A facile method for the synthesis of foamed silicone rubber

Foamed silicone rubber was prepared by mixing 45% vinyl silicone oil (Base), Karstedt platinum catalyst (Cata), and hydrogenated silicone oil (SiH) and the resulting material was subjected to secondary vulcanization, which led to its performance requirements. Vinyl silicone oil and hydrogenated silicone oil underwent an addition reaction under the action of a platinum catalyst to form an elastomer with a cross-linked network structure. The results showed that by increasing the content of hydrogenated silicone oil in the formulation, the elongation at break of the foamed silicone gel material decreased but the tensile strength increased. When the content of hydrogenated silicone oil in the formulation decreased, the elongation at break of the foamed silicone material increased. When the content of Karstedt catalyst in the formulation increased, the formation time of the reaction gel was greatly shortened, and the cell structure tended to be dense but delicate. When the proportion of vinyl silicone oil in the formulation increased, the elongation at break of the foamed, molded silicone rubber increased. However, the elastic modulus decreased, and the thermal stability improved. Finally, a more suitable formulation of V_Base:V_Cata:V_SiH = 32:1:2 was obtained, which showed a tear resistance of 5.52 KN/m, ductility of 133%, and limiting oxygen index of 26 with a stability temperature of 346.8 °C when the thermal mass loss reached 95%.