Higher flow and retention of rigidity and ductility after gamma sterilization: That's what Bayer MaterialScience LLC scientists say their Makrolon Rx2435 polycarbonate (PC) exhibited in a series of studies comparing Rx2435 to radiation-stabilized Makrolon grades and a competitive copolyester. Pierre Moulinie and John J. Charles, scientists with Bayer MaterialScience LLC published their findings in a paper entitled, "Property Retention of High-Flow Medical Resins After Gamma Irradiation" and presented at the Society of Plastics Engineers (SPE) ANTEC annual technical conference.
The Bayer scientists summarized that their grades maintained stiffness, toughness, and other key properties after gamma sterilization, while a medical copolyester displayed greater relative changes in viscosity than polycarbonates. Properties were examined after gamma irradiation up to 60 kGy.
The presentation also discusses color shifts that occur after gamma sterilization and the danger of assuming that the lack of color shift means there hasn't been property loss. For a copy of the paper, visit Bayer. A competitive copolyester showed greater molecular weight loss and change in chemical resistance than Makrolon polycarbonate after gamma sterilization.