Preparation, structure and properties of hybrid materials based on geopolymers and polysiloxanes

New hybrid materials with no phase separation up to nanometric level were obtained by performing the in situ co-reticulation of an aluminosilicate source (metakaolin), a mixture of dialkylsiloxane oligomers with different degrees of polymerization and an alkaline solution. As supported by SEM and NMR analyses, these hybrid materials are characterized by a highly interpenetrated structure due to the chemical similarity between the components, resulting in excellent physical and mechanical properties compared to neat geopolymers. These promising results represent a further step in developing alternative low-carbon binders (as also geopolymers) with improved engineering properties in the concrete technology. The enhanced mechanical properties, along with the high fire resistance, also suggest their utilization for structural applications as heat insulating and heat-resistant panels for the construction industry, and in the production of heat-resistant protective coatings or adhesives for technologically advanced uses. © 2015 Elsevier Ltd.