Chain friction

A second model was proposed by Benkoski et al. [16] based on the idea that chain friction and pull-out, rather than chain scission are the important molecular scale failure processes. It is assumed that the chain failure force is given by fc = N/mono, where N is the number of monomers in a loop that crosses the interface, and that... 

The hydrodynamic radius is the equivalent spherical radius obtained from the Stokes law for the chain friction coefficient, Eq. (41), with substituted by R[j. It is easily verified that... 

Here we are drawing a hydrodynamic analogy between multi-tube reptation and polymer branching. deGennes s work indicates that a branched chain frictional coefficient should increase exponentially with the size or number of branches. 

To imderstand d5mamics and transport properties, a set of (nonlinear) Langevin equations describing the Edwards model and the solvent velocity field is proposed as a minimal model. Comparison of the outcome of the model with experimental results has revealed that this minimal model is reasonable (47) but closely studied, less than minimal. The importance of the direct chain-chain friction must not be underestimated (48). With this additional elfect, the model seems minimal, but a more careful study may be needed. 

This may be expressed in terms of a chain friction coefficient (the inverse of the mobility), which is ... 

Tensor of hyperfine interaction Anisotropic hyperfine interaction constant (mT) Orientation degree of chains Friction force... 

The chain friction constant Cch = is directly measured in sedimentation experiments the... 

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