Constructing fibrillated skeleton with highly aligned boron nitride nanosheets confined in alumina fiber via electrospinning and sintering for thermally conductive composite

• Published in: Composites. Part A, Applied science and manufacturing Vol. 143; p. 106282
• Main Authors: Fan, Li, Zhang, Shuai, Zhao, Guojie, Fu, Qiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2021
• Subjects: Boron nitride; Electrospinning; Skeleton; Thermal conductivity; Boron nitride; Electrospinning; Thermal conductivity; Skeleton
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2021.106282

Various fillers and methods have been utilized to enhance the thermal conductivity (TC) of polymer-based electronic packaging materials, however, the enhancement was limited by disconnected pathway for phonon transferring. Herein, a novel fibrillated hybrid skeleton (f-AO@BNNS skeleton) was fabricated by dispersing boron nitride nanosheet (BNNS) into alumina (AO) sol, electrospinning and sintering, where long-range phonon transferring highway was successfully constructed by both macroscopically interconnected fiber and microscopically oriented and overlapped BNNSs confined in nanofiber. Besides, crystal AO and atomic-level bonding were acquired on BNNS-AO interface by sintering, largely decreasing interface thermal resistance inside skeletons. Prepared polybenzoxazine/f-AO@BNNS composites exhibited the highest TC of 3.24 Wm−1 K−1 at a skeleton loading of 6.9 vol%. The higher TC was achieved at lower filler content when compared with other reported skeletons, demonstrating the superiority of f-AO@BNNS skeleton. This work provides a new strategy of preparing fibrillated hybrid skeleton for high thermally conductive composites.