Isoprene inclusion method

Another approach to the characterization of fiber microstructure is the isoprene inclusion method (Section 4.4.2.5). This was applied to the study of PET fibers [57] and to aramid fibers [58] for the purpose of showing their radial microporous and fibrillar texture. Any holes or voids are filled by inclusion of isoprene in the fiber. They are then stained by the reaction of osmium tetroxide with the included isoprene. Longitudinal sections of high speed spim PET are shown in the TEM micrographs in Fig. 5.15A and B of fibers before and after the reaction, respectively. Similar views at lower magnification were shown (Fig. 4.12) in... 

Application of this method to polyester fibers [203] is shown in the TEM micrographs in Fig. 4.14 of longitudinal sections of a PET fiber before (A) and after (B) inclusion with isoprene and staining with OSO4. Dense, stained isoprene regions are observed in teardrop shaped voids adjacent to delustrant particles. This method is useful for observation of void sizes and shapes, which relate to factors such as dyeability. 

---