SiSiB® PC7970 is a colourless to yellowish liquid, not miscible with water, decomposes with water and moisture under formation of acetic acid.
Color and Appearance
Colorless or yellowish clear liquid
Refractive Index [20°C]
SiSiB® PC7970 propyltriacetoxysilane, PTAS silane, is used as a raw material (crosslinker) for acetoxy crosslinking RTV-1 sealants.
Acetoxy silanes are more reactive than alkoxy silanes. Acetoxy silanes are frequently used as one-component mixtures to make RTV-1 silicone sealants. These mixtures have an excess of multi-functional acetoxy silane added to silanol-terminated PDMS, which results in a PDMS chain with acetoxy groups at the ends.
When this compound is exposed to moisture some acetoxy groups are hydrolyzed and self-condense or react with other acetoxy and rapid crosslinking takes place. Acetic acid formation is one of the driving forces of this reaction.