Deformation of chain

Go, N., Scheraga, H.A. Ring closure and local conformational deformations of chain molecules. Macromolecules 1970, 3, 178-87. 

Ring Closure and Local Conformational Deformations of Chain Molecules Go, N.j Scheraga, H. A. Macromolecules 1970, 3, 178. 

Here Fcmc is the free energy due to deformation of chains in the micelle core... 

When the chains are deformed during a bounce, a stress is applied and then rapidly removed. The time required for the chains to regain their original positions is measured by the relaxation time x, as defined in Chapter 13, Section 13.4. Thus, relaxation times are a measure of the ability of the chains to rotate at room temperature the butyl rubber with the bulky methyl groups will not rotate as readily as the civ-polyisoprene, so that when the deformation of chains in the sample of butyl rubber occurs, the chains do not return to their equilibrium positions as rapidly as the natural rubber i.e., X is longer. 

To understand the deformation of chains in a network it is useful to take into account the orientation of the network chains with respect to the stretching direction. The second order (Herman s) orientation function of the statistical segments with respect to the stretching direction is given by... 

In addition, more sophisticated techniques have been developed for a more precise analysis of the structure and the behavior of networks dynamic iight scattering proved to be useful to determine the fluctuation of density in networks, and neutron scattering allows one to understand the mechanism of deformation of chains when submitting the network to a macroscopic deformation. 

Attenburrow GE, Bassett DC. Plastic-deformation of chain-extended polyethylene. yMufer Set 1977 12(l) 192-200. 

These criteria describe different states of local excitation and deformation of chain segments. The stress bias criterion [86, 139] refers implicitely to two mechanisms cavitation in a dilatational stress field and stabilization of cavities through a deviatoric stress component. These mechanisms have been more explicitely considered in the mathematical model of cavity expansion in a rigid plastic by Haward et al. [137] and in the molecular models by Argon [152] and Kausch [11]. 

However, Struik has shown by quenching polymer rods under torsion below Tg and investigating the effect of the temperature on the torque that even at this temperature where all segments are assumed to be frozen in, strong forces due to orientation and deformation of chains are measurable. Apparently, the fact that is very small does not imply that the effect of variation of Ze with deformation vanishes nor does it imply that the effect of variations of I must be small. Since the free energy is proportional to the logarithm of 1, it is the relative variation of with deformation that appears in the elastic free energy. 

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