Degradation limiting molecular weight

Low-molecular weight chains do not experience enough shear force to induce scission. Watson et al." demonstrated (by the intrinsic viscosity characterization of masticated NR) that the limiting molecular weight for the shear-induced degradation is in the order of 0.7-1.0 X 10 Frenkel independently speculated that shear-induced cleavage occurs near the midpoint of the polymer chain. 

A limiting molecular weight is obtained when the amidation and degradation terms of the equation are equal. To obtain the highest... 

A limiting molecular weight for each shear condition below in which there is no further degradation (see Section II.D.l). Conversely for each composition, viz. molecular weight, there is a critical shear stress Tc [3-5] or shear rate % [6, 7] for the onset of degradation below which there is no measurable reaction. 

Values of the Limiting Molecular Weight Af,i and of the Rate Constant k of Mechanical Degradation for Various Polymers"... 

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