Study of Flame Retardation of Polycarbonate Modified by Polyhedral Oligomeric Silsesquioxane and Caged Bicyclic Phosphate

The flame-retarded polycarbonate (PC) has been made with octaphenyl polyhedral silsesquioxane (OPS) and/or caged bicyclic phosphate (Trimer). Thermal gravimetric analysis (TGA), Fourier-transform infrared (FTIR), TGA-FTIR, limiting oxygen index (LOI), and mechanical tests have been employed to characterize the modified PC. The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si. The role of OPS and Trimer in PC degradation are different: OPS participates in the charring of PC, while Trimer makes PC degrade in advance. In addition, OPS and Trimer induced obvious differences in the mechanical properties of PC.