Micromechanical properties of melamine–formaldehyde microcapsules by nanoindentation: Effect of size and shell thickness

Melamine–formaldehyde (MF) microcapsules have been widely applied in many functional materials. Micromechanical properties are important characters determining the survival of the microcapsules during fabrication and application. In this study, nanoindentation was successfully applied as an effective method to measure the micromechanical properties of microcapsules containing paraffin. A series of MF-shell microcapsules had been fabricated with various size and thickness by controlling the core material stirring rates (1000–8000 r min−1) and core/shell weight ratios (1/1, 1/2 and 1/3). The load–displacement curves indicated that the MF shells had the ability of elastic–plastic deformation. Both of hardness and Young's modulus of microcapsules depended on parameters of size and shell thickness. The results confirmed that larger microcapsule had higher modulus and thicker shell could increase the ability resisting deformation of microcapsules.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Micromechanical properties of melamine–formaldehyde (MF) microcapsules were investigated by nanoindentation. ► Both of average size and shell thickness of microcapsules affected Young's modulus and hardness of microcapsules. ► The load–displacement curves of MF-shell microcapsules were obtained.