Preparation and Flame Retardancy of Polyurethane/POSS Nanocomposites

Polyurethane/polyhedral oligomeric sisesquioxane (PU/POSS) nanocomposites were syn-thesized via polymerization utilizing the compatibility between POSS nanoparticles and 4,4'-diphenyl methylene diisocyanate. Scanning electron microscope images and Fouriertransform infrared spectra revealed that POSS nanoparticles were dispersed in PU matrix.Thermal gravimetric analysis was employed to investigate the thermal decomposition be-havior of PU/POSS nanocomposites at elevated temperatures. Then fire performance wasevaluated by limiting oxygen index, underwriters laboratories 94 testing and char residue morphology. These results showed that the addition of POSS promoted the formation of char residues which were covered on the surface of polymer composites, leading to the im-provement of thermal stability and flame retardancy.