Role of Micro-nano Hexagonal Boron Nitride Coordination on Thermal Conductivity and Breakdown Strength of Epoxy Composites

2020 ◽  
Author(s):  
Zhuolin Cheng ◽  
Jiao Xiang ◽  
Chuang Zhang ◽  
Hang Fu ◽  
Lei Xin ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Breakdown Strength ◽  
Hexagonal Boron Nitride ◽  
Epoxy Composites

scholarly journals Temperature Effects on the Dielectric Properties and Breakdown Performance of h-BN/Epoxy Composites

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4112 ◽  
Author(s):  
Yongzhe Tang ◽  
Peng Zhang ◽  
Mingxiao Zhu ◽  
Jiacai Li ◽  
Yuxia Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Boron Nitride ◽  
Mass Fraction ◽  
Breakdown Strength ◽  
Hexagonal Boron Nitride ◽  
Glassy State ◽  
Internal Heat ◽  
Heat Accumulation ◽  
Different Temperatures

Epoxy–boron nitride composites are promising insulating materials, and it is highly important to understand their insulating performances at different temperatures with different nano-doping amounts. In this study, we investigated the effects of different mass fractions of epoxy–micron hexagonal boron nitride composites on their thermal conductivity, as well as the effects of temperature and mass fraction on their insulating performances. The results demonstrated that the thermal conductivity of epoxy–micron hexagonal boron nitride composites was superior to that of neat epoxy. The thermal conductivity of epoxy–micron hexagonal boron nitride composites increased with the mass fraction of hexagonal boron nitride, and their dielectric constant and dielectric loss increased with temperature. The dielectric constant of epoxy–micron hexagonal boron nitride composites decreased as the mass fraction of hexagonal boron nitride increased, while their dielectric losses decreased and then increased as the mass fraction of hexagonal boron nitride increased. Due to internal heat accumulation, the alternating current breakdown strength of epoxy–micron hexagonal boron nitride composites increased and then decreased as the mass fraction of hexagonal boron nitride increased. Additionally, as the temperature increased, the composites transitioned from the glassy state to the rubbery or viscous state, and the breakdown strength significantly degraded.

Nano–micro structure of functionalized boron nitride and aluminum oxide for epoxy composites with enhanced thermal conductivity and breakdown strength

RSC Advances ◽  
2014 ◽  
Vol 4 (40) ◽  
pp. 21010-21017 ◽  
Author(s):  
Lijun Fang ◽  
Chao Wu ◽  
Rong Qian ◽  
Liyuan Xie ◽  
Ke Yang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Aluminum Oxide ◽  
Breakdown Strength ◽  
High Thermal Conductivity ◽  
Epoxy Composites ◽  
Micro Structure ◽  
Ceramic Fillers ◽  
Enhanced Thermal Conductivity

Nano-micro structure of modified 2-D and 0-D ceramic fillers is designed for epoxy with high thermal conductivity and breakdown strength.

scholarly journals Boron nitride nanoplatelets as two-dimensional thermal fillers in epoxy composites: new scenarios at very low filler loadings

2020 ◽  
Vol 40 (10) ◽  
pp. 859-867
Author(s):  
Yao Shi ◽  
Genlian Lin ◽  
Xi-Fei Ma ◽  
Xiao Huang ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Boron Nitride ◽  
Filler Content ◽  
Hexagonal Boron Nitride ◽  
Filler Loading ◽  
Epoxy Composites ◽  
General Phenomenon ◽  
Sudden Drop ◽  
Reduced Graphene ◽  
Thermal Conducting

AbstractHexagonal boron nitride (h-BN) nanoplatelets (0.6 μm in diameter and 100 nm in thickness) are introduced into epoxy resin to improve the polymer’s thermal conducting ability. As expected, the thermal conductivities (TCs) of the composites, especially the in-plane TCs, are significantly increased. The in-plane TC of the epoxy composites can reach 1.67 W/mK at only 0.53 wt% loading, indicating h-BN nanopletelets are very effective thermal fillers. However, after carefully studied the correlation of the TC improvement and filler content, a sudden drop of the TC around 0.53 wt% filler loading is observed. Such an unexpected decrease in TC has never been reported and is also found to be consistent with the Tg changes versus filler content. Similar trend is also observed in other 2-D nanofillers, such as graphene oxide, reduced graphene oxide, which may indicate it is a general phenomenon for 2-D nanofillers. SEM results suggest that such sudden drop in TC might be coming from the enrichment of these 2-D nanofillers in localized areas due to their tendency to form more ordered phase above certain concentrations.

scholarly journals Simultaneously Enhanced Thermal Conductivity and Breakdown Performance of Micro/Nano-BN Co-Doped Epoxy Composites

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3521
Author(s):  
Chuang Zhang ◽  
Jiao Xiang ◽  
Shihang Wang ◽  
Zhimin Yan ◽  
Zhuolin Cheng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Frequency ◽  
Breakdown Strength ◽  
Epoxy Composites ◽  
Endurance Time ◽  
Insulating Materials ◽  
Power Frequency ◽  
High Frequency Devices ◽  
Co Doped ◽  
Enhanced Thermal Conductivity

Micro/nano- BN co-doped epoxy composites were prepared and their thermal conductivity, breakdown strength at power frequency and voltage endurance time under high frequency bipolar square wave voltage were investigated. The thermal conductivity and breakdown performance were enhanced simultaneously in the composite with a loading concentration of 20 wt% BN at a micro/nano proportion of 95/5. The breakdown strength of 132 kV/mm at power frequency, the thermal conductivity of 0.81 W∙m−1∙K−1 and voltage endurance time of 166 s were obtained in the composites, which were approximately 28%, 286% and 349% higher than that of pristine epoxy resin. It is proposed that thermal conductive pathways are mainly constructed by micro-BN, leading to improved thermal conductivity and voltage endurance time. A model was introduced to illustrate the enhancement of the breakdown strength. The epoxy composites with high thermal conductivity and excellent breakdown performance could be feasible for insulating materials in high-frequency devices.

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