Tacticity-dependent cross-plane thermal conductivity in molecularly engineered amorphous polymers

2021 ◽  
Vol 12 (7) ◽  
pp. 975-982
Author(s):  
Jaekyo Lee ◽  
Youngmu Kim ◽  
Shalik Ram Joshi ◽  
Min Sang Kwon ◽  
Gun-Ho Kim
Keyword(s):  
Thermal Conductivity ◽  
Steric Hindrance ◽  
Conductive Polymer ◽  
Amorphous Polymers ◽  
Chain Conformation ◽  
Chain Extension ◽  
Extended Chain ◽  
Thermally Conductive

The present study demonstrated that not only chain extension but also torsion of repeating units and steric hindrance should be considered when designing a thermally conductive polymer by extended chain conformation.

scholarly journals Explore High Thermal Conductivity Amorphous Polymers using Reinforcement Learning

2021 ◽  
Author(s):  
RUIMIN MA ◽  
Hanfeng Zhang ◽  
Tengfei Luo
Keyword(s):  
Thermal Conductivity ◽  
Reinforcement Learning ◽  
Conductive Polymer ◽  
Md Simulations ◽  
Amorphous Polymers ◽  
Inverse Design ◽  
Materials Development ◽  
Material Development ◽  
Machine Learning Model ◽  
Thermally Conductive

Developing amorphous polymers with desirable thermal conductivity has significant implications, as they are ubiquitous in applications where thermal transport is critical. Conventional Edisonian approaches are slow and without guarantee of success in material development. In this work, using a reinforcement learning scheme, we design polymers with thermal conductivity above 0.4 W/m- K. We leverage a machine learning model trained against 469 thermal conductivity data calculated from high-throughput molecular dynamics (MD) simulations as the surrogate for thermal conductivity prediction, and we use a recurrent neural network trained with around one million virtual polymer structures as a polymer generator. For all newly generated polymers with thermal conductivity > 0.400 W/m-K, we have evaluated their synthesizability by calculating the synthesis accessibility score and validated the thermal conductivity of selected polymers using MD simulations. The best thermally conductive polymer designed has a MD-calculated thermal conductivity of 0.693 W/m-K, which is also estimated to be easily synthesizable. Our demonstrated inverse design scheme based on reinforcement learning may advance polymer development with target properties, and the scheme can also be generalized to other materials development tasks for different applications.

scholarly journals Explore High Thermal Conductivity Amorphous Polymers using Reinforcement Learning

2021 ◽  
Author(s):  
RUIMIN MA ◽  
Hanfeng Zhang ◽  
Tengfei Luo
Keyword(s):  
Thermal Conductivity ◽  
Reinforcement Learning ◽  
Conductive Polymer ◽  
Md Simulations ◽  
Amorphous Polymers ◽  
Inverse Design ◽  
Materials Development ◽  
Material Development ◽  
Machine Learning Model ◽  
Thermally Conductive

Developing amorphous polymers with desirable thermal conductivity has significant implications, as they are ubiquitous in applications where thermal transport is critical. Conventional Edisonian approaches are slow and without guarantee of success in material development. In this work, using a reinforcement learning scheme, we design polymers with thermal conductivity above 0.4 W/m- K. We leverage a machine learning model trained against 469 thermal conductivity data calculated from high-throughput molecular dynamics (MD) simulations as the surrogate for thermal conductivity prediction, and we use a recurrent neural network trained with around one million virtual polymer structures as a polymer generator. For all newly generated polymers with thermal conductivity > 0.400 W/m-K, we have evaluated their synthesizability by calculating the synthesis accessibility score and validated the thermal conductivity of selected polymers using MD simulations. The best thermally conductive polymer designed has a MD-calculated thermal conductivity of 0.693 W/m-K, which is also estimated to be easily synthesizable. Our demonstrated inverse design scheme based on reinforcement learning may advance polymer development with target properties, and the scheme can also be generalized to other materials development tasks for different applications.

Manipulating thermal conductivity of polyimide composites by hybridizing micro- and nano-sized aluminum nitride for potential aerospace usage

2019 ◽  
Vol 33 (8) ◽  
pp. 1017-1029 ◽  
Author(s):  
Honglin Luo ◽  
Jikui Liu ◽  
Zhiwei Yang ◽  
Quanchao Zhang ◽  
Haiyong Ao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Conductive Polymer ◽  
Total Content ◽  
Thermally Conductive ◽  
Polyimide Composites ◽  
First Time ◽  
Dielectric And Mechanical Properties ◽  
Simple Economic

Electrically insulating yet thermally conductive polymer-based composites are highly sought after in aerospace field. In this work, for the first time, electrically insulating but thermally conductive polyimide (PI) composites are fabricated by simultaneously incorporating micro- and nano-sized aluminum nitride (AlN) particles via a simple, economic, and scalable method of ball milling and subsequent hot-pressing process. The thermal conductivity, dielectric, and mechanical properties of the PI composites depend on the ratio of micro-sized AlN (m-AlN) to nano-sized AlN (n-AlN) and the total content of AlN in the PI composites. The thermal conductivity of the PI composites with 40 wt% m-AlN and 20 wt% n-AlN is 1.5 ± 0.05 W·m−1·K−1, which is 10 times higher than that of bare PI. The PI composites hold a great potential in aerospace industries.

scholarly journals Surface modification of a BN/ETDS composite with aniline trimer for high thermal conductivity and excellent mechanical properties

RSC Advances ◽  
2018 ◽  
Vol 8 (40) ◽  
pp. 22846-22852 ◽  
Author(s):  
Seokgyu Ryu ◽  
Taeseob Oh ◽  
Jooheon Kim
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Surface Modification ◽  
Boron Nitride ◽  
Polymer Composites ◽  
Conductive Polymer ◽  
High Thermal Conductivity ◽  
Conductive Polymer Composites ◽  
Thermally Conductive

Boron nitride (BN) particles surface-treated with different amounts of aniline trimer (AT) were used to prepare thermally conductive polymer composites with epoxy-terminated dimethylsiloxane (ETDS).

Zinc Composites With Enhanced Thermal Conductivity for Use in Fused Deposition Modeling Systems

2017 ◽  
Author(s):  
Tyler J. Sonsalla ◽  
Leland Weiss ◽  
Arden Moore ◽  
Adarsh Radadia ◽  
Debbie Wood ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Fused Deposition Modeling ◽  
Waste Heat ◽  
Conductive Polymer ◽  
Three Dimensional ◽  
Sem Images ◽  
Fused Deposition ◽  
Thermally Conductive ◽  
Deposition Modeling ◽  
Enhanced Thermal Conductivity

Waste heat is a major energy loss in manufacturing facilities. Thermally conductive polymer composite heat exchangers could be utilized in the ultralow temperature range (below 200° C) for waste heat recovery. Fused deposition modeling (FDM), also known as three-dimensional (3-D) printing, has become an increasingly popular technology and presents one approach to fabrication of these exchangers. The primary challenge to the use of FDM is the low-conductivity of the materials themselves. This paper presents a study of a new polymer-Zn composite designed for enhanced thermal conductivity for usage in FDM systems. Thermal properties were assessed in addition to basic printability. Filler volume percentages were varied to study the effects on material properties. Scanning electron microscope (SEM) images were taken of the 3-D printed test pieces to determine filler orientation and filler distribution. Lastly, experimentally obtained thermal conductivity values were compared to the theoretical thermal conductivity values predicted from the Lewis-Nielsen model.

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 Development of Thermally Conductive Polymer Materials and their Investigation

2012 ◽  
Vol 729 ◽  
pp. 80-84 ◽  
Author(s):  
András Suplicz ◽  
József Gábor Kovács
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Conduction ◽  
Filler Content ◽  
New Products ◽  
Conductive Polymer ◽  
Polymer Materials ◽  
Electronic Industry ◽  
Conductive Composites ◽  
Thermally Conductive

In the recent years a remarkable development can be observed in the electronics. New products of electronic industry generate more and more heat. To dissipate this heat, thermally conductive polymers offer new possibilities. The goal of this work was to develop a novel polymer based material, which has a good thermal conduction. The main purpose during the development was that this material can be processed easily with injection molding. To eliminate the weaknesses of the traditional conductive composites low-melting-point alloy was applied as filler. Furthermore in this work the effect of the filler content on thermal conductivity, on structure and on mechanical properties was investigated.

scholarly journals The combination of Al2O3 and BN for enhancing the thermal conductivity of PA12 composites prepared by selective laser sintering

RSC Advances ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1984-1991
Author(s):  
Yue Yuan ◽  
Wei Wu ◽  
Huanbo Hu ◽  
Dongmei Liu ◽  
Hui Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Polymer Composites ◽  
Selective Laser Sintering ◽  
Conductive Polymer ◽  
High Thermal Conductivity ◽  
Complex Structures ◽  
Conductive Polymer Composites ◽  
Hybrid Fillers ◽  
Thermally Conductive

The introduction of hybrid fillers in SLS technology is an effective method for the manufacture of thermally conductive polymer composites with high thermal conductivity, complex structures and good mechanical properties.

Construction of 3D aluminum flake framework by sponge template to prepare thermally conductive polymer composites

2021 ◽  
Author(s):  
Baojie Wei ◽  
xi cheng ◽  
Shuangqiao Yang
Keyword(s):  
Thermal Conductivity ◽  
Polymer Composites ◽  
Thermal Management ◽  
Conductive Polymer ◽  
Ceramic Materials ◽  
Electrical Systems ◽  
Conductive Polymer Composites ◽  
Management Application ◽  
Thermally Conductive ◽  
Aluminum Flake

Ceramic-based polymer composites with high thermal conductivity and electrically insulation has been wildly used in modern electrical systems for thermal management application. Compared with ceramic materials, metals usually exhibit better...

scholarly journals Thermal Conductance of Epoxy/Alumina Interfaces

2021 ◽  
Vol 2133 (1) ◽  
pp. 012002
Author(s):  
Wei Yang ◽  
Yun Chen ◽  
Yipeng Zhang ◽  
Yongsheng Fu ◽  
Kun Zheng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Polymer Composites ◽  
Polymer Matrix ◽  
Time Domain ◽  
Conductive Polymer ◽  
Thermal Conductance ◽  
Interfacial Thermal Conductance ◽  
Piranha Solution ◽  
Conductive Polymer Composites ◽  
Thermally Conductive

Abstract The interfacial thermal conductance (ITC) between filler and polymer matrix is considered as one of the important factors that limits the thermal conductivity of thermally conductive polymer composites. The effect of two different surface treatments (piranha solution and plasma) on ITC of epoxy/alumina was investigated using Time-domain thermoreflectance method (TDTR). The TDTR results show that compared with non-treated samples, the ITC of samples treated by piranha solution and plasma increased 2.9 times and 3.4 times, respectively. This study provides guidance for improving the thermal conductivity of thermally conductive polymer composites.

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