Trimethylsilyl-Capped Polysiloxane Macromonomers Containing Polar Fluorinated Side-Chains
A method for reducing the modulus of polymer siloxane hydrogel compositions by employing monomeric polysiloxanes endcapped with trimethylsilyl to reduce the crosslinking density of the hydrogel. The synthesis consists of a single vessel acid catalyzed ring opening polymerization and may be employed to produce copolymers useful as hydrogel contact lens materials.
1 . Fluorinated siloxane-containing monomers having the following general schematic representation (I):
wherein;
A is an activated unsaturated radical;
R 1 , R 2 and R 7 -R 9 are independently an alkyl, cycloalkyl or aryl, arylalkyl, or siloxanyl,
R 3 -R 6 are independently alkyl, aryl, alkylaryl, or fluoroalkyl with the proviso that at least one of R 3 -R 6 is a fluoroalkyl;
m and n are independently 0 to 200, m+n being from about 3 to 200; and a is 1 to 10.
2 . A siloxane-containing, hydrogel comprising the monomer of claim 1 .
3 . The hydrogel of claim 2 , wherein m+n of said polysiloxane prepolymer is about 3 to 200.
4 . The hydrogel of claim 2 , wherein said polysiloxane prepolymer is endcapped within the range of 1 to 70 mole % trimethylsilyl.
5 . The hydrogel of claim 2 , wherein said prepolymer is endcapped within the range of 25 to 50 mole % trimethylsilyl.
6 . The hydrogel of claim 2 , wherein said prepolymer is endcapped within the range of 40 to 50 mole % trimethylsilyl.
7 . A contact lens comprising the hydrogel of claim 2 .
8 . An intraocular lens comprising the hydrogel of claim 2 .