A method of preparing a mixed-phase thermoplastic biomaterial comprises contacting and reacting a diol and a graft pre-polymer comprising a diol and at least one covalently bonded unsaturated monomer with an organic diisocyanate compound. The reaction is conducted within an aprotic solvent and for a period of time and at a temperature sufficient to produce the mixed-phase thermoplastic biomaterial. The diol may be selected from the group consisting of siloxane diols, polyether diols, polyester diols and polycarbonate diols while the at least one covalently bonded unsaturated monomer may be selected from the group consisting of a fluorinated monomer, a siloxane monomer, an aliphatic ester of methacrylic acid, a cyclic ester of methacrylic acid, a charged monomer, a sulfonium salt, a vinyl monomer with phenol or benzoic acid, N-vinyl pyrrolidone, an aminoglucoside, and a therapeutic agent. The mixed-phase thermoplastic biomaterial may further include an anti-microbial, a therapeutic agent or both.
