A new shape‐memory polymer is presented, in which both the stable phase as well as the switching unit consist of two different metal complexes. Suitable metal ions, which simultaneously form labile complexes with histidine and stable ones with terpyridine ligands, are identified via isothermal titration calorimetry (ITC) measurements. Different copolymers are synthesized, which contain butyl methacrylate as the main monomer and the metal‐binding ligands in the side chains. Zn(TFMS)2 and NiCl2 are utilized for the dual crosslinking, resulting in the formation of metallopolymer networks. The switching temperature can simply be tuned by changing the composition as well as by the choice of the metal ion. Strain fixity rates (about 99%) and very high strain recovery rates (up to 95%) are achieved and the mechanism is revealed using different techniques such as Raman spectroscopy.

This work presents the synthesis and characterization of easily tuneable shape-memory metallopolymers. Furthermore, the structural design enables excellent rewriting properties. For this purpose, two different polymers were synthesized using either...

Shape‐memory polymers (SMPs) are well investigated smart materials. With their ability to memorize their original shape they are interesting candidates for a large range of applications. Certain SMPs feature triple shape‐memory behavior. In these cases, it is possible to fix two different temporary shapes. However, the exact quantification of the individual steps regarding their programming and recovery rate is difficult and has not been possible so far. In this work, a novel approach for the analysis and exact quantification of triple SMPs is presented. By applying a customized rheology protocol, it is possible to perform and to analyze torsional and tensional experiments simultaneously. Consequently, different shapes in different directions (vertical and horizontal) can be fixed and the individual steps can be investigated independently at different switching temperatures.

Shape memory polymers represent an interesting class of stimuli-responsive polymers. With their ability to memorize and recover their original shape, they could be useful in almost every area of our daily life. We herein present the synthesis of shape-memory metallopolymers in which the switching unit is designed by using bis(pyridine–triazole) metal complexes. The polymer networks were synthesized via free radical polymerization of methyl-, ethyl- or butyl-methacrylate, tri(ethylene glycol) dimethacrylate and a methacrylate moiety of the triazole–pyridine ligand. By the addition of zinc(II) or cobalt(II) acetate it was possible to achieve metallopolymer networks featuring shape-memory abilities. The successful formation of the metal-ligand complex was proven by Fourier transform infrared (FT-IR) spectroscopy and by 1H NMR spectroscopy. Furthermore, the shape-recovery behavior was studied in detailed fashion and even triple-shape memory behavior could be revealed.

The supramolecular halogen bonding (XB) is utilized for the first time for the preparation of shape‐memory polymers. For this purpose, an iodotriazole‐based bidentate XB donor featuring a methacrylamide is synthesized. Free radical polymerization of the XB donor monomer together with butyl methacrylate, triethylene glycole dimethacrylate, and methacrylic acid results in covalently cross‐linked polymer networks bearing both, halogen bond acceptors and donors, in their side chains. While the reversible halogen bond interactions can act as switching unit, the required stable phase of the shape‐memory polymers is formed by covalent cross‐links. The successful formation of the supramolecular cross‐links is proven via Fourier‐transform Raman spectroscopy. Furthermore, the thermal properties are investigated via differential scanning calorimetry and thermo gravimetric analysis. Thermo‐mechanical analysis reveals excellent shape‐memory abilities with fixity rates above 95% and recovery rates up to 99%. Moreover, it is possible to 3D‐print this kind of material exhibiting the ability to recover its shape within a few seconds at 130 °C.