Photoinitiator-Free Plasma-Induced Polymerization and Microstructuring of Acrylate-Based Coatings on 3D Substratesa

The process of plasma curing of functional acrylates has been studied. For these purposes, a nitrogen plasma generated by a flat and a cylindrical electrode configuration, respectively, was used to provide both planar and 3D curing conditions. In selected cases, a double bond conversion >95% was observed by ATR-IR spectroscopy for a 15 mu m (wet thickness) acrylate coating even without the addition of any photoinitiator. Compared to UV curing, the surface energy of the cured substrates was significantly higher when plasma curing was applied (>70 mN . m(-1)); however, the hydrophilic surfaces experienced hydrophobic recovery. Finally, the generation of microstructures on uniaxially oriented substrates during the plasma process was studied and conditions for their tailor-made creation are suggested.