High Performance Adhesive Bonding of High TemperatureResistant Polymer

摘要

This paper highlights effects of atmospheric pressure plasma treatment on adhesive joints of poly (ether ether ketone) (PEEK) fabricated with high temperature resistant epoxy adhesive and nano-adhesive, i.e., by dispersing carbon nanofibers (CNFs) into the adhesive matrix. Thermogravimetric analysis (TGA) demonstrates that there is an increase in thermal stability up to 15% for nano-adhesive. Substantial improvement in the surface energy of PEEK is observed after the atmospheric pressure plasma treatment. It is observed that polar component of surface energy leading to higher total surface energy of PEEK increases considerably. Atomic force microscopic (AFM) analysis of untreated and atmospheric plasma treated specimens was carried out to examine topography of the polymer surfaces. After atmospheric plasma treatment, surface roughness of the polymer increases which helps in improving the adhesion properties of the polymer. Atmospheric pressure plasma treatment results in significant increase in oxygen functionalities as detected by X-ray photoelectron spectroscopy (XPS). The improvement in adhesion properties of polymer is correlated with lap shear strength of adhesive bonded joints. Adhesive bonded joints were fabricated by employing recently developed ultrahigh temperature resistant epoxy adhesive, DURALCO 4703. Lap shear test results show that adhesion characteristic of PEEK improves considerably after atmospheric plasma treatment. Finally, the fractured surfaces of the joints were examined by scanning electron microscopy to investigate the failure mechanism.