Characterization of a Rigid Silicone Resin

Sillcone resins have been used as binders for ceramic frit coatings and can withstand temperatures of 650°C to 1260°C. Conceptually, silicone resins can potentially be used as matrices for high temperature fiber-reinforced composites. The mechanical and thermal properties of a commercially available silicone resin, Dow Corning® 6-2230, were characterized. Neat 6-2230 resin was found to have inferior room temperature mechanical properties such as flexural, tensile and fracture properties when compared to epoxy. The room temperature flexural properties and short beam shear strength of the silicone/glass composites were also found to be lower than those of epoxy/glass composite with similar glass content. However, the silicone resin had better elevated temperature properties. At an elevated temperature of 316°C, the retentions of flexural modulus and strength were 80% and 40% respectively of room temperature values; these were superior to those of phenolic/glass. Unlike the carbon-based resins, the drop in flexural properties of the silicone/glass laminates with temperature leveled off with increase In temperature beyond 250°C. The resin weight loss at 316°C in 100 cm³/min of flowing air was small compared to other carbon-based resins such as PMR-15 and LaRC TPI. Only Avimid-N appeared comparable to Dow Corning® 6-2230.