5 × 10–3. Meanwhile, the epoxy can be completely degraded within 40 min in a mildly acidic environment, and the cast copper winding can be effectively recycled after degradation. This study can provide theoretical guidance for the application of degradable epoxy based on Schiff base to insulating materials in power equipment.
研究领域:
材料科学
·
电气工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Qiyang Guo,Ruixiang Yao,Huili Cheng,Kai Yin,Xiangrong Chen,Yaqing Lu,Ashish Paramane
The strategy of functionalized PS-NPs via PPy (PPy@PS-NPs) forming heterogeneous interface composition is highly efficient in increasing the insulation properties of linear low-density polyethylene (LLDPE). The morphology results show that PPy@PS-NPs are monodispersed in the LLDPE matrix after melting blend, which exhibits unparalleled engineering application value. The electrical insulation results show that PPy@PS-NPs introduced into the LLDPE matrix can reduce its DC electrical conductivity, enhance DC breakdown strength, and inhibit space charge accumulation. When the PPy@PS-NPs concentration is 0.5 wt%, the DC breakdown strength is 35.3 % higher than that of LLDPE. Mechanism research indicates that the depths of carrier traps are decreased due to high electron affinity caused by the introduction of PPy@PS-NPs, but the trap density is increased. The reported strategy of using functionalized polymer nanoparticles to improve the polymer insulation property provides new insights for developing future high-insulation materials and other functional materials based on functionalized polymer nanofillers.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2024
·
IF 5
Hechen Liu,Chang Liu,Yunpeng Liu,Yuzhe Jiang,Xinyang Li,Yining Bai
Petroleum-based epoxy resin is commonly used in electrical equipment due to its outstanding performance and affordability. However, its non-melting characteristics present challenges for recycling, leading to significant resource waste and environmental pollution. To address this issue, this study prepared and synthesized a kind of vitrimer epoxy resin polymer material based on disulfide bonds with 2,2′-Diaminodiphenyl disulphide as the curing agent. The research investigated the impact of the curing agent ratio on the resin's structure and properties. The resin was mechanically recovered through hot pressing at high temperature and pressure, and its chemical degradation and recovery were achieved via the reduction reaction of the thiol and disulfide bond. The findings revealed that a curing agent to epoxy group material ratio of 0.75 improved the resin system's electrothermal properties. The electrical insulation property retention rate after hot pressing recovery reached 95 %, with a mechanical property retention rate of 85 %. The disulfide bonds can be reoxidized and crosslinked to realize the recovery and reuse of vitrimer resin degradation solution. Vitrimer epoxy resin based on disulfide bonds is a significant way to realize the environmental protection of epoxy electrical equipment.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
·
2025
·
IF 3.1
Zhonglei Li,Shuai Zhao,Yifan Yin,Boxue Du
This paper investigates the enhancement of thermo-oxidative aging resistance in PP cable insulation by grafting dual-functional monomer. Accelerated aging experiments are conducted at 135°C, and the electrical and physicochemical properties of the grafted-PP blended elastomer sample (PP-GB) and PP blended elastomer sample (PP-B) are tested at various aging times. The results show that grafting with Irganox 3052 effectively enhances the thermo-oxidative aging resistance of PP. After 1440 h of aging, PP-GB maintains excellent oxidative induction time (OIT) and elongation at break, with a significantly lower carbonyl index (CI) and less degradation of PP molecular chains than PP-B. Moreover, Irganox 3052 introduces multiple localized state energy levels, which effectively mitigate the degradation of the dielectric properties of PP cable insulation during aging. Even after 1440 h of aging, PP-GB retains excellent insulating properties, exhibiting an approximately two orders of magnitude improvement in DC volume resistivity and a 33.23% improvement in DC breakdown strength at 90 °C compared to PP-B. Additionally, dual-function grafting inhibits the generation of polar molecular groups, phase separation of PP and POE phases, and destruction of the crystalline region during aging, reducing the β relaxation strength (Δεβ) and increasing the activation energy of δ relaxation (Eδ) and α relaxation (Eα). These findings can be effectively applied to improve the long-term operational reliability of PP cable insulation.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2024
·
IF 6.5
Chuang Wang,XinFa Yang,HaoLin Zhang,Chi Chen,ZaiQin Zhang,He Li
In this paper, epoxy resin (EP) composites with different phase structures were prepared by introducing hydroxyl-terminated liquid nitrile rubber (HTBN) and hydroxyl-terminated polyethersulfone (PES) individually or simultaneously into the resin matrix. The results revealed that the rational distribution of phase structure of rigid PES and flexible HTBN can effectively contributed to the enhancement in their mechanical and electrical insulation strengths. The synergistic effect of the two reinforcing fillers granted the optimized ternary composite a tougher structural network, leading to significant improvements of 73.13 % and 18.98 % in mechanical impact strength and electrical breakdown strength, respectively, compared to the pristine EP. Furthermore, compared to HTBN, PES exhibited inhibited HTBN dielectric interfacial polarization and EP molecular chain segment relaxation, resulting in decreased dielectric constant and loss in the composites. This study provide insights into the dielectric properties and design strategies for the development of resin-based dielectric materials, ensuring their broader applicability.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 7
