Structural Analyses of Biomaterial Surfaces by X-ray Diffraction

点击翻译按钮获取中文摘要

First of all, the experimental apparatus for so-called "Thin Films X-ray Diffraction" and/or "Glazing Angle Incidence of X-ray Diffraction" was set up.After that, by using these system, the surface was analyzed for poly-α-olefins, such as isotactic polypropylene and polybutene-1. The comparison of the crystallinities between the surface and the bulk was done for the films annealed in air at different temperature and times. The crystallinity was lower for the surface compared with the bulk irrespective of annealing conditions. The change in crystallinity drastically occurred up to several micrometers depth from the surface, and the crystallinity was getting low near the surface. The apparent crystallite sizes were smaller for the surface. These showed that crystal growth was restricted near the surface because of localized defects (including chain ends), and high chain mobility. Annealing at higher temperature brought the surface oxidation, which also decreased the surface crystallinity. The residual stress near the surface owing to the quenching from the melt was also detected by this method. The blends of these poly-α-olefins were also investigated. It was found that polypropylene component was predominant at the surface because of its low surface free energy compared with that of polybutene-1.Next, these system were extended for analyses of surface and interface structures of poly (vinyl alcohol) and its laminates. These novel X-ray diffraction methods were found to be quite powerful to investigate the surface and interfacial structures of polymeric biomaterials.