3D Printing of Supramolecular Polymers: Impact of Nanoparticles and Phase Separation on Printability

• DOI: 10.1002/marc.201900467
• Publication Date: 2019-11-28T14:56:10Z
• Authors: Harald Rupp; Diana Döhler; Philipp Hilgeroth; Nasir Mahmood; Mario Beiner; Wolfgang H. Binder
• Keywords: Models, Molecular; Molecular Structure; Macromolecular Substances; Polymers; Surface Properties; Printing, Three-Dimensional; Nanoparticles; Particle Size; 01 natural sciences; Micelles; 0104 chemical sciences

Abstract3D printing of linear and three‐arm star supramolecular polymers with attached hydrogen bonds and their nanocomposites is reported. The concept is based on hydrogen‐bonded supramolecular polymers, known to form nano‐sized micellar clusters. Printability is based on reversible thermal‐ and shear‐induced dissociation of a supramolecular polymer network, which generates stable and self‐supported structures after printing, as checked via melt‐rheology and X‐ray scattering. The linear and three‐arm star poly(isobutylene)s PIB‐B2 (Mn = 8500 g mol −1), PIB‐B3 (Mn = 16 000 g mol −1), and linear poly(ethylene glycol)s PEG‐B2 (Mn = 900 g mol−1, 8500 g mol −1) are prepared and then probed by melt‐rheology to adjust the viscosity to address the proper printing window. The supramolecular PIB polymers show a rubber‐like behavior and are able to form self‐supported 3D printed objects at room temperature and below, reaching polymer strand diameters down to 200–300 µm. Nanocomposites of PIB‐B2 with silica nanoparticles (12 nm, 5–15 wt%) are generated, in turn leading to an improvement of their shape persistence. A blend of the linear polymer PIB‐B2 and the three‐arm star polymer PIB‐B3 (ratio ≈ 3/1 mol) reaches an even higher structural stability, able to build free‐standing structures.