scholarly journals Synergistic Effects of Various Ceramic Fillers on Thermally Conductive Polyimide Composite Films and Their Model Predictions

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 484 ◽  
Author(s):  
Heeseok Song ◽  
Byoung Kim ◽  
Yong Kim ◽  
Youn-Sang Bae ◽  
Jooheon Kim ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Hybrid System ◽  
Prediction Models ◽  
Synergistic Effects ◽  
Composite Films ◽  
Hybrid Filler ◽  
Model Predictions ◽  
Thermally Conductive ◽  
Ceramic Fillers ◽  
Polyimide Matrix

In this study, thermally conductive composite films were fabricated using an anisotropic boron nitride (BN) and hybrid filler system mixed with spherical aluminum nitride (AlN) or aluminum oxide (Al2O3) particles in a polyimide matrix. The hybrid system yielded a decrease in the through-plane thermal conductivity, however an increase in the in-plane thermal conductivity of the BN composite, resulting from the horizontal alignment and anisotropy of BN. The behavior of the in-plane thermal conductivity was theoretically treated using the Lewis–Nielsen and modified Lewis–Nielsen theoretical prediction models. A single-filler system using BN exhibited a relatively good fit with the theoretical model. Moreover, a hybrid system was developed based on two-population approaches, the additive and multiplicative. This development represented the first ever implementation of two different ceramic conducting fillers. The multiplicative-approach model yielded overestimated thermal conductivity values, whereas the additive approach exhibited better agreement for the prediction of the thermal conductivity of a binary-filler system.

High Thermal Conductive Si3N4 Particle Filled Epoxy Composites With a Novel Structure

2007 ◽  
Vol 129 (4) ◽  
pp. 469-472 ◽  
Author(s):  
Hong He ◽  
Renli Fu ◽  
Yanchun Han ◽  
Yuan Shen ◽  
Deliu Wang
Keyword(s):  
Thermal Conductivity ◽  
Volume Fraction ◽  
Conductive Polymer ◽  
Cost Effective ◽  
Structure Design ◽  
Low Dielectric ◽  
Novel Structure ◽  
Particle Form ◽  
Thermally Conductive ◽  
Ceramic Fillers

Traditionally, large quantities of ceramic fillers are added to polymers in order to obtain high thermally conductive polymer composites, which are used for electronic encapsulants. However, that is not cost effective enough. In this study, Si3N4 particle filled epoxy composite with a novel structure was fabricated by a processing method and structure design. Epoxy resin used in particle form was obtained by premixing and crushing. Different particle sizes were selected by sieving. High thermal conductivity was achieved at relative low volume fraction of the filler. The microstructure of the composites indicates that a continuous network is formed by the filler, which mainly completes the heat conduction. Thermal conductivity of the composites increases as the filler content increases, and the samples exhibit a highest thermal conductivity of 1.8W∕mK at 30% volume fraction of the filler in the composites using epoxy particles of 2mm. The composites show low dielectric constant and low dielectric loss.

scholarly journals Incorporating MXene into Boron Nitride/Poly(Vinyl Alcohol) Composite Films to Enhance Thermal and Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 379
Author(s):  
Seonmin Lee ◽  
Jooheon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Boron Nitride ◽  
Composite Film ◽  
Vinyl Alcohol ◽  
Composite Films ◽  
Poly Vinyl Alcohol ◽  
Thermal And Mechanical Properties ◽  
Conduction Path ◽  
Thermally Conductive

Aggregated boron nitride (ABN) is advantageous for increasing the packing and thermal conductivity of the matrix in composite materials, but can deteriorate the mechanical properties by breaking during processing. In addition, there are few studies on the use of Ti3C2 MXene as thermally conductive fillers. Herein, the development of a novel composite film is described. It incorporates MXene and ABN into poly(vinyl alcohol) (PVA) to achieve a high thermal conductivity. Polysilazane (PSZ)-coated ABN formed a heat conduction path in the composite film, and MXene supported it to further improve the thermal conductivity. The prepared polymer composite film is shown to provide through-plane and in-plane thermal conductivities of 1.51 and 4.28 W/mK at total filler contents of 44 wt.%. The composite film is also shown to exhibit a tensile strength of 11.96 MPa, which is much greater than that without MXene. Thus, it demonstrates that incorporating MXene as a thermally conductive filler can enhance the thermal and mechanical properties of composite films.

scholarly journals Effective Heat Transfer Pathways of Thermally Conductive Networks Formed by One-Dimensional Carbon Materials with Different Sizes

