Enhanced thermal conductivity and flame retardancy of polyamide 6/flame retardant composites with hexagonal boron nitride

2018 ◽  
Vol 38 (8) ◽  
pp. 767-774 ◽  
Author(s):  
Liang Wang ◽  
Luchong Zhang ◽  
Andreas Fischer ◽  
Yuhua Zhong ◽  
Dietmar Drummer ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
High Performance ◽  
Heat Dissipation ◽  
Hexagonal Boron Nitride ◽  
Light Emitting Diode ◽  
Polyamide 6 ◽  
Twin Screw

Abstract High performance composite of polyamide 6 (PA6)/flame retardant (FR)/hexagonal boron nitride (hBN) was prepared via twin screw extrusion, followed by injection molding. The heat dissipation of the composite was significantly improved by incorporating 40 vol% of hBN, and the corresponding thermal conductivity was up to 5.701 W/(m·K), nearly 17 times that of the PA6/FR composites. In addition, the combination effect of hBN and FR to the flame retardancy of the composites was observed, and the addition of hBN could dramatically enhance the flame retardancy of composites, achieving a UL94 V-0 rating with a limited oxygen index (LOI) value of 37%. This multifunctional modification would broaden the application field of PA6 composites in light-emitting diode (LED) lamps, electronic products, and so on.

Flame-retardant porous hexagonal boron nitride for safe and effective radioactive iodine capture

2019 ◽  
Vol 7 (28) ◽  
pp. 16850-16858 ◽  
Author(s):  
Juan Wang ◽  
Kelong Ai ◽  
Lehui Lu
Keyword(s):  
Boron Nitride ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
High Stability ◽  
Radioactive Iodine ◽  
Spent Nuclear Fuel ◽  
Hexagonal Boron Nitride ◽  
Spent Nuclear Fuel Reprocessing ◽  
Nuclear Fuel Reprocessing ◽  
Fuel Reprocessing

The porous hexagonal BN with flame retardancy and high stability could serve as the adsorbent for radioactive iodine under harsh spent nuclear fuel reprocessing conditions.

scholarly journals Enhanced Thermal Conductivity of Silicone Composites Filled with Few-Layered Hexagonal Boron Nitride

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2072
Author(s):  
Wei-Cheng Cheng ◽  
Yi-Ting Hsieh ◽  
Wei-Ren Liu
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Heat Dissipation ◽  
Hexagonal Boron Nitride ◽  
Low Cost ◽  
Laser Flash ◽  
Force Microscopy ◽  
Surface Areas ◽  
Laser Flash Analysis ◽  
Surface Morphologies

In this study, we demonstrate the use of silicone/few-layered hexagonal boron nitride (FL-hBN) composites for heat dissipation applications. FL-hBN is synthesized via a green, facile, low-cost and scalable liquid exfoliation method using a jet cavitation process. The crystal structures, surface morphologies and specific surface areas of pristine h-BN and FL-hBN were characterized by XRD, SEM, TEM and AFM (atomic force microscopy). The results confirmed that FL-hBN with a thickness of ~4 nm was successfully obtained from the exfoliation process. In addition, we introduced both pristine h-BN and FL-hBN into silicone with different ratios to study their thermal properties. The results of the laser flash analysis indicate that the silicon/FL-hBN composite exhibited a higher thermal conductivity than that of the silicone/h-BN composite. With the optimal loading content of 30 wt.% FL-hBN content, the thermal conductivity of the composite could be enhanced to 230%, which is higher than that of silicone/h-BN (189%). These results indicate that jet cavitation is an effective and swift way to obtain few-layered hexagonal boron nitride that could effectively enhance the thermal conductivity of silicone composites.

scholarly journals Effect of Thermal Conductive Fillers on the Flame Retardancy, Thermal Conductivity, and Thermal Behavior of Flame-Retardant and Thermal Conductive Polyamide 6

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4114 ◽  
Author(s):  
Fang Wang ◽  
Wenbo Shi ◽  
Yuliang Mai ◽  
Bing Liao
Keyword(s):  
Thermal Conductivity ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Combustion Process ◽  
Polyamide 6 ◽  
Gravimetric Analysis ◽  
Limiting Oxygen Index ◽  
Conductive Fillers ◽  
Ul 94 ◽  
The Impact

In this work, polyamide 6 (PA6) composites with improved flame retardancy and thermal conductivity were prepared with different thermal conductive fillers (TC fillers) such as aluminum nitride (AlN) and boron nitride (BN) in a PA6 matrix with aluminum diethylphosphinate (AlPi) as a fire retardant. The resultant halogen-free flame retardant (HFFR) and thermal conductive (TC) PA6 (HFFR-TC-PA6) were investigated in detail with a mechanical property test, a limiting oxygen index (LOI), the vertical burning test (UL-94), a cone calorimeter, a thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The morphology of the impact fracture surface and char residue of the composites were analyzed by scanning electron microscopy (SEM). It was found that the thermal conductivity of the HFFR-TC-PA6 composite increased with the amount of TC fillers. The TC fillers exerted a positive effect for flame retardant PA6. For example, the HFFR-TC-PA6 composites with the thickness of 1.6 mm successfully passed the UL-94 V-0 rating with an LOI of more than 29% when the loading amount of AlN-550RFS, BN-SW08 and BN-NW04 was 30 wt%. The morphological structures of the char residues revealed that TC fillers formed a highly integrated char layer surface (without holes) during the combustion process, as compared to that of flame retardant PA6/AlPi composites. In addition, the thermal stability and crystallization behavior of the composites were studied.

