Studying the healing behavior at a microsopic scale

Abstract

Research in the field of smart materials that exhibit self-repair mechanisms has greatly expanded over the last few years. This is especially true for polymers and polymer composite materials. One class of self-healing polymer materials is the reversible polymer network systems that use dynamic covalent bonds as a means to repair sustained damage. Currently a range of different dynamic covalent bonds is considered, of which the reversible Diels-Alder chemistry has drawn the most attention. Reversible covalent bonds have been incorporated into polymer network structures based on the Diels-Alder reaction between a furan and a maleimide [1-2]. Repair of sustained damage can be established by means of heating-used selfhealing in bulk materials as well as in coating applications. The aim of this research is to study the healing mechanism and healing kinetics at the microscopic scale and to compare this healing mechanism for different polymer network structures and chemistries. The self-healing behavior is studied with local and surface analysis techniques, including Atomic Force Microscopy as an important tool. A better understanding of the healing mechanism at the microscopic level will lead to a better understanding of the macroscopic healing phenomena and ultimately to the adaptation of the polymer network structure to obtain the desired material properties, such as mechanical properties, healing conditions and additional functional properties. The research can then be extended towards self-healing polymer composites, with e.g. a reversible polymer matrix, to evaluate the recovery of the composite material properties [3].