The aim of this study is to examine the impact of surface modification on properties of flax fiber and flax-reinforced composites. For this purpose, acetic anhydride, sodium hydroxide, and silane were used to treat surface of the flax fiber. The effects of treatments on fiber were investigated by using contact angle, attenuated total reflectance-Fourier transform infrared, atomic force microscopy (AFM), and scanning electron microscopy (SEM). Contact angle and AFM results revealed that sodium hydroxide-treated flax fibers have higher adhesion force on the fiber surface. Particularly, NaOH treatment improved the mechanical properties of the epoxy matrix composite.
