Effects of a silane treatment on the mechanical interfacial properties of montmorillonite/epoxy nanocomposites

In this study, montmorillonite (MMT) was modified using silane coupling agents (SCAs) to improve its interfacial adhesion to an epoxy matrix. The effects of the SCAs on the mechanical interfacial properties of MMT/epoxy nanocomposites were investigated by FT-IR, XRD, and TEM and with reference to the surface energetics. In the results, the SCAs led to an improvement of the organic functional groups, including the silanol and siloxane groups, on the MMT surfaces. This surface modification also led to an enhancement of the specific component of the surface free energy of the MMT. Regarding the mechanical interfacial properties, the critical stress intensity factor (KIC) and interlaminar shear stress (ILSS) values for all of the treated MMT/epoxy composites were enhanced; those of the γ-amino propyl triethoxy silane (APS)-treated MMT/epoxy composite showed the highest values of 3.55 MPa m1/2 and 13.8 MPa, respectively.