| 초록 |
Surface treatment techniques such as plasma modification, ion sputtering, and corona discharge can affect mainly the chemical and physical properties of the surface layer without changing the bulk material properties. Plasma surface treatment was used to increase the surface wettability by the introduction of surface functional groups and the removement of impurity materials. Major advantage of plasma treatment over other techniques is to modify just the outer most atomic layers of a substrate, the minimization of thermal degradation, and fast treatment time. Organic fiber with fibril structure may show different microfailure mechanisms and interfacial properties with respect to ceramic-type fiber having monofilament structures such as carbon fiber, etc. Mechanical properties of poly-p-phenylene benzobisoxazole (PBO) and kevlar fibers were higher than those of ceramic-type fiber, whereas interfacial adhesion was very poor. In order to improve interfacial shear strength (IFSS), surface of PBO and kevlar fibers was modified with hydrophilic group using oxygen plasma. IFSS was measured using microdroplets test and the fracture signals of organic fibers were detected by acoustic emission (AE). Acknowledgement: This study was supported financially by KoSEF through Research Center for Aircraft Parts Technology (ReCAPT), GNU. |
