The Transition Zone in Polymers of Low Molecular Weight

The preceding sections have dealt with polymers of high molecular weight, well above the critical value for entanglement coupling, because only in such substances 

forage and loss shear moduli of a polyfdimethyl siloxane) with number-average molecular weight Mn = 16,000, plotted logarithmically against frequency v with reduced scales, r i is the terminal relaxation time calculated as it]oM /ir pRT. Solid curves, experimental dashed curves, from modified Rouse theory for most probable distribution of molecular weights. (Barlow, Harrison, and Lamb.3 ) 

Recoverable creep compliance of narrow-distribution polystyrene with molecular weight 16,400, measured at various temperatures as indicated and reduced to 100°C with reduction factors appropriate in the transition zone. (Plazek and O Rourke. ) 

Litovitz, in Non-Crystalline Solids, edited by V. D. Frechette, Wiley, New York, I960, p. 252. 

Plazek, Proc, Conference on Polymer Structure arul Mechanical Properties, U. S. Army Natick Laboratories, 1967. 

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