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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 4: Focus: The Physics of Adaptive Polymer Networks
CPP 4.3: Vortrag
Dienstag, 28. September 2021, 11:15–11:30, H3
Chain connectivity of tetra-PEG - tetra-PCL amphiphilic end-linked polymer model networks — •Lucas Löser1, Carolin Bunk2, Frank Böhme2, and Kay Saalwächter1 — 1Inst. f. Physik - NMR, Martin-Luther-Universität Halle-Wittenberg — 2Leibnitz-Institut f. Polymerforschung Dresden e.V., Hohe Str. 6, Dresden
A new approach for the synthesis of model-like amphiphilic co-networks is introduced, and their structure analysed by static 1H time-domain nuclear magnetic resonance (NMR) methods. A novel approach of hetero-complementary end-linking [1] of two well-defined tetra-armed polyethylene glycol (PEG) stars based on Sakai et al. [2] is used and modified in a way, that amphiphilic gels are obtained. We link PEG stars with a hydrophobic poly-ε-caprolactone star (tetra-PCL) terminated with an oxazinone group, resulting in the formation of an amphiphilic network. By using static 1H-1H multiquantum-NMR, as initially performed by Lange et al. [3], we show that our method is capable of distinguishing different chain species in the swollen PEG-PCL networks, allowing quantification of network connectivity defects arising from the end-linking reaction of A4- and B4-type stars, as well as accurate quantification of inelastic material. The parameter space of the synthesis is explored and changes in microscopic network structure are studied depending on polymer concentration and different temperature programs during synthesis. [1] Jakisch et al. ; Macromol. Chem. Phys 2017, 219 [2] Sakai, T. et al.; Macromolecules 2008, 41 [3] Lange, F. et al.; Macromolecules 2011, 44