PROCUREMENT OF PRIMARY REFERENCE MATERIALS

所提出的工作涉及大量无添加剂的合成

The proposed work involves the synthesis of a lot of additive-free polytetramethylene (PTMO), 4, 4 diphenylmethane diisothionate (MDI), and polyurethaneurea (PUU). They will study bulk and surface characterization, and fabrication into tubes and sheets. Pilot quantity material goals have been identified. Fabrication details are provided. Sterile, packaged samples of the polyurethaneurea will be characterized to determine the effect of gamma radiation and to assess time dependent surface changes in the polyurethaneurea primary reference materials. These studies are aimed at determining the effect of degradation by the gamma irradiation sterilization technique. In addition, the investigators will also address time-dependent changes that might occur during storage prior to application.