Synergistic effects of polyhedral oligomeric silsesquioxane (POSS) and oligomeric bisphenyl A bis(diphenyl phosphate) (BDP) on thermal and flame retardant properties of polycarbonate

A series of flame retardant hybrids were prepared based on bisphenol A polycarbonate (PC), trisilanolphenyl-polyhedral oligomeric silsesquioxane (TPOSS) and oligomeric bisphenyl A bis(diphenyl phosphate) (BDP) by melt blending method. The thermal stability and flame retardant properties of the hybrids were investigated by thermogravimetry analysis and cone calorimeter. Combination TPOSS with BDP in the appropriate ratio enhanced the thermal stability and the flame retardant properties of the PC matrix. The char residues of the hybrids were investigated by scan electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The synergistic effect of BDP and TPOSS enhances the thermal stability and fire-resistance of the char layer which builds up on the surface of the burning polymer.