Highly anisotropic thermal conductivity of mesogenic epoxy resin film through orientation control

2021 ◽  
pp. 51396
Author(s):  
Ning Tang ◽  
Shingo Tanaka ◽  
Yoshitaka Takezawa ◽  
Kiyoshi Kanie
Keyword(s):  
Thermal Conductivity ◽  
Epoxy Resin ◽  
Orientation Control ◽  
Anisotropic Thermal Conductivity ◽  
Resin Film

scholarly journals Effect of Particle Sizes of Nickel Powder on Thermal Conductivity of Epoxy Resin-Based Composites under Magnetic Alignment

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1990
Author(s):  
Zheng Jin ◽  
Fei Liang ◽  
Wenzhong Lu ◽  
Jinhang Dai ◽  
Shunliang Meng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Particle Size ◽  
Aluminum Nitride ◽  
Epoxy Resin ◽  
Nickel Powder ◽  
Chain Structure ◽  
Particle Sizes ◽  
Anisotropic Thermal Conductivity ◽  
Powder Particles

Magnetically oriented three-phase composite systems of epoxy resin, aluminum nitride, and nickel have been prepared, the thermal conductivity of composites filled with nickel powder with different particle sizes and content under different applied magnetic fields was studied. The vibrating scanning magnetometer (VSM) and scanning electron microscopy (SEM) were applied to investigate the dispersion of nickel powder in the composites. The results showed that the anisotropic thermal conductivity of the composites treated by applied magnetic field forming chain structure is obtained. The epoxy resin-based composites filled with 30 vol% aluminum nitride with particle size of 1 μm and 2 vol% nickel powder with particle size of 1 μm and aligned with vertical magnetic field have the highest thermal conductivity (1.474 W/mk), which increases the thermal conductivity of the composites by 737% and 58% compared to the pure epoxy resin (0.2 W/mk) and the composites filled with 30 vol% aluminum nitride (0.933 W/mk). In addition, we simulated the influence of nickel powder particles with different particle sizes and arrangements on the thermal conductivity of the composite material in COMSOL Multiphysics software, and the results were consistent with the experimental results.

scholarly journals Thermophysical Properties of Multifunctional Syntactic Foams Containing Phase Change Microcapsules for Thermal Energy Storage

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1790
Author(s):  
Francesco Galvagnini ◽  
Andrea Dorigato ◽  
Luca Fambri ◽  
Giulia Fredi ◽  
Alessandro Pegoretti
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Epoxy Resin ◽  
Storage Modulus ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Neat Epoxy ◽  
Low Density ◽  
Syntactic Foams

Syntactic foams (SFs) combining an epoxy resin and hollow glass microspheres (HGM) feature a unique combination of low density, high mechanical properties, and low thermal conductivity which can be tuned according to specific applications. In this work, the versatility of epoxy/HGM SFs was further expanded by adding a microencapsulated phase change material (PCM) providing thermal energy storage (TES) ability at a phase change temperature of 43 °C. At this aim, fifteen epoxy (HGM/PCM) compositions with a total filler content (HGM + PCM) of up to 40 vol% were prepared and characterized. The experimental results were fitted with statistical models, which resulted in ternary diagrams that visually represented the properties of the ternary systems and simplified trend identification. Dynamic rheological tests showed that the PCM increased the viscosity of the epoxy resin more than HGM due to the smaller average size (20 µm vs. 60 µm) and that the systems containing both HGM and PCM showed lower viscosity than those containing only one filler type, due to the higher packing efficiency of bimodal filler distributions. HGM strongly reduced the gravimetric density and the thermal insulation properties. In fact, the sample with 40 vol% of HGM showed a density of 0.735 g/cm3 (−35% than neat epoxy) and a thermal conductivity of 0.12 W/(m∙K) (−40% than neat epoxy). Moreover, the increase in the PCM content increased the specific phase change enthalpy, which was up to 68 J/g for the sample with 40 vol% of PCM, with a consequent improvement in the thermal management ability that was also evidenced by temperature profiling tests in transient heating and cooling regimes. Finally, dynamical mechanical thermal analysis (DMTA) showed that both fillers decreased the storage modulus but generally increased the storage modulus normalized by density (E′/ρ) up to 2440 MPa/(g/cm3) at 25 °C with 40 vol% of HGM (+48% than neat epoxy). These results confirmed that the main asset of these ternary multifunctional syntactic foams is their versatility, as the composition can be tuned to reach the property set that best matches the application requirements in terms of TES ability, thermal insulation, and low density.

scholarly journals Preparation and Thermal Conductivity of Epoxy Resin/Graphene-Fe3O4 Composites

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2013
Author(s):  
Zhong Wu ◽  
Jingyun Chen ◽  
Qifeng Li ◽  
Da-Hai Xia ◽  
Yida Deng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Thermal Stability ◽  
Epoxy Resin ◽  
Thermomechanical Properties ◽  
Packaging Materials ◽  
Mass Ratio ◽  
Degree Of Orientation ◽  
Ep Matrix ◽  
Electrical Insulation Properties

By modifying the bonding of graphene (GR) and Fe3O4, a stable structure of GR-Fe3O4, namely magnetic GR, was obtained. Under the induction of a magnetic field, it can be orientated in an epoxy resin (EP) matrix, thus preparing EP/GR-Fe3O4 composites. The effects of the content of GR and the degree of orientation on the thermal conductivity of the composites were investigated, and the most suitable Fe3O4 load on GR was obtained. When the mass ratio of GR and Fe3O4 was 2:1, the thermal conductivity could be increased by 54.8% compared with that of pure EP. Meanwhile, EP/GR-Fe3O4 composites had a better thermal stability, dynamic thermomechanical properties, and excellent electrical insulation properties, which can meet the requirements of electronic packaging materials.

Thermal stable honokiol-derived epoxy resin with reinforced thermal conductivity, dielectric properties and flame resistance

2021 ◽  
Vol 412 ◽  
pp. 128647
Author(s):  
Jingjing Meng ◽  
Pengfei Chen ◽  
Rui Yang ◽  
Linli Dai ◽  
Cheng Yao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Properties ◽  
Epoxy Resin ◽  
Flame Resistance ◽  
Thermal Stable

scholarly journals A novel h-BN–RGO hybrids for epoxy resin composites achieving enhanced high thermal conductivity and energy density

RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23355-23362 ◽  
Author(s):  
Tao Huang ◽  
Xiaoliang Zeng ◽  
Yimin Yao ◽  
Rong Sun ◽  
Fanling Meng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Energy Density ◽  
Epoxy Resin ◽  
High Thermal Conductivity ◽  
Resin Composites ◽  
Epoxy Resin Composites ◽  
Significant Attention

In recent decades, significant attention has been focused on developing composite materials with high thermal conductivity utilizing h-BN, which has outstanding thermal conductivity.

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