PU Rigid Nanocomposite Foams Containing Spherical Nanofillers

Abstract

The inclusion of spherical nanoparticles as nanofillers into PURFs improves their closed-cellular morphology, mechanical properties, thermal stability and flame retardant behavior. For spherical nano-sized fillers, nanosilica, polyhedral oligomeric silsesquioxanes (POSS), TiO<inf>2</inf> and ZnO can be given as nanoadditive examples that have been used as nanoadditives in PURNCFs. However, among PURF/spherical nano-sized filler studies, the most generally investigated nanoadditive is nanosilica due to its excellent thermal stability and decomposition behavior, mechanical, thermal and thermomechanical properties in comparison with other types of spherical nanoparticles. This chapter systematically examines significant PURNCF/spherical nano-sized filler works in detail by highlighting subtopics such as morphology, mechanical, thermal and thermomechanical properties, thermal degradation and flammability. In addition, besides using one type of nanofiller such as nanosilica in PURNCFs, the importance of using mixtures containing nanosilica and another type of nanofiller or flame retardant with distinct properties is pointed out in order to fabricate PURNCFs with advanced properties. © 2019, Springer Nature Switzerland AG.