POSS-based hybrids by melt/reactive blending

Organic-inorganic polyhedral oligomeric silsesquioxane (POSS)-polymer hybrids have gained a wide research interest in the last decade, thanks to the great versatility of POSS synthesis and availability of different chemical structures, aimed at modifications of physical/chemical properties of polymers or at delivering new functional properties. Traditionally, in situ copolymerisation of POSS to produce hybrid organic-inorganic polymers with pendent POSS groups has been used both for thermoplastics and thermosets. In recent years, attention has been also given to the possibility of preparing POSS-polymer systems by melt blending techniques, taking advantage of (i) miscibility of POSS into polymers thanks to physical interactions or (ii) chemical reaction between POSS and the polymer. These two methods, usually referred to respectively as melt blending and reactive blending, represent very appealing, inexpensive and environmentally friendly processes for industrial development of POSS technology. This paper reviews the present state of the art on both melt blending and reactive blending of POSS into thermoplastic polymers, discussing present achievements and limitations from both methods.