Stereoregular poly(methyl(3,3,3-trifluoropropyl)-siloxane) polymers and methods for making

摘要

The present invention provides stereoregular poly{methyl(3,3,3-trifluoropropyl)siloxane} polymers and copolymers with methods for their making. The process involves reacting isomers of 1,3,5-trimethyl-1,3,5-tris-(3',3',3'-trifluoropropyl)cyclotrisiloxane in the presence of an aprotic polar promoter and a lithium compound. The lithium compound initiates ring opening and polymerization of the isomers without effecting the steric arrangement of the isomers. Elastomers prepared by cross-linking polymers of the present invention can have sufficient cis 3,3,3-trifluoropropyl substitution to allow the elastomers to strain-crystallize and provide reinforcement to the elastomers at typical use temperatures.