Biomaterial

1. A block copolymer of the formula [polybutadiene][polyalkyl ether][polysiloxane][polyalkylether][polybutadiene].

2. A block copolymer of formula I

wherein:

each represents a point of attachment to a urethane or urea linkage;

each of R 1 , R 2 , R 3 , and R 4 is independently selected from one or more of halogen, R, OR, —CO 2 R, a fluorinated hydrocarbon, a polyether, a polyester or a fluoropolymer;

each R is independently hydrogen, an optionally substituted C 1-20 aliphatic group, or an optionally substituted group selected from phenyl, 8-10 membered bicyclic aryl, a 4-8 membered monocyclic saturated or partially unsaturated heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulphur, or 5-6 membered monocyclic or 8-10 membered bicycle heteroaryl group having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

each of m n and p is independently 2 to 100; and

each of L 1 and L 2 is independently a bivalent C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently replaced by —O—, —S—, —N(R)C(O)O—, —N(R)C(O)N(R)—, —OC(O)N(R)—, —N(R)—, —C(O)—, —C(O)N(R)—, —N(R)C(O)—, —SO 2 —, —SO 2 N(R)—, —N(R)SO 2 —, —OC(O)—, —C(O)O—, or a bivalent cycloalkylene, arylene, heterocyclene, or heteroarylene.

3. The copolymer according to claim 2 , wherein R 1 and R 2 are methyl, one or both of R 3 and R 4 is independently a C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently substituted by halogen, and L 1 and L 2 are independently a bivalent C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently replaced by —NHC(O)O— or —NHC(O)NH—.

4. The copolymer according to claim 2 , wherein R 1 and R 2 are methyl, one or both of R 3 and R 4 is independently a C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently substituted by halogen, L 1 is —NHC(O)O— or —NHC(O)NH—, and L 2 is a C 1-20 hydrocarbon chain.

5. The copolymer according to claim 2 , wherein R 1 and R 2 are methyl, one or both of R 3 and R 4 is independently a C 1-20 hydrocarbon chain, L 1 is —NHC(O)O— or —NHC(O)NH—, and L 2 is a C 1-20 hydrocarbon chain.

6. The copolymer according to claim 2 , wherein m and p are each independently between 2 and 50 and n is between 2 and 20.

7. The copolymer according to claim 6 , wherein m and p are each independently between 2 and 30 and n is between 2 and 20.

8. The copolymer according to claim 6 , wherein each of m, n, and p are 8-16.

9. The copolymer according to claim 2 , wherein one or more of R 1 , R 2 , R 3 , and R 4 is independently an optionally substituted C 1-6 alkyl.

10. The copolymer according to claim 9 , wherein each of R 1 , R 2 , R 3 , and R 4 is independently methyl, ethyl, propyl, isopropyl, cyclopropyl, butyl, isobutyl, or cyclobutyl.

11. The copolymer according to claim 10 , wherein each of R 1 , R 2 , R 3 , and R 4 is independently mono-, di-, tri, or perfluorinated methyl, ethyl, propyl, butyl, or phenyl.

12. The copolymer according to claim 9 , wherein each of R 1 , R 2 , R 3 , and R 4 is independently methyl, ethyl, propyl, trifluoromethyl, trifluoroethyl, or trifluoropropyl.

13. The copolymer according to claim 2 wherein each of L 1 and L 2 is independently a bivalent C 1-20 alkylene chain.

14. The copolymer according to claim 13 wherein each of L 1 and L 2 is independently a bivalent C 1-10 alkylene chain.

15. The copolymer according to claim 13 wherein each of L 1 and L 2 is independently a bivalent methylene, ethylene, propylene, or butylene chain.

16. The copolymer according to claim 2 wherein each of L 1 and L 2 is independently —OCH 2 —, —OCH 2 CH 2 —, —OCH 2 CH 2 CH 2 —, or —OCH 2 CH 2 CH 2 CH 2 —.

17. The copolymer according to claim 2 wherein each of L 1 and L 2 is independently a bivalent C 1-6 alkylene chain wherein at least one methylene unit of the chain is replaced by —O— and at least one methylene unit of the chain is replaced by a bivalent arylene.

18. The copolymer according to claim 17 wherein each of L 1 and L 2 is independently —OCH 2 -phenylene-, —OCH 2 CH 2 -phenylene-, —OCH 2 CH 2 -phenylene-CH 2 —, or —OCH 2 CH 2 CH 2 CH 2 -phenylene-.

19. The copolymer according to claim 2 , wherein at least one of L 1 and L 2 is a bivalent C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently replaced by: —N(H)C(O)N(H)—, —N(H)C(O)O—, or —OC(O)N(H)—.

