Study on a polyacrylate-based waterborne coating: facile preparation, convenient self-healing behavior and photoluminescence properties

Abstract

Room temperature self-healing coatings featuring high transparency, robust mechanical properties and efficient self-healing are highly desirable in many emerging applications. However, it remains challenging to integrate all these beneficial features in a single polymer coating. Herein, waterborne polyacrylate copolymers combining ionic bonds and hydrogen bonds, in which the ionic bonds could form ionic aggregates, were successfully synthesized via a simple and environmentally friendly way. The ionic aggregates can construct a robust but dynamic (triggered by water) network, while the flexible side chains can enhance the chain mobility. Hence, this coating demonstrates efficient and repeatable self-healing of surface scratches, mechanical damages and transparency at room temperature with the assistance of water. Once damaged by scratching, the coating can instantly recover a transparency of 91.6% (at 550 nm) and a final recovered transparency of up to 97.0%. Meanwhile, the self-healed materials can restore 2.96 MPa of tensile strength. To confirm its potential applications in optical areas, water-soluble carbon quantum dots were prepared and incorporated into the coating to endow it with remarkable photoluminescence properties. This study presents unique insights for preparing new self-healing coatings and for better understanding the self-healing mechanism of self-healing materials.