Micropatterning of polyurethanes with lasers

Y. Martele, K. Callewaert, I. Swennen, K. Naessens, R. Baets, V. Van Speybroeck, M. Waroquier, H. Van Aert, P. Dierickx, E. Schacht
Polymer International
51(11), 1172–1177


The micropatterning of a series new poly(carbonate-urethanes) with IR and excimer lasers is discussed. A series of segmented polyurethanes consisting of a soft segment and a hard segment was prepared. The soft segment, a thermodegradable polycarbonate diol, degrades by a syn-elimination at higher temperature. The hard segment was selected as to increase the sensitivity of the polymers for UV excimer laser ablation. The thermal and mechanical properties of the segmented polyurethanes (SPU) were investigated. By varying the building blocks in the polymer (soft and hard segments), the ablation properties were studied in terms of absorption coefficient and threshold value. Polymers with an aromatic chain-extender and an diisocyanate showed the highest absorption coefficient at wavelengths of 248 and 193 nm. Irradiation of these polymers led to cavities with high dimensional quality, sharp edges and no accumulation of degradation products near the cavities (no debris formation). Ablation with an IR laser led to a decrease in film thickness of the polymer deposited on a substrate. This was investigated with FTIR/ATR analysis and atomic force microscopy. Debris formation was found near the cavities. The differentiation of polarity between the exposed and unexposed areas was not efficient enough to use them as a coating for printing plates.