Abstract
In this investigation, we attempted to improve the peel strength of PTFE (polytetrafluoroethylene) by nitrogen ion irradiation. Nitrogen ions were irradiated on PTFE-surface at an accelerating voltage of 100, 300, 500, 1000 and 2000 V with its dose ranging from 5×1020 to 1.5×1022 ions/cm2. The surface properties of the modified PTFE were characterized by XPS (X-ray photoelectron spectroscopy), AFM (atomic force microscopy), water contact angle and 180 degree peel test. In the result, under condition of accelerating voltage 2000 V and ion dose 1.2×1022 ions/cm2, a maximum adhesion force of 1500 N/m was obtained. However, there was no correlation between the adhesive strength and the surface energy, because, the contact angle obtained was affected by the superhydrophobic effect and the net surface energy should not be evaluated. From the observation at the peeled off surface, it was confirmed that the inner PTFE was ripped off. Accordingly, it was ascertained that adhesion strengths between PTFE and epoxy adhesive were higher than the strengths of PTFE.
