Dual Microcapsulation of an Environmentally‐Friendly‐Based Reactive Multifunctional Acrylated Epoxy Resin and Thiol by Internal Phase Separation Technique for Self‐healing Applications

Abstract

In this research, the microcapsules were individually prepared via internal phase separation technique using reactive bio-based acrylated epoxidized soybean oil, AESO, and trimethylolpropane tris(3-mercaptopropionate), TMPMP as healing and curing agents respectively in PMMA shell for self-healing intentions. The desired variables used were the ratio of the shell/core, the type of surfactant (ionic and polymeric) and PMMA molecular weights. FTIR confirmed very fast crosslinking reaction between reactive epoxy and acrylate functional groups in AESO and thiol groups in TMPMP, which is very important for self-healing purposes. Furthermore, FTIR and thermal characterization results confirmed the encapsulation of both the resin and the curing agent components in two different core–shell microcapsules. The surface morphology of microcapsules obtained changed from dimpled and holed to plain for AESO and TMPMP respectively suggesting that it depends strongly on the nature of the core, type of surfactant and the ratio of shell/core. The produced core–shell microcapsules had a mean diameter of 7.9–169.7 µm and 9.9–64.1 µm for AESO/PMMA and TMPMP/PMMA, respectively. With changing the percentage of shell revealed that increasing the PMMA dosage in both surfactants causes a decrease in the size of TMPMP-filled microcapsules.