Networks formed from α, ω divinyl poly(dimethylsiloxane) end-linked with tri- and tetrafunctional hydrosilanes are used to test several theoretical relations for the small strain modulus. The results indicate that topological interactions between chains have a large influence on the modulus, however, the suppression of junction fluctuation by topological interactions seems to be small for PDMS networks. Independent measurement of the topological interactions between chains, the plateau modulus GNO on linear PDMS, agrees well with that determined from the networks. The influence of hydrosilane side reactions on determination of network structure parameters was accounted for.
Bibliographical noteFunding Information:
Acknowledgement - This research was supported by a grant from the Army Research Office. We are pleased to acknowledge N. R. Langley and T. Maxson of Dow Corning Corporation and E. W. Merrill and K. 0. Meyers of Massachusetts Institute of Technology for providing materials. We are also indebted to them and M. Gottlieb for helpful discussions during the course of the work.