Triple-shape polymers

M. Behl, A. Lendlein, Triple-shape polymers. J. Mater. Chem. 20, 3335-3345 (2010)... 

Zotzmann, J., Behl, M., Feng, Y., and Lendlein, A. (2010) Copolymer networks based on poly(co-pentadeca-lactone) and poly(e-caprolactone) segments as a versatile triple-shape polymer system. Advanced Functional Materials, 20, 3583-3594. 

Beilin, L, Kelch, S., and Lendlein, A. (2007) Dual-shape properties of triple-shape polymer networks with crystallizable network segments and grafted side chains. Journal of Materials Chemistry, 17, 2885-2891. 

Cyclic, Thermomechanical Testing of Triple-Shape Polymers. 130... 

Mostly, SMPs are dual-shape materials, which are able to change from a first shape (A) into a second shape (B) when exposed to an external stimulus. Shape (A) is a temporary shape while shape (B) is the permanent shape obtained as a result of the initial polymer processing. Besides SMPs with dual-shape capability another class of SMPs, showing a triple-shape capability, have recently been developed to enable complex active movements [10, 24-27]. Triple-shape polymers consist of... 

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. 

Pretsch, T. (2010) Durability of a polymer with triple-shape properties. Polymer Degradation and Stability, 95, 2515-2524. 

Xie, T., Xiao, X., and Cheng, Y.T. (2009) Revealing triple-shape memory effect by polymer bilayers. Macro-molecular Rapid Communications, 30, 1823 1827. 

Li, J. and Xie, T. (2011) Significant impact of thermo-mechanical conditions on polymer triple-shape memory effect. Macromolecules, 44, 175-180. 

Behl, M., Beilin, I., Kelch, S., Wagermaier, W., and Lendlein, A. (2009) One-step process for creating triple-shape capability of AB polymer networks. Advanced Functional Materials, 19, 102-108. 

Shape memory polymers (SMPs) and composites thereof are emerging smart materials in different applications, especially in biomedical, aerospace, and construction engineering helds. SMPs may adopt one (dual-shape), two (triple-shape). 

Kumar, U.N., Kratz, K., Behl, M., and Lendlein, A. (2012) Shape-memory properties of magnetically active triple-shape nanocomposites based on a grafted polymer network with two crystallizable switching segments. eXPRESS Polym. 

Fig. 8 Triple-shape effect of a multiphase polymer network with poly(s-caprolactone) network chains and poly(ethylene glycol) side chains. The picture series shows the recovery of shapes B and C by subsequent heating from 20 to 60°C, beginning from shape A, which was obtained as a result of the two-step triple-shape creation process. The object consisting of a plate with anchors demonstrates a fastener device...

In a study on an AB polymer network system with triple-shape capability, the influence of the programming and recovery process on the crystalline domains was investigated by means of WAXS and SAXS experiments [24,25]. The triple-shape capability obtained by a one-step triple-shape creation process, similar to a conventional dual-shape programming process, was reported for networks based on PCL and PCHMA. Favorable compositions for obtaining a triple-shape effect contained... 

The creation of the triple-shape capability for an AB polymer network system by a simple one-step process similar to a conventional dual-shape progranuning process was shown for networks based on PCL and PCHMA [24] (see Sect. 2.4). In these materials a stress-controlled cyclic, thermomechanical experiment was used to quantify the triple-shape effect. The sample was deformed at 150°C (liigh) to 50% (Ein) and subsequently cooled to —10°C (Tio ). The large temperature interval of around 160 K led to a strong reduction of the strain. When the sample was heated... 

A detailed understanding of the underlying mechanisms for the SME requires a systematic characterization, especially quantification of the shape-memory properties. As typical for a material function, numerous physical parameters are in-fiuencing the SME. Therefore the determination of structure/physical parameter function relationships is challenging. Specific methods are required for dual-shape or triple-shape properties as well as for the different stimuli. The knowledge-based development of SMPs can be supported by modeling approaches for simulating the thermomechanical behavior of such polymers. 

A triple-shape memory polymer containing a UPy unit (Ware efa/., 2012). 

Ware, X, Hearon, K., Lonnecker, A., Wooley, K. L., Maitland, D. J., Voit, W. (2012), Triple-shape memory polymers based on self-complementary hydrogen bonding. Macromolecules, 45(2), 1062-9. 

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