Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 3: Polymer Networks and Elastomers
CPP 3.4: Vortrag
Montag, 7. März 2016, 10:30–10:45, H40
Shape-memory polymer networks on the basis of high-density polyethylene — •Oleksandr Dolynchuk1, Igor Kolesov2,3, Hans-Joachim Radusch2,3, and Jens-Uwe Sommer1 — 1Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Str. 6, D-01069 Dresden, Germany — 2Martin Luther University Halle-Wittenberg, Center of Engineering Sciences, D-06099 Hale (Saale), Germany — 3Polymer Service GmbH Merseburg, D-06217 Merseburg, Germany
Shape-memory (SM) polymers lead to many applications, in particular, as stimuli-responsive sensors and actuators. Polyethylene is considered as a promising SM material due to suitable thermal and mechanical properties, low costs and highly developed production. A theory of two-way invertible SME was developed and allowed calculation of the free energy change of high-density polyethylene (HDPE) drawn under constant load σ and cooled down below crystallization temperature. The free energy ΔF was assumed to consist of three terms: ΔF of transferring links from the amorphous to crystalline region, surface free energies, and the entropy change in the amorphous subchains. The analysis of ΔF predicted the possible morphology and orientation of crystallites generated at cooling. Experimentally determined crystallinity, size and orientation of the crystals formed in HDPE under different σ were compared with theoretical predictions got by modeling the two-way SME in HDPE. All qualitative and quantitative characteristics of the two-way SME, the experimental curves of temperature dependent strain as well as the features of generated crystalline structures are in good accordance with the results of our theoretical analysis.