Ball mill enhances the functionalization of boron nitride: The application for polyimide fillers

Polymer properties can be tuned by the addition of filler materials such as carbon-base materials and inorganic materials. In recent years, 2D filers as additives for polymers have extensively been studied. Among them, functionalized hexagonal boron nitride (FBN) improves polymers’ physical properties. In this study, we prepared 27 types of FBNs by using different ball milling parameters in the presence of amine molecules. Ball mill conditions, such as the ratios of h-BN and the amine, rotation speeds, and treatment times of ball milling, were investigated, and then, the FBNs were covalently bonded with polyimide (PI) in all specimens. An optimum FBN-PI composite showed tensile strength and tensile modulus of 151.1 MPa and 3.8 GPa, respectively. Finally, we found that the tensile strength and modulus were increased to 159.2 MPa and 3.9 GPa by addition of a small amount of graphene oxide (GO) that were combined with FBN and PI. The ball milling and covalent bonding approach efficiently developed high-performance BN-polymer composite films.