Biomaterial

A block copolymer of formula I

• wherein:
• each represents a point of attachment to a urethane or urea linkage;
• each of R1, R2, R3, and R4 is independently selected from one or more of halogen, R, OR, —CO2R, a fluorinated hydrocarbon, a polyether, a polyester or a fluoropolymer;
• each R is independently hydrogen, an optionally substituted C1-20 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 L1 and L2 is independently a bivalent C1-20 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)—, —SO2—, —SO2N(R)—, —N(R)SO2—, —OC(O)—, —C(O)O—, or a bivalent cycloalkylene, arylene, heterocyclene, or heteroarylene.

A block copolymer of formula II:

• wherein:
• each of Rx and Ry is independently —OH, —NH2, a protected hydroxyl or a protected amine;
• each of R1, R2, R3, and R4 is independently selected from one or more of halogen, R, OR, —CO2R, a fluorinated hydrocarbon, a polyether, a polyester or a fluoropolymer;
• each R is independently hydrogen, an optionally substituted C1-20 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 L1 and L2 is independently a bivalent C1-20 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)—, —SO2—, —SO2N(R)—, —N(R)SO2—, —OC(O)—, —C(O)O—, or a bivalent cycloalkylene, arylene, heterocyclene, or heteroarylene.

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 R1, R2, R3, and R4 is independently selected from one or more of halogen, R, OR, —CO2R, a fluorinated hydrocarbon, a polyether, a polyester or a fluoropolymer;
• each R is independently hydrogen, an optionally substituted C1-20 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 L1 and L2 is independently a bivalent C1-20 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)—, —SO2—, —SO2N(R)—, —N(R)SO2—, —OC(O)—, —C(O)O—, or a bivalent cycloalkylene, arylene, heterocyclene, or heteroarylene.