Non-entangled regime

O Shaughnessy B, Yn J. Non-steady state free radical polymerization kinetics at high conversions entangled regimes. Macromolecnles 1998 31 5240-5354. 

N. El Kissi and J.-M. Piau, The diiferent capillary flow regimes of entangled poly-dimethylsiloxane polymers macroscopic slip at the wall, hysteresis and cork flow, J. Non-Newtonian Fluid Mech., 37 (1990) 55-94. 

The important general result is that when the polymer melt is sheared against a surface on which polymer chains are strongly attached three different friction regimes are observed when increasing the shear rate, provided the surface chains are able to entangle with the bulk polymer. This non trivial friction behavior is illustrated in figure 5 a,b,c and d ... 

Fig. 4. The zero shear viscosity, no as a function of molecular weight, M, of polybutadiene as reported by Colby, Fetters and Grasseley.The data in this plot has not been corrected to the iso-free-volume state. The viscosities are reduced by M in order to remove any pure reptation component. Therefore, any non-zero slope represents a departure from reptation theory. The negative slope of about -2 for the first dozen points corresponds to the Rouse regime (M

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