17704-22-2 2,4,6,8,10-Pentamethyl-2,4,6,8,10-pentavinylcyclopentasiloxane Cyclopentasiloxane, 2,4,6,8,10-pentaethenyl-2,4,6,8,10-pentamethyl- EINECS 241-712-3 Methylvinylsiloxane cyclic pentamer