Threshold tear strength molecular networks

Threshold Tear Strength of Some Molecular Networks... 

Values of Mc calculated from the small-strain tensile modulus, i.e., using C- + C2 in equation 2 in place of Cj, were, of course, smaller than those obtained from Ci values. However, the general form of the dependence of threshold tear strength upon Mc and the relative values obtained for different polymers at the same Mc were not significantly affected by this alternate procedure for calculating the mean molecular weight of network strands. 

The threshold tear strength of elastomeric molecular networks does not appear to depend strongly, if at all, upon the uniformify of network strand lengths. It is found to be proportional to Mc where Mc is the mean molecular weight of the strands, in accordance with the theory of Lake and Thomas (3). However, it is considerably smaller for Si-0 networks than for C-C networks at equal Mc values. This is attributed to differences in strand length and extensibility. 

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