Magnetic Field-Induced Orientation of Modified Boron Nitride Nanosheets in Epoxy Resin with Improved Flame and Wear Resistance
Huili Shi, Huanhuan Wang, Haitao Lu, Xia Zhang, Zhijun Zhang
Abstract
In this work, self-lubricating boron nitride nanosheets (BNNs) were decorated with flame-retardant zinc ferrite (ZnFe2O4), followed by stearic acid modification to obtain magnetic and hydrophobic properties. Under the external magnetic field, the obtained ZnFe2O4–BNNs can be well ordered into one-dimensional orientation in the epoxy resin (EP) matrix—enabling improved flame retardant properties. Compared to a randomly oriented ZnFe2O4–BNN equivalent, the well-orientated ZnFe2O4–BNNs (at 10% mass fraction) reduce the peak heat release rate and CO production by 47 and 51%, respectively. Furthermore, the ZnFe2O4–BNN/EP composite monoliths demonstrate excellent durability, displaying continued superhydrophobicity under Taber abrasion, high external pressure, knife scratch, long-term exposure to acids/bases, and harsh UV irradiation. In addition, the result shows that the well-oriented ZnFe2O4–BNN/EP composite demonstrates better tribological performance and the friction coefficient is reduced by 76.9%.