Synthesis of phosphorus-containing polyhedral oligomeric silsesquioxanes via hydrolytic condensation of a modified silane

A simple route to synthesize a new type of phosphorus-containing polyhedral oligomeric silsesquioxanes (DOPO-POSS) in high yield, by the hydrolytic condensation of a modified silane, is reported. The starting material was a phosphorus-containing triethoxy silane (DOPO-VTES), which was synthesized by addition reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and vinyl triethoxy silane (VTES). This product was subjected to hydrolytic condensation using an HCl catalyst in methanol. The new types of phosphorus-containing POSS were obtained and characterized using ¹H, ¹³C, ²⁹Si-NMR, MALDI-TOF MS, XRD, DSC, and FTIR. All of these results suggested that the DOPO-POSS were amorphous mixtures of T ₈, T₉(OH), and TGA curve of DOPO-POSS shows that the cage-like compound has high thermal stability.