Fringed micelle model, semicrystalline

For convenience, we can regard an isotropic semicrystalline polymer as being made up of an isotropic polycrystalline phase and an isotropic amorphous phase, as shown in Fig. 6, which is purely diagrammatic (it shows the classical fringed micelle model for simplicity). From a geometrical standpoint, we cannot discriminate a priori between two continuous interpenetrating phases, a dispersion of a crystalline phase in an amorphous phase, or of an amorphous phase in a crystalline phase. The distinction may depend upon the volume fractions. 

Fig. 2.4. The fringed-micelle model of semicrystalline polymers. The solid consists of an intimate mixture of ordered crystals and randomly structured amorphous regions. The molecuiar iength is considerably greater than the length of a crystal. A molecule thus passes through several crystals and several amorphous regions. The integrity of the two-phase solid is thus maintained by the long molecules.

Fig. 2.5. Chain molecules in (A) amorphous, (B) crystalline and (C) semicrystalline regions of polymers (fringed micelle model).

Fig. 13.10. Fringed micelle model of semicrystallinity in polymers. (Reprinted from Paul J. Flory, Principles of Polymer Chemistry. Copyright 1953, Cornell University and Copyright 1981 Paul J. Flory. Used by permission from the publisher, Cornell University Press).

Crystalline polymers appear to be the most studied by ESR techniques. The model wiiich seems to emerge from these results is, in fact, a variant of a model proposed over twenty years ago by Cumberbirch and associates (Shirley Institute Memoirs) to explain the tenacity of wet raycm monofilaments. Briefly, Cumberbirch, et al propose a fringe-micelle structure in which the fringe r ons, swollen by water, are assumed to obey rubber elasticity theory. These fringe reglcms are, of course, the more accessble (to water), more disordered, r ons of the semicrystalline structure. 

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