Rheological Evaluation of a Thermosetting Urethane Sealant Used in a Medical Device
However, the uncured monomer is often highly reactive at ambient conditions, and, as such, manufacturing procedures must be properly regulated. For example, feedstock urethane resin must be kept frozen to suppress pre-cure and rapidly delivered to the mold to ensure optimal post-cure performance.
One manufacturer of medical devices uses a polyurethane sealant in a heat-exchange device often used during open-heart surgery. Because of the medical application, there is zero tolerance for failure of the sealant as this could result in biological contamination. The manufacturer was interested in the time-to-cure and the viscosity profile of the urethane as a function of time and/or temperature.