Abstract: In order to investigate the effects of the inorganic particle and ammonium polyphosphate (APP) com- pound of different morphologies on the flame retardancy and mechanical properties of silicone rubber,acicular wol- lastonite (WS)，tubular halloysite (HNTs) and layered α-zirconium phosphate (α-ZrP),which were modified by a coupling agent,were selected to incorporate into silicone rubber together with APP to prepare the flame retardant silicone rubber composite (FRSR) through a mechanical blending process.Then,the morphology structure and particle size distribution of inorganic particles and their dispersity in the FRSRwere characterized by using a SEM,a TEM and a laser particle size analyzer,and the mechanical property,thermal stability and flame retardancy of the FRSR were systematically investigated with the help of TGA,the vertical burning test (UL-94) and the limit oxy- gen index (LOI), The results show that the three kinds of inorganic particles are dispersed well in the FRSR matrix as their original geometrical shape,and that,when the content of the inorganic particle and APP compound is 25phr,the FRSR incorporated with 1phr OHNTs is of higher mechanical property (specifically,the tensile strength and the elongation at break are 8. 8MPa and 218. 6%,respectively),and the FRSR incorporated with 1 phr α- OZrP is of the best thermal stability and flame retardancy (specifically,the limiting oxygen index,the UL-94 level,and the initial decomposition temperature are respectively 32. 3，V-0 and 312. 9℃). Besides,the residues of the FRSR were analyzed by a SEM,and the formation mechanism of the residue was preliminarily investigated.

Key words: silicone rubber, inorganic particle, ammonium polyphosphate, flammability, mechanical property