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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 23: Polymer Dynamics

CPP 23.12: Talk

Wednesday, March 13, 2013, 12:45–13:00, H39

Interplay of morphology and rheology during foaming of block copolymers of polystyrene and poly(methyl methacrylate) — Golda Louis Chakkalakal¹, •Ulrich A. Handge¹, Ulla Vainio², and Volker Abetz¹ — ¹Institute of Polymer Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, 21502 Geesthacht, Germany — ²Deutsches Elektronen-Synchrotron (DESY), Notkestraße 85, 22607 Hamburg

Porous and cellular polymers are technologically used in a variety of applications, e.g. in lightweight applications or for acoustic and thermal insulation. Furthermore, porous polymers with an open-cell structure can be used as membranes for microfiltration purposes. If a block copolymer is chosen for preparation of a porous or cellular polymer, then the phenomenon of microphase-separation yields an additional degree of freedom to prepare nanostructured materials. In this study, we systematically investigate the influence of morphological and rheological properties on the preparation of foams of polystyrene (PS)-b-poly(methyl methacrylate) block copolymers. The foams were prepared using the technique of batch foaming with carbon dioxide as blowing agent. The analysis of rheological data reveals that molecular weight and morphology strongly influence the complex modulus and the creep compliance. The solution of carbon dioxide in PS-b-PMMA block copolymers leads to a reduction of the glass transition temperature of the PS and the PMMA phase. Generally, foaming of PS-b-PMMA block copolymers with a cylindrical morphology leads to foams with a lower density than the foams with a lamellar morphology.