M. Toselli et al., Poly(epsilon-caprolactone)-poly(fluoroalkylene oxide)-poly(epsilon-caprolactone) block copolymers. 2. Thermal and surface properties, POLYMER, 42(5), 2001, pp. 1771-1779
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.