scholarly journals High thermal conductivity of high-quality monolayer boron nitride and its thermal expansion

2019 ◽  
Vol 5 (6) ◽  
pp. eaav0129 ◽  
Author(s):  
Qiran Cai ◽  
Declan Scullion ◽  
Wei Gan ◽  
Alexey Falin ◽  
Shunying Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Boron Nitride ◽  
Density Functional ◽  
Heat Dissipation ◽  
Hexagonal Boron Nitride ◽  
High Thermal Conductivity ◽  
Unit Weight ◽  
High Quality ◽  
Dynamic Simulations

Heat management has become more and more critical, especially in miniaturized modern devices, so the exploration of highly thermally conductive materials with electrical insulation is of great importance. Here, we report that high-quality one-atom-thin hexagonal boron nitride (BN) has a thermal conductivity (κ) of 751 W/mK at room temperature, the second largest κ per unit weight among all semiconductors and insulators. The κ of atomically thin BN decreases with increased thickness. Our molecular dynamic simulations accurately reproduce this trend, and the density functional theory (DFT) calculations reveal the main scattering mechanism. The thermal expansion coefficients of monolayer to trilayer BN at 300 to 400 K are also experimentally measured for the first time. Owing to its wide bandgap, high thermal conductivity, outstanding strength, good flexibility, and excellent thermal and chemical stability, atomically thin BN is a strong candidate for heat dissipation applications, especially in the next generation of flexible electronic devices.

Thermal and dielectric properties of epoxy-based composites filled with flake and whisker type hexagonal boron nitride materials

2020 ◽  
pp. 095400832095941
Author(s):  
Rongkun Yang ◽  
Mingming Sheng ◽  
Yujun Zhang ◽  
Hongyu Gong ◽  
Xiao Lin ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Properties ◽  
Boron Nitride ◽  
Epoxy Resin ◽  
Heat Dissipation ◽  
Hexagonal Boron Nitride ◽  
Transmission Efficiency ◽  
Pure Epoxy ◽  
The Matrix ◽  
Properties Of Composites

In this work, the epoxy-based composites filled with 3-Aminopropyltriethoxysilane (KH-550) modified binary filler of hexagonal boron nitride (h-BN) flakes and h-BN whiskers were fabricated, and the thermal and dielectric properties of composites were systematically investigated. Adding h-BN whiskers to the filler could effectively form heat conduction paths and improve the phonon transmission efficiency, thereby improving the thermal conductivity of the composites. According to our results, the thermal conductivity of composite with 27 wt% h-BN flakes and 3 wt% h-BN whiskers reached up to 0.819 W·m−1·K−1, which was 3.9 times that of pure epoxy resin. At the same time, the dielectric loss value and dielectric constant of this composite at 1 MHz were 0.02678 and 4.55, respectively, while pure epoxy resin were 0.03602 and 4.33. In addition, introducing h-BN whiskers into the matrix could effectively improve the thermal stability and heat dissipation performance of composites.

Self-Extinguishing and Non-Drip Flame Retardant Polyamide 6 Nanocomposite: Mechanical, Thermal, and Combustion Behavior

2018 ◽  
Vol 1 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Hao Wu ◽  
Rogelio Ortiz ◽  
Renan De Azevedo Correa ◽  
Mourad Krifa ◽  
Joseph H. Koo
Keyword(s):  
Maleic Anhydride ◽  
Flame Retardant ◽  
Polymer Matrix ◽  
Flame Retardants ◽  
Polyamide 6 ◽  
Twin Screw Extrusion ◽  
Elongation At Break ◽  
Combustion Behavior ◽  
Screw Extrusion ◽  
Twin Screw

AbstractIncorporation of flame-retardant (FR) additives and nanoclay fillers into thermoplastic polymers effectively suppresses materials flammability and melt dripping behavior. However, it largely affects other properties, such as toughness and ductility. In order to recover the lost toughness and ductility of flame retardant polyamide 6, various loadings of maleic anhydride modified SEBS elastomer were added and processed by twin screw extrusion. TEM images showed exfoliated nanoclay platelets and reveals that the clay platelets well dispersed in the polymer matrix. By balancing the ratio of flame retardants, nanoclay and elastomers, formulation with elongation at break as high as 76% was achieved. Combining conventional intumescent FR and nanoclay, UL-94 V-0 rating and the LOI value as high as 32.2 were achieved. In conclusion, effective self-extinguishing and non-drip polyamide 6 nanocomposite formulations with significant improvement in toughness and ductility were achieved.

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