Emergency chain

The tube is a construct which we might continue to sketch around an emerging chain as it diffuses out of the original sleeve. Instead, it is convenient to start with the tube initially in place and consider how long it takes for the molecule to escape. The initial entanglements which determine the contours of the tube comprise a set of constraints from which the molecule is relaxing, even if only to diffuse into another similar set. Accordingly, we identify this reptation time as a relaxation time r for the molecule. 

If the ordered, crystalline regions are cross sections of bundles of chains and the chains go from one bundle to the next (although not necessarily in the same plane), this is the older fringe-micelle model. If the emerging chains repeatedly fold buck and reenter the same bundle in this or a different plane, this is the folded-chain model. In either case the mechanical deformation behavior of such complex structures is varied and difficult to unravel unambiguously on a molecular or microscopic scale. In many respects the behavior of crystalline polymers is like that of two-ph ise systems as predicted by the fringed-micelle- model illustrated in Figure 7, in which there is a distinct crystalline phase embedded in an amorphous phase (134). 

The emergency chain, in the management of chemical splashes in the eye both in occupational and domestic environment is that allowing quick and coordinated management of any type of emergency to limit morbidity or mortality. 

D > ] the factor from randomization of direction. If the chains all parallel in the crystal are still straight in the amorphous region, but have an isotropic distribution of directions, then D 2, a result first obtained in the polymer context by Flory, I believe. Note in passing that if the emerging chains randomized their directions over the hemisphere we should have D — , but the distribution would not be isotropic to produce isotropy the probability of changing direction by 0 from the normal must be weighted by a factor cos 6 that s how the sun comes to look about equally bright across the whole disc. 

Type 3, the sopearl necklace, corresponds to fullerenes lined up in the polymer as constituents of the main chain. It forms when each fuUerene molecule is linked to the polymer at two sites. The reaction of Qo with p-xylylene is a classical example. In the emerging chains the fuUerenes are statisticaUy distributed in between oligomeric xylylene units. Composites with a structure slightly deviating from this real pearl necklace can be obtained from employing derivatives of C o that carry functional groups with two reactive sites. These may be incorporated... 

The regular folded array with adjacent reentry of the ehains, but with some loose folding and emergent chain ends or cilia that contribute to the disordered surface... 

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