·1-12
·
IF 2.8
Zhang Xinle,Chi Qingguo,Tang Chao,Li Hua,Zhang Changhai,Li Zhonghua,Zhang Tiandong
The rapidly growing third-generation wide-band-gap semiconductor electronic device industry urgently requires high-temperature-resistant packaging materials. However, the epoxy molding compound materials cannot suffer the high-temperature working condition due to the intrinsic molecular chain structure of epoxy materials (EP). In this paper, bisphenol A-type cyanate (BADCy) with triazine ring structure was introduced into EP to improve its heat resistance. The curing reaction as well as the curing mechanism has been clearly revealed for BADCy/EP with different contents of BADCy according to the Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) results. In the whole copolymer system, the copolymer at higher BADCy concentration (50–60 mol%) achieved the highest crosslink density (12.8 × 10 –3 mol/cm 3 ), thus, showing excellent glass transition temperature (> 200 °C) and thermal decomposition temperature( T 5% > 400 °C). The heat resistance and electrical insulation property of BADCy/EP system have been systematically investigated, and a balance between high heat resistance and good electrical insulation are achieved at 66 mol% BADCy content, where the glass transition temperature reaches 215 °C, which is 73 °C higher than that of the EP system of anhydride copolymer. The volume resistivity of 1.5 × 10 15 Ω·m and dielectric constant of 3.3 is obtained, indicating excellent electrical insulation and dielectric properties of BADCy/EP. This work provides a facile and efficient strategy to improve the overall properties of EP by optimizing the molecular chain structure.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 19
·8701-8713
·
IF 4.682
Gao Yufu,Wu Shaohua,Li Chuncheng,Xiao Yaonan,Liu Jiajian,Zhang Bo
Poly(p-phenylene benzobisoxazole) (PBO) fibre-based specialty paper has become a promising candidate for high-performance insulating materials due to the remarkable properties of PBO fibres. However, the porous structure and poor interfacial interaction of PBO paper seriously weaken its mechanical strength and greatly limit its practical application. Herein, proposed for the first time, a homogeneous reinforcement strategy is developed to regulate the microstructure of PBO paper and efficiently enhance its overall properties. For this reason, flexible ortho-hydroxy polyamic acid (HPAA) was first synthesized and used to impregnate PBO paper. Subsequently, HPAA was thermally converted into a benzoxazole-containing resin, manifesting excellent interfacial compatibility with PBO paper. As a result, the compact structure and solid interface endow the composite paper with impressive performance. The tensile strength, modulus, and electrical breakdown strength of the composite paper are 116.86 MPa, 5.47 GPa, and 63.7 kV mm −1 , respectively, increasing by 33.1, 8.1, and 1.1 times compared with those parameters of the original paper (3.43 MPa, 0.60 GPa, and 30.5 kV mm −1 ). Moreover, the composite paper also exhibits an ultra-low dielectric constant and loss tangent (1.6 and 0.004 at 10 6 Hz, respectively), as well as superhigh thermal stability (maximum decomposition temperature, T max ≈ 600 °C) due to the elaborate design of the structure. Thus, the mechanical strength has been successfully integrated with the outstanding insulation and thermal properties, rendering the lightweight PBO composite paper promising in the field of high-temperature and high-voltage electrical insulation. Graphical abstract
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2022
·Vol. 34
·期 43
·2206855
·
IF 32.086
Xiao-Feng Pan,Guan-Hua Yu,Huai-Ling Gao,Zhe-Zhao Wang,Zhiwei Bao,Xiaoguang Li,Shu-Hong Yu
Compared with raw rectorite microplatelets (RMs), rectorite nanosheets (RNs) have considerably greater application prospects in the preparation of advanced composite materials because of their larger aspect ratio, higher surface reactivity, and intrinsically superior mechanical and physical properties. However, the difficulty in the efficient preparation of RNs significantly limits their large-scale applications. Here, a scalable poly(vinylpyrrolidone)-assisted stirring approach is developed to prepare ultrathin RNs from the abundant natural RMs. A higher production rate (≈0.675 g h −1 ) is achieved compared with that of most other nanosheets. Additionally, instead of using conventional time- and energy-consuming high-speed centrifugation, an efficient poly(dienedimethylammonium chloride)-assisted sedimentation strategy is proposed here to rapidly separate the exfoliated RNs from the RN dispersion. Then, the RNs are co-assembled with aramid nanofibers (ANFs) into large-scale nacre-mimetic ANF-RN nanopapers with considerably enhanced mechanical, electrical insulating, and high-temperature-resistant properties compared with pure ANF nanopapers and ANF-RM micropapers. Moreover, these properties are superior to those of previously reported ANF-based nanopapers and commercial insulating micropapers.
