Improvement of interfacial adhesion for plasma-treated aramid fiber-reinforced poly(phthalazinone ether sulfone ketone) composite and fiber surface aging effects

Interfacial adhesion between the fiber and the matrix in a composite is a primary factor for stress transfer from the matrix to the fiber. In this study, oxygen plasma treatment method was applied to modify the fiber surface for improving interfacial adhesion of aramid fiber-reinforced poly(phthalazinone ether sulfone ketone) (PPESK) composite. Composite interfacial adhesion properties were determined by interlaminar shear strength (ILSS) using a short-beam bending test. The composite interfacial adhesion mechanism was discussed by SEM. The changes of chemical composition and wettability for plasma-treated fiber surfaces stored in air as long as 10 days were investigated by XPS and dynamic contact angle analysis (DCAA), respectively. Results indicated that oxygen plasma treatment was an effective method for improving interfacial adhesion; plasma-treated fiber surface suffered aging effects during storage in air. Copyright (C) 2008 John Wiley & Sons, Ltd.