Investigation into time dependant degradation and atmospheric conditions on the wettability of nylon 6,6 which has undergone CO₂ laser surface modification

Although CO2 lasers have been shown to be capable of modifying the wettability of polymeric materials, it is known that the CO2 laser induced wettability modifications of these materials can degrade over time. This can be seen to be crucial from a commercial point of view as this would indicate that a shelf-life has to be established. But at the same time, atmospheric pressure will affect the contact angle and must therefore be accounted for as a control variable in any long-term study of wettability. In this study four CO2 laser irradiated nylon 6,6 samples with differing topographical patterns and one unirradiated sample were analysed over a nine month period by obtaining the characteristic contact angle every two weeks, in addition to recording the atmospheric pressure at the same time. To assess the physical and chemical degradation, the samples were also analysed using WLI, SEM, optical microscopy and EDX before and after the nine month period. This research allowed for the correlation of time dependant degradation, with consideration of the atmospheric pressure, of the nylon 6,6 samples to be obtained, which in turn yielded whether a shelf-life was required for this particular process.