Effect of Thermal Treatment on the Dielectric Performance of a Silicone Rubber

Poly(dimethylsiloxane) (PDMS) is the most widely known silicone rubber with many applications. Commercial PDMS products, such as the one featured here, might not be optimized for electrical applications, as suppliers tend to keep their products’ compositions secret. PDMS is synthesized by chemical routes that typically yield volatile by-products. Lately it has been demonstrated that a post-curing thermal treatment might be advantageous due to removal of such volatile species. In this study we investigate the effect of post-curing on the DC conductivity, as well as the dielectric performance of a popular, commercially available PDMS product. It is revealed that the elastomer’s performance improves in both aspects upon post-curing. Analytical methods such as thermogravimetric analysis (TGA), as well as Raman spectroscopy show removal of up to ~1.5 wt.% of cyclic oligomeric volatiles, as well as complete depletion of unreacted reactive species, upon post-curing.