ma501492u_si_001.pdf (841.38 kB)
Download fileSupramolecular Polymers with Orthogonal Functionality
journal contribution
posted on 23.12.2014, 00:00 authored by Souleymane Coulibaly, Christian Heinzmann, Frederick
L. Beyer, Sandor Balog, Christoph Weder, Gina L. FioreSupramolecular
polymers with orthogonal interactions are of broad
interest, and reports on such materials with multifunctional stimuli-responsive
behavior are rare. Polymer blends based on a poly(ethylene-co-butylene) core (PEB) terminated with either 2-ureido-4[1H]-pyrimidinone (UPy) hydrogen-bonding motifs (UPy-PEB-UPy)
or 2,6-bis(1′-methylbenzimidazolyl)pyridine (Mebip) ligands
coordinated to metal ions ([M(Mebip-PEB-Mebip)]2+ (M =
Zn, Fe)) were prepared. The degree of orthogonality of the supramolecular
polymer blends was explored by UV–vis spectroscopy, small-angle
X-ray scattering, and dynamic mechanical thermal analysis (DMTA).
Polymer blends of [Zn(Mebip-PEB-Mebip)](NTf2)2 and UPy-PEB-UPy resulted in a statistical mixture of noncovalent
interactions, whereas blends with [Fe(Mebip-PEB-Mebip)](ClO4)2 and UPy-PEB-UPy assembled in an orthogonal fashion.
Additionally, the DMTA showed two transitions for the disassembly
of UPy (ca. 60 °C) and Fe2+-Mebip (ca. 180 °C)
phases. The Fe2+-Mebip interactions were selectively disrupted
by the addition of a competitive ligand, demonstrating that each supramolecular
motif can be targeted with either a thermal or chemical stimulus.