Fabrication of high-temperature aromatic polyamides with ultra-high breakdown strength via complex-assisted chain arrangement

2021 ◽  
pp. 134407
Author(s):  
Dajie Zhang ◽  
Junwei Lv ◽  
Yu Dai ◽  
Yongjiu Li ◽  
Taijun He ◽  
...  
Keyword(s):  
High Temperature ◽  
Breakdown Strength ◽  
Aromatic Polyamides

scholarly journals Temperature Dependence of Mechanical, Electrical Properties and Crystal Structure of Polyethylene Blends for Cable Insulation

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1922 ◽  
Author(s):  
Lunzhi Li ◽  
Lisheng Zhong ◽  
Kai Zhang ◽  
Jinghui Gao ◽  
Man Xu
Keyword(s):  
High Temperature ◽  
Electrical Properties ◽  
Temperature Dependence ◽  
Elevated Temperatures ◽  
Breakdown Strength ◽  
Temperature Stability ◽  
Xrd Analysis ◽  
Insulation Material ◽  
Cable Insulation ◽  
Polyethylene Blends

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.

High Temperature Performance of Coiled Glass Capacitors

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000192-000198 ◽  
Author(s):  
Eugene Furman ◽  
Amanda Baker ◽  
Steve Perini ◽  
Mohan Monoharan ◽  
Douglas Kushner ◽  
...  
Keyword(s):  
High Temperature ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Temperature Stability ◽  
Sodium Content ◽  
Flat Panel Display ◽  
High Temperature Stability ◽  
Thin Glass ◽  
High Dielectric ◽  
Power Capability

Alkali-free flat panel display glass is produced in large quantity and has excellent electrical insulating properties at high temperature. Aluminum borosilicate glass with alkaline-earth modifier has low sodium content and low dielectric loss (tan δ <0.1 at 250°C), high dielectric breakdown strength (109 V/m) and excellent high temperature stability. In addition, roll-to-roll processing of thin glass sheet has been demonstrated and glass capacitors that are configured in a coil. Excellent high power capability of these glasses was confirmed by analytical, finite element, and finite difference modeling. The modeling work indicates that a combination of hybrid electrode design and effective heat loss at the interface can further extend power capability of glass capacitors. Alkali-free glass is an ideal candidate material for high temperature capacitors.

Dielectric Breakdown Mechanism of Perovskite-Structured Ceramics

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000116-000120 ◽  
Author(s):  
Takuya Hoshina ◽  
Mikio Yamazaki ◽  
Hiroaki Takeda ◽  
Takaaki Tsurumi
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Dielectric Breakdown Strength ◽  
Breakdown Mechanism ◽  
High Dielectric ◽  
Measurement Efficiency ◽  
Breakdown Model

We precisely measured the dielectric breakdown strength of SrTiO3, CaTiO3, and CaZrO3 ceramics as a function of temperature, and revealed the dielectric breakdown mechanism of the ceramics. For the dielectric breakdown test, ceramics specimens with a lot of round-bottom holes were prepared. Using the specimens, the breakdown positions were stabilized and a reliability of breakdown strength was improved as well as the measurement efficiency. As a result of the dielectric breakdown tests, it was found that the dielectric breakdown strength decreased with increasing permittivity at room temperature and the permittivity dependence of breakdown strength obeyed Griffith type energy release rate model. At high temperature above 100ºC, the dielectric breakdown mechanism of SrTiO3 and CaTiO3 ceramics was explained by an intrinsic breakdown model. In contrast, an intrinsic dielectric breakdown of CaZrO3 ceramics didn't occur in the measurement temperature range up to 210ºC. To obtain a high dielectric breakdown strength at high temperature, the dielectric permittivity is required to be low to some extent and the defect concentration of oxygen vacancies should be minimized in the perovskite-structured oxide.

scholarly journals The Effects of Aluminum-Nitride Nano-Fillers on the Mechanical, Electrical, and Thermal Properties of High Temperature Vulcanized Silicon Rubber for High-Voltage Outdoor Insulator Applications

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3562 ◽  
Author(s):  
Chang Liu ◽  
Yiwen Xu ◽  
Daoguang Bi ◽  
Bing Luo ◽  
Fuzeng Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Thermal Properties ◽  
High Temperature ◽  
High Voltage ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Theoretical Models ◽  
Dielectric Constants ◽  
Silicon Rubber ◽  
Electrical Breakdown Strength

