7 - Rubber nanocomposites with polyhedral oligomeric silsesquioxanes (POSS) as the nanofiller

Abstract

This chapter provides a comprehensive review on the role of polyhedral oligomeric silsesquioxanes (POSS) as reinforcing fillers for polymer and rubber nanocomposites. POSS, having an SiOSi framework, provides the high thermal stability, while the peripheral organic functionality offers the better polymer–filler interface adhesion. The peripheral organic functionalities of POSS were reported to play a key role in controlling the POSS dispersion in fumed silica based addition cured liquid silicone rubber. The radical grafting of organo-functionalized POSS was reported to reinforce the ethylene propylene diene monomer (EPDM) based rubbers, whilst causing a detrimental effect on radically curable polysiloxane elastomers. On the other hand, the matrix–filler incompatibility and the preferential crystallization of POSS segments were effectively leveraged as tunable linkages to fabricate thermoplastic elastomeric materials. The use of POSS based molecular units were also explored for developing functional structures like radiation protective coatings, nanoporous organic–inorganic frameworks for gas storage, or in low dielectric composites.