The effects of excimer laser irradiation on surface morphology development in stretched poly(ethylene terephthalate), poly(butylene terephthalate) and polystyrene films

摘要

Polystyrene (PS), poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) surfaces were irradiated using an excimer laser (LPX 240i, Lambda Physik). Polymer films were made first by cast film processing and then stretched with a biaxial stretching machine. With excimer laser treatment of polymer surfaces, it was found that 1-2-μm size structures could be produced depending on material properties and film processing conditions. Materials with lower UV absorption coefficient produced double-digit micrometer-size structures, while those with higher UV absorption coefficients produced single-digit micrometer-size structures. In all these cases the structures formed only on stretched films. In addition to these rnicrostructure developments, the determination of ablation threshold fluence was of interest mainly for understanding the fundamentals of ablation behavior and technological applications. To understand the ablation phenomenon, and how microstructures could be developed during ablation, different material processing and excimer laser conditions were chosen for experimentation. From the observation of microstructures, we found that the initial microstructure development was a key for the following microstructures. We proposed a mechanism for this initial structure development based on polymer chain or melt movement caused by non-homogeneous ablation on the surface.