20. The copolymer according to claim 2 , wherein L 1 is a urethane.

21. The copolymer according to claim 2 , wherein L 2 is —CH 2 CH 2 —.

22. A block copolymer of formula II:

wherein:

each of R x and R y is independently —OH, —NH 2 , a protected hydroxyl or a protected amine;

each of R 1 , R 2 , R 3 , and R 4 is independently selected from one or more of halogen, R, OR, —CO 2 R, a fluorinated hydrocarbon, a polyether, a polyester or a fluoropolymer;

each R is independently hydrogen, an optionally substituted C 1-20 aliphatic group, or an optionally substituted group selected from phenyl, 8-10 membered bicyclic aryl, a 4-8 membered monocyclic saturated or partially unsaturated heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulphur, or 5-6 membered monocyclic or 8-10 membered bicyclic heteroaryl group having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

each of m, n, and p is independently 2 to 100; and

each of L 1 and L 2 is independently a bivalent C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently replaced by —O—, —S—, —N(R)C(O)O—, —N(R)C(O)N(R)—, —OC(O)N(R)—, —N(R)—, —C(O)—, —C(O)N(R)—, —N(R)C(O)—, —SO 2 —, —SO 2 N(R)—, —N(R)SO 2 —, —OC(O)—, —C(O)O—, or a bivalent cycloalkylene, arylene, heterocyclene, or heteroarylene.

23. The copolymer according to claim 22 , wherein both of R x and R y are —OH.

24. The copolymer according to claim 22 , selected from any of formulae II-a, II-b, II-c, and II-d:

25. The copolymer according to claim 2 , selected from:

26. A biomaterial comprising the block copolymer according to claim 2 .

27. A medical device comprising the block copolymer according to claim 2 .

28. A viscoelastic biostable foam comprising the block copolymer of formula I

wherein:

each represents a point of attachment to a urethane or urea linkage;

each of R 1 , R 2 , R 3 , and R 4 is independently selected from one or more of halogen, R, OR, —CO 2 R, a fluorinated hydrocarbon, a polyether, a polyester or a fluoropolymer;

each R is independently hydrogen, an optionally substituted C 1-20 aliphatic group, or an optionally substituted group selected from phenyl, 8-10 membered bicyclic aryl, a 4-8 membered monocyclic saturated or partially unsaturated heterocyclic ring having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulphur, or 5-6 membered monocyclic or 8-10 membered bicyclic heteroaryl group having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

each of m n and p is independently 2 to 100; and

each of L 1 and L 2 is independently a bivalent C 1-20 hydrocarbon chain wherein 1-4 methylene units of the hydrocarbon chain are optionally and independently replaced by —O—, —S—, —N(R)C(O)O—, —N(R)C(O)N(R)—, —OC(O)N(R)—, —N(R)—, —C(O)—, —C(O)N(R)—, —N(R)C(O)—, —SO 2 —, —SO 2 N(R)—, —N(R)SO 2 —, —OC(O)—, —C(O)O—, or a bivalent cycloalkylene, arylene, heterocyclene, or heteroarylene.

29. The viscoelastic biostable foam according to claim 28 , comprising the triblock copolymer selected from

30. The viscoelastic biostable foam according to claim 28 , wherein said foam is stable to gastric fluid for at least 3 months, for at least 4 months, for at least 5 months, for at least 6 months, for at least 7 months, for at least 8 months, for at least 9 months, for at least 10 months, for at least 11 months, or for at least one year.

31. The viscoelastic biostable foam according to claim 28 , wherein said foam takes up less than about 5%, less than about 10%, less than about 15%, less than about 20%, less than about 25%, or less than about 30% by weight of water at equilibrium.

32. The viscoelastic biostable foam according to claim 28 , wherein said foam has an elongation capacity of about 200-1200%.

33. The viscoelastic biostable foam according to claim 28 , wherein said foam has a tensile strength of about 0.1 to about 1.0 MPa.

34. The viscoelastic biostable foam according to claim 28 , wherein said foam has a density of 0.1 to 1.5 g/cm 3 .

35. The viscoelastic biostable foam according to claim 28 , wherein R 1 is hydrogen, methyl, chloro or fluoro.

36. The viscoelastic biostable foam according to claim 28 , wherein R 2 is hydrogen or methyl.

37. The viscoelastic biostable foam according to claim 28 , wherein R 3 is methyl, phenyl, fluoro, or —CH 2 CH 2 F.

38. The viscoelastic biostable foam according to claim 28 , wherein R 4 is methyl, phenyl, fluoro, or —CH 2 CH 2 F.

39. A biomaterial comprising the block copolymer of claim 1 .

40. A medical device comprising the block copolymer according to claim 1 .

41. A viscoelastic biostable foam comprising the block copolymer of claim 1 .

42. The viscoelastic biostable foam according to claim 41 , wherein said foam is stable to gastric fluid for at least 3 months, for at least 4 months, for at least 5 months, for at least 6 months, for at least 7 months, for at least 8 months, for at least 9 months, for at least 10 months, for at least 11 months, or for at least one year.

43. The viscoelastic biostable foam according to claim 41 , wherein said foam takes up less than about 5%, less than about 10%, less than about 15%, less than about 20%, less than about 25%, or less than about 30% by weight of water at equilibrium.

44. The viscoelastic biostable foam according to claim 41 , wherein said foam has an elongation capacity of about 200-1200%.

45. The viscoelastic biostable foam according to claim 41 , wherein said foam has a tensile strength of about 0.1 to about 1.0 MPa.

46. The viscoelastic biostable foam according to claim 41 , wherein said foam has a density of 0.1 to 1.5 g/cm 3 .