US 5,401,822 A · Stereoregular poly(methyl(3,3,3-trifluoropropyl)-siloxane) polymers and methods for making

Abstract

The present invention is stereoregular poly{methyl(3,3,3-trifluoropropyl)siloxane} polymers and copolymers and 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.

Claims19

Dependent claims

A process for making poly{methyl(3,3,3-trifluoropropyl)siloxane} polymers, the process comprising:

(A) forming a mixture comprising an aprotic polar promoter, isomer of 1,3,5-trimethyl-1,3,5-tris(3',3',3'-trifluoropropyl)cyclotrisiloxane where 30 to 100 mole percent of the isomer is in cis configuration, optionally about 0.05 to 5.0 mole percent of an organocyclotrisiloxane comprising at least one reactive cross-linkable substituent bonded to silicon per organocyclotrisiloxane molecule, and a lithium compound comprising at least one lithium atom attached to a silicon atom through an oxygen atom;
and
(B) maintaining the mixture under essentially anhydrous conditions at a temperature at which the lithium compound and the isomer react.

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims19