Because a large excess of silane is used, the probability of
two different chains reacting with the same silane molecule
is remote. Consequently, all the chains are end-blocked with
two acetoxy functional groups. The resulting product is still
liquid and can be packaged in sealed tubes and cartridges.
Upon opening the acetoxy groups are hydrolyzed by the ambient
moisture to give silanols, which allow further condensation
to occur.