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How does electron beam sterilization affect Eastman Tritan™ copolyester?
Sterilizing medical devices can have a negative effect on the optical and physical properties of transparent polymers.
Electron beam (e-beam) radiation is one of the most popular methods for sterilizing medical devices—along with gamma radiation, ethylene oxide (EtO), autoclave, and low-temperature hydrogen peroxide gas plasma.
Eastman conducted studies to determine the effects of e-beam radiation on the optical and physical properties of Eastman Tritan™ copolyester and other transparent medical polymers.
The objective of sterilizing medical devices is to reduce the bioburden to a safe level with minimal effects on the desired properties of its constituent polymers.
Technology advances have improved the performance of e-beam radiation, making it a safe, efficient, and reliable source of energy for sterilization. High dose rates reduce the time of exposure, which can make e-beam a less costly alternative to gamma radiation.
To study the effect of e-beam radiation on Tritan MX711, Eastman measured color shifting and physical property retention after e-beam radiation.
Optical properties
Samples were exposed to e-beam radiation (25 and 50 kGy), then stored in darkness and their color measured at Days 3, 7, 14, and 42 using HunterLab UltraScan™ Sphere 8000 and the CIE L*, a*, b* color scale. (Samples were stored in darkness and only exposed to light for color measurement.)
Figure 1 shows the changes in b* value, which measures the blue to yellow scale after e-beam exposure at 50 kGy. Photos of the molded samples before and after exposure are available upon request.
Figure 1. Eastman Tritan™ copolyester and other transparent resins after e-beam exposure at 50 kGY—b* color measurements
Figure 2 shows the difference in b* color values between unexposed samples and sterilized samples at Day 42—after e-beam radiation at both 25 and 50 kGy.
Figure 2. Change in b* color 42 days after e-beam radiation—25 and 50 kGy
Physical properties were measured before and after e-beam sterilization at 25 and 50 kGy. No physical property degradation was noted for Tritan MX711 or the other resins tested. The polyesters and copolyesters in the study showed no statistical change in molecular weight although Tenite™ propionate 360 did show a loss of molecular weight, as expected from an aliphatic polymer.
For complete details of these studies or more information about the advantages of Eastman Tritan™ copolyesters, email Eastman today.
Electron beam (e-beam) radiation is one of the most popular methods for sterilizing medical devices—along with gamma radiation, ethylene oxide (EtO), autoclave, and low-temperature hydrogen peroxide gas plasma.
Eastman conducted studies to determine the effects of e-beam radiation on the optical and physical properties of Eastman Tritan™ copolyester and other transparent medical polymers.
| Formula | Resin type |
|---|---|
| Eastman Tritan™ copolyester MX711 | copolyester |
| Eastar™ polyester MN052 | polyester |
| Eastar™ copolyester MN211 | copolyester |
| Eastar™ copolyester MN006 | copolyester |
| DuraStar™ polymer MN611 | copolyester |
| Tenite™ propionate 360A40012 | Cellulose acetate propionate (CAP) |
| Lipid resistant PC | polycarbonate |
| TABS | Transparent ABS |
| Medical grade acrylic | Acrylic (PMMA) |
The objective of sterilizing medical devices is to reduce the bioburden to a safe level with minimal effects on the desired properties of its constituent polymers.
Technology advances have improved the performance of e-beam radiation, making it a safe, efficient, and reliable source of energy for sterilization. High dose rates reduce the time of exposure, which can make e-beam a less costly alternative to gamma radiation.
To study the effect of e-beam radiation on Tritan MX711, Eastman measured color shifting and physical property retention after e-beam radiation.
Optical properties
Samples were exposed to e-beam radiation (25 and 50 kGy), then stored in darkness and their color measured at Days 3, 7, 14, and 42 using HunterLab UltraScan™ Sphere 8000 and the CIE L*, a*, b* color scale. (Samples were stored in darkness and only exposed to light for color measurement.)
Figure 1 shows the changes in b* value, which measures the blue to yellow scale after e-beam exposure at 50 kGy. Photos of the molded samples before and after exposure are available upon request.
Figure 1. Eastman Tritan™ copolyester and other transparent resins after e-beam exposure at 50 kGY—b* color measurements
Figure 2 shows the difference in b* color values between unexposed samples and sterilized samples at Day 42—after e-beam radiation at both 25 and 50 kGy.
Figure 2. Change in b* color 42 days after e-beam radiation—25 and 50 kGy
Physical properties were measured before and after e-beam sterilization at 25 and 50 kGy. No physical property degradation was noted for Tritan MX711 or the other resins tested. The polyesters and copolyesters in the study showed no statistical change in molecular weight although Tenite™ propionate 360 did show a loss of molecular weight, as expected from an aliphatic polymer.
For complete details of these studies or more information about the advantages of Eastman Tritan™ copolyesters, email Eastman today.
