Description of Molecular Mobility Using Fractal Characteristics

10 Description of Molecular Mobility Using Fractal Characteristics 

Now we shall consider examples of using the dimension D for the solution of applied problems. When polymer samples are obtained by solid-phase extrusion, the macroscopic (extrusion) draw ratio is determined by the ratio [122, 142,143]  

However, the structure and properties of oriented polymers are characterised much more adequately by the molecular draw ratio mol [125]. The following expression relating and D to one another has been obtained [123]  

It follows from this relationship that the lower D, i.e., the more frozen the molecular mobility of the chain during drawing, the greater (the more efficient the orientation process), all other factors being the same. 

The limiting draw ratio attained by stretching a polymer is determined, in terms of the rubbery high-elasticity theory, by the equality [124]  

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