Mechanical response of polymer/BN composites investigated by molecular dynamics method

Boron nitride (BN) nanomaterials are being proposed as reinforcement materials in the next-generation structural composite materials for aerospace applications. Considering that the polymer/reinforcement interface characteristics can significantly affect the bulk-level properties, we focus on the representative cases of cyanate esters, epoxy, and bismaleimide (BMI) resins forming interfaces with a bilayer BN. While the fluorinated cyanate ester interface demonstrates lower interaction energy than non-fluorinated cyanate ester due to steric hindrance provided by fluorine groups, BMI shows higher interaction energy than epoxy because of the planarity of BMI. Calculations simulating pull-apart transverse tension experiments using molecular dynamics find that the non-fluorinated ester interface exhibits higher peak strength and stiffness than the fluorinated interface. On the other hand, the epoxy/BN interface is predicted to have significantly lower toughness than the BMI/BN interface. The results based on interaction energy and pull-apart transverse tension show that the BMI with BN can be considered superior to epoxy and ester polymers with BN. Graphical abstract