Experimental characterization of contact angle and surface energy on aramid fibers

In this paper, both contact angles and surface energy of aramid fibers are investigated using the liquid droplet method. First, the contact angles between matrix resin and aramid fibers are measured at different degrees of cure, which indicate that the contact angles increased initially and then decreased after the consolidation. Second, surface energy components of aramid fibers are determined from the contact angle using the geometric-mean equations. Finally, the influences of various surface treatments on the surface energy of aramid fibers are analyzed. These results play an important role for designing and evaluating the fiber/matrix interfacial strength of aramid fiber-reinforced composites.