AlN nanoparticles were added into commercial high-temperature-vulcanized silicon rubber composites, which were designed for high-voltage outdoor insulator applications. The composites were systematically studied with respect to their mechanical, electrical, and thermal properties. The thermal conductivity was found to increase greatly (>100%) even at low fractions of the AlN fillers. The electrical breakdown strength of the composites was not considerably affected by the AlN filler, while the dielectric constants and dielectric loss were found to be increased with AlN filler ratios. At higher doping levels above 5 wt% (~2.5 vol%), electrical tracking performance was improved. The AlN filler increased the tensile strength as well as the hardness of the composites, and decreased their flexibility. The hydrophobic properties of the composites were also studied through the measurements of temperature-dependent contact angle. It was shown that at a doping level of 1 wt%, a maximum contact angle was observed around 108°. Theoretical models were used to explain and understand the measurement results. Our results show that the AlN nanofillers are helpful in improving the overall performances of silicon rubber composite insulators.

High temperature breakdown strength and voltage endurance characterization of nanofilled polyamideimide

2012 ◽  
Vol 19 (6) ◽  
pp. 2090-2101 ◽  
Author(s):  
L. S. Schadler ◽  
J. K. Nelson ◽  
C. Calebrese ◽  
A. Travelpiece ◽  
D. L. Schweickart
Keyword(s):  
High Temperature ◽  
Breakdown Strength

Synthesis of novel organic-soluble high-temperature aromatic polymers

1995 ◽  
Vol 7 (3) ◽  
pp. 337-345 ◽  
Author(s):  
Yoshio Imai
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Main Chain ◽  
Phenyl Group ◽  
Current Work ◽  
Transition Temperatures ◽  
Polymer Backbone ◽  
Glass Transition Temperatures ◽  
Aromatic Polyamides ◽  
Polymer Main Chain

This paper reviews our current work on the synthesis of new organic-soluble aromatic polyamides and polyimides having high glass transition temperatures above 300 °C. Our strategy to achieve this goal is to introduce a bulky pendant phenyl group along the polymer backbone and to incorporate a crank and twisted non-coplanar structure into the polymer main chain.

New high temperature aromatic polyamides

1964 ◽  
Vol 2 (12) ◽  
pp. 1171-1174 ◽  
Author(s):  
J. Preston ◽  
F. Dobinson
Keyword(s):  
High Temperature ◽  
Aromatic Polyamides

Fabrication of PMIA/fBN Dielectric Composite with Enhanced Breakdown Strength and Thermal Conductivity

2019 ◽  
Vol 960 ◽  
pp. 256-262
Author(s):  
Guang Yu Duan ◽  
Zu Ming Hu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
High Temperature ◽  
Dielectric Property ◽  
Dielectric Loss ◽  
Breakdown Strength ◽  
Dielectric Composite ◽  
Novel Method ◽  
Thermal Conductivities

A high-temperature poly (m-phenyleneisophthalamide) (PMIA) dielectric composite was successfully manufactured with functionalized BN (fBN) fillers. Due to effective modification by KH-550, fBN particles evenly dispersed in PMIA matrix. The dielectric property, breakdown strength and thermal conductivity of PMIA/fBN dielectric composite were researched. The consequences indicate that fBN fillers can not only decrease the dielectric loss but also enhance the breakdown strength of PMIA/fBN dielectric composites. Furthermore, owing to the generated heat transfer pathways by fBN particles, the thermal conductivities improved from 0.23 W·m-1·K-1 of fBN-0 to 0.86 W·m-1·K-1 of fBN-30, demonstrating a significant improvement. These results present a novel method for fabricating high-temperature PMIA/fBN dielectric composites with improved breakdown strength and thermal conductivity.

High Temperature Dielectric Breakdown of Alkali Halides

1960 ◽  
Vol 13 (2) ◽  
pp. 270 ◽  
Author(s):  
JJ O'Dwyer
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Experimental Work ◽  
Temperature Region ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Alkali Halides ◽  
Thermal Breakdown ◽  
High Temperature Region ◽  
The Difference

In the high temperature region much of the experimental work on the dielectric breakdown of the alkali halides is apparently conflicting. If, however, it is assumed that, breakdown is thermal in nature instead of intrinsic, reasons can be given which reduce the difference between various sets of existing experimental results. A calcula� t,ion of the thermal breakdown strength is given based on the assumption that the electrical conductivity is principally ionic. The magnitude and temperature variation of the breakdown strength is given correctly without disposable constants. Some suggestions are given for experimental work which may clear up outstanding difficulties.

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