Polycarbonate urethanes were the first biomedical polyurethanes promoted for their biostability. Bionate® thermoplastic polycarbonate urethane (TPU) is one of the most extensively tested biomedical polymers ever developed. Polyurethanes have been broadly used in the medical device industry because of their combination of outstanding physical properties and in vivo biostability and biocompatibility. The need for a polyurethane that would exhibit stability in applications where Metal Ion Oxidation (MIO) and Environmental Stress Cracking (ESC) are the degradation mechanisms, resulted in the development of polycarbonate-based polyurethanes. This class of polyurethanes maintains virtually all the elastomeric properties of polyether urethanes, but without the presence of oxidation-prone ether linkages.
Bionate® TPU is a thermoplastic elastomer formed as the reaction product of a hydroxyl terminated polycarbonate, an aromatic diisocyanate, and a low molecular weight glycol used as a chain extender. Carbonate linkages adjacent to hydrocarbon groups give this family of materials oxidative stability, making these polymers attractive in applications where oxidation is a potential mode of degradation, such as in pacemaker leads, ventricular assist devices, catheters and stents. They are also extensively used in orthopedic applications for their tough, load bearing qualities. Bionate TPUs are stable to dry heat, as well as EtO and Gamma sterilization. Bionate TPUs are backed by a very extensive FDA Master File.
Bionate® TPUs are manufactured using a high throughput, continuous reactor or traditional batch process and are currently available in five hardness grades: 80A, 90A, 55D, 65D and 75D. These materials accept fillers well and are heat-sealable and easily post-formed. All grades of the polymer are available with various Surface Modifying End Groups (SME™), such as Silicone, Fluorocarbon, PEO, etc.