HTV methyl vinyl silicone rubber composite filled with micron sized modified carbonyl iron powder
was prepared. Effects of coupling agent type and coupling agent dosage on the mechanical properties of composite were studied. On this basis,effects of carbonyl iron powder爷s amount on the mechanical properties of composite were inves tigated. The microstructure of vulcanized rubber was analyzed with SEM. The results indicate that modification of carbonyl iron powder by using both coupling agents KH570 and KH151 can increase the tensile strength of composites,but the modification effect of KH151 on carbonyl iron powder is better than that of KH570. The optimum dosage of KH151 is 1% of carbonyl iron powder爷s amount. In a certain range,the tensile strength of composite increases with increasing volume fraction of modified carbonyl iron powder. It is defficult to mix on the mill when the volume traction of modified carbongl iron powder is more than 60%.