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  -