Perfluorocyclobutane copolymers

1. A copolymer containing perfluorocyclobutane groups in the polymer backbone and comprising at least two of the following units;

(a) an oxyalkylene unit of the formula

wherein R 2 and R 3 are independently hydrogen, a straight or branched C 1 -C 6 alkyl group, a C 3 -C 30 cycloalkyl group, a C 5 -C 30 aryl group, a straight or branched C 1 -C 6 fluoroalkyl group, a C 3 -C 30 fluorocycloalkyl group, a C 5 -C 30 fluoroaryl group, an ether group, a C 1 -C 20 ester group, an amide group, an amine group, fluorine, a vinyl group, or a hydroxyl group, m is 1 to about 10 and n is 1 to about 100,000;

(b) a polysiloxane unit of the formula

wherein R 4 and R 5 are independently hydrogen, a straight or branched C 1 -C 6 alkyl group, a C 3 -C 30 cycloalkyl group, a C 5 -C 30 aryl group, a straight or branched C 1 -C 6 fluoroalkyl group, a C 3 -C 30 fluorocycloalkyl group, a C 5 -C 30 fluoroaryl group, an ether group, a C 1 -C 20 ester group, C 1 -C 6 alkoxy group, an amide group, an amine group, fluorine, a vinyl group, or a hydroxyl group and n is 1 to about 100,000; and

(c) a perfluorocyclobutane unit of the formula

wherein X′ is independently a bond, an oxygen atom, a sulfur atom, a carboxylic or thiocarboxylic ester group, a sulfone, a sulfoxide, perfluoroalkylene, perfluoroalkylene ether, alkylene, acetylene, a phosphine, a carbonyl or thiocarbonyl group; seleno; telluro; nitrido; a silanediyl group, a trisilanediyl group, a tetrasilanetetrayl group, a siloxanediyl group, a disiloxanediyl group, a trisiloxyl group, a trisilazanyl group, a silythio group, or a boranediyl group, R 6 independently represents one or more inertly substituted groups and n is 1 to about 100,000.

2. The copolymer of claim 1 , comprising one or more of the oxyalkylene units (a) and one or more of the perfluorocyclobutane units (c).

3. The copolymer of claim 2 , wherein in the oxyalkylene unit (a) R 2 and R 3 are independently a straight or branched C 1 -C 6 alkyl group or a straight or branched C 1 -C 6 fluoroalkyl group and the oxyalkylene units are formed as random copolymers, and in the perfluorocyclobutane unit (c) X′ is O and R 6 comprises a cyclic or polycyclic group optionally containing one or more heteroatoms.

4. The copolymer of claim 2 , wherein in the oxyalkylene unit (a) R 2 and R 3 are independently a straight or branched C 1 -C 6 alkyl group or a straight or branched C 1 -C 6 fluoroalkyl group and the oxyalkylene units are formed as block copolymers, and in the perfluorocyclobutane unit (c) X′ is O and R 6 comprises a cyclic or polycyclic group optionally containing one or more heteroatoms.

5. The copolymer of claim 1 , comprising one or more of the oxyalkylene units (a) and one or more of the polysiloxane units (b).

6. The copolymer of claim 5 , wherein in the oxyalkylene unit (a) R 2 and R 3 are independently a straight or branched C 1 -C 6 alkyl group or a straight or branched C 1 -C 6 fluoroalkyl group and wherein in the polysiloxane unit (b) R 4 and R 5 are independently a straight or branched C 1 -C 6 alkyl group or a C 1 -C 6 alkoxy group.

7. The copolymer of claim 1 , comprising one or more of the polysiloxane units (b) and one or more of the perfluorocyclobutane units (c).

8. The copolymer of claim 7 , wherein in the polysiloxane unit (b) R 4 and R 5 are independently a straight or branched C 1 -C 6 alkyl group or a C 1 -C 6 alkoxy group, and in the perfluorocyclobutane unit (c) X′ is O and R 6 comprises a cyclic or polycyclic group optionally containing one or more heteroatoms.

9. The copolymer of claim 1 , comprising one or more of the oxyalkylene unit (a), one or more of the polysiloxane units (b) and one or more of the perfluorocyclobutane units (c).

10. A biomedical device comprising the copolymer of claim 1 .

11. The biomedical device of claim 10 , which is an ophthalmic lens.

12. The biomedical device of claim 11 , wherein the ophthalmic lens is a contact lens.

13. The biomedical device of claim 12 , wherein the contact lens is a rigid gas permeable lens.