Tribological and Mechanical Properties of Brazilian Hair

The static H and E values of Brazilian hair are consistent with the high Brazilian ethnical mixture. Nanoscratch failure mechanisms can be explained based on the dynamic H and E values. The scratch resistance in the direction from root to tip is associated to the cuticle mechanical properties, but in the opposite direction increased mechanical property values lead to increased damage. The surface friction behavior is determined by roughness of the fibers, however, when the tip goes into the cortex friction decreases due to its softer nature.