Polymer Melt Viscosity
  The research is important for a molecular theory of liquid and has a wide interest as an example solving the problem when dynamic parameters of systems can be indirectly connected with their equilibrium properties. In frameworks of the reptation model the power law with the 3.5-exponent for the melt viscosity relation to the molecular weight of flexible-chain polymer is obtained. In order to find the exponent close to experimental values it should be taken into account the rotation vibration precession motion of chain ends with respect to the polymer melt flow direction. 
Andrei N. Yakunin