Biocompatible terpolymers are manufactured to include a zwitterionic monomer, an alkoxy acrylate monomer, and a hydrophobic monomer. The alkoxy acrylate monomer can be a 2-methoxyethyl methacrylate (MOEMA) or a 2-methoxyethyl methacrylate (EOEMA). Alternatively, the alkoxy acrylate can be 2-methoxyethyl acrylate (MOEA) or 2-methoxyethyl acrylate (EOEA). The alkoxy acrylate monomers advantageously give the zwitterionic copolymers greater ductility, strength, and toughness while maintaining a desired amount of hydrophilicity. The improved toughness allows the zwitterionic copolymers to be processed without cross-linking, which improves the elongation properties of the zwitterionic copolymer, and reduces the risk of cracking during use.