Analysis of Rubber Elasticity in Terms of Crosslinks and Entanglement Contributions.

End-linked poly(dimethylsiloxane) (PDMS) networks synthesized from telechelic precursor chains of different molar mass were prepared with varying volume fractions of non-reactive chains acting as solvent. Uni-axial extension and compression measurements were performed on these networks to investigate their stress-strain behavior and examine the role of cross-links and entanglements on their properties. The measurements were carried out for both the swollen networks (as prepared) and the dried networks (after extraction of the non-reactive solvent chains). Deviations from ideal rubber elasticity increased with both molar mass of the precursor chains and the reactive polymer concentration of the networks. Analysis of the data in terms of the two components of the modulus (Gc and Ge) of the non-affine slip tube model are presented. [ABSTRACT FROM AUTHOR]