Facile conversion of commercial silicones from thermoset to ultraviolet-set for increased processing versatility

Abstract

Traditional platinum catalyzed hydrosilation chemistry used in thermoset silicones is ubiquitous in academic labs but has disadvantages in both curing time and the susceptibility of the catalyst to poisoning when exposed to common chemical species. This report presents the simple modification of commercial thermoset polydimethylsiloxane (PDMS) kits to yield ultraviolet (UV)-set silicones. The new UV-set characteristics take advantage of thiol–ene click chemistry to allow rapid and efficient curing while maintaining robust crosslinking chemistry supportive of comparable mechanical and chemical properties in the product material. The new UV-set formulation is easy to produce using commercially available reagents that are shelf stable and instantly convert thermoset kits (e.g., Sylgard 184) to UV-set materials, broadly expanding the operational versatility of these silicones. The simple “UV part C” described here offers facile conversion of Sylgard 184 into a UV-set silicone that is compatible with traditional laboratory workflows (e.g., soft lithography) and applicable to the production of liquid metal composites.