Silicone polymers display an exceptionally wide range of chemistries and physical properties. These polymers can be low viscosity liquids, crosslinkable elastomers, or hard solids. Applications for silicone sealants are extremely broad. Markets include construction, automotive, assembly, maintenance, electrical/electronic, aerospace, and consumer products. Silicone sealants often compete with other materials such as polyurethanes, polysulfides, and acrylics. However, in applications requiring long-term durability to harsh environments, silicones are generally specified.
RESULTING PROPERTIES
Utilization of an oxime crosslinker increases the skin-over time and tack-free time, but has little effect on the cured physical properties. The oxime crosslinker will provide lower corrosive behavior than acetoxy systems. The above table shows starting formulations for a medium modulus oxime RTV silicone sealants. The reaction rate of the moisture cure RTV silicone sealants depends primarily on their formulation, relative humidity, and temperature.
