Condensed-Matter Physics (1986) / Chapter Skim
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10 Polymers
10 Polymers
Pages 206-214
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From page 206... ...
; light, x-ray, and electron scattering; electron microscopy; new surface probes; computerized instrumentation; and computer simulation, have had a large impact. Paralleling this have been theoretical breakthroughs 206
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From page 207... ...
Formally it is found that the polymer problem is in the same universality class as a magnet of zero-spin dimensionality This may make no physical sense for magnets, but it illustrates the importance in modern theory of limits defined only mathematically. Once the theory of critical phenomena was applied to polymer problems it proved capable of describing a vast array of observations, both static and dynamic.
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From page 208... ...
When a strain is induced in a polymer melt the individual molecules are distorted and continue to exert a force (stress) resisting that strain, until the molecules have moved out of the strained, entangled mass and have relaxed to an equilibrium entangled condition.
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An aim, actually achieved to some extent' is to tailor-make materials with desired physical properties by controlling the molecular or physical structure. Glass The glassy state is extremely common in polymeric materials.
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From page 210... ...
. In the course of the process whereby a collection of single molecules is transformed into a totally connected network by progressive crosslinking, there is one critical amount of cross-linking that leads to the first appearance of a cluster spanning the sample.
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From page 211... ...
In a large ring or a long chain, however, the polymer lowers its energy by displacing atoms to create alternating single and double bonds between carbon atoms, which gives rise to insulating electronic bands. There are two degenerate structures formed by this d~mer~zat~on, each formed from the other by the interchange of the double bonds.
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From page 212... ...
The combination of the mechanical properties of polymers combined with piezoelectric and other physical properties offers the promise of a variety of technological applications. Other Polymer Properties There are other types of polymers, and properties of polymers, no less interesting and important than those just described, that space does not permit us to discuss in any detail.
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From page 213... ...
9. Description of the various polymer crystal nucleation, growth, and aging processes, to explain such observations as curved crystals, spherulitic growth of twisted fibrils, and thickening of lamellae during annealing.
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From page 214... ...
Description of how the ordering influences biological function, especially with respect to complex processes such as enzymatic action and membrane transport. Structure and function of membranes and their protein inclusions.
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