1 research outputs found
Reversible Shape-Memory Effect in Cross-Linked Linear Poly(ε-caprolactone) under Stress and Stress-Free Conditions
The
effect of cross-link density on the reversible shape-memory effect
(SME) under constant load was systematically studied in cross-linked
linear polyÂ(ε-caprolactone) (PCL). A remarkable reversible SME
under stress-free conditions was observed in PCL with the highest
achieved cross-link density. Thermal properties as well as morphology,
size, and orientation of the nanocrystalline structure formed in covalent
networks of PCL under load were compared with those in PCL crystallized
under stress-free conditions. As shown, the oriented growth of crystals
is the origin of both the reversible SME under and without load. Furthermore,
a significant rise of crystallinity and crystal thickness was detected
in PCL crystallized under constant load. The fitting curves of the
temperature-dependent strain as well as the quantities of crystallinity,
type of crystalline structure, size, and orientation of the crystals
got by modeling the reversible SME in PCL under stress well correspond
to their values obtained experimentally