Fibrillar superstructures

PET fibers and filaments are characterized by a fibrillar superstructure that corresponds to the general concept of the fibrillar structure of synthetic fibers. The fibrillar... 

Fibrillar superstructures were also obtained when the amphiphilic diphenylglucol-uril X was used to complex magneson, Y, by clipping onto the dihydroxphenyl unit. The clip molecules X formed globular associates, which transformed to nanotubes upon complexation of Y [426,427] Scheme 7. 

The precise function of microfibrils in hard elastic polymers is not well understood. Their importance in various models of crystalline polymers has ranged from mere tie points [4,5] to the fundamental element [9]. The recent disclosure of hard elastic behavior in crazed HIPS [11] clearly revealed the connection between microfibrillar superstructure and hard elastic behavior, since no lamellae exists in this material. Polymers with a fibrillar structure are not necessarily hard elastic,however. Gore-Tex has an extensive fibrillar domain as shown in Figure 2c. Its loading cycle (Figure 5), however, clearly reveals an inelastic material. Hence, the necessary criterion of microfibrillar structure for a hard elastic polymer must be established. 

During elongation of a semicrystalline polymer several different processes, sudi as elastic deformation of the original spherulitic superstructure, tran ormation of a spherulitic into a fibrillar structure, plastic deformation of microfibrils by sliiqiage processes and elongation of molecular chains in the amorphous regions may occur simultaneously, successively or partly superimposed One of the advanta s... 

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