Design kristallisationsinhibierter Polymernetzwerke zur Adsorption und Speicherung großer mechanischer Schocks
Zusammenfassung der Projektergebnisse
We have shown that a cold-programmable SMP is suitable as shock- and energy absorber for effective cushioning of impact force, vibration, and chatter as it is needed when such a material is used, for example, as safety line for catching a free-falling deadweight. While coldprogrammable SMNR failed under the used test conditions, critically cross-linked x-sPP shows excellent shock- and energy-absorption capability. A deadweight of 0.7 kg dropped from a height of 80 mm causes for x-sPP a maximum impact force of 12.8 N, which is only 38% and 54% of that caused by Dyneema and rubber, respectively. A kinetic energy absorption of x-sPP of 91% within the first impact in contrast to Dyneema and rubber with 48% and 19%, respectively, results in an extremely short oscillation time of about 2 s until the deadweight comes to rest. Although the maximum jerk for x-sPP is slightly higher than that of the rubber reference for a deadweight of 0.7 kg and a drop height of 80 mm, this important quantity stays nearly constant or is even getting smaller for x-sPP with increasing mass of the deadweight or drop height. Thus, x-sPP avoids harmful jerks better the more it is loaded. Further, x-sPP can be reused for at least 10 times, since it restores its original dimensions after being heated above the melting temperature of the strain-stabilizing crystals and, subsequently cooled to room temperature. Altogether, x-sPP merges the impact force cushioning of an elastomer with the kinetic energy dissipation of a plastically deformable material and, thus, is principally well suited for applications such as, safety lines for climbers or bungee ropes after the problem of thermal crystallisation has been overcome.
Projektbezogene Publikationen (Auswahl)
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Heating Rate Sensitive Multi-Shape Memory Polypropylene: A Predictive Material. ACS Applied Materials & Interfaces, 8, 13684-13687 (2016)
R. Hoeher, T. Raidt, F. Katzenberg, J. C. Tiller
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Ionically Cross-Linked Shape Memory Polypropylene. Macromolecules, 49 (18), 6918-6927 (2016)
T. Raidt, R. Hoeher, M. Meuris, F. Katzenberg, J. C. Tiller
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Multiaxial Reinforcement of Cross-Linked Isotactic Polypropylene upon Uniaxial Stretching. Macromolecular Materials and Engineering 302, 1600308 (2017)
T. Raidt, R. Hoeher, F. Katzenberg, J. C. Tiller
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Cross-Linking of Semi-Aromatic Polyesters Towards High Temperature Shape Memory Polymers with Full Recovery. Macromolecular Rapid Communications 39 (6), 1700768 (2018)
T. Raidt, M. Schmidt, J.C. Tiller, F. Katzenberg
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Shock-and Energy Absorption Capability of Cold-Programmable Shape Memory Polymers. Macromolecular Chemistry and Physics 1800274 (2018)
T. Raidt, P. Santhirasegaran, R. Hoeher, J.C. Tiller, F. Katzenberg