Self-healing and reprocessing of transparent UV-cured polysiloxane elastomer

It is still a challenge to explore self-healable and reprocessable polysiloxane elastomer with improved mechanical strength and superior transparency. In this work, a self-healable and reprocessable polysiloxane elastomer with fine mechanical strength and optical transparency is facilely constructed by thiol-ene photopolymerization between thiol-functionalized silicone resin (MDT-SH) and vinyl-terminated polysiloxane and diboronic ester. The UV radiation intensity, molecular structure of MDT-SH and thiol/ene molar ratio play an important role in the thiol-ene photopolymerization and mechanical properties of polysiloxane elastomer. The damaged elastomer is completely repaired at 80 °C after 3 h, and the waste elastomer can be reprocessed into new items with 90% recovery of mechanical property. More importantly, its transmittance at 400–800 nm is higher than 95%, and it is almost unaffected by the healing process. This self-healable, transparent and tough polysiloxane elastomer has the potential to develop flexible electronics and wearable devices.