Anionic polymerization of 1,3,5-tris(trifluoropropylmethyl)cyclotrisiloxane (F-3) in miniemulsion

The synthesis of poly(trifluoropropylmethyl)siloxane (PTFPMS) by anionic ri ng-opening polymerization of 1,3,5-tris(trifluoropropylmethyl)cyclotrisilox ane (F-3) was studied in miniemulsion using didodecyldimethylammonium bromi de (DDDBr) as emulsifier and sodium hydroxide as initiator. This new proces s of polymerization produced well-defined alpha,omega -dihydroxylated polym er in very high yields and with molar masses ranging from 2000 to 30 000 g mol(-1). A kinetic study showed that polymerization occurs in two stages. D uring the first stage, which corresponds to the anionic kinetically control led ring-opening polymerization of F-3, the maximum nonequilibrium yield is close to 100%. The second stage involves condensation and backbiting react ions. The delay between these steps offers a broad "termination window" for achieving high polymer yield.