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Siegel der Universität
Department für Chemie - Arbeitsgruppe Prof. Strey

Formulierung von neuen Polyol-Mikroemulsionen zur Synthese von Polyurethan-Nanoschäumen

Stefan Lülsdorf, 2014

 

In view of a sustainable use of resources, the optimization of heat insulation materials is a major research objective. Widely used thermal insulation materials are microporous polyurethane foams, which can be produced cost-effectively and on a large scale. An increase in efficiency of these thermal insulation materials should be possible by a reduction of the pore size. A promising approach for the production of nanoporous foams derives from the Principle of Supercritical Microemulsion Expansion (POSME), developed by Strey et al. This procedure utilizes thermodynamically stable microemulsions which contain a supercritical fluid in order to provide a high number density of blowing agent pools. To transfer the nanostructure to foams via POSME, a distinct structure of the polyol?based microemulsions is essential. Therefore, in this work, a number of new polyols and surfactants were initially examined with respect to their phase behavior, in order to achieve both a reduction of the monomeric solubility of supercritical carbon dioxide in the polyol and an optimization of the microemulsion structure. In a further step, microemulsions with supercritical sulfur hexafluoride as blowing agent were formulated. Due to its high density, this non-flammable and non-toxic blowing agent should exhibit improved interactions with the surfactants and a decreased monomeric solubility. The resulting enhancement of the microemulsion structure should bring the preparation of nanoporous polyurethane-foams decisively forward.