Model elastomeric networks prepared by selectively cross- linking polydimethylsiloxane chains having known amounts of reactive side chains

One of the most important issues in the area of rubberlike elasticity concerns the relationship between the modulus of an elastomeric material and its degree of cross-linking or the average molecular weight Me between cross-links in the network structure. Molecular theories of rubberlike elasticityl,2 provide predictions of this relationship, of course, for any value of the network functionality q>. Relevant experimental data are rather scarce, however, because of the difficulty in obtaining a reliable independent value of Me for a network.