Studies On The Preparation And Properties Of Irradiation Crosslinked Silicone Rubber Foam

The silicone rubber foam was prepared through irradiation crosslinking of electron beam or gamma ray, which make the crosslinking and foaming of silicone rubber progress separately, avoids the matching problems of crosslinking and foaming for the conventional peroxide crosslinking, and the complexities of controlling the foaming process and properties of silicone rubber foam, etc. The average cell diameter of irradiation crosslinked silicone rubber foam is 20～40μm, foam density is 0.31～0.53 g/cm³, the tensile strength is great than 0.9 MPa, the elongation at break is about 240%, and the compression set is less than 6%. In this paper, the effects of irradiation dose, silicon dioxide(SiO₂)content, hydroxyl silicon oil content, the type of blowing agents and its content, and the post-irradiation after foaming on the structure and properties of silicone rubber foam were studied in this paper, the experimental results show that:1) With the increase of irradiation dose, the crosslinking density, gel content and tensile strength of silicone rubber increase, the tensile strength reaches the maximum value when the irradiation dose is 40 kGy. The elongation at break of silicone rubber decreases with the increase of irradiation dose.2) With the increase of irradiation dose, the nucleation density, bubble density - of silicone rubber foam increase, the average cell diameter decrease, and the foamdensity increases. The tensile strength, tensile modulus and the elongation at break of silicone rubber foam increase with the irradiation dose.3) With the increase of SiO₂ content, the nucleation density, bubble density of silicone rubber foam increase, the average cell diameter decrease, the foam density declines to a minimum value and then increases. With the increase of SiO₂ content, the tensile strength of silicone rubber foam increases and the compression set...