Research data for: Graded metallopolymer structures with shape-memory abilities via DLP-based 3D-prining

In this study, the digital light processing (DLP) based three-dimensional (3D) printing of graded metallopolymer structures with shape-memory ability is presented. Herein, ligand-containing monomers based on terpyridine and triphenylmethyl(trt)-histidine are complexed with zinc(II) and nickel(II) salts, respectively. Subsequently, photopolymerization with 2-phenoxy ethyl acrylate as comonomer is conducted. During 3D-printing, resin vat exchanges are performed after a certain amount of printing time. The newly added resin mixture is based on a different metal-ligand combination and can be printed under the same conditions as the previous mixture, thereby resulting in graded structures.

The obtained materials are characterized according to their thermo-mechanical properties via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Temperature dependent Raman spectroscopy is utilized to investigate materials with a special focus on the interface between the different segments. Here, a narrow dynamic region at the intersection thinner than one printing layer (about 20 µm) was detected.

During the shape-memory investigation the graded structures enable the recovery of the permanent shape in two distinct steps showing excellent shape-memory behavior. Thermo-mechanical analysis (TMA) measurements reveal fixity rates after mechanical deformation close to 100% and overall recovery rates as high as 99%.