Morphology of crystalline

Fig. XV-7. Fluorescence micrographs showing morphology of crystalline L-a-dimyris-tolphosphatidylethanolamine domains following a t jump to the plateau region of the v-a plot (a) after 2 sec b) after 1 min (c) after 20 min (d) following a second pressure jump after condition (c). (From Ref. 40.)...

F. Khoury and E. Passaglia, The morphology of crystalline synthetic polymers. In N.B. Hannay (Ed.), Treatise on Solid State Chemistry, 3rd ed., Plenum Press, New York, 1976, p. 335. 

Electron Microscopy can be used for resolution of smaller objects the practical limit of resolution being a few angstrom units. Electron Microscopy has been used in the study of the morphology of crystalline polymers. The usual techniques of replication, heavy-metal shadowing, and solvent etching are widely used. The direct observation of thin specimens, like polymer single crystals, is also possible and permits the observation of the electron-diffraction pattern of some specimen area, which is invaluable for... 

K. Sangwal and R. Rodriguez-Clemente, Surface Morphology of Crystalline Solids, Zurich, Trans. Tech., 1991... 

The thermal properties of fillers differ significantly from those of thermoplastics. This has a beneficial effect on productivity and processing. Decreased heat capacity and increased heat conductivity reduce cooling time [16]. Changing thermal properties of the composites result in a modification of the skin-core morphology of crystalline polymers and thus in the properties of injection molded parts as well. Large differences in the thermal properties of the components, on the other hand, lead to the development of thermal stresses, which also influence the performance of the composite under external load. 

Young, T-H., Lin, D.-J., Gau, J.-J., Chuang, W.-Y., and Cheng, L.-P. (1999), Morphology of crystalline Nylon-610 membranes prepared by the immersion-precipitation process Competition between crystallization and liquid-liquid phase separation, Polymer, 40, 5011-5021. 

Chen, Y. Yang, D.C. Hu, Y.M. Zhang, X.Q. Effects of crystal growth conditions on morphology of crystalline syndiotatic 1,2-polybutadiene. Cryst. Growth Des. 2004, 4, 117. 

The morphology of crystalline isotactic polystyrene, i-PS, has been investigated by others, and they have concluded that i-PS normally crystallizes as stacks of folded chain lamellae which are arranged in volume filling spherulites. The melting point of lamellar polymer crystals depends on the lamella thickness, L, as follows (28 )... 

Watson EB, Cherniak DJ (1997) Oxygen diffusion in zircon. Earth Planet Sci Letters 148 527-544 Weis PL (1980) Graphite skeleton crystals—A newly recognized morphology of crystalline carbon in metasedimentary rocks. Geology 8 296-297... 

The complicated morphology of crystalline polymer solids and the coexistence of crystalline and amorphous phases make the stress and strain fields extremely nonhomogeneous and anisotropic. The actual local strain in the amorphous component is usually greater and that in the crystalline component is smaller than the macroscopic strain. In the composite structure, the crystal lamellae and taut tie molecules act as force transmitters, and the amorphous layers are the main contributors to the strain. Hence in a very rough approximation, the Lennard-Jones or Morse type force field between adjacent macro-molecular chain sections (6, 7) describes fairly well the initial reversible stress-strain relation of a spherulitic polymer solid almost up to the yield point, i.e. up to a true strain of about 10%. 

Figure 11.1 IS. Schematic view of (a) electronic wave functions (i localisation length) (b) potential, and (c) morphology of crystalline metallic regions and amorphous barriers.

Dynamic mechanical tests provide useful information about the viscoelastie nature of a polymer. It is a versatile tool for studying the effects of molecular structure on polymer properties. It is a sensitive test for studying glass transitions and secondary transitions in polymer and the morphology of crystalline polymers. 

Clydesdale, G. and Roberts, K.J. (1991) Structural stability and morphology of crystalline n-alkanes. AIChE Symposium Series No. 284, 87, 130-142. 

Day, D. and J.B. Lando. 1980. Morphology of crystalline diacetylene monolayers polymerized at the gas-water interface. Macromolecules 13 1478. 

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