Improvement of “point‐plane”‐like hetero‐structured fillers on thermal conductivity of poly(vinyl alcohol) composites

Abstract

AbstractWith the rapid growth of highly integrated electrical devices, the urgent demand for polymer composites with high thermal conductivity (TC) is increasing for effective thermal management. In this work, boron nitride nanosheets (BNNSs) were chemically grafted with aluminum oxide (Al2O3) to develop hetero‐structured filler (BNNSs@Al2O3). The BNNSs@Al2O3 fillers were uniformly dispersed in the poly(vinyl alcohol) (PVA) by solvent mixing, verified by SEM, and the oriented BNNSs@Al2O3/PVA composites were produced by the doctor blade method. The results exhibited that the synergistic effect of BNNSs and Al2O3 was achieved, and the thermal conductivities of BNNSs@Al2O3/PVA composites were improved. When keeping the filler content at 30 wt%, the in‐plane and out‐of‐plane TC of BNNSs@Al2O3/PVA composite reached 5.641 and 0.651 W/(m·K), respectively. The BNNSs@Al2O3 filler may improve the performance of composite heat dissipation by reducing the interfacial resistance between fillers and making it easier to establish directed heat‐transfer pathways. This composite demonstrates promising application in the field of electronic packaging.