Stretchable Ion-Conductive Porous Polymers with a Semi-Interpenetrating Polymer Network Prepared via Thiol–Acrylate Chain Transfer Reaction

Porous polymers have received extensive attention due to their low density, high porosity, and large surface area. However, their inherent pore structures predominantly enhance compressive and flexural properties, yet they exhibit poor tensile performance. To address this challenge, we developed an ion-conductive porous polymer (ICPP) with excellent mechanical flexibility via a thiol–acrylate chain transfer reaction. A 60% water-in-oil emulsion was prepared using <i>n</i>-butyl acrylate (BA), trimethylolpropane triacrylate (TMPTA), and trimethylolpropane tris(3-mercaptopropionate) (TMPTMP) as the organic phase, with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the ionic conductor. Upon UV irradiation at 365 nm, a semi-interpenetrating polymer network (semi-IPN) with dangling chains was formed, significantly enhancing energy dissipation. After vacuum drying, the ICPP exhibited an elongation at break of 125% and recovered well under repeated 100% strain. These results demonstrate strong potential for applications in flexible sensors.