End-Linked Poly(dimethylsiloxane) Elastomer Structure: 2H-NMR Transverse Dephasing Data Compared to Predictions of Statistical and Thermodynamic Models

2 H-NMR measurements of deuterated poly(dimethylsiloxane) [PDMS(d)] elastomers with systematically varied elastic and swelling properties are presented. 2 H-NMR transverse dephasing data are compared to the predictions of a model describing elastomer deuterium transverse dephasing data as a linear superposition of contributions from elastic and pendant chains. Structural parameters obtained from the model for 2 H-NMR transverse dephasing are compared to structural parameters inferred from swelling measurements using statistical and thermodynamic models. As predicted by the model for transverse dephasing data, dephasing time constants for elastic chains are directly proportional to number-average molecular weights of elastic chains obtained from swelling measurements.