Substantial improvement of thermal conductivity and mechanical properties of polymer composites by incorporation of boron nitride nanosheets and modulation of thermal curing reaction

Abstract

Thermal conductive polymer‐based composites synchronously with stable dielectric and excellent mechanical properties are urgently needed for high‐temperature‐resistant electronic devices. Here, a significant improvement in the thermal conductivity (TC), thermal stability, dielectric, and mechanical performance was simultaneously achieved in the polyarylene ether nitrile (PEN)/divinyl siloxane‐bisbenzocyclobutene (BCB) matrix through the incorporation of boron nitride nanosheets (BNNS) combined together with the post‐solid phase chemical reaction technique. The significant increase in the effective filler‐filler and filler‐crystal contacts in the composites was the main reason for the improvement in TC and dielectric constant. Besides, glass transition temperature (Tg) and mechanicals were enhanced in the presence of cross‐linked networks. By synchronously adding 15 vol% BNNS, the TC of composites after treatment reached up to 5.582 W/m.K, enhanced by 4.4 times higher than untreated. The dielectric constant was down to 2.93 at 1 MHz and the loss remained at a relatively low level. Meanwhile, the composite showed significantly enhanced thermal stability, mechanicals, and hydrophobicity (Tg = 336°C, T5% = 529°C, tensile strength and modulus was 94.5 MPa and 5.3 GPa, respectively, the contact angle was 101.76°). Thus, it promotes an effective strategy for fabricating a high‐performance‐polymer composite, which has the potential used in electronic materials.Highlights Crystallization‐crosslinking strategy optimizes overall performance. Crystals fill gaps between BNNS layers and connect thermal conductive pathway. Crosslinked networks limit molecular chain motion to reduce phonon scattering. The highest TC of the PEN/BCB/BNNS composite is up to 7.451 W/m.K. Thermal property shows significant improvement after crosslinking especially Tg.

A Multi-Objective Optimization of Neural Networks for Predicting the Physical Properties of Textile Polymer Composite Materials

“…The specific physical characteristics of polymers become imperative to meet precise functional requisites across various applications [ 27 ]. These characteristics may encompass mechanical properties such as tensile strength [ 28 ], flexibility [ 29 ], and impact resistance [ 30 ], alongside thermal attributes like heat resistance [ 31 ] and thermal conductivity [ 32 ]. Thus, a comprehensive understanding of the polymer composite composition and structure is pivotal, facilitating the customization of the properties to align with distinct application demands.…”

Interlayer growth of SiC nanowires in graphene aerogel for thermal conductivity enhancement of epoxy resin and its mechanism

“…The demand for high thermal conductivity composite materials is increasing in the fields of LED lighting, electronic packaging, batteries, and solar energy. [1][2][3][4][5] Among numerous thermal conductive fillers, graphene is considered to be a promising thermal conductive filler due to its excellent inplane thermal conductivity ($5300 W/mK) and mechanical properties. 6 In recent years, three-dimensional graphene thermal conductivity networks have become one of the research highlights in thermal conductive materials due to their greatly improved phonon transmission efficiency and reduced interfacial thermal resistance, which can provide greater thermal conductivity with a small filler loading.…”