SKM 2023 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 35: Poster Session II
CPP 35.42: Poster
Wednesday, March 29, 2023, 11:00–13:00, P1
Characterisation and transport within 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, Halle/D — 2Leibnitz-Institut für Polymerforschung Dresden e.V., Hohe Str. 6, Dresden/D
A new approach for the synthesis of model-like amphiphilic co-networks is introduced, and their structure is analyzed by static 1H time-domain nuclear magnetic resonance (NMR) methods [1]. The hetero-complementary end-linking reaction of two well-defined star precursors [2] is implemented to obtain amphiphilic gels. We link PEG stars with hydrophobic poly-*-caprolactone stars (tetra-PCL), resulting in the formation of an amphiphilic network. NMR is shown to be capable of distinguishing different chain species in the swollen PEG-PCL networks, allowing quantification of network connectivity defects arising from the end-linking reaction, as well as accurate quantification of inelastic material. The mesh size of the networks is studied by Pulsed-Field Gradient (PFG) NMR, using dextrans as hydrophilic probe molecules for the network swollen in selective solvents. Furthermore, we performed measurements using small-angle x-ray scattering and 1H MAS recoupling NMR for information on the properties of the selectively swollen networks, e.g., estimates for the correlation length of PCL domains, and chem. shift-specific information about the chain dynamics. [1] Bunk et al.; Macromolecules 2022, 55, (15), 6573-6589 [2] Sakai, T. et al.; Macromolecules 2008, 41, (14), 5379-5384