Technologies
Medical Urethanes
The Versatility of Polyurethanes
The proper selection of a material in the development of a medical device is critical for the device engineer and the design team involved. Lubrizol offers that team a family of thermoplastic polyurethanes that have been specially formulated and manufactured for medical applications.
Lubrizol’s polyurethanes are available in a wide range of durometers, from 72 Shore A to 84 Shore D, making them useful for a large variety of medical devices and components. Lubrizol’s polyurethanes (TPUs) exhibit excellent abrasion resistance and flexural endurance as compared to other polymers of similar durometers.
The ease of processing and high strength of polyurethanes makes them the material of choice for soft elastomer applications. Silicone, for example, another common polymer used in low durometer applications, is difficult to extrude and does not bond easily to other components made of non-silicone materials. Because of the much greater strength of polyurethanes as compared to silicone, the walls of polyurethane tubing can be made much thinner, allowing for either a smaller overall diameter or a larger inside diameter for increased flow — both great benefits for indwelling device applications.
Polyurethanes eliminate the problems associated with other materials used in mid-durometer applications such as PVC, where the dangers of leachable plasticizers become a concern. TPUs also retain their elastomeric characteristics even at low temperatures where PVC becomes brittle. Lubrizol's urethanes compare favorably to harder grade polymers like the fluorinated hydrocarbons. Fluorocarbons are very difficult to bond to other materials and have poor kink resistance. Again, the bondability, strength and processability of our polyurethanes make them a better choice for harder durometer applications.
Most of Lubrizol's polyurethanes for medical applications can be loaded with radiopaque materials for detection on X-ray or fluoroscope and colored for product identification. All radiopaque or color additives are introduced and dispersed at the time of polymerization, creating extremely consistent mixture and superior smoothness of the final polymer. All additives to our polyurethanes are thoroughly screened and carefully tested for chemical stability, biocompatibility and performance in our products before use as a radiopaque or coloring agent.
The many requirements necessary for safe, practical use of an elastomer in medical devices quickly narrows the field of suitable materials. Lubrizol polyurethanes pass the tests of biocompatibility, processability and chemical stability for medical device use. Wide durometer range and smooth radiopaque surfaces enhance Lubrizol’s standing as the optimal supplier of polyurethane materials for medical device components.
