Epoxy Networks Containing Large Mass Fractions of a Monofunctional Polyhedral Oligomeric Silsesquioxane (POSS)

By M. Abad, L. Barral, D. Fasce, Roberto J. J. Williams. 2003

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A polyhedral oligomeric silsesquioxane (POSS) containing one epoxy group and seven isobutyl groups per molecule was incorporated into an epoxy network following a two-stage process. In the first stage, POSS was reacted with an aromatic diamine, employing a 1:1 molar ratio of both reactants. The distribution of species at the end of reaction, determined by size exclusion chromatography (SEC), was close to the ideal one. In a second step, this precursor was reacted with the stoichiometric amount of an aromatic diepoxide to generate an organic−inorganic hybrid material containing 51.8 wt % POSS. A primary liquid−liquid phase separation process occurred at the time of adding the diepoxide to the POSS−diamine precursor. This led to a macrophase separation into epoxy-rich and POSS-rich regions, possibly derived from the incompatibility of the isobutyl groups attached to the POSS with the aromatic epoxy−amine network. A secondary phase separation occurred in the epoxy-rich phase in the course of polymerization, ...

Subfields: Biomaterials, Inorganic Chemistry, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/e759d87d91a87b6791701f1388dc948cd8aeaf49