Self-healing polythiophene phenylenes for stretchable electronics

Abstract

Electroactive graft copolymers with self-healing properties and stretchability were prepared using a conducting polythiophene phenylene backbone and self-healing poly(acetamidoalkyl acrylate) side chains. Two different acetamidoalkyl acrylate monomers were used for the grafted side chains, which were added via controlled radical polymerization: 3-acetamidopropyl acrylate and 6-acetamidohexyl acrylate. The graft copolymers were studied as thin films and in bulk form to determine the structure, electrochemical and mechanical properties of the materials. The difference in chemical nature of the two grafted side chains gives rise to materials with different glass transition temperatures, Young’s moduli and self-healing ability. We compare these two types of materials to understand the effect of the side chains on the self-healing properties of the materials. The grafted polythiophene phenylenes were observed to self-heal, at room temperature, within one minute of being cut. The copolymers had good electroactivity and conductivity when doped; however the doped material had reduced elasticity.