... . Appearance: colorless liquid 4. Purity (by GC ): 99% Product introduction:Heptamethyltrisiloxane, chemical name : Bis(trimethylsiloxy)methylsilane,1,1,1,3,5 ... ,5,5,- Heptamethyltrisiloxane. It has high-active Si-H . It s a raw ... in seal drum at room , dry place , usable life1 year. Heptamethyltrisiloxane