Novel polyurethane networks based on hybrid inorganic/organic phosphazene-containing nanotubes with surface active hydroxyl groups

Recently, our group reported a novel preparation of poly(cyclotriphosphazene‐co‐4,4′‐sulfonyldiphenol) nanotubes (PZSNTs), which could be conveniently prepared in a one‐pot process at room temperature without any surfactant or other compatibilizing agent. PZSNTs were a new kind of phosphazene‐containing crosslinked polymers which attracted considerable interest for their outstanding biocompatibility, thermal stability, and flame‐retardant property. Moreover, PZSNTs which possessed inherent surface active hydroxyl groups could be directly used as a crosslinking agent to prepare polyurethane hybrid networks. PZSNTs were homogeneously dispersed in the polyurethane matrix. Tensile tests indicated that the nanocomposites were significantly reinforced by crosslinking of PZSNTs. The tensile strength was enhanced from 11.4 to 21.5 MPa while the elongation at break was almost invariable (460–430%). The storage moduli of the nanocomposites were significantly higher than that of the pure polyurethane. In terms of thermogravimetric analysis (TGA), the nanocomposites displayed an improved thermal stability. Copyright © 2010 John Wiley & Sons, Ltd.