On the size effect of additives in amorphous shape memory polymers
E. Zirdehi, G. Eggeler, F. Varnik.
Materials, MDPI AG,, 14, 327, (2021)
first_page settings Order Article Reprints Open AccessEditor’s ChoiceArticle On the Size Effect of Additives in Amorphous Shape Memory Polymers by Elias M. Zirdehi 1 [ORCID] , Hakan Dumlu 2, Gunther Eggeler 2 and Fathollah Varnik 1,* [ORCID] 1 Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum, Germany 2 Institute for Materials (IFM), Ruhr-Universität Bochum, Universitätsstr. 150, 44801 Bochum, Germany * Author to whom correspondence should be addressed. Materials 2021, 14(2), 327; https://doi.org/10.3390/ma14020327 Received: 13 December 2020 / Revised: 30 December 2020 / Accepted: 6 January 2021 / Published: 10 January 2021 (This article belongs to the Special Issue Strong Coupling of Thermo-Chemical and Thermo-Mechanical States in Applied Materials) Download Browse Figures Versions Notes Abstract Small additive molecules often enhance structural relaxation in polymers. We explore this effect in a thermoplastic shape memory polymer via molecular dynamics simulations. The additive-to-monomer size ratio is shown to play a key role here. While the effect of additive-concentration on the rate of shape recovery is found to be monotonic in the investigated range, a non-monotonic dependence on the size-ratio emerges at temperatures close to the glass transition. This work thus identifies the additives’ size to be a qualitatively novel parameter for controlling the recovery process in polymer-based shape memory materials.
Keyword(s): shape memory polymers; size effect of additives; molecular dynamics simulations