No abstract

This study was performed on cycloolefin materials. These polymers are more and more used in the cosmetic and pharmaceutical fields. Samples were subjected to an electron beam radio-sterilization. Different irradiation doses ranging from 25 to 150 kGy were used to study the irradiation effect on the structure and properties of the material. In this study, we were mainly interested in additive degradation, and in the modification of polymer thermomechanical properties, as elasticity, glass transition temperature, and swelling ability. Although the modification of the polymer chains was important, effect on thermomechanical properties was quite weak.

No abstract

Polyurethane catheters were irradiated with electron-beam. We looked at the way the catheter is physically and chemically modified after incubation in different media. An extracting medium (methanol) was compared to other oxidative, enzymatic, and saline aqueous media, mimicking some aspects of biological fluids. Irradiation had a strong impact on the stability of polymer during incubation. For nonirradiated samples incubated in aqueous media, only a small diffusion of additives was observed; no oligomer release was put into evidence, and the polymer was almost not degraded. But the chain branching that occurred because of irradiation created some weaknesses in the polymer chains: irradiated samples were mostly sensitive to chain scission and oligomers released during incubation; this trend increased with the irradiation dose.