TY  - JOUR
A1  - Ghobadi, Ehsan
A1  - Heuchel, Matthias
A1  - Kratz, Karl
A1  - Lendlein, Andreas
T1  - Simulating the shape-Memory behavior of amorphous switching domains of Poly(L-lactide) by molecular dynamics
JF  - Macromolecular chemistry and physics
N2  - The thermally induced shape-memory effect of polymers is typically characterized by cyclic uniaxial thermomechanical tests. Here, a molecular-dynamics (MD) simulation approach of such a cyclic uniaxial thermomechanical test is presented for amorphous switching domains of poly(L-lactide) (PLLA). Uniaxial deformation of the constructed PLLA models is simulated with a Parinello-Rahman scheme, as well as a pragmatic geometrical approach. We are able to describe two subsequent test cycles using the presented simulation approach. The obtained simulated shape-memory properties in both test cycles are similar and independent of the applied deformation protocols. The simulated PLLA shows high shape fixity ratios (Rf 94%), but only a moderate shape recovery ratio is obtained (Rr 30%). Finally, the structural changes during the simulated test are characterized by analysis of the changes in the dihedral angle distributions.
KW  - molecular modeling
KW  - polyesters
KW  - shape-memory properties
KW  - stimuli-sensitive polymers
KW  - thermomechanical properties
Y1  - 2013
U6  - https://doi.org/10.1002/macp.201200450
SN  - 1022-1352
VL  - 214
IS  - 11
SP  - 1273
EP  - 1283
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Julich-Gruner, Konstanze K.
A1  - Löwenberg, Candy
A1  - Neffe, Axel T.
A1  - Behl, Marc
A1  - Lendlein, Andreas
T1  - Recent trends in the chemistry of shape-memory polymers
JF  - Macromolecular chemistry and physics
N2  - Shape-memory polymers (SMPs) are stimuli-sensitive materials capable of performing complex movements on demand, which makes them interesting candidates for various applications, for example, in biomedicine or aerospace. This trend article highlights current approaches in the chemistry of SMPs, such as tailored segment chemistry to integrate additional functions and novel synthetic routes toward permanent and temporary netpoints. Multiphase polymer networks and multimaterial systems illustrate that SMPs can be constructed as a modular system of different building blocks and netpoints. Future developments are aiming at multifunctional and multistimuli-sensitive SMPs.
KW  - multifunctional polymers
KW  - networks
KW  - shape-memory polymers
KW  - stimuli-sensitive polymers
KW  - triple-shape effect
Y1  - 2013
U6  - https://doi.org/10.1002/macp.201200607
SN  - 1022-1352
VL  - 214
IS  - 5
SP  - 527
EP  - 536
PB  - Wiley-VCH
CY  - Weinheim
ER  -