研究领域:
材料科学
·
纳米技术
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 33
·期 9
·2210901
·
IF 19.924
Xiao-Feng Pan,Zhiwei Bao,WenLong Xu,Huai-Ling Gao,Bao Wu,YinBo Zhu,Guan-Hua Yu,Jungen Chen,Si-Chao Zhang,Liangbin Li,Heng-An Wu,Xiaoguang Li,Shu-Hong Yu
The emerging aramid-mica nanopapers, composed of aramid nanofibers (ANFs) and mica nanosheets (Mica), exhibit superiority in the field of electrical insulation compared with commercial aramid-mica micropapers. Unfortunately, their mechanical and electrical insulating properties are still less than ideal due to insufficient control of their microstructures. Herein, it is presented that by integrating ANFs and Mica into nacre-like aramid-mica nanopapers with improved structural orderliness, densification, and interlayer interaction, simultaneously improved mechanical and electrical insulating properties are achieved. Their maximum tensile strength and breakdown strength reach ≈292 MPa and ≈176 kV mm −1 , respectively, which are superior to those of the state-of-the-art ANFs-based nanopapers. Particularly, the aramid-mica nanopapers show high resistance to high-temperature (250–300 °C) and oil-bath (100 °C) environments commonly involved in practical applications, and can be recycled many times, demonstrating their great potential as high-performance sustainable electrical insulating papers to be applied in advanced electrical equipment.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xi Zhu,Xiuhan Guan,Luyi Dai,Xinglei Cui,Jiajie Fan,Zhi Fang
High-voltage power modules inevitably face the critical problem of electric field distortion at triple-junction point (Cu/insulation substrate/potting material) and accidental introduction of unexpected micro-metal defects on insulation substrate, which damages electrical insulating properties and induces breakdown. In this study, a novel precise surface treatment method based on atmospheric pressure micro-plasma jet (μ-APPJ) is proposed for rejuvenating and improving electrical insulating properties of defective Cu/epoxy resin (EP) substrate in power modules. Results show that a typical μ-APPJ with a diameter of about 200 μm is developed to precisely treat the micro-level metal defect in Cu/EP interface, and a spherical-clustered Si-containing functional film (∼Si-O 4 ) can be fabricated on EP substrate by optimized Ar/Hexamethyldisiloxane (HMDSO)/μ-APPJ, which significantly enhances the hydrophobicity of EP surface. Moreover, the plasma-assisted film deposition around μm-defect improves interface electrical properties of defective Cu/EP samples, evidenced by higher flashover voltages and suppressed partial discharge. Further analysis based on simulations reveals that the deposited typical film not only promotes charge mobility and creepage distance on EP, but also introduces additional trap levels that capture electrons and inhibit electric field around metal defects, thereby suppressing partial discharge failure and improving electrical insulating properties.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 6
·767
·
IF 4.7
Changhai Zhang,Ziyang Liu,Chao Tang,Tiandong Zhang,Yue Zhang,Yongquan Zhang,Qingguo Chi
With the policy tilt and increased investment in research and development in the world, new energy vehicle technology continues to progress and the drive motor power density continues to improve, which puts forward higher requirements for the comprehensive performance of the core insulating material enameled wire enamel for drive motors. Polyimide (PI) has excellent electrical insulation properties, and heat resistance is often used to drive the motor winding insulation. To further improve the corona resistance and insulating properties of PI wire enamel varnish, in this paper, firstly, fluorene groups with a rigid conjugated structure were introduced into the molecular chain of the PI film by molecular structure modulation, and then uniformly dispersed alumina nanoclusters (AOCs) were introduced into the PI matrix by using an in situ growth process to inhibit the migration of high-energy electrons. The quantum size effect of the alumina nanoclusters was exploited to synergistically enhance the suppression and scattering of energetic moving electrons by PI-based composite films. The results show that the breakdown field strength of the PI-based composite film (MPI/1.0 vol% AOC) reaches 672.2 kV/mm, and the corona resistance life reaches 7.9 min, which are, respectively, 1.55 and 2.19 times higher than those of the initial PI film. A PI-based composite film with excellent insulating and corona resistance properties was obtained.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2018
·Vol. 135
·期 30
·46528
·
IF 1.901
Lili Ma,Qingquan Lei
Polyimide (PI) films used in aerospace and rail applications are degraded by thermal, chemical, and electric power under the effect of insulation aging. To prevent these types of degradation, we prepared nanocomposite films of PI and layered double hydroxide (LDH) modified with the potassium perfluorooctane sulfonate (FS) by an in situ method. On the whole, the glass-transition temperature, dielectric constant (ɛ′), and corona-resistance lifetime of the nanocomposite films increased over those of the pure PI film, but the temperature at 10 wt % weight loss, breakdown strength, and volume resistance decreased correspondingly as a whole. The PI matrix was protected by the inorganic material of LDH–FS with a high ɛ′ from corona corrosion. Furthermore, the heat and chemical interactions of the composite films improved the corona-resistance lifetime, despite the decrease in the breakdown strength; this should result in promising applications for insulation parts of variable-frequency motors. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46528.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）