Release properties of plasma polymeric coated polymer films and adhesive strength of transferred polyurethane coatings to fiber-reinforced thermosets

An investigation of plasma-polymeric coatings on stretchable polymer films utilizing hexamethyldisiloxane and oxygen has been performed. The influence of the plasma parameters on release properties to polyurethane paints as well as the unpreventable transfer of traces of plasma-polymeric coatings to paints or thermosets were investigated. The elemental composition and physical properties have been analyzed using contact angle measurement and X-ray photoelectron spectroscopy (XPS) with peak fitting. The release properties of the coatings are discussed. The results show that a higher ratio of oxygen to hexamethyldisiloxane during the plasma process leads to an increase of peel forces to polyurethane paints. The XPS shows that the transfer of plasma coating to the paint is on average below 0.4 at% of silicon, which is below the critical fraction of 2 at% silicon reported in the literature. Therefore, the clear-coat paint shows no difference in its adhesion to thermosets between untreated and pretreated surfaces.