Silsesquioxanes (POSS)
Polyhedral oligomeric silsesquioxanes (POSS) are cage- like hybrid molecules of silicon and oxygen with similarities to both silica and silicone. When mixed with virtually any ordinary polymer, they bond to the organic molecules and to one another, forming large chains that weave through the polymer. The result is a nanostructured organic- inorganic hybrid polymer. The POSS chains act like nanoscale reinforcing fibers, producing extraordinary gains in heat resistance. This substance (RSiO1.5) is an intermediate between and SiO2 and R2SiO. This structure is large, equivalent to most polymer segments and coils. (RDC 6/8/2009) (http://www.reade.com/Products/Polymeric/poss.html, 6/8/2009)
POSS chemical feedstocks can be added to nearly all polymer types (glassy, elastomeric, rubbery, semicrystalline and crystalline) and compositions. Benefits include enhanced fire retardation, higher use temperatures and low density. (RDC 6/8/2009) (http://www.reade.com/Products/Polymeric/poss.html, 6/8/2009)
Recent Journal Articles
Solventless silicone hybrids based on polyhedral oligomeric silsesquioxane and hyperbranched polysiloxane for vacuum pressure impregnation process
(2415–2423)Polymers for Advanced Technologies 22 #12 (2011)
Zhang et al ofSoochow University, China, developed a solventless silicone hybrids (SSiH) containing branched poly(methylphenylvinylsiloxane) (PMPVSi), end-capped hydrogen-functionalized hyperbranched polysiloxane (EHFHPSi), and octavinyl-polyhedral oligomeric silsesquioxane (OVPOS) through a hydrosilylation reaction. The new hybrids are suitable for vacuum pressure impregnation process, and can serve as an excellent class C insulating material. (RDC 11/25/2011)