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1661 ◽  
Author(s):  
Lee ◽  
Lee ◽  
Kim ◽  
Noda ◽  
Shim ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Polymer Matrix ◽  
Carbon Materials ◽  
Interfacial Resistance ◽  
Hybrid Films ◽  
Hybrid Filler ◽  
One Dimensional ◽  
Effective Heat ◽  
Thermally Conductive

We investigated the heat transfer behavior of thermally conductive networks with one-dimensional carbon materials to design effective heat transfer pathways for hybrid filler systems of polymer matrix composites. Nano-sized few-walled carbon nanotubes (FWCNTs) and micro-sized mesophase pitch-based carbon fibers (MPCFs) were used as the thermally conductive materials. The bulk density and thermal conductivity of the FWCNT films increased proportionally with the ultrasonication time due to the enhanced dispersibility of the FWCNTs in an ethanol solvent. The ultrasonication-induced densification of the FWCNT films led to the effective formation of filler-to-filler connections, resulting in improved thermal conductivity. The thermal conductivity of the FWCNT-MPCF hybrid films was proportional to the MPCF content (maximum thermal conductivity at an MPCF content of 60 wt %), indicating the synergistic effect on the thermal conductivity enhancement. Moreover, the MPCF-to-MPCF heat transfer pathways in the FWCNT-MPCF hybrid films were the most effective in achieving high thermal conductivity due to the smaller interfacial area and shorter heat transfer pathway of the MPCFs. The FWCNTs could act as thermal bridges between neighboring MPCFs for effective heat transfer. Furthermore, the incorporation of Ag nanoparticles of approximately 300 nm into the FWCNT-MPCF hybrid film dramatically enhanced the thermal conductivity, which was closely related to a decreased thermal interfacial resistance at the intersection points between the materials. Epoxy-based composites loaded with the FWCNTs, MPCFs, FWCNT-MPCF hybrids, and FWCNT-MPCF-Ag hybrid fillers were also fabricated. A similar trend in thermal conductivity was observed in the polymer matrix composite with carbon-based hybrid films.

scholarly journals Achieving a 3D Thermally Conductive while Electrically Insulating Network in Polybenzoxazine with a Novel Hybrid Filler Composed of Boron Nitride and Carbon Nanotubes

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2331
Author(s):  
Yi Wang ◽  
Wei Wu ◽  
Dietmar Drummer ◽  
Chao Liu ◽  
Florian Tomiak ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Boron Nitride ◽  
Condensation Reaction ◽  
Heat Accumulation ◽  
Hybrid Filler ◽  
Excessive Heat ◽  
Hybrid Fillers ◽  
Thermally Conductive ◽  
Treated Carbon

To solve the problem of excessive heat accumulation in the electronic packaging field, a novel series of hybrid filler (BN@CNT) with a hierarchical “line-plane” structure was assembled via a condensation reaction between functional boron nitride(f-BN) and acid treated carbon nanotubes (a-CNTs). The reactions with different mass ratios of BN and CNTs and the effect of the obtained hybrid filler on the composites’ thermal conductivity were studied. According to the results, BN@15CNT exhibited better effects on promoting thermal conductivity of polybenzoxazine(PBz) composites which were prepared via ball milling and hot compression. The thermally conductive coefficient value of PBz composites, which were loaded with 25 wt% of BN@15CNT hybrid fillers, reached 0.794 W· m−1· K−1. The coefficient value was improved to 0.865 W· m−1· K−1 with 15 wt% of BN@15CNT and 10 wt% of BN. Although CNTs were adopted, the PBz composites maintained insulation. Dielectric properties and thermal stability of the composites were also studied. In addition, different thermal conduction models were used to manifest the mechanism of BN@CNT hybrid fillers in enhancing thermal conductivity of PBz composites.

scholarly journals Synergistic Effects of Hybrid Carbonaceous Fillers of Carbon Fibers and Reduced Graphene Oxides on Enhanced Heat-Dissipation Capability of Polymer Composites

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 909 ◽  
Author(s):  
Yun Seon Lee ◽  
Jaesang Yu ◽  
Sang Eun Shim ◽  
Cheol-Min Yang
Keyword(s):  
Thermal Conductivity ◽  
Synergistic Effect ◽  
Carbon Fibers ◽  
Heat Dissipation ◽  
Synergistic Effects ◽  
Epoxy Composites ◽  
Graphene Oxides ◽  
Reduced Graphene ◽  
Thermally Conductive ◽  
Loading Amount

In this study, we investigated the synergistic effects of thermally conductive hybrid carbonaceous fillers of mesophase pitch-based carbon fibers (MPCFs) and reduced graphene oxides (rGOs) on the thermal conductivity of polymer matrix composites. Micro-sized MPCFs with different lengths (50 μm, 200 μm, and 6 mm) and nano-sized rGOs were used as the thermally conductive fillers used for the preparation of the heat-dissipation polymer composites. For all MPCF fillers with a different length, the thermal conductivity values of the MPCF/epoxy composites were proportional to the MPCF length and loading amount (0–50 wt%) of MPCFs. For an MPCF:rGO weight ratio of 49:1 (total loading amount of 50 wt%), the thermal conductivity values of MPCF-rGO/epoxy composites loaded with MPCFs of 50 μm, 200 μm, and 6 mm increased from 5.56 to 7.98 W/mK (approximately 44% increase), from 7.36 to 9.80 W/mK (approximately 33% increase), and from 11.53 to 12.58 W/mK (approximately 9% increase) compared to the MPCF/epoxy composites, respectively, indicating the synergistic effect on the thermal conductivity enhancement. The rGOs in the MPCF-rGO/epoxy composites acted as thermal bridges between neighboring MPCFs, resulting in the formation of effective heat transfer pathways. In contrast, the MPCF-rGO/epoxy composites with MPCF:rGO weight ratios of 48:2 and 47:3 decreased the synergistic effect more significantly compared to rGO content of 1 wt%, which is associated with the agglomeration of rGO nanoparticles. The synergistic effect was inversely proportional to the MPCF length. A theoretical approach, the modified Mori-Tanaka model, was used to estimate the thermal conductivity values of the MPCF-rGO/epoxy composites, which were in agreement with the experimentally measured values for MPCF-rGO/epoxy composites loaded with short MPCF lengths of 50 and 200 μm.

scholarly journals Carbonization of Polydopamine-Coating Layers on Boron Nitride for Thermal Conductivity Enhancement in Hybrid Polyvinyl Alcohol (PVA) Composites

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1410 ◽  
Author(s):  
Youjin Kim ◽  
Jooheon Kim
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Polyvinyl Alcohol ◽  
Composite Films ◽  
Analytical Techniques ◽  
Conductive Filler ◽  
Sustainable Chemistry ◽  
Conductivity Enhancement ◽  
Nanocrystalline Graphite ◽  
Thermally Conductive

Inspired by mussel adhesion proteins, boron nitride (BN) particles coated with homogeneous polydopamine (BNPDA) were prepared, and through an annealing process, a carbonized PDA layer on the surface of BN was obtained, which exhibited a nanocrystalline graphite-like structure. The effect of carbonization of PDA coating layer on BN particles was characterized by various analytical techniques including SEM, TEM, Raman spectroscopy, and XPS. When the resulting particles were used as a thermally conductive filler for polyvinyl alcohol (PVA) composite films, enhanced thermal conductivity was observed compared to raw BN composite due to the ordered structure and improved solubility in water. Furthermore, the homogeneous dispersion of the filler and excellent flexibility of the modified composite film with 21 wt % filler may be attributed to compatibility with the PVA chain. As the whole fabrication process did not use toxic chemicals (mainly water was used as the solvent), it may contribute to green and sustainable chemistry.

Thermally Conductive and Electrically Insulating PVP/Boron Nitride Composite Films for Heat Spreader

2019 ◽  
Vol 2019 (NOR) ◽  
pp. 000001-00005
Author(s):  
Ya Liu ◽  
Nan Wang ◽  
Lilei Ye ◽  
Abdelhafid Zehri ◽  
Andreas Nylander ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Thermal Management ◽  
Hexagonal Boron Nitride ◽  
Composite Films ◽  
High Thermal Conductivity ◽  
Thermally Conductive ◽  
Promising Solution ◽  
Mechanical Pressing ◽  
Insulating Properties

Abstract Thermally conductive materials with electrically insulating properties have been extensively investigated for thermal management of electronic devices. The combined properties of high thermal conductivity, structural stability, corrosion resistance and electric resistivity make hexagonal boron nitride (h-BN) a promising candidate for this purpose. Theoretical studies have revealed that h-BN has a high in-plane thermal conductivity up to 400 - 800 W m−1 K−1 at room temperature. However, it is still a big challenge to achieve high thermally conductive h-BN thick films that are commercially feasible due to its poor mechanical properties. On the other hand, many polymers exhibit advantages for flexibility. Thus, combining the merits of polymer and the high thermal conductivity of h-BN particles is considered as a promising solution for this issue. In this work, orientated PVP/h-BN films were prepared by electrospinning and a subsequent mechanical pressing process. With the optimized h-BN loading, a PVP/h-BN composite film with up to 22 W m−1 K−1 and 0.485 W m−1 K−1 for in-plane and through-plane thermal conductivity can be achieved, respectively. We believe this work can help accelerate the development of h-BN for thermal management applications.

scholarly journals Robust Biomimetic Nacreous Aramid Nanofiber Composite Films with Ultrahigh Thermal Conductivity by Introducing Graphene Oxide and Edge-Hydroxylated Boron Nitride Nanosheet

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2544
Author(s):  
Cenkai Xu ◽  
Chengmei Wei ◽  
Qihan Li ◽  
Zihan Li ◽  
Zongxi Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Boron Nitride ◽  
Composite Film ◽  
Performance Enhancement ◽  
Composite Films ◽  
Dielectric Materials ◽  
Boron Nitride Nanosheet ◽  
Brick And Mortar ◽  
Thermally Conductive

Dielectric materials with excellent thermally conductive and mechanical properties can enable disruptive performance enhancement in the areas of advanced electronics and high-power devices. However, simultaneously achieving high thermal conductivity and mechanical strength for a single material remains a challenge. Herein, we report a new strategy for preparing mechanically strong and thermally conductive composite films by combining aramid nanofibers (ANFs) with graphene oxide (GO) and edge-hydroxylated boron nitride nanosheet (BNNS-OH) via a vacuum-assisted filtration and hot-pressing technique. The obtained ANF/GO/BNNS film exhibits an ultrahigh in-plane thermal conductivity of 33.4 Wm−1K−1 at the loading of 10 wt.% GO and 50 wt.% BNNS-OH, which is 2080% higher than that of pure ANF film. The exceptional thermal conductivity results from the biomimetic nacreous “brick-and-mortar” layered structure of the composite film, in which favorable contacting and overlapping between the BNNS-OH and GO is generated, resulting in tightly packed thermal conduction networks. In addition, an outstanding tensile strength of 93.3 MPa is achieved for the composite film, owing to the special biomimetic nacreous structure as well as the strong π−π interactions and extensive hydrogen bonding between the GO and ANFs framework. Meanwhile, the obtained composite film displays excellent thermostability (Td = 555 °C, Tg > 400 °C) and electrical insulation (4.2 × 1014 Ω·cm). We believe that these findings shed some light on the design and fabrication of multifunctional materials for thermal management applications.

scholarly journals Hot pressing-induced alignment of hexagonal boron nitride in SEBS elastomer for superior thermally conductive composites

RSC Advances ◽  
2018 ◽  
Vol 8 (45) ◽  
pp. 25835-25845 ◽  
Author(s):  
Cuiping Yu ◽  
Wenbin Gong ◽  
Jun Zhang ◽  
Weibang Lv ◽  
Wei Tian ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Dimensional Stability ◽  
Hot Pressing ◽  
Hexagonal Boron Nitride ◽  
Composite Films ◽  
Conductive Composites ◽  
Thermally Conductive

Orientational hBN/SEBS composite films embued with superior thermal conductivity and improved dimensional stability were prepared by hot-pressing treatment.

scholarly journals Tailoring the Thermal Conductivity of Rubber Nanocomposites by Inorganic Systems: Opportunities and Challenges for Their Application in Tires Formulation

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3555
Author(s):  
Lorenzo Mirizzi ◽  
Mattia Carnevale ◽  
Massimiliano D’Arienzo ◽  
Chiara Milanese ◽  
Barbara Di Di Credico ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Heat Dissipation ◽  
Interfacial Thermal Resistance ◽  
Rubber Matrix ◽  
Heat Management ◽  
Hybrid Filler ◽  
Thermal Transfer ◽  
Conductive Rubber ◽  
Thermally Conductive ◽  
Rubber Nanocomposites

The development of effective thermally conductive rubber nanocomposites for heat management represents a tricky point for several modern technologies, ranging from electronic devices to the tire industry. Since rubber materials generally exhibit poor thermal transfer, the addition of high loadings of different carbon-based or inorganic thermally conductive fillers is mandatory to achieve satisfactory heat dissipation performance. However, this dramatically alters the mechanical behavior of the final materials, representing a real limitation to their application. Moreover, upon fillers’ incorporation into the polymer matrix, interfacial thermal resistance arises due to differences between the phonon spectra and scattering at the hybrid interface between the phases. Thus, a suitable filler functionalization is required to avoid discontinuities in the thermal transfer. In this challenging scenario, the present review aims at summarizing the most recent efforts to improve the thermal conductivity of rubber nanocomposites by exploiting, in particular, inorganic and hybrid filler systems, focusing on those that may guarantee a viable transfer of lab-scale formulations to technological applicable solutions. The intrinsic relationship among the filler’s loading, structure, morphology, and interfacial features and the heat transfer in the rubber matrix will be explored in depth, with the ambition of providing some methodological tools for a more profitable design of thermally conductive rubber nanocomposites, especially those for the formulation of tires.

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