Abstract: Polysiloxane flame retardants were synthesized through co-hydrolysis condensation reaction using tetraethoxysilane, phenyltrimethoxysilicone, diphenyldimethoxysilane, and methyltrimethoxysilane as the starting materials. Taking the weight ratios of TEOS/Si, R-Si, and Ph-R as 0.17, 0.9, and 0.75, respectively, the product was used in polycarbonate at 5 wt%, the LOI was increased from 26 to 35.5.

Key words: polysiloxane, flame retardant, polycarbonate