Relaxation nuclear magnetic resonance imaging (R-NMRI) of PDMS/PDPS siloxane copolymer desiccation

Relaxation nuclear magnetic resonance imaging (R-NMRI) was employed to study the effects of desiccation on SiO2-filled and unfilled polydimethylsiloxane–polydiphenylsiloxane (PDMS/PDPS) copolymers. Uniform NMR spin–spin relaxation time (T2) profiles were observed across the sample thickness indicating that the drying process is approximately uniform, and that the desiccation of the silicone copolymer is not a H2O diffusion limited process. In a P2O5 desiccation environment, significant reduction of T2 was observed for the SiO2-filled and unfilled copolymer material for desiccation up to 225 days. A very small reduction in T2 was observed for the unfilled copolymer between 225 and 487 days. The increase in relative stiffness with desiccation was found to be higher for the unfilled copolymer.