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

The thermal and the surface properties of PCL-PEPE-PCL block copolymers hav ing different PCL and PFPE block lengths were investigated by DSC, contact angles and XPS measurements. DSC analysis reveals for all the copolymers th e presence of different amorphous phases; the phase located at low temperat ure was attributed to the fluorinated moiety. T-m values also demonstrated that PCL crystallizes from a pure phase. XPS measurements showed a strong s urface enrichment in PFPE with respect to the bulk. Contact angle values sh owed a hydrophobic character of the film surface even if the trend was foun d not depending on the fluorine concentration as detected by XPS: this beha vior may be explained by the presence of very flexible blocks, providing a highly dynamic surface. These structures can be potentially used as additiv es for the formation of polymers having 'smart surfaces' with selective adh esive properties. (C) 2000 Elsevier Science Ltd. All rights reserved.