ABSTRACT
Abstract-Vectran® fibers, made using high-performance liquid crystal polymer (LCP), were treated with XeCl pulsed excimer laser (308 nm) to improve their adhesion to epoxy resin. The laser treatments were carried out in diethylenetriamine (DETA) environment. Varying numbers of laser pulses at different laser fluences were used. The effects of the laser treatment on the fiber surface topography, chemistry and wettability have been investigated. The surface roughness was characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The fiber/epoxy resin interfacial shear strength (IFSS) was characterized using microbead test. The surface roughness of laser-treated fibers increased by up to 2.5-times the value of the control fiber. However, the characteristic wavy structures on the laser-treated fiber surface that were seen when the treatment was carried out in air were not seen after any laser treatment in DETA. After the laser treatment, the dispersion component of the surface energy decreased, while the acid-base component of the surface energy increased significantly. The Vectran® fiber/epoxy resin IFSS increased by up to 50% after the laser treatment. A large part of this improvement could be attributed to higher surface roughness of the laser-treated fibers.
