Poly(ε-caprolactone)-poly(fluoroalkylene oxide)-poly(ε-caprolactone) block copolymers. 2. Thermal and surface properties

The thermal and the surface properties of PCL-PFPE-PCL block copolymers having different PCL and PFPE block lengths were investigated by DSC, contact angles and XPS measurements. DSC analysis reveals for all the copolymers the presence of different amorphous phases; the phase located at low temperature was attributed to the fluorinated moiety. Tm values also demonstrated that PCL crystallizes from a pure phase. XPS measurements showed a strong surface enrichment in PFPE with respect to the bulk. Contact angle values showed a hydrophobic character of the film surface even if the trend was found not depending on the fluorine concentration as detected by XPS: this behavior may be explained by the presence of very flexible blocks, providing a highly dynamic surface. These structures can be potentially used as additives for the formation of polymers having 'smart surfaces' with selective adhesive properties