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

Abstract

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.

Thermal Conductivity for Polymer Composite Materials: Recent Advances in Polyimide Materials

“…Moreover, a TC of 2.23 W/(m•K) was achieved when SiC whisker and AlN were co-added at a volume ratio of 25 : 75 to make up 50 vol% of the total ller content. Moreover, coadditions of AlN and hBN have been carried out by Kume et al (2009), Song et al (2019), andLiu et al (2020).…”

Enhancing thermal conductivity of polyimide composite film by electrostatic self-assembly and two-step synergism of Al2O3 microspheres and BN nanosheets

“…In the practical application, considering the economy and process simplicity, the >30 wt% micro-sized BN, 41,42 Al 2 O 3 (ref. 31) and AlN 31 were commonly introduced to the PI matrix to achieve an increase of 1000% in the thermal conductivity, while also meeting a practical requirement of heat management. 43 By comparison, the 35 wt% Al 2 O 3 @BN&BN/PI composite lm containing 17 wt% BN and 18 wt% Al 2 O 3 achieved the thermal conductivity of 3.35 W m À1 K À1 and a relatively high enhancement of 1664%.…”

“…The as-prepared Al 2 O 3 @PI thin lm was obtained with an effective thermally conductive network, and also has good thermal and mechanical properties. Song et al 31 found that anisotropic BN and spherical Al 2 O 3 or aluminum nitride (AlN) formed a synergistic thermally conductive network structure, thus improving the thermal conductivity of the composite lm. Due to its good insulation performance and high thermal conductivity of up to 600 W m À1 K À1 , BN has been well known as a relatively ideal ller for the preparation of composites with high thermal conductivity and electrical insulation.…”

Size, Concentration and Content Effect of Copper/Graphite Hybrid Dopant on Mechanical, Thermal and Electrical Conductivity Characteristics of Unsaturated Polyester Resin

“…The Maxwell, Hashin-Shtrikman, and Lewis-Nielsen models were used in the theoretical calculations. The Maxwell model is limited to single filler component and hence more than one filler was used in this study, and Lewis-Nielsen model is used [31]. However, the most frequently used model in the literature for 3-phase systems is modified Lewis-Nielsen approach.…”