Modified boron nitride-basalt fiber/epoxy resin composite laminates and their enhanced mechanical properties

At present, the application of epoxy resin and its composites was severely restricted by its disadvantages of intrinsic brittleness after curing, poor fatigue strength, and low fracture energy. In order to improve its mechanical performances and broaden its applied range, the modified boron nitride-basalt fiber/epoxy resin composite laminates (EP-BF/mBN) were successfully prepared via a hot-press process by using BF as reinforcement of epoxy resin composites and BN nanosheets treated by codeposition of PDA and PEI as toughening agent. The effects of the concentration of modified BN solution on the mechanical properties of the composites were studied in terms of flexural strength, flexural modulus, the interlaminar shear strength (ILSS), and the mode II interlaminar fracture toughness (G(IIC)). When 6 g L-1 modified BN solution was added, the flexural strength, flexural modulus, ILSS, and G(IIC) increased by 12.7%, 10.4%, 37.0%, 62.3%, respectively. And flexural strength, flexural modulus, ILSS, and G(IIC) approached to 894.6 MPa, 34.6 GPa, 60.4 MPa, and 483.9 J m(-2), respectively, which was 20.0%, 10.7%, 38.9%, and 68.9% higher than that of EP-BF at -60 degrees C, suggesting that EP-BF/mBN even had better mechanical performances at low temperature, which would be widely used in more fields in the future.