Shape-changing polymers

Behl, M., Zotzmann, J., and Lendlein, A. 2010. Shape-memory polymers and shape-changing polymers. Advances in Polymer Science 226 1M0. 

Meng, H. and Li, G. (2013) Reversible switching transitions of stimuli-responsive shape changing polymers. Journal of Materials Chemistry A, 1, 7838-7865. 

Shape-Memory Polymers and Shape-Changing Polymers... 

Fig. 14 Humidity-sensitive shape-changing polymer film. The relative humidity of the environment is given at the bottom of each picture. Reprinted with permission from [151]. Copyright 2005 American Chemical Society...

Triple-shape polymers can change on demand from a first shape (A) to a second shape (B) and from there to a third shape (C), when stimulated by two subsequent temperature increases [10, 26, 27]. Specific cyclic, thermomechanical tensile experiments were developed to characterize the triple-shape effect (Chapter Shape-Memory Polymers and Shape-Changing Polymers [101] and Sect. 2.2) quantitatively. Analogous to the experiments for dual-shape materials, each cycle of these tests consisted of a programming and a recovery module. A cycle started with creating the two temporary shapes (B and A) by a two-step uniaxial deformation, followed by the recovery module, where shape (B) and finally shape (C) were recovered. 

Behl M, Zotzmann J, Lendlein A (2009) Shape-Memory Polymers and Shape-Changing Polymers. In Advances in Polymer Sciences, Volume Shape-Memory Polymers, Springer... 

Table 3.2 Classes of stimuli-responsive polymers, regarding shape-changing polymers...

Shape-changing polymers Principle of response References... 

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