1996 Volume 45 Issue 3 Pages 328-333
Polyetherimide (PEI) resin has more excellent characteristics in mechanical, thermal, and electrical and in crack resistance, in comparison with other engineering plastics. Because of this advantage, PEI resin applications have been extending as a material for use in precise mechanical devices and medical equipment.In these applications, different kinds of cleaning should be implemented. Especially, in the area of medical care, the severe cleaning and disinfection by irradiation is repeatedly provided to medical tools after their use to disinfect them from bacteria. It is, therefore, believed that a systematic appreciation of the degradation behavior of PEI resin under various environmental factors is essential. From these view points, we have tried to identify the degradation behavior under such environmental factors as water absorption, ozone water absorption, ultraviolet (UV) ray irradiation, and the coexistence of water absorption and UV ray irradiation, using analytic methods with chemical devices. We also studied how those degradation behaviors influence fatigue characteristics. As a result, it became clear that strength against fatigue was deteriorated by disintegration of the principal chain structure under the coexistent environment of water absorption and UV ray irradiation.
