Effect of Imidazolium Monomer Structure on Properties of Imidazolium‐Functionalized Self‐Healing UV‐Cured Polymers for Flexible Electronic Devices

Abstract

AbstractSelf‐healing UV‐cured polymeric materials based on ionic interactions possess many distinct advantages such as reliability, long lifetime, and green preparation process, and thus obtain great potential development. In this work, a series of UV‐curable imidazolium monomers with different structures are designed and synthesized, and then imidazolium ionic interaction‐based self‐healing materials are prepared through fast and eco‐friendly UV‐curing technology. Also, the structures of imidazolium monomers on properties of self‐healing UV‐cured polymers are investigated. The results show that the structures of imidazolium monomers have no obvious influences on photopolymerization properties of the polymers. The hydroxyl group and polar ether chains in imidazolium monomers can increase the glass transition temperature (Tg) of the polymers. The large substituent at 1‐position of the imidazole ring enhances tensile strain of the polymers due to the reduction of the intermolecular force. The intermolecular forces and content of imidazole ionic groups all affect self‐healing efficiency of the polymers. The polymer containing HD‐IM‐E with a long and nonpolar pendent side chains exhibits an excellent self‐healing efficiency (>90%) and can be healed repeatedly. Importantly, the self‐healing polymer can also be used as a flexible electronic substrate to fabricate a flexible electronic device with good self